title: Experimental performance of water cooled building integrated photovoltaic/thermal solar collectors

authors: Anderson, Timothy Nicholas

subjects: BIPVT

abstract: The idea of integrating water cooled photovoltaic/thermal collectors into building structures (BIPVT collectors) to provide electrical and heat energy is an area that has received only limited attention. BIPVT collectors are particularly attractive, as the integration of a single photovoltaic and thermal collector into the long-run roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies. In this study, the thermal efficiency of a novel low cost water cooled building integrated photovoltaic/thermal (BIPVT) solar collector was experimentally measured. The results show that despite being made of a typical roofing material, the thermal efficiency is not unreasonably affected. Furthermore, it is shown that the measured efficiency is similar to that predicted by the Hottel-Whillier equations.

text: Experimental performance of water cooled building integrated photovoltaic/thermal solar collectors The idea of integrating water cooled photovoltaic/thermal collectors into building structures (BIPVT collectors) to provide electrical and heat energy is an area that has received only limited attention. BIPVT collectors are particularly attractive, as the integration of a single photovoltaic and thermal collector into the long-run roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies. In this study, the thermal efficiency of a novel low cost water cooled building integrated photovoltaic/thermal (BIPVT) solar collector was experimentally measured. The results show that despite being made of a typical roofing material, the thermal efficiency is not unreasonably affected. Furthermore, it is shown that the measured efficiency is similar to that predicted by the Hottel-Whillier equations.

year: 2008

title: Designing, measuring and modelling a small-scale coil and stimulation circuit for transcranial magnetic stimulation

authors: Khokhar, Farah Adeebah

abstract: In Transcranial Magnetic Stimulation (TMS) rapid electromagnetic (EM) fields are applied to the brain, via an external current-carrying coil. This technique has been tried for many neurological disorders such as stroke, Parkinson’s disease and major depression. The fundamental effects of TMS are poorly understood so there is a need to carry out invasive measurements on mice to gain deep understanding about the underlying principles of TMS. However, we require smaller coils than used for a human, equivalent to the size of the mouse brain. Based on established physics principles we designed and built a cylindrical coil consisting of 50 turns of 0.2 mm diameter copper wire around a 4 mm diameter soft ferrite core. We built a simple electronic circuit to discharge a capacitor through this coil. With an applied voltage of 45 V, we measured the magnetic flux density (B-field) with a Hall probe as 338 mT and induced electric field with a wire loop as 10 – 15 V/m. The temperature increased by 31°C after 1200 pulses at 5 Hz. We modelled the coil using MATLAB which gave similar B-field and E field results of around 500 mT and 8 V/m respectively. Although this coil performs better than previously constructed mouse coils, the EM fields are still considerably lower than those of typical human coil of 2 T and 250 V/m. This now allows us to stimulate mouse brains with higher B-fields and E-fields than in previous experiments.

text: Designing, measuring and modelling a small-scale coil and stimulation circuit for transcranial magnetic stimulation In Transcranial Magnetic Stimulation (TMS) rapid electromagnetic (EM) fields are applied to the brain, via an external current-carrying coil. This technique has been tried for many neurological disorders such as stroke, Parkinson’s disease and major depression. The fundamental effects of TMS are poorly understood so there is a need to carry out invasive measurements on mice to gain deep understanding about the underlying principles of TMS. However, we require smaller coils than used for a human, equivalent to the size of the mouse brain. Based on established physics principles we designed and built a cylindrical coil consisting of 50 turns of 0.2 mm diameter copper wire around a 4 mm diameter soft ferrite core. We built a simple electronic circuit to discharge a capacitor through this coil. With an applied voltage of 45 V, we measured the magnetic flux density (B-field) with a Hall probe as 338 mT and induced electric field with a wire loop as 10 – 15 V/m. The temperature increased by 31°C after 1200 pulses at 5 Hz. We modelled the coil using MATLAB which gave similar B-field and E field results of around 500 mT and 8 V/m respectively. Although this coil performs better than previously constructed mouse coils, the EM fields are still considerably lower than those of typical human coil of 2 T and 250 V/m. This now allows us to stimulate mouse brains with higher B-fields and E-fields than in previous experiments.

year: 2018

title: 'Chris Finlayson and James Christmas, He Kupu Taurangi'

authors: Simon, Hemopereki

abstract: Twenty-five years on from the Ngāi Tahu Treaty settlement this book authored by Former Minister for Treaty of Waitangi Negotiations Hon. Chris Finlayson QC and Senior Ministerial Advisor James Christmas seems timely to capture the modern history and processes of the Treaty Settlement here in Aotearoa New Zealand. After all, the effects of these settlements is driving change economically, socially, environmentally, and politically, not only within hapū and iwi but nationally.

text: 'Chris Finlayson and James Christmas, He Kupu Taurangi' Twenty-five years on from the Ngāi Tahu Treaty settlement this book authored by Former Minister for Treaty of Waitangi Negotiations Hon. Chris Finlayson QC and Senior Ministerial Advisor James Christmas seems timely to capture the modern history and processes of the Treaty Settlement here in Aotearoa New Zealand. After all, the effects of these settlements is driving change economically, socially, environmentally, and politically, not only within hapū and iwi but nationally.

year: 2022