title: Self-Mixing Diode Laser Interferometry

authors: Shrestha, Pawan Kumar

subjects: Self-mixing

abstract: Self-mixing interferometry in a laser diode is a very powerful tool in measurement science. The Self-mixing interferometer is a very robust and low cost interferometer with extreme simplicity in alignment and setup. In this thesis, a self-mixing interferometer is analysed and developed. The measurements of the self-mixing interferometer are verified using a Michelson interferometer. It is then followed by the signal processing of the detected signal. Three different methods are developed to retrieve the movement of the target. Results obtained by applying these methods to different experimental data sets are presented.
In the later part of the thesis, a phase locked self-mixing interferometer is developed. This slightly modified interferometer follows the target movement. As a result no additional circuitry or signal processing is necessary for the recovery of the target movement. Phase locked interferometer developed in this thesis was able to measure down to 1 nm of vibration. It is then followed by a novel method to detect cracks in eggshells using the phase locked vibrometer. The proposed method is tested and proved to be capable of differentiating between the intact and cracked eggs.

text: Self-Mixing Diode Laser Interferometry Self-mixing interferometry in a laser diode is a very powerful tool in measurement science. The Self-mixing interferometer is a very robust and low cost interferometer with extreme simplicity in alignment and setup. In this thesis, a self-mixing interferometer is analysed and developed. The measurements of the self-mixing interferometer are verified using a Michelson interferometer. It is then followed by the signal processing of the detected signal. Three different methods are developed to retrieve the movement of the target. Results obtained by applying these methods to different experimental data sets are presented.
In the later part of the thesis, a phase locked self-mixing interferometer is developed. This slightly modified interferometer follows the target movement. As a result no additional circuitry or signal processing is necessary for the recovery of the target movement. Phase locked interferometer developed in this thesis was able to measure down to 1 nm of vibration. It is then followed by a novel method to detect cracks in eggshells using the phase locked vibrometer. The proposed method is tested and proved to be capable of differentiating between the intact and cracked eggs.

year: 2010

title: The (pre-) history of medical physics

authors: Round, W. Howell

abstract: Conference presentation about medical physics history.

text: The (pre-) history of medical physics Conference presentation about medical physics history.

year: 2013

title: Activating whanau (extended family) processes within a community and school literacy partnership

authors: Glynn, Ted

subjects: Maori Education

abstract: "The paper describes the positive outcomes of a home and school literacy partnership in one mainstream primary school where the principal and the large majority of students, teachers, and whānau belong to one Māori hapū (sub-tribe), Ngāti Whakaue. Participating students were identified by teachers as experiencing difficulties with reading and writing. They were assigned randomly to one of two conditions: (1) participating in their school’s regular reading programme (school group) or (2) participating also in the home tutored reading and writing programme (home and school group).

Students in the home and school group improved their reading and writing outcomes over and above the outcomes achieved by students participating only in the regular school programme. There were two key reasons for the success of this partnership. The first was parents and whānau members successful implementation of both a Māori language reading tutoring programme, Tatari, Tautoko Tauawhi, and the two components of the writing programme, Tuhi Atu Tui Mai and Whakaputa Whakaaro. The second was the professional educational and cultural expertise of the home and school liaison worker, Hiro. Because of her language and cultural expertise and her mana (acknowledged authority and standing), Hiro was able to engage Māori parents and whānau actively in the home and school project. The co-constructed narrative between Hiro and Mere (the second author) provided a salient context for understanding the power of culturally preferred pedagogy in establishing effective home and school partnerships."

text: Activating whanau (extended family) processes within a community and school literacy partnership "The paper describes the positive outcomes of a home and school literacy partnership in one mainstream primary school where the principal and the large majority of students, teachers, and whānau belong to one Māori hapū (sub-tribe), Ngāti Whakaue. Participating students were identified by teachers as experiencing difficulties with reading and writing. They were assigned randomly to one of two conditions: (1) participating in their school’s regular reading programme (school group) or (2) participating also in the home tutored reading and writing programme (home and school group).

Students in the home and school group improved their reading and writing outcomes over and above the outcomes achieved by students participating only in the regular school programme. There were two key reasons for the success of this partnership. The first was parents and whānau members successful implementation of both a Māori language reading tutoring programme, Tatari, Tautoko Tauawhi, and the two components of the writing programme, Tuhi Atu Tui Mai and Whakaputa Whakaaro. The second was the professional educational and cultural expertise of the home and school liaison worker, Hiro. Because of her language and cultural expertise and her mana (acknowledged authority and standing), Hiro was able to engage Māori parents and whānau actively in the home and school project. The co-constructed narrative between Hiro and Mere (the second author) provided a salient context for understanding the power of culturally preferred pedagogy in establishing effective home and school partnerships."

year: 2004