title: Use of sisal microfibres and bleached eucalyptus pulp as reinforcement of MgO-SiO2 fibre cement

authors: Gauss, Christian

subjects: clinker-free

abstract: In this work, minimally processed sisal microfibres along with commercial eucalyptus pulp were used as reinforcement of composites based on magnesium oxide and silica cement (60/40 ratio by weight of MgO/SiO2) with high filler content. The fibre cement composites were submitted to a fast carbonation process, resulting in the formation of hydrated magnesium carbonate, which contributed to improved physical and mechanical properties. All composites presented a strain-hardening behaviour and high specific energy under flexural loading, in special the composites with 10% of fibres. We demonstrated that the sisal microfibres produced by a chemical/mechanical process can be used as an efficient reinforcing material in combination with commercial cellulose pulp for MgO-SiO2 composites.

text: Use of sisal microfibres and bleached eucalyptus pulp as reinforcement of MgO-SiO2 fibre cement In this work, minimally processed sisal microfibres along with commercial eucalyptus pulp were used as reinforcement of composites based on magnesium oxide and silica cement (60/40 ratio by weight of MgO/SiO2) with high filler content. The fibre cement composites were submitted to a fast carbonation process, resulting in the formation of hydrated magnesium carbonate, which contributed to improved physical and mechanical properties. All composites presented a strain-hardening behaviour and high specific energy under flexural loading, in special the composites with 10% of fibres. We demonstrated that the sisal microfibres produced by a chemical/mechanical process can be used as an efficient reinforcing material in combination with commercial cellulose pulp for MgO-SiO2 composites.

year: 2022-05-26

title: Performance of new technology liquid scintillation counters for 14C dating

authors: Polach, H.

abstract: The results are presented of an investigation comparing the performance of commercially available liquid scintillation spectrometers claiming 'low-level' radioisotope detection abilities. Determination of ¹⁴C at naturally occurring concentrations was carried out in both old and new technology liquid scintillation counters using a ¹⁴C labelled benzene sample with butyl-PBD as scintillant. The signal to noise ratio and the ¹⁴C detection efficiency were evaluated.
The results show a wide range of merit for radiocarbon dating of so called 'low-lever instruments.

text: Performance of new technology liquid scintillation counters for 14C dating The results are presented of an investigation comparing the performance of commercially available liquid scintillation spectrometers claiming 'low-level' radioisotope detection abilities. Determination of ¹⁴C at naturally occurring concentrations was carried out in both old and new technology liquid scintillation counters using a ¹⁴C labelled benzene sample with butyl-PBD as scintillant. The signal to noise ratio and the ¹⁴C detection efficiency were evaluated.
The results show a wide range of merit for radiocarbon dating of so called 'low-lever instruments.

year: 1988

title: Māori students and issues of hybrid identity: The response of one inner-city state school

authors: Johnson, Diane

subjects: New Zealand

abstract: As a result of a more liberal national migration policy than was the case in the past, school communities in Aotearoa /New Zealand are increasingly multi-cultural, with both students and teachers coming from a wide range of linguistic and cultural backgrounds. In these global village environments, managers and governors strive (with varying degrees of success) to acknowledge, value and accommodate the heritage of new-migrant groups and to address the particular educational needs, interests and aspirations of the individuals within them. While it is extremely important to be inclusive of those students who are newly-arrived in the country, another imperative is, of course to protect and enhance, within an increasingly global educational perspective, the special status of indigenous Māori students, particularly those in mainstream education, as they explore and shape the hybrid identity (part indigenous / part global citizen) that will undoubtedly characterize their lives in the 21st century. The purpose of this paper is to discuss some identity-building strategies which one central-city, state, single-sex secondary school has initiated to support its indigenous students. While the strategies discussed must be considered as part of an ongoing, evolutionary process, indications are that the approach adopted is having a significant impact on the personal, social and academic development of Māori students.

text: Māori students and issues of hybrid identity: The response of one inner-city state school As a result of a more liberal national migration policy than was the case in the past, school communities in Aotearoa /New Zealand are increasingly multi-cultural, with both students and teachers coming from a wide range of linguistic and cultural backgrounds. In these global village environments, managers and governors strive (with varying degrees of success) to acknowledge, value and accommodate the heritage of new-migrant groups and to address the particular educational needs, interests and aspirations of the individuals within them. While it is extremely important to be inclusive of those students who are newly-arrived in the country, another imperative is, of course to protect and enhance, within an increasingly global educational perspective, the special status of indigenous Māori students, particularly those in mainstream education, as they explore and shape the hybrid identity (part indigenous / part global citizen) that will undoubtedly characterize their lives in the 21st century. The purpose of this paper is to discuss some identity-building strategies which one central-city, state, single-sex secondary school has initiated to support its indigenous students. While the strategies discussed must be considered as part of an ongoing, evolutionary process, indications are that the approach adopted is having a significant impact on the personal, social and academic development of Māori students.

year: 2008