title: Fibrillation - Improving the fibre/matrix adhesion of lyocell fibres for use in short fibre-reinforced and 3D printed composites

authors: Graupner, Nina

subjects: additive manufacturing

abstract: This study investigates the influence of fibrillation of lyocell fibres on the mechanical properties of
compression moulded polylactide (PLA), polypropylene (PP) composites, and 3D printed PLA
composites. Fibrillation was shown to reduce the strength and elongation at break of the fibres without
affecting the Young's modulus compared to untreated fibres. Nevertheless, fibrillation in composites
resulted in a 1.15 higher strength for PP composites and 1.62 for PLA composites. Young’s modulus
and impact strength were increased by factors of 1.41 and 1.38 for PP composites and 1.2 and 1.23 for
PLA composites. Applying the fibrillated fibres in 3D printed PLA shows a significant increase in the
mechanical properties. For example, with a fibre mass fraction of 30%, the tensile strength of the
composites with fibrillated fibres was increased by a factor of 1.18 compared to composites with
untreated fibres. The use of maleic anhydride in the PLA matrix in combination with composite heat
treatment further increased the strength by a factor of 1.46. With a strength of 85 MPa, a Young's
modulus of 7.2 GPa and an elongation at break of 3.2%, these are some of the highest values reported
for this kind of 3D printed materials.

text: Fibrillation - Improving the fibre/matrix adhesion of lyocell fibres for use in short fibre-reinforced and 3D printed composites This study investigates the influence of fibrillation of lyocell fibres on the mechanical properties of
compression moulded polylactide (PLA), polypropylene (PP) composites, and 3D printed PLA
composites. Fibrillation was shown to reduce the strength and elongation at break of the fibres without
affecting the Young's modulus compared to untreated fibres. Nevertheless, fibrillation in composites
resulted in a 1.15 higher strength for PP composites and 1.62 for PLA composites. Young’s modulus
and impact strength were increased by factors of 1.41 and 1.38 for PP composites and 1.2 and 1.23 for
PLA composites. Applying the fibrillated fibres in 3D printed PLA shows a significant increase in the
mechanical properties. For example, with a fibre mass fraction of 30%, the tensile strength of the
composites with fibrillated fibres was increased by a factor of 1.18 compared to composites with
untreated fibres. The use of maleic anhydride in the PLA matrix in combination with composite heat
treatment further increased the strength by a factor of 1.46. With a strength of 85 MPa, a Young's
modulus of 7.2 GPa and an elongation at break of 3.2%, these are some of the highest values reported
for this kind of 3D printed materials.

year: 2024

title: The contribution of lakes to greenhouse gas emissions – fact sheet

authors: Santoso, A

abstract: Greenhouse gases such as carbon dioxide (C0₂) , methane (CH₄)  and nitrous oxide (N₂0) trap heat in the atmosphere. Lakes can play an important role in regulating these gases at global scales. Total carbon uptake by lakes is of the same magnitude as that of oceans or forests, despite lakes occupying <1% of the Earth's area. In lakes, GHGs are mostly produced in the bottom sediment as products of organic matter decomposition. Geothermal activities - of importance to some Rotorua lakes - may also contribute substantial amounts of C0₂ and CH₄.

text: The contribution of lakes to greenhouse gas emissions – fact sheet Greenhouse gases such as carbon dioxide (C0₂) , methane (CH₄)  and nitrous oxide (N₂0) trap heat in the atmosphere. Lakes can play an important role in regulating these gases at global scales. Total carbon uptake by lakes is of the same magnitude as that of oceans or forests, despite lakes occupying <1% of the Earth's area. In lakes, GHGs are mostly produced in the bottom sediment as products of organic matter decomposition. Geothermal activities - of importance to some Rotorua lakes - may also contribute substantial amounts of C0₂ and CH₄.

year: 2015

title: Different coloured tears: Dual cultural identity and Tangihanga – A directed study

authors: Edge, Kiri

subjects: bereavement

abstract: Although whānau/family that are configured by both Pākehā and Māori identities number significantly within New Zealand, there has been little or no attention paid to the ways in which these identities influence the bereavement processes that will inevitably impact upon the lives of these whānau/family. The present study explored the experiences of an individual, whose whānau/family included two life ways; Māori and Pākehā. Of specific focus was the ways in which these identities influenced his bereavement subsequent to the death of his beloved wife, who was of Māori descent. One elderly male Pākehā participant was interviewed, using an open-ended narrative approach. The interview was semi structured around five broad themes, but the focus was upon the participant’s experiences and his preference in expressing these. The data analysis utilised a thematic process, which allowed the participant’s experiences to determine the emergent themes. The results depicted the diversity of issues that may be raised for dual cultural whānau/family within bereavement processes. Two central themes are discussed in relation to intercultural conflict and the eventual resolution that was created. Decision making processes, cultural and language differences played significant roles within the conflict and exclusion experienced by the participant. Communication and compromise provided resolution to the prior conflicts experienced. This created positive and unexpected outcomes which resulted in increased understandings and the strengthening of links between the participant, his whānau/family and his wife’s marae.

text: Different coloured tears: Dual cultural identity and Tangihanga – A directed study Although whānau/family that are configured by both Pākehā and Māori identities number significantly within New Zealand, there has been little or no attention paid to the ways in which these identities influence the bereavement processes that will inevitably impact upon the lives of these whānau/family. The present study explored the experiences of an individual, whose whānau/family included two life ways; Māori and Pākehā. Of specific focus was the ways in which these identities influenced his bereavement subsequent to the death of his beloved wife, who was of Māori descent. One elderly male Pākehā participant was interviewed, using an open-ended narrative approach. The interview was semi structured around five broad themes, but the focus was upon the participant’s experiences and his preference in expressing these. The data analysis utilised a thematic process, which allowed the participant’s experiences to determine the emergent themes. The results depicted the diversity of issues that may be raised for dual cultural whānau/family within bereavement processes. Two central themes are discussed in relation to intercultural conflict and the eventual resolution that was created. Decision making processes, cultural and language differences played significant roles within the conflict and exclusion experienced by the participant. Communication and compromise provided resolution to the prior conflicts experienced. This created positive and unexpected outcomes which resulted in increased understandings and the strengthening of links between the participant, his whānau/family and his wife’s marae.

year: 2010-01