title: Structural Changes and Chain Mobility During Processing of Bloodmeal-Based Thermoplastics

authors: Bier, James Michael

subjects: protein

abstract: The purpose of this study was to use concepts from classical polymer physics to develop a fundamental understanding of the interdependent relationship between structure, properties and processing in NovateinTM Thermoplastic Protein (NTP). NTP is produced from bloodmeal, a by-product of the meat industry which is 95% protein, by extruding with sodium sulphite, urea, sodium dodecyl sulphate, water and tri-ethylene glycol.  Dynamic mechanical thermal analysis (DMA) and differential scanning calorimetry (DSC) were used to investigate thermal transitions and chain relaxation, accompanied by synchrotron based Fourier transform infrared spectroscopy (FT-IR) to investigate chain architecture and structural changes. Extrusion, injection moulding and mechanical testing were used to investigate macroscopic properties, such as processability and mechanical properties.
Material pocket DMA enabled detection of glass transition temperatures not only for moulded NTP test pieces, but also for each processing step: bloodmeal,  NTP prior to extrusion, extruded NTP, and conditioned NTP. The pockets increased resolution for injection moulded and conditioned samples, revealing multiple transitions which indicated the presence of more than one phase. Spatially resolved FT-IR experiments were used to characterise the relative content and distribution of protein secondary structures in bloodmeal and NTP after each processing step. Increased chain mobility was observed due to the additives used, and also drastic structural rearrangement consistent with consolidation into a thermoplastic material after extrusion. Viscoelastic phenomena such as creep and stress relaxation further confirmed processed NTP was a consolidated thermoplastic, exhibiting time dependent behaviour characteristic of thermoplastic polymers.
The thermal properties of NTP suggested an underlying semi-crystalline structure, with protein secondary structures such as α-helices and β-sheets constraining motion in the amorphous phase, contributing to a broad glass transition region. These structures do not melt at typical temperatures encountered during extrusion processing, but are dispersed more evenly throughout an amorphous matrix.  Other than plasticisation, strong hydrogen bonding interactions stabilising secondary structures were the dominant influence on mechanical properties of the processed NTP. When TEG was included as a plasticiser, the degree of crystallinity decreased, and the fraction of randomly coiled protein chains was greater at all stages of processing compared to NTP without TEG. TEG competes with protein side groups for hydrogen bonding sites on the protein backbone, reducing secondary structure formation. β-sheets increased when NTP was heated in the absence of shear, displacing TEG and causing it to migrate out of the particles. The short residence time and presence of shear and mixing during extrusion and injection moulding prevented migration during processing, but an overall increase in β-sheet content was still observed after these processing steps.
The relationship between structure, properties and processing of NTP is therefore characterised by its semi crystalline nature, in which additives overcome protein-protein interactions in the amorphous phase enabling β-sheet dispersion throughout the material during processing. Future attempts at modifying properties should be informed by this understanding.

text: Structural Changes and Chain Mobility During Processing of Bloodmeal-Based Thermoplastics The purpose of this study was to use concepts from classical polymer physics to develop a fundamental understanding of the interdependent relationship between structure, properties and processing in NovateinTM Thermoplastic Protein (NTP). NTP is produced from bloodmeal, a by-product of the meat industry which is 95% protein, by extruding with sodium sulphite, urea, sodium dodecyl sulphate, water and tri-ethylene glycol.  Dynamic mechanical thermal analysis (DMA) and differential scanning calorimetry (DSC) were used to investigate thermal transitions and chain relaxation, accompanied by synchrotron based Fourier transform infrared spectroscopy (FT-IR) to investigate chain architecture and structural changes. Extrusion, injection moulding and mechanical testing were used to investigate macroscopic properties, such as processability and mechanical properties.
Material pocket DMA enabled detection of glass transition temperatures not only for moulded NTP test pieces, but also for each processing step: bloodmeal,  NTP prior to extrusion, extruded NTP, and conditioned NTP. The pockets increased resolution for injection moulded and conditioned samples, revealing multiple transitions which indicated the presence of more than one phase. Spatially resolved FT-IR experiments were used to characterise the relative content and distribution of protein secondary structures in bloodmeal and NTP after each processing step. Increased chain mobility was observed due to the additives used, and also drastic structural rearrangement consistent with consolidation into a thermoplastic material after extrusion. Viscoelastic phenomena such as creep and stress relaxation further confirmed processed NTP was a consolidated thermoplastic, exhibiting time dependent behaviour characteristic of thermoplastic polymers.
The thermal properties of NTP suggested an underlying semi-crystalline structure, with protein secondary structures such as α-helices and β-sheets constraining motion in the amorphous phase, contributing to a broad glass transition region. These structures do not melt at typical temperatures encountered during extrusion processing, but are dispersed more evenly throughout an amorphous matrix.  Other than plasticisation, strong hydrogen bonding interactions stabilising secondary structures were the dominant influence on mechanical properties of the processed NTP. When TEG was included as a plasticiser, the degree of crystallinity decreased, and the fraction of randomly coiled protein chains was greater at all stages of processing compared to NTP without TEG. TEG competes with protein side groups for hydrogen bonding sites on the protein backbone, reducing secondary structure formation. β-sheets increased when NTP was heated in the absence of shear, displacing TEG and causing it to migrate out of the particles. The short residence time and presence of shear and mixing during extrusion and injection moulding prevented migration during processing, but an overall increase in β-sheet content was still observed after these processing steps.
The relationship between structure, properties and processing of NTP is therefore characterised by its semi crystalline nature, in which additives overcome protein-protein interactions in the amorphous phase enabling β-sheet dispersion throughout the material during processing. Future attempts at modifying properties should be informed by this understanding.

year: 2013

title: Educational leadership for international partnerships between New Zealand and east Asian Chinese higher education institutions

authors: Ho, Ai-Hsin

subjects: educational leadership

abstract: This study examines how higher education leaders in different socio-cultural contexts are involved in the practice of distributed leadership in international partnerships. This study employs socio-cultural theorising to help explain the 22 New Zealand, Singaporean, Chinese and Taiwanese higher education leaders' multiple experiences, perceptions and practices in international partnerships. In this study, socio-cultural theorising entails a view of constructivist epistemology and the ontology of constructive realism. Grounded theory methodology and Wallner's strangifications were employed to acquire, analyse, interpret and compare qualitative data across different contexts in this study. Semi-structured interviewing and document collection were the methods used for data generation. 
The findings suggest that distributed leadership in international higher education partnerships should move beyond simply arranging formal leadership roles, responsibilities, and resources. Distributed leadership in such cross-cultural contexts should be conceived as an inclusive approach to multiple leadership practices. Five interrelated key elements of distributed leadership emerged. They are formal arrangements, enhanced leadership opportunities, understanding the context, sustainability and learning. All the key elements entailed certain levels and aspects of learning. Learning and distributed leadership practices are closely intertwined and informing each other.
A conceptual framework for the learning and practice of distributed leadership in international partnership is proposed to theorise the relationship between three sources of learning of distributed leadership, and multiple distributed leadership practices. The three sources of learning identified in this study are understandings of the context (in actuality), prior knowledge (in lifeworlds), and knowledge of leadership capital, issues and factors (in microworlds). This study provides wider implications for education practitioners in other contexts to explore in international partnerships how social, cultural and economic forms leadership capital can be successfully distributed, exchanged and sustained, and how higher education leaders at all levels can actively participate and learn in international partnerships. Recommendations for researchers to conduct cross-cultural studies are provided.

text: Educational leadership for international partnerships between New Zealand and east Asian Chinese higher education institutions This study examines how higher education leaders in different socio-cultural contexts are involved in the practice of distributed leadership in international partnerships. This study employs socio-cultural theorising to help explain the 22 New Zealand, Singaporean, Chinese and Taiwanese higher education leaders' multiple experiences, perceptions and practices in international partnerships. In this study, socio-cultural theorising entails a view of constructivist epistemology and the ontology of constructive realism. Grounded theory methodology and Wallner's strangifications were employed to acquire, analyse, interpret and compare qualitative data across different contexts in this study. Semi-structured interviewing and document collection were the methods used for data generation. 
The findings suggest that distributed leadership in international higher education partnerships should move beyond simply arranging formal leadership roles, responsibilities, and resources. Distributed leadership in such cross-cultural contexts should be conceived as an inclusive approach to multiple leadership practices. Five interrelated key elements of distributed leadership emerged. They are formal arrangements, enhanced leadership opportunities, understanding the context, sustainability and learning. All the key elements entailed certain levels and aspects of learning. Learning and distributed leadership practices are closely intertwined and informing each other.
A conceptual framework for the learning and practice of distributed leadership in international partnership is proposed to theorise the relationship between three sources of learning of distributed leadership, and multiple distributed leadership practices. The three sources of learning identified in this study are understandings of the context (in actuality), prior knowledge (in lifeworlds), and knowledge of leadership capital, issues and factors (in microworlds). This study provides wider implications for education practitioners in other contexts to explore in international partnerships how social, cultural and economic forms leadership capital can be successfully distributed, exchanged and sustained, and how higher education leaders at all levels can actively participate and learn in international partnerships. Recommendations for researchers to conduct cross-cultural studies are provided.

year: 2009

title: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002

authors: Ashwell, Allanah

subjects: Maori students

abstract: The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

text: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002 The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

year: 2003-06