title: Single screw extruder performance characteristics during processing of corn protein blends

authors: Rosentrater, Kurt A.

abstract: During the last decade, the global biofuels industry has experienced exponential growth. By-products such as distillers dried grains with solubles (DDGS) have grown in parallel. DDGS is primarily an animal feed, but it has also been shown to be suitable as a biopolymer. In this study, the extrusion processing behaviour of DDGS was evaluated. Prior to processing, water was added to DDGS at a level of 3 kg DDGS to 1.5 kg water (water at 50 parts per hundred (pph)). Additionally, a DDGS/water blend with 50 pph CaCO₃ was used as a tracer to determine residence time during processing. The blends were processed in a single screw autogenous extruder, which relied solely upon friction for dissipative heating. Two die plates were used: one consisted of 6 orifices equally spaced, 2 mm diameter each, with a total opening area of 18.85 mm²; the other consisted of multiple orifices (960 in total) arranged concentrically around the plate, with a diameter of 2.30 mm each, for a total opening area of 3988.45 mm². Processing began with DDGS blends without tracer; after reaching steady state, the tracer blend was introduced. Samples were collected every 5 sec during processing to determine extrudate changes over time. Extruder power consumption, mass flow rate, and temperature profile were determined during processing. Extrudates were analysed for Hunter colour (L-a-b) changes over time. Extrusion processing characteristics were highly influenced by the die opening area. Die exit temperatures ranged from room temperature (25°C) to more than 100°C, purely due to increased friction for the smaller die opening. Future work should characterize the mechanical properties of these extrudates to assess their suitability as either bioplastic feedstocks or pelletized animal feeds.

text: Single screw extruder performance characteristics during processing of corn protein blends During the last decade, the global biofuels industry has experienced exponential growth. By-products such as distillers dried grains with solubles (DDGS) have grown in parallel. DDGS is primarily an animal feed, but it has also been shown to be suitable as a biopolymer. In this study, the extrusion processing behaviour of DDGS was evaluated. Prior to processing, water was added to DDGS at a level of 3 kg DDGS to 1.5 kg water (water at 50 parts per hundred (pph)). Additionally, a DDGS/water blend with 50 pph CaCO₃ was used as a tracer to determine residence time during processing. The blends were processed in a single screw autogenous extruder, which relied solely upon friction for dissipative heating. Two die plates were used: one consisted of 6 orifices equally spaced, 2 mm diameter each, with a total opening area of 18.85 mm²; the other consisted of multiple orifices (960 in total) arranged concentrically around the plate, with a diameter of 2.30 mm each, for a total opening area of 3988.45 mm². Processing began with DDGS blends without tracer; after reaching steady state, the tracer blend was introduced. Samples were collected every 5 sec during processing to determine extrudate changes over time. Extruder power consumption, mass flow rate, and temperature profile were determined during processing. Extrudates were analysed for Hunter colour (L-a-b) changes over time. Extrusion processing characteristics were highly influenced by the die opening area. Die exit temperatures ranged from room temperature (25°C) to more than 100°C, purely due to increased friction for the smaller die opening. Future work should characterize the mechanical properties of these extrudates to assess their suitability as either bioplastic feedstocks or pelletized animal feeds.

year: 2013

title: Taste predicates and retraction data: An improved framework

authors: Wyatt, Jeremy

abstract: Predicates of personal taste (PPT), which include words like ‘tasty,’ ‘fun,’ and ‘cool,’ have been at the centre of a set of lively, interdisciplinary debates spanning the past 20 years. Over this period, philosophers and linguists have developed five major accounts of what PPT mean and the sort of truth (if any) for which assertions involving PPT are apt. In this talk, I will explore one of the main empirical diagnostics that should be used in evaluating the ‘big five’ analyses of PPT, which involves considerations about retraction. After setting out the ‘big five’ analyses, I'll review the most influential account of why retraction data matter in the PPT debates, which comes from John MacFarlane. I take MacFarlane’s account to suffer from two significant problems, and after identifying them, I’ll develop an improved framework for thinking about retraction data and PPT. I'll then draw on this improved framework in reframing the significance of our current empirical data.

text: Taste predicates and retraction data: An improved framework Predicates of personal taste (PPT), which include words like ‘tasty,’ ‘fun,’ and ‘cool,’ have been at the centre of a set of lively, interdisciplinary debates spanning the past 20 years. Over this period, philosophers and linguists have developed five major accounts of what PPT mean and the sort of truth (if any) for which assertions involving PPT are apt. In this talk, I will explore one of the main empirical diagnostics that should be used in evaluating the ‘big five’ analyses of PPT, which involves considerations about retraction. After setting out the ‘big five’ analyses, I'll review the most influential account of why retraction data matter in the PPT debates, which comes from John MacFarlane. I take MacFarlane’s account to suffer from two significant problems, and after identifying them, I’ll develop an improved framework for thinking about retraction data and PPT. I'll then draw on this improved framework in reframing the significance of our current empirical data.

year: 2022

title: Pretty difficult: Implementing kaupapa Māori theory in English-medium secondary schools

authors: Bishop, Russell

subjects: Te Kotahitanga Project

abstract: Developed in New Zealand some twenty years ago, kaupapa Māori has had a successful impact in education, notably in Māori-medium settings such as kōhanga reo, kura kaupapa Māori and wharekura. However, in mainstream educational settings, where the vast majority of Māori children continue to be educated, achievement disparities between Māori and their non-Māori peers persist. This article focuses on Te Kotahitanga, a large-scale kaupapa Māori school reform project that seeks to address educational disparities by improving the educational achievement of Māori students in mainstream schooling. Experiences with implementing Te Kotahitanga would suggest that reforming mainstream educational practices along kaupapa Māori lines is not easy. This article examines three main impediments encountered in attempts to implement the Te Kotahitanga project in mainstream schools: confusion about the culture of the Māori child; uneven implementation of the project; and problems with measuring student progress. For the project’s aims to be realised, professional development needs to be ongoing, iterative and responsive.

text: Pretty difficult: Implementing kaupapa Māori theory in English-medium secondary schools Developed in New Zealand some twenty years ago, kaupapa Māori has had a successful impact in education, notably in Māori-medium settings such as kōhanga reo, kura kaupapa Māori and wharekura. However, in mainstream educational settings, where the vast majority of Māori children continue to be educated, achievement disparities between Māori and their non-Māori peers persist. This article focuses on Te Kotahitanga, a large-scale kaupapa Māori school reform project that seeks to address educational disparities by improving the educational achievement of Māori students in mainstream schooling. Experiences with implementing Te Kotahitanga would suggest that reforming mainstream educational practices along kaupapa Māori lines is not easy. This article examines three main impediments encountered in attempts to implement the Te Kotahitanga project in mainstream schools: confusion about the culture of the Māori child; uneven implementation of the project; and problems with measuring student progress. For the project’s aims to be realised, professional development needs to be ongoing, iterative and responsive.

year: 2012