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: Sulfide-bridged aggregates from the metalloligand [Pt₂(μ-S)₂(PPh₃)₄] and β-diketonate complexes of cobalt(II) and zinc(II)

authors: Bridson, James Hadley

subjects: Zinc complexes

abstract: Reaction of [Pt₂(μ-S)₂(PPh₃)₄] with a range of zinc(II) and cobalt(II) complexes ML₂, where L is a β-diketonate ligand CH₃COCHCOCH₃, PhCOCHCOPh, CF₃COCHCOTh (Th = 2-thienyl)] permits the synthesis of adducts [Pt₂(μ-S)₂(PPh₃)₄M(diketonate)]⁺, isolated as their BPH₄⁻salts in moderate yields. The cobalt and zinc acetylacetonate complexes were characterised by single-crystal X-ray diffraction studies, which reveal isomorphous structures, with tetrahedral heterometal centres.

text: Sulfide-bridged aggregates from the metalloligand [Pt₂(μ-S)₂(PPh₃)₄] and β-diketonate complexes of cobalt(II) and zinc(II) Reaction of [Pt₂(μ-S)₂(PPh₃)₄] with a range of zinc(II) and cobalt(II) complexes ML₂, where L is a β-diketonate ligand CH₃COCHCOCH₃, PhCOCHCOPh, CF₃COCHCOTh (Th = 2-thienyl)] permits the synthesis of adducts [Pt₂(μ-S)₂(PPh₃)₄M(diketonate)]⁺, isolated as their BPH₄⁻salts in moderate yields. The cobalt and zinc acetylacetonate complexes were characterised by single-crystal X-ray diffraction studies, which reveal isomorphous structures, with tetrahedral heterometal centres.

year: 2006-01-01

title: The legacy of Ngatoroirangi: Maori customary use of geothermal resources

authors: Stokes, Evelyn

subjects: geothermal resources

abstract: Geothermal activity has always been regarded as a significant traditional resource among Maori communities of the Bay of Plenty, Rotorua and Taupo districts. The principal settlements of the tribes of Te Arawa, Ngati Tahu and Ngati Tuwharetoa were associated with geothermal areas. Outside the Taupo Volcanic Zone there were numerous other hot springs which were also highly valued by Maori. Areas of surface geothermal activity all have some traditions, cultural and historical associations for local tribes. Geothermal resources were used in various ways.

text: The legacy of Ngatoroirangi: Maori customary use of geothermal resources Geothermal activity has always been regarded as a significant traditional resource among Maori communities of the Bay of Plenty, Rotorua and Taupo districts. The principal settlements of the tribes of Te Arawa, Ngati Tahu and Ngati Tuwharetoa were associated with geothermal areas. Outside the Taupo Volcanic Zone there were numerous other hot springs which were also highly valued by Maori. Areas of surface geothermal activity all have some traditions, cultural and historical associations for local tribes. Geothermal resources were used in various ways.

year: 2000