title: The effects of precipitation chemistry and catchment area lithology on the quality of river water in selected catchments in eastern Australia

authors: Douglas, Ian

abstract: The results of partial chemical analyses of precipitation and river water samples from north-east Queensland and south-eastern New South Wales are presented. Comparisons of water quality in the two areas are made using ionic ratios. While the sodium and chloride contents of precipitation in the two areas are similar, higher concentrations of calcium, magnesium and potassium occur in precipitation samples collected in New South Wales. Precipitation supplies between 25% and 70% of the total solute loads of the rivers studied. In the Southern Tablelands of New South Wales more chloride is supplied to the catchment areas than is removed by the rivers. River water quality reflects catchment lithology more than the climatic contrasts between the two study areas. Nevertheless, precipitation chemistry exerts an influence on the ionic ratios of these Australian rivers with low total dissolved solids concentrations.

text: The effects of precipitation chemistry and catchment area lithology on the quality of river water in selected catchments in eastern Australia The results of partial chemical analyses of precipitation and river water samples from north-east Queensland and south-eastern New South Wales are presented. Comparisons of water quality in the two areas are made using ionic ratios. While the sodium and chloride contents of precipitation in the two areas are similar, higher concentrations of calcium, magnesium and potassium occur in precipitation samples collected in New South Wales. Precipitation supplies between 25% and 70% of the total solute loads of the rivers studied. In the Southern Tablelands of New South Wales more chloride is supplied to the catchment areas than is removed by the rivers. River water quality reflects catchment lithology more than the climatic contrasts between the two study areas. Nevertheless, precipitation chemistry exerts an influence on the ionic ratios of these Australian rivers with low total dissolved solids concentrations.

year: 1968

title: Characterizing the mechanical properties of fused deposition modelling natural fiber recycled polypropylene composites

authors: Milosevic, M.

abstract: The objective of this investigation was to characterize the performance of natural fiber reinforced polypropylene composites in fused deposition modelling (FDM). Composite filaments comprising of pre-consumer recycled polypropylene with varying contents of hemp or harakeke fibers were extruded from which tensile test specimens were made using FDM. Filament and test specimens were tensile tested and properties were compared with plain polypropylene samples; the ultimate tensile strength and Young’s modulus of reinforced filament increased by more than 50% and 143%, respectively, for both 30 wt % hemp or harakeke compared to polypropylene filament. However, the same degree of improvement was not seen with the FDM test specimens, with several compositions having properties lower than for unfilled polypropylene. SEM analysis of fracture surfaces revealed uniform fiber dispersion and reasonable fiber alignment, but porosity and fiber pull-out were also observed. Fiber reinforcement was found to give benefit regarding dimensional stability during extrusion and FDM, which is of major importance for its implementation in FDM. Recommendations for optimization of processing in order to enhance build quality and improve mechanical properties are provided.

text: Characterizing the mechanical properties of fused deposition modelling natural fiber recycled polypropylene composites The objective of this investigation was to characterize the performance of natural fiber reinforced polypropylene composites in fused deposition modelling (FDM). Composite filaments comprising of pre-consumer recycled polypropylene with varying contents of hemp or harakeke fibers were extruded from which tensile test specimens were made using FDM. Filament and test specimens were tensile tested and properties were compared with plain polypropylene samples; the ultimate tensile strength and Young’s modulus of reinforced filament increased by more than 50% and 143%, respectively, for both 30 wt % hemp or harakeke compared to polypropylene filament. However, the same degree of improvement was not seen with the FDM test specimens, with several compositions having properties lower than for unfilled polypropylene. SEM analysis of fracture surfaces revealed uniform fiber dispersion and reasonable fiber alignment, but porosity and fiber pull-out were also observed. Fiber reinforcement was found to give benefit regarding dimensional stability during extrusion and FDM, which is of major importance for its implementation in FDM. Recommendations for optimization of processing in order to enhance build quality and improve mechanical properties are provided.

year: 2017

title: The cost of aquatic weed control in the Rotorua Te Arawa Lakes

authors: Champion, Paul

abstract: We will present information on the costs of aquatic weed control in the Rotorua, Te Arawa Lakes and thank all of the people who have willingly given us their estimated costs. Hopefully, this provides guidance on what current activities cost and what future scenarios might be feasible.

text: The cost of aquatic weed control in the Rotorua Te Arawa Lakes We will present information on the costs of aquatic weed control in the Rotorua, Te Arawa Lakes and thank all of the people who have willingly given us their estimated costs. Hopefully, this provides guidance on what current activities cost and what future scenarios might be feasible.

year: 2017