title: Thermographic inspection to provide quality assurance for reinforced 3D printer filaments

authors: Huang, Ding Yi Monique

subjects: Thermography inspection natural fibre reinforced filaments

abstract: This research demonstrates the feasibility of active thermography in inspecting 3D printing filaments. Examine the potential of pulsed phase thermography in quality assurance of short and natural fibre reinforced polymer composites. Signal analysis scripts were built in Matlab to process the raw data recordings collected. These scripts included were; Single Pixel Analysis (SPA) that consisted of 2D wavelet denoising and single pixel plotted through time; Thermal Signal Reconstruction (TSR); and Pulsed
Phase Thermography (PPT) that implemented the inbuilt with Fast Fourier Transform (FFT). 3D printed natural fibre composites offer sustainable and cost-effective solutions to material challenges. When considering combining natural fibres and 3D printing there are several manufacturing challenges that must be overcome. The focus of this research is to ascertain if active thermography is a suitable tool for online inspection of fibre reinforced filaments used for 3D printing composites. The aim of the inspection is to
identify fibre rich and fibre poor regions along the filament, where uniformly distributed fibres and heating along the filament are preferred. Regions with a locally high weight percent of fibres, known as a fibre bunch, can cause problems when used to print a part resulting in a waste of materials and failed print jobs. The paper presents a feasibility study showing the potential of using pulsed thermography to identify fibre bunching. An external heating stimulus is applied to the sample and an infrared detector is used to monitor the thermal decay. The thermal contrast produced by fibre bunches compared to regions of uniformly distributed fibres is used to identify potential problem areas and provide a means of quality control. Investigation includes variation of the heating stimulus, data collection and data processing routines. Flat bottom holes (FBH) and notches of the samples were easiest to detect, filaments mixed with fibres and salt were more challenging and difficult to detect, which will require further investigations.

text: Thermographic inspection to provide quality assurance for reinforced 3D printer filaments This research demonstrates the feasibility of active thermography in inspecting 3D printing filaments. Examine the potential of pulsed phase thermography in quality assurance of short and natural fibre reinforced polymer composites. Signal analysis scripts were built in Matlab to process the raw data recordings collected. These scripts included were; Single Pixel Analysis (SPA) that consisted of 2D wavelet denoising and single pixel plotted through time; Thermal Signal Reconstruction (TSR); and Pulsed
Phase Thermography (PPT) that implemented the inbuilt with Fast Fourier Transform (FFT). 3D printed natural fibre composites offer sustainable and cost-effective solutions to material challenges. When considering combining natural fibres and 3D printing there are several manufacturing challenges that must be overcome. The focus of this research is to ascertain if active thermography is a suitable tool for online inspection of fibre reinforced filaments used for 3D printing composites. The aim of the inspection is to
identify fibre rich and fibre poor regions along the filament, where uniformly distributed fibres and heating along the filament are preferred. Regions with a locally high weight percent of fibres, known as a fibre bunch, can cause problems when used to print a part resulting in a waste of materials and failed print jobs. The paper presents a feasibility study showing the potential of using pulsed thermography to identify fibre bunching. An external heating stimulus is applied to the sample and an infrared detector is used to monitor the thermal decay. The thermal contrast produced by fibre bunches compared to regions of uniformly distributed fibres is used to identify potential problem areas and provide a means of quality control. Investigation includes variation of the heating stimulus, data collection and data processing routines. Flat bottom holes (FBH) and notches of the samples were easiest to detect, filaments mixed with fibres and salt were more challenging and difficult to detect, which will require further investigations.

year: 2020

title: Design of robust total site heat recovery loops via Monte Carlo simulation

authors: Schlosser, Florian

subjects: Science & Technology

abstract: For increased total site heat integration, the optimal sizing and robust operation of a heat recovery loop (HRL) are prerequisites for economic efficiency. However, sizing based on one representative time series, not considering the variability of process streams due to their discontinuous operation, often leads to oversizing. The sensitive evaluation of the performance of an HRL by Monte Carlo (MC) simulation requires sufficient historical data and performance models. Stochastic time series are generated by distribution functions of measured data. With these inputs, one can then model and reliably assess the benefits of installing a new HRL. A key element of the HRL is a stratified heat storage tank. Validation tests of a stratified tank (ST) showed sufficient accuracy with acceptable simulation time for the variable layer height (VLH) multi-node (MN) modelling approach. The results of the MC simulation of the HRL system show only minor yield losses in terms of heat recovery rate (HRR) for smaller tanks. In this way, costs due to oversizing equipment can be reduced by better understanding the energy-capital trade-off.

text: Design of robust total site heat recovery loops via Monte Carlo simulation For increased total site heat integration, the optimal sizing and robust operation of a heat recovery loop (HRL) are prerequisites for economic efficiency. However, sizing based on one representative time series, not considering the variability of process streams due to their discontinuous operation, often leads to oversizing. The sensitive evaluation of the performance of an HRL by Monte Carlo (MC) simulation requires sufficient historical data and performance models. Stochastic time series are generated by distribution functions of measured data. With these inputs, one can then model and reliably assess the benefits of installing a new HRL. A key element of the HRL is a stratified heat storage tank. Validation tests of a stratified tank (ST) showed sufficient accuracy with acceptable simulation time for the variable layer height (VLH) multi-node (MN) modelling approach. The results of the MC simulation of the HRL system show only minor yield losses in terms of heat recovery rate (HRR) for smaller tanks. In this way, costs due to oversizing equipment can be reduced by better understanding the energy-capital trade-off.

year: 2019

title: Mai ngā pouwhirinaki - The experiences of whānau caring for Māori tangata whaiora with traumatic brain injury in the Waikato

authors: Silveira, Maia

subjects: Traumatic brain injury

abstract: In Aotearoa today, Māori have a disproportionate experience of Traumatic Brain Injury (TBI) in the community and in prisons compared to non-Māori. Furthermore, Māori have higher mortality rates following TBI, and are more likely to have a prolonged stay in hospital then be discharged without community support services compared with non-Māori. Currently, many of the post-acute rehabilitation services are located in the Auckland region which causes undue pressure of whānau needs, finances, and work commitments for many whānau and individuals with TBI from the Waikato region. My research focuses on the experiences of whānau navigators experience of caring for Māori tangata whaiora with TBI in the Waikato region. Whānau navigators for this thesis refers to members of the whānau who have familial obligations of care. Within this thesis I consult and engage with whānau about post-acute rehabilitation services. This is a qualitative based research project, which draws upon narrative inquiry, and a Kaupapa Māori research paradigm. Documenting these experiences will provide empirical evidence to highlight the invaluable role whānau have within recovery and the value of whānau support. This research can be used to identify the dynamic needs of whānau and encourage the healthcare system to provide a service that is consistent with Kaupapa Māori health frameworks and practices which at present is non- existent. As a result, the project will help inform the development of a service model within TBI that can better reflect and support the needs of whānau and Māori communities, that is a locally derived practice and more applicable and appropriate for Māori. Mauri ora!

text: Mai ngā pouwhirinaki - The experiences of whānau caring for Māori tangata whaiora with traumatic brain injury in the Waikato In Aotearoa today, Māori have a disproportionate experience of Traumatic Brain Injury (TBI) in the community and in prisons compared to non-Māori. Furthermore, Māori have higher mortality rates following TBI, and are more likely to have a prolonged stay in hospital then be discharged without community support services compared with non-Māori. Currently, many of the post-acute rehabilitation services are located in the Auckland region which causes undue pressure of whānau needs, finances, and work commitments for many whānau and individuals with TBI from the Waikato region. My research focuses on the experiences of whānau navigators experience of caring for Māori tangata whaiora with TBI in the Waikato region. Whānau navigators for this thesis refers to members of the whānau who have familial obligations of care. Within this thesis I consult and engage with whānau about post-acute rehabilitation services. This is a qualitative based research project, which draws upon narrative inquiry, and a Kaupapa Māori research paradigm. Documenting these experiences will provide empirical evidence to highlight the invaluable role whānau have within recovery and the value of whānau support. This research can be used to identify the dynamic needs of whānau and encourage the healthcare system to provide a service that is consistent with Kaupapa Māori health frameworks and practices which at present is non- existent. As a result, the project will help inform the development of a service model within TBI that can better reflect and support the needs of whānau and Māori communities, that is a locally derived practice and more applicable and appropriate for Māori. Mauri ora!

year: 2022