Engineering: Conference Contributions

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  • ItemOpen Access
    Microfluidic Models for Spiking Neural Networks
    (2023) Moore, Ciaran
    Could spiking neural networks be implemented using droplet microfluidics, to create monolithic systems that automatically manipulate and analyse biological samples? This would greatly expand the sophistication of analysis tools available to researchers, allowing advances in the fields of drug discovery, disease detection and directed evolution
  • ItemOpen Access
    Auswirkungen der Verwendung von Virtueller Realität auf die Beziehung zwischen Patienten und Therapeuten in der Neurorehabilitation
    (2024) Crowe S; Shahri B; Piumsomboon T; Waller A; Hoermann, Simon
    Introduction: The use of virtual reality (VR) has promising potential for use in neurorehabilitation. However, concerns remain regarding its impact on the patient-therapist relationship. This relationship, also called the therapeutic alliance, is crucial for the success of rehabilitation and is based on the patient and therapist's agreement on tasks, goals, and interpersonal relationships.
  • ItemOpen Access
    Performance enhancement of an Ag-Au bimetallic SPR sensor
    (2024) Babu , Roshni S.; Colenso , Hamish R.; Gouws , Gideon J.; Auguié , Baptiste; Moore, Ciaran
  • ItemOpen Access
    Development of SPR biosensor using a customized experimental setup
    (2019) Babu , Roshni W.; Moore, Ciaran; Gouws , Gideon; Auguié , Baptise
  • ItemOpen Access
    Shape Shifting Device for Plant Condition Monitoring and Control
    (2023) Agnieray , Heiana; Lv , Yifan; Singamneni , Sarat; Moore, Ciaran; Wakelin , Steve
  • ItemOpen Access
    Effect of thickness on the energy dissipation efficiency of GSI with gravel-rubber mixtures
    (2024) Chiaro, Gabriele; Forcellini, D.; Palermo, A.; Banasiak, L.
    Geotechnical seismic isolation (GSI) using gravel-rubber mixtures (GRM), as an energy dissipative horizontal layer, is a foundation system that can enhance the seismic resilience of low-rise residential buildings. This paper presents the results of a numerical study carried out to evaluate the seismic performance of a selected GSI(VRC40) system (having volumetric rubber content of 40%) and compare it to that of a standard foundation system placed on a compacted gravel layer (i.e., without rubber). To this scope, a 3-dimensional FE model is implemented in OpenSees and calibrated using experimental data. In the model, a 12 m × 6 m × 0.5 m concrete raft foundation is placed on a layer of VRC40 with varying thicknesses (i.e., 0.6, 1.2, 1.8, 2.4, 3.0 and 3.6 m). No structures are considered in this study. The model is subjected to a ramped sinusoidal input base acceleration (ab = 0.1 - 0.5 g) at different frequency levels (f = 1 - 8 Hz). The accelerations at the base (aGIS,base) and top (aGIS,top) of the GSI layer are measured and it is found that the seismic performance of the GSI system significantly increases with increasing ab and f, as well as the GSI thickness, as the GSI(VRC40) layer is able to drastically reduced the acceleration transmitted at the GSI top (i.e., at the base of the concrete raft) as compared to that of the non-isolated gravel foundation. Using a recently proposed GSI efficiency index (EGSI), the effect of the thickness on the energy dissipation efficiency of GSI(VRC40) systems is further examined and it is found that GSI(VRC40) layers of 1.2‒1.8 m thicknesses represent cost-effective foundation systems to significantly reduce the seismic load on/improve the seismic performance of low rise-residential buildings.
  • ItemOpen Access
    Development of a 2D biomechanical model to simulate seated multidirectional arm strength of people with C5-C7 tetraplegia
    (Cambridge University Press (CUP), 2023) Stilwell, George; Symons, Digby; Gooch , Shayne
    People living with tetraplegia experience a significant loss of sensory and motor function; with the severity depending on their injury level and completeness. To complete tasks independently, people with tetraplegia often rely on assistive devices. To avoid upper extremity pain, designs should not require applications of force near the limits of the user's physical strength. This paper establishes a 2D biomechanical model using static equilibrium and joint torque limits to predict multidirectional strength patterns in the sagittal plane for people with C5 to C7 tetraplegia in a seated position. The results from the biomechanical model highlight the areas and directions of high strength. The strength patterns observed in this paper provide an opportunity for designers to evaluate strength requirements and take advantage of areas and directions of high strength and ensure that users are not required to apply force near their physical limit. In doing this, designs such as assistive devices can be developed that enable users with a reduction in strength to operate them independently.
  • ItemUnknown
    Evaluation of E-Scooter Tyre Performance Using Dynamometer-Based Coast-Down Tests
    (Cambridge University Press (CUP), 2023) Stilwell, George; Gooch S; Goodwin M; Zarifeh H
    E-scooters have become a popular form of personal transport with millions of E-scooters used worldwide. This paper details an initial investigation into the relative differences in rolling resistance for a range of e-scooter tyres. Tyre performance was measured using dynamometer-based coast-down tests to determine the coast-down distance and coefficient of rolling resistance of each tyre. Insights from testing showed that e-scooter tyres had coefficients of rolling resistance that were 3.5 to 6 times the coefficient of rolling resistance of a 700x32C bike tyre. Comparisons between tyres of similar specification showed the tyres with solid inserts had more rolling resistance than a pneumatic tyre at the rated pressure. Comparisons of equivalent airless and pneumatic tyres the rated pressure indicated airless tyres had slightly better performance in terms of coast-down distance. The results also show how a decrease in tyre pressure increases rolling resistance, highlighting the importance of maintaining rated tyre pressure to improve e-scooter efficiency. The results from this study provide useful insights into the performance of tyres that can be used on low-powered vehicles.
  • ItemOpen Access
    Comparison of e-scooter tyre performance using rolling resistance trailer
    (Cambridge University Press (CUP), 2024) Stilwell, George; Gooch S; Lafitte M
    E-scooters are a cost-effective means of urban transport, however, there have been questions about their safety, performance, and energy efficiency. This paper investigates the rolling resistance of scooter tyres so that the performance of scooters can be more accurately determined. A rolling resistance trailer was manufactured to directly measure tractive force and closely approximate the rolling resistance force for nine commonly used scooter tyres at low speed on a smooth concrete surface. The results of this study will enable a better understanding of the energy losses of these devices.
  • ItemUnknown
    Exploring Empathy Development in Mechanical Engineering Students During Conceptual Design Task
    (2024) Stilwell, George; Gooch S
    CONTEXT Students studying mechanical engineering are exposed to a range of engineering design methodologies to aid them through a variety of engineering design tasks. In a 4th year mechanical systems design class, mechanical engineering students were given a broad design task for a situation where they need to ideate, evaluate, and develop concepts to aid someone with reduced limb function due to a cervical spinal cord injury (SCI). This type of design problem is topical, as engineers are increasingly required to incorporate universal design principles such that the products they develop can be used by a diverse group of users. This study provide insight into how well undergraduate students compete a design task which requires them to empathise with a use that has different function to themselves. PURPOSE Few researchers have investigated the development of empathy in undergraduate mechanical engineering students as they complete a conceptual design task. The purpose of this study was to investigate how students’ empathy, in terms of their understanding of the specific requirements, limitations and life perspective of an end user with a cervical SCI develop during a concept design task. This data will provide useful insights that will enable the current teaching method to be evaluated and improved. METHODOLOGY Three anonymous online surveys were completed with the class to gather information regarding how students’ self-reported understanding of the end users’ requirements, limitations and life perspective change over the course of the design task. To compare student responses to how well their designs could be used by an individual with a cervical SCI, the designs submitted by students were evaluated against three objective measures. ACTUAL OUTCOMES The results of the surveys showed that students’ self-reported understanding of requirements, limitations and life perspective increased throughout the duration of the conceptual design task. Students commented on the value of discussing the details of the project with both a registered physiotherapist and an individual with a C6 cervical SCI. When the concept designs were compared to the results from the objective measures, many students had submitted designs that were ultimately unusable by the target population of the design problem. This result indicated that many students overestimated their self-reported understanding of the end user. CONCLUSIONS This work highlighted that the current teaching methods enabled students to increase their self reported empathy and understanding for the end user through the completion of a conceptual design task. However, many students were not able to accurately evaluate their own understanding, as solutions were submitted that were unable to be used independently by the Proceedings of AAEE 2024, University of Canterbury, Christchurch, New Zealand. Copyright © George Stilwell, Shayne Gooch, 2024 target population. Future work could investigate changes to the current teaching methods. This could include the development of an alternative or virtual reality experience to help student develop a better understanding of the unique challenges of people who have reduced function.
  • ItemUnknown
    Semiconductor Device Fabrication Lab Demonstration during and after COVID-19
    (2024) Chen L; Hayali A; Adams R; Wislang K; Hou C; Alkaisi M; Nock, Volker; Allen M
    CONTEXT The Solar Cell Lab is a vital element of the popular ENEL491 Nano Engineering course offered by the Electrical and Computer Engineering at the University of Canterbury. The course and associated lab introduce and demonstrate basic semiconductor device fabrication processes to 400-level students. The lab has attracted students from multiple departments and the number of enrolled students increased from less than 20 in 2012 to nearly 70 in 2024. Students fabricate and characterise solar cells from a plain silicon wafer received at the beginning of the lab session. PURPOSE OR GOAL To minimize virus transmission and, at the same time, maintain the quality of the delivered teaching. To ensure students have the opportunity for sufficient hands-on experience in semiconductor fabrication processes, the measures described were implemented during the COVID-19 pandemic. APPROACH OR METHODOLOGY/METHODS The original arrangement of the lab demonstration was designed for fully immersive face-to-face delivery. There were 2 streams with 6 to 8 groups of students (2 or 3 per group) per stream depending on numbers. Students are expected to attend 1 stream for a duration of 3 weeks, learning different fabrication techniques. Each student will submit a report individually at the end of the three weeks of labs. After the pandemic, the maximum number of students for each stream was reduced to 6 students per stream and the number of available streams increased to a maximum of 12 streams. In addition, videos were recorded during wafer preparation and lab sessions, and made available via UC Learn, thus maintaining student engagement during mandatory COVID-19 isolation. ACTUAL OR ANTICIPATED OUTCOMES There are better interactions between the teaching assistants (TAs) and students after the change in the arrangement. Students are more likely to ask questions during lab sessions when the maximum student number per stream decreases. With the change in lab session arrangements, students were able to work on each process step without time pressure, allowing for a more hands on experience, with students thus receiving more information transfer from TAs and staff. CONCLUSIONS/RECOMMENDATIONS/SUMMARY Before the pandemic, students were allocated less than 12 minutes per group per step. After changes were implemented, better interactions with students could be observed during lab sessions, and the TA workload could be better balanced for preparation between sessions, thus providing a better work/rest balance. Interestingly, despite challenges experienced during the pandemic, students were still able to achieve similar solar cell performance compared to pre-COVID years.
  • ItemUnknown
    Effects of thickness on the energy dissipation efficiency of GSI
    (2024) Chiaro, Gabriele; Forcellini , D.; Palermo , A.; Banasiak , L.
    Geotechnical seismic isolation (GSI) using gravel-rubber mixtures (GRM), as an energy dissipative horizontal layer, is a foundation system that can enhance the seismic resilience of low-rise residential buildings. This paper presents the results of a numerical study carried out to evaluate the seismic performance of a selected GSI(VRC40) system (having volumetric rubber content of 40%) and compare it to that of a standard foundation system placed on a compacted gravel layer (i.e., without rubber). To this scope, a 3-dimensional FE model is implemented in OpenSees and calibrated using experimental data. In the model, a 12 m × 6 m × 0.5 m concrete raft foundation is placed on a layer of VRC40 with varying thicknesses (i.e., 0.6, 1.2, 1.8, 2.4, 3.0 and 3.6 m). No structures are considered in this study. The model is subjected to a ramped sinusoidal input base acceleration (ab = 0.1 - 0.5 g) at different frequency levels (f = 1 - 8 Hz). The accelerations at the base (aGIS,base) and top (aGIS,top) of the GSI layer are measured and it is found that the seismic performance of the GSI system significantly increases with increasing ab and f, as well as the GSI thickness, as the GSI(VRC40) layer is able to drastically reduced the acceleration transmitted at the GSI top (i.e., at the base of the concrete raft) as compared to that of the non-isolated gravel foundation. Using a recently proposed GSI efficiency index (EGSI), the effect of the thickness on the energy dissipation efficiency of GSI(VRC40) systems is further examined and it is found that GSI(VRC40) layers of 1.2‒1.8 m thicknesses represent cost-effective foundation systems to significantly reduce the seismic load on/improve the seismic performance of low rise-residential buildings
  • ItemUnknown
    Mechanical Behaviour of Well-graded Gravel-rubber Mixtures in Static and Cyclic Fields
    (2024) Abate G; Chiaro, Gabriele; Fiamingo Angela; Massimino MR
    The necessity to repurpose End-of-Life Tires (ELTs) has driven researchers to seek new methods for converting them into useful products. Recently, shredded rubber from ELTs has been increasingly utilised in various civil engineering fields due to its valuable mechanical properties. Over the past few years, numerous experimental tests have been conducted on the use of shredded scrap tyres mixed with poorly-graded granular soil, primarily sand or gravel, as backfill material for retaining walls, liquefaction mitigation, structural fill, and geotechnical seismic isolation (GSI). Many studies in literature have focused on the mechanical properties of sand-rubber mixtures, while limited research has been done on the behaviour of gravel-rubber mixtures. This paper aims to explore the physical and mechanical properties of more economic and easy-to-prepare geomaterials combining well-graded gravel mixed with scrap rubber grains (wgGRMs) through isotropically consolidated drained monotonic and cyclic triaxial (TxCD and CLTxT) tests. The tests were carried out by varying the confining pressure and the volumetric rubber content (VRC). The results highlight the effect of confining pressure and VRC on the stress-strain relationship and volumetric and cyclic behaviour.
  • ItemUnknown
    Quantifying tree-level Eucalyptus defoliation using UAV LiDAR​
    (2024) Pariyar S; Xu C; Pawson S; Morgenroth, Justin; Ye N
  • ItemUnknown
    Extremely large post-liquefaction deformations of saturated sand under cyclic torsional shear loading
    (2009) Chiaro, Gabriele; Kiyota , Takashi; De Silva , Laddu Indika Nalin; Sato , Takeshi; Koseki , Junichi
    The effect of static shear stress on the undrained cyclic behavior of saturated Toyoura sand was studied by conducting a series of torsional shear tests up to double amplitude shear strain of about 100%. After being isotropically consolidated, the specimens were subjected to drained monotonic torsional shear loading, and then, cyclic torsional shear stress was applied under undrained condition. The amplitude of combined static and cyclic shear stress was kept constant by correcting the measured value for the effect of membrane force. Based on these test results, it was found that the effective stress path and the stress-strain curve were affected by the initial static shear stress. Accumulation of shear strain was clearly noticed in the same direction where the static shear stress was applied. Localization of specimen deformation, which increases with the shear strain level, was observed.
  • ItemUnknown
    What Determines VR Integration in Design Practice? An Investigation of Industrial Designer's Acceptance of VR Visualisation Tools
    (Cambridge University Press, 2023) Zhang, Wendy; Ranscombe C; Piumsomboon, Thammathip; Mallya P
    Emerging visualisation tools based on eXtended Reality (XR) platforms offer designers new possibilities and benefits, attracting increasing interest from academia and industry. However, as the users and consumers of these tools, practising designers' perceptions of XR visualisation tools need to be further verified as they shape the tools' acceptance and integration in the industry. This paper investigates industrial designers' acceptance of VR visualisation tools using the Unified Theory of Acceptance and Use of Technology (UTAUT) model. Semi-structured interviews were undertaken with 12 designers from 3 countries to discuss their attitudes, motivations, experiences, and expectations regarding adopting VR visualisation tools as professional tools. The study highlights key opportunities to promote VR integration in industrial design as the tools' practical capabilities to support design performance and the social influence of stakeholders and peer designers on the professional use of VR. The main barriers lie in designers' expected effort to learn and use the tools and the investment and upkeep of VR systems and facilities in the industry. The paper concludes with recommendations for reaping benefits and overcoming barriers.
  • ItemOpen Access
    Enhancing Seedling Detection in New Zealand Forestry: A Multi-Datastream Approach
    (2024) Singleton B; Xu C; Ye N; morgenroth, justin