System design of a hydrogen induction system as a retrofit item compatible with existing internal combustion engines

As the current method of delivering the world’s transportation energy demand via fossil fuels becomes increasingly unsustainable, vehicle manufactures and organisations are looking to alternative energy sources for vehicle propulsion such as hydrogen fuel. This project has been undertaken to establish the feasibility of the System Design of a Hydrogen Induction System as a Retrofit Item Compatible with Existing Internal Combustion Engines, by examining the conversion of a Holden 5.0L V8 to accommodate hydrogen combustion. The for the purpose of analysis, a Holden HX GTS sedan has been chosen as a case study vehicle, commonly optioned with the first generation Holden 5.0L V8. Analysis of urban and extra-urban drive cycles provided theoretical power requirements for the operation of the vehicle for the duration of the cycles. Outputs from the drive cycle analysis were used in an engine simulation model that was modified to accommodate simulation of hydrogen combustion. Input values for average power and engine speed required to maintain velocity along the drive cycles are supplied to the engine simulation model. The engine simulation model returns a hydrogen fuel consumption of 4.18 kg/100km and 5.34 kg/100km for the extra- urban and urban driving cycles respectively, a gasoline gallon equivalent of 15.4 L/100km and 20.27 L/100km. This provides a theoretical endurance of 133.62 km and 104.14 km from vehicles proposed 5.6 kg of useable hydrogen storage for the cycles respectively. An extensive literature review is used to identify design modifications that are required to accommodate hydrogen combustion in internal combustion engines. A trade study is used to identify the measures specifically required to adapt the Holden 5.0L case study engine to dual hydrogen/petrol operation modes. The modifications and additional components required were costed where possible, resulting in an estimated minimum cost of AUD $12,664 in parts for the conversion

A chemical sensor based on a photonic-crystal L3 nanocavity defined in a silicon-nitride membrane

The application of a silicon-nitride based L3 optical nanocavity as a chemical sensor is explored. It is shown that by adjusting the thickness of an ultra-thin Lumogen Red film deposited onto the nanocavity surface, the fundamental optical mode undergoes a progressive red-shift as the layer-thickness increases, with the cavity being able to detect the presence of a single molecular monolayer. The optical properties of a nanocavity whose surface is coated with a thin layer of a porphyrin-based polymer are also explored. On exposure of the cavity to an acidic-vapour, it is shown that changes in the optical properties of the porphyrin-film (thickness and refractive index) can be detected through a reversible shift in the cavity mode wavelength. Such effects are described using a finite difference time-domain model

Bio-inspired Distributed Strain and Airflow Sensing for Small Unmanned Air Vehicle Flight Control

Flying animals such as birds, bats and insects all have extensive arrays of sensory or- gans distributed in their wings which provide them with detailed information about the airflow over their wings and the forces generated by this airflow. Using two small modified unmanned air vehicle platforms (UAVs), one with a distributed array of 12 strain gauge sensors and one with a chord-wise array of 4 pressure sensors, we have examined the dis- tribution of the strain and air pressure signals over the UAV wings in relation to flight conditions, including wind tunnel testing, indoor free flight and outdoor free flight. We have also characterised the signals provided by controlled gusts and natural turbulence. These sensors were then successfully used to control roll motions in the case of the strain sensor platform and pitch motions in the case of the pressure sensor platform. These results suggest that distributed mechanosensing and airflow sensing both offer advantages beyond traditional flight control based on rigid body state estimation using inertial sensing. These advantages include stall detection, gust alleviation and model-free measurement of aerodynamic forces. These advantages are likely to be important in the development of future aircraft with increasing numbers of degrees of freedom both through flexibility and active morphing.</p

The impact of sugar particle size manipulation on the physical and sensory properties

peer-reviewedThe overall objective of this research was to assess the effect of sugar particle size manipulation on the physical and sensory properties of chocolate brownies. A control sugar (commercially available, 200-5181 μm) and four of its sieved sugar separates (mesh size of 710, 500, 355 and 212 μm) were determined by grinding and sieving. The particle diameter and diameter distributions of the control sugar and each sugar fraction were measured. As a result, five sugar treatments were determined for chocolate brownie formulations; Control (C200-5181 μm), Large-particle replacement (LPR924-1877 μm), Medium-particle replacement (MPR627-1214 μm), Small-particle replacement (SPR459-972 μm) and a known MIX sample. Samples were tested using sensory (hedonic & intensity), instrumental (texture and colour) and compositional analyses (moisture and fat). Brownie samples containing the smallest sugar fraction (SPR459-972 μm) were perceived as significantly sweeter than any other sample (p < 0.05). Brownies containing this fraction were also the softest and moistest samples (p < 0.05). Texture liking was significantly associated with the LPR924-1877 μm brownie (p < 0.05). Darkness of brownie samples increased (p < 0.05) as sugar particle size decreased. Therefore, sugar particle size alteration affects the physical and sensory properties of chocolate brownies and could be used as a viable approach to reduce sugar in confectionery-type products

Distributed pressure sensing–based flight control for small fixed-wing unmanned aerial systems

Small fixed-wing unmanned aerial systems (UAS) may require increased agility when operating in turbulent wind fields. In these conditions, conventional sensor suites could be augmented with additional flow-sensing to extend the aircraft’s usable flight envelope. Inspired by distributed sensor arrays in biological systems, a UAS with a chordwise array of pressure sensors was developed. Wind-tunnel testing characterized these sensors alongside a conventional airspeed sensor and an angle-of-attack (AoA) vane, and showed a single pressure measurement gave a linear response to AoA prestall. Flight tests initially manually piloted the vehicle through pitching maneuvers, then in a series of automated maneuvers based on closed-loop feedback using an estimate of AoA from the single pressure port. The AoA estimate was successfully used to control the attitude of the aircraft. An artificial neural network (ANN) was trained to estimate the AoA and airspeed using all pressure ports in the array, and validated using flight-trial data. The ANN more accurately estimated the AoA over a single-port method with good robustness to stall and unsteady flow. Distributed flow sensors could be used to supplement conventional flight control systems, providing enhanced information about wing flow conditions with application to systems with highly flexible or morphing wings

BVLOS UAS Operations in Highly-Turbulent Volcanic Plumes

Long-range, high-altitude Unoccupied Aerial System (UAS) operations now enable in-situ measurements of volcanic gas chemistry at globally-significant active volcanoes. However, the extreme environments encountered within volcanic plumes present significant challenges for both air frame development and in-flight control. As part of a multi-disciplinary field deployment in May 2019, we flew fixed wing UAS Beyond Visual Line of Sight (BVLOS) over Manam volcano, Papua New Guinea, to measure real-time gas concentrations within the volcanic plume. By integrating aerial gas measurements with ground- and satellite-based sensors, our aim was to collect data that would constrain the emission rate of environmentally-important volcanic gases, such as carbon dioxide, whilst providing critical insight into the state of the subsurface volcanic system. Here, we present a detailed analysis of three BVLOS flights into the plume of Manam volcano and discuss the challenges involved in operating in highly turbulent volcanic plumes. Specifically, we report a detailed description of the system, including ground and air components, and flight plans. We present logged flight data for two successful flights to evaluate the aircraft performance under the atmospheric conditions experienced during plume traverses. Further, by reconstructing the sequence of events that led to the failure of the third flight, we identify a number of lessons learned and propose appropriate recommendations to reduce risk in future flight operations

Understanding the Effects of Gamification and Juiciness on Players

Gamification is widely applied to increase user engagement and motivation, but empirical studies on effectivenessare inconclusive, and often limited to the integration of tangible elements such as leaderboards or badges. In this paper, we report findings from a study with 36 participants that uses the lens of Self-Determination Theory to compare traditional gamification elements, and the concept of juiciness (the provision of abundant audiovisual feedback) in the VR simulation Predator!. Results show that gamification and juiciness improve user experience, but that only juiciness fulfills all basic psychological needs that facilitate intrinsic motivation when applied in nongaming settings. User preferences favour the combination of both approaches, however, neither improved performance, and there is evidence of juicy elements influencing user behaviour. We discuss implications of these findings for the integration of gamification, reflect on the role of both approaches in the context of feedback, and outline challenges and opportunities for further research. Index Term

Activity patterns and reproductive behavior of the Critically Endangered Bermuda skink (Plestiodon longirostris)

The study of rare or cryptic species in zoos can provide insights into natural history and behavior that would be difficult to obtain in the field. Such information can then be used to refine population assessment protocols and conservation management. The Bermuda skink (Plestiodon longirostris) is an endemic Critically Endangered lizard. Chester Zoo's successful conservation breeding program is working to safeguard, increase and reinforce skink populations in the wild. A key aim of this program is to develop our understanding of the behavior of this species. In this study, using 24 h video recordings, we examined the daily activity patterns, basking behavior and food preferences of four pairs of Bermuda skinks. The skinks displayed a bimodal pattern of activity and basking, which may have evolved to avoid the strength of the midday sun in exposed habitats in Bermuda. Captive Bermuda skinks appear to prefer a fruit‐based diet to orthopteran prey. We also documented their reproductive behavior and compared it against two closely related species. Although there were many similarities between the courtship and mating behaviors of the three species, there was a significantly shorter period of cloacal contact in the Bermuda skink. Oophagia was also documented for the first time in this species. This knowledge has enabled the evaluation of the current ex‐situ management practices of this species, filled gaps in knowledge that would be challenging to obtain in the field, and enabled the enhancement of both animal husbandry and reproductive success for the conservation breeding program