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Solidago canadensis modifies microbial community and soil physicochemical properties through litter leachates and root exudates
Get PDFInvasive plants alter soil microbial communities and physicochemical properties through chemical inputs from litter, root exudates and leachate, impacting a range of soil processes, but precise effects are poorly understood. We investigated the little effects of Solidago canadensis, a common invasive species in China, on soil microbial communities under natural conditions. Experimental treatments included S. canadensis seedling density (1 and 2 plants/pot) and litter quantity (10 and 20 g/pot), with control groups containing no plants or litter. After 120 days, soil samples were analyzed for physico-chemical properties, GC–MS chemical composition, and bacterial community composition using high-throughput sequencing. Results showed that S. canadensis seedlings and litter inputs significantly increased soil pH, soil organic matter (SOM), and total nitrogen (TN), while phosphorus and potassium remained unchanged. We identified 66 chemical compounds, predominantly ketones, alcohol, aldehyde, hydrocarbon, ester, acid, terpenoids and alkaloids, associated with the presence of S. canadensis, alongside shifts in dominant bacterial genera including Sphingomonas, Acidobacteriales and Gemmatimonas. Rarer genera under the invasive treatment species, such as Candidatus, Rhodoplanes and Novosphingobium, were positively correlated with soil TN, pH, and SOM. Collectively, these findings demonstrate that allelochemical inputs from S. canadensis litter and root exudates significantly reshape soil properties and microbial communities, with potential implications for ecosystem dynamics and invasion success
The use of ammonia as a zero carbon heavy duty IC engine fuel for low criteria pollutant emissions– Simulation of an I.C. Engine with exhaust reforming
No full textAmmonia has many advantages for use as a net-zero fuel, primarily potentially lowest lifecycle cost and reasonable energy storage density (by volume) compared with other zero carbon contenders. Handling and safety is not without concern, but its safe use is not unprecedented, and studies have been done concluding it could be used with acceptable safety compared with existing fuels. An area requiring demonstration however is the achievement of adequately low levels of emissions for higher regulated countries (HRC1) such as Heavy duty Euro VI, or non-road Stage V in a reciprocating IC engine and the necessary aftertreatment requirements. The purpose of this paper is to present a possible approach using exhaust heat to partially reform ammonia back into hydrogen and nitrogen. This provides the (hydrogen) promoter fuel required for sufficiently rapid and stable SI combustion, and allows, for example, lambda = 1 combustion so that criteria pollutants and ammonia slip can probably be controlled to low levels by simple three-way catalyst. The various trade-offs are shown which control the reforming reactions using exhaust heat, which being endothermic can result in a net gain of fuel energy between fuel supply and the mixture entering the cylinder. The importance of good heat transfer from the exhaust to the fuel to be reformed is shown. The overall system is then compared in 1d simulation with a lean burn port injected hydrogen engine demonstrating the trade-offs for relative overall efficiency, airsystem requirements and in-cylinder component temperatures. It is concluded that many of the obstacles associated with ammonia IC engine combustion with low criteria pollutants may be possible to overcome, but hardware demonstration is now required
Advancements in Electrical Machines for Aircraft Propulsion
No full textElectrical machines are at the center of future aircraft propulsion architectures, and their improvement is key in increasing the market uptake of cleaner transport. This paper investigates recent/ongoing improvements within the constituent technology bricks, including the magnetic materials, insulation, thermal management, coil winding, and wire technologies, and estimates the performance entitlements from each considering an 800 kW 1800 rpm direct drive aircraft propulsion motor. The combination of advanced technology bricks is then discussed for two aerospace machine case studies involving a 4 MW, 15 krpm, 17.3 kW/kg generator and a 300 kW, 6500 rpm, 15-25 kW/kg motor
Vector-based neural network turbulent heat flux closures in near-wall cooling jet flows
Get PDFNear-wall jet cooling flows are difficult to model using industrially appropriate CFD methods such as Reynolds-Averaged Navier–Stokes (RANS) approaches. Previous work has addressed the Reynolds stress closure and simple approaches to improve the turbulent heat flux closure. In this paper, two novel vector-based neural network models have been developed to capture complex turbulent heat flux trends found in near-wall cooling jet flows to improve RANS modelling approaches of these complex flows. The first model features diffusion-based vector inputs which can replicate the early jet development region while the second model which uses a broader vector feature space and captures the turbulent heat flux in the early jet development region and the downstream jet region. The latter model replicated the LES streamwise, normal and spanwise profiles of turbulent heat flux and provided improved results over GDH and HOGGDH turbulent heat flux models
Secreted factors of Aspergillus fumigatus cause lung epithelial barrier disruption: A study using an air–liquid interface cell culture model
No full textThe effects of Aspergillus fumigatus-conditioned medium (AFCM) on the integrity of the Calu-3 cell lung epithelial barrier were investigated. AFCM led to a decrease in transepithelial electrical resistance and the disruption of the occludin network in the epithelial barrier. Preincubation with protease inhibitors reduced the effect of AFCM by ~ 90%, demonstrating the role of fungal proteases in epithelial barrier disruption. By mass spectrometry, we identified 494 unique proteins in AFCM, including 14 peptidases of different families. Together, these findings suggest that proteases secreted by A. fumigatus were able to modulate host epithelial barrier disruption in this fungal infection process
Research Handbook on Adult Learning and Education
No full textThis innovative Research Handbook rethinks current paradigms in adult education, providing a toolkit for responding to the challenges and opportunities for adult education and lifelong learning amidst a changing world. Contributing authors analyse key aspects of the field through the lenses of democracy, sustainability, and social justice
Microwave-coupled optical bistability in driven and interacting Rydberg gases
Get PDFNonequilibrium dynamics are closely related to various fields of research, in which vastly different phases emerge when parameters are changed. However, it is difficult to construct nonequilibrium systems that have sufficiently tunable controllable parameters. Using microwave field coupling induced optical bistability, Rydberg gases exhibit a range of significantly different optical responses. In conjunction with electromagnetically induced transparency, the microwave coupling can create versatile nonequilibrium dynamics. In particular, the microwave coupling of two Rydberg states provides an additional handle for controlling the dynamics. And the microwave-controlled nonequilibrium phase transition has the potential to be applied in microwave field measurement. This study opens a new avenue to exploring bistable dynamics using microwave-coupled Rydberg gases, and developing quantum technological applications
Tangles: Unpacking Extended Collision Experiences with Soma Trajectories
Get PDFWe reappraise the idea of colliding with robots, moving from a position that tries to avoid or mitigate collisions to one that considers them an important facet of human interaction. We report on a soma design workshop that explored how our bodies could collide with telepresence robots, mobility aids and a quadruped robot. Based on our findings, we employed soma trajectories to analyse collisions as extended experiences that negotiate key transitions of consent, preparation, launch, contact, ripple, sting, untangle, debris and reflect. We then employed these ideas to analyse two collision experiences, an accidental collision between a person and a drone and the deliberate design of a robot to play with cats, revealing how real-world collisions involve the complex and ongoing entanglement of soma trajectories. We discuss how viewing collisions as entangled trajectories, or ‘tangles’, can be used analytically, as a design approach, and as a lens to broach ethical complexity
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