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Background: Predicting fire behaviour is an ongoing challenge in temperate peatlands and heathlands, where live fuels can form the dominant fuel load for wildfire spread, and where spatial heterogeneity in fuel moisture is important but not typically represented in fuel models. Aims: We examine the impact of fuel moisture variation on simulated fire behaviour across a temperate peatland/heathland landscape. Methods: We collected field measurements of fuel moisture content in Calluna vulgaris shrub from 36 sites across the North Yorkshire Moors, United Kingdom. We used these to define fuel moisture inputs within existing shrubland fuel models to simulate fire behaviour in BehavePlus. Key results: Simulated rates of spread varied with fuel moisture content; average mean variance of 23–80% from the landscape average rate of spread. The driest sites had simulated rates of spread up to 135% above the landscape average and the wettest sites up to 86% below average. Fuel model selection dramatically impacted simulated rates of spread by a factor of five. Conclusions: We need to constrain the role of live fuel moisture within temperate fuel models to develop accurate fire behaviour predictions. Implications: Capturing cross-landscape heterogeneity in fire behaviour is important for safe and effective land and wildfire management decision-making. Predicted fire behaviour varies significantly when cross-landscape fuel moisture differences are included in simulations. In temperate fuels, where live fuel moisture is not well represented in models, this may create dangerous situations where fire behaviour is underpredicted during the typical spring fire season, which has implications for fire management decision-making. [ABSTRACT FROM AUTHOR]

A summary of methods for process intensification in stirred reactors is presented, based mainly on the experience from R&D in the minerals processing industry. The process intensification concept is broadened to include innovations which lead to dramatically increased throughput for large-scale processing reactors, in contrast to the traditional definition of reactor size reduction, which has so far been ignored by the minerals industry. Methods enabling operating at high solids concentrations in processing tanks are reviewed to increase the throughput. It is proposed that the agitation power constraint at a high solids loading can be overcome by removal of baffles, for slowly reacting slurry systems typical in minerals processing. It is also suggested that the difficulty of pumping of high-concentration slurry feed can be overcome by operating with stratification, such that the solids residence time is made longer than the bulk flow residence time. Production loss through tank downtime is common in the mineral process industry, thus, a need to reduce the tank downtime should not be underestimated in the context of process intensification. Methods including the swirl flow technology developed by CSIRO and Queensland Alumina Ltd in Australia to suppress the scaling growth, and agitator design principles to reduce erosion are introduced. Enhanced mass transfer toward process intensification is also discussed. [ABSTRACT FROM AUTHOR]

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In a Hodgkin-Huxley neuron model driven just above threshold, external noise can increase both jitter and latency of the first spike, an effect called “noise delayed decay” (NDD). This phenomenon is important when considering how neuronal information is represented, thus by the precise timing of spikes or by their rate. We examine how NDD can be affected by network activity by varying the model's membrane time constant, τm. We show that NDD is significant for small τm or high network activity, and decreases for large τm, or low network activity. Our results suggest that for inputs just above threshold, the activity of the network constrains the neuronal coding strategy due to, at least in part, the NDD effect. [ABSTRACT FROM AUTHOR]

By using a programmed sequence of boundary motions to introduce flow reorientation to a steady, laminar axial flow in an open duct, we develop a novel device to investigate and exploit chaotic advection of viscously dominated (low Reynolds number) flows. The design and operation of the Rotated Arc Mixer (RAM) is discussed. Among other things, the RAM can effect good continuous mixing of viscous materials without use of any internal elements; moreover, the RAM has several control parameters to tune the chaotic advection, making it flexible for applications and theoretical developments. Numerical methods to discover the robust parameter regions where chaos covers the entire flow domain, and how these parameters change with fluid properties is also discussed. Poincaré sections, dye advection and residence time calculations are presented for Newtonian and non-Newtonian fluids. Experiments, including advection field, velocity field and residence-time measurements, confirm all aspects of the device for Newtonian fluids. [ABSTRACT FROM AUTHOR]

It has been suggested that the frequency spectrum of an acoustic emission burst may be a partial ''signature,'' identifying the source. To explore this possibility we have studied in some detail, theoretically and experimentally, two qualitatively different simulated acoustic emissions. The first is the fracture of small (20-40 μm) silicon carbide grains on a steel slab. The second is the impact of a small elastic sphere of various materials on the same slab. Our primary objective has been to test our understanding of the medium response, and, consequently, the extent to which we can determine the source spectrum from the observed spectrum. [ABSTRACT FROM AUTHOR]

A broad-band acoustic instrument consisting of a white-noise generator and a damped piezoelectric receiver has been used to analyze the frequency spectra of 0-3 MHz acoustic surface waves on complex structures. By varying the path length, the frequency dependence of attenuation can be obtained. This attenuation data are used in the design of acoustic emission monitoring systems, where the frequency-dependent characteristics of the acoustic paths between possible acoustic emission sources and the detection transducer are needed. In addition, the data can be directly used in characterizing structures such as honeycomb sandwich panels where defects produce changes in the surface wave attenuation. The system used to make these measurements are described and results for a variety of structures are presented. [ABSTRACT FROM AUTHOR]