Biodiesel blends for fueling diesel engines (2006)

Commercially produced biodiesel is a safe and reliable alternative fuel that can be used in diesel engines with little or no need for modification to existing engines and fuel systems. Most commercially available biodiesel fuels are actually biodiesel blends that are properly referenced with the letter B followed by a one- or two-digit number that represents the percentage of biodiesel used in the blend with petroleum diesel fuel. Pure biodiesel is sometimes called "neat" biodiesel and is also referred to as B100. The most common biodiesel blends are B2, B5, B10, B20 and B50. The remaining fraction is petroleum-based diesel fuel, which is often referred to as petrodiesel.New 11/06/3M

Adhesion of volcanic ash particles under controlled conditions and implications for their deposition in gas turbines

A particular (representative) type of ash has been used in this study, having a particle size range of ~10-70 µm. Experimental particle adhesion rate data are considered in conjunction with CFD modeling of particle velocities and temperatures. This ash becomes soft above ~700˚C and it has been confirmed that a sharp increase is observed in the likelihood of adhesion as particle temperatures move into this range. Particle size is important and those in the approximate range 10-30 µm are most likely to adhere. This corresponds fairly closely with the size range that is most likely to enter a combustion chamber and turbine.This work forms part of a research programme funded by EPSRC (EP/K027530/1). In conjunction with this project, a consortium of partners has been set up under the PROVIDA ("PROtection against Volcanic ash Induced Damage in Aeroengines") banner and information about its operation is available at http://www.ccg.msm.cam.ac.uk/initiatives/provida. The invaluable assistance of Kevin Roberts (Materials Department in Cambridge) with operation of the plasma spray facility is gratefully acknowledged. The authors are also grateful to Dr. Margaret Hartley, of the University of Manchester, for kindly collecting the Laki ash (and several other types) during field trips to Iceland, which were funded by EasyJet.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/adem.201500371 In compliance with current EPSRC requirements, input data for the modelling described in this paper, including meshing and boundary condition specifications, are available at the following URL: www.ccg.msm.cam.ac.uk/publications/resources. These files can be downloaded and used in COMSOL Multiphysics packages. Data supplied are for a representative case

Sound Signalling in Orthoptera

The sounds produced by orthopteran insects are very diverse. They are widely studied for the insight they give into acoustic behaviour and the biophysical aspects of sound production and hearing, as well as the transduction of sound to neural signals in the ear and the subsequent processing of information in the central nervous system. The study of sound signalling is a multidisciplinary area of research, with a strong physiological contribution. This review considers recent research in physiology and the links with related areas of acoustic work on the Orthoptera

Investigation of High-Frequency Internal Wave Interactions with an Enveloped Inertia Wave

Using ray theory, we explore the effect an envelope function has on high-frequency, small-scale internal wave propagation through a low-frequency, large-scale inertia wave. Two principal interactions, internal waves propagating through an infinite inertia wavetrain and through an enveloped inertia wave, are investigated. For the first interaction, the total frequency of the high-frequency wave is conserved but is not for the latter. This deviance is measured and results of waves propagating in the same direction show the interaction with an inertia wave envelope results in a higher probability of reaching that Jones' critical level and a reduced probability of turning points, which is a better approximation of outcomes experienced by expected real atmospheric interactions. In addition, an increase in wave action density and wave steepness is observed, relative to an interaction with an infinite wavetrain, possibly leading to enhanced wave breaking