Encapsulated formulation of the Selective Frequency Damping method

We present an alternative "encapsulated" formulation of the Selective Frequency Damping method for finding unstable equilibria of dynamical systems, which is particularly useful when analysing the stability of fluid flows. The formulation makes use of splitting methods, which means that it can be wrapped around an existing time-stepping code as a "black box". The method is first applied to a scalar problem in order to analyse its stability and highlight the roles of the control coefficient $\chi$ and the filter width $\Delta$ in the convergence (or not) towards the steady-state. Then the steady-state of the incompressible flow past a two-dimensional cylinder at $Re=100$, obtained with a code which implements the spectral/hp element method, is presented

Reduction and analysis of data from OGO-4 experiment 15 Final report, 1 Nov. 1969 - 30 Nov. 1970

Procedures for processing atmospheric composition data obtained through use of sweeping quadrupole mass spectrometer on OGO-4 satellit

Who is failing abused and neglected children?

This is a response to an article by Nigel Speight and Jane Wynne, ‘Is the Children Act failing severely abused and neglected children?’, published in this journal in March 2000.1 Overall, we consider the article to be polemical and inadequately argued. Many of the points made are unsubstantiated and there are errors of fact. Where does evidence based practice go if senior practitioners prefer anecdotes and personal belief to research findings? Restrictions on space preclude an exhaustive reply to all the points Speight and Wynne raise, so we have confined ourselves to addressing those considered most significant

Contractual Versus Generic Outsourcing: The Role of Proximity

We explore the relationship between proximity of buyers and sellers and the organizational form of outsourcing. Outsourcing can be "contractual" in which suppliers undertake specific investments or involve "generic" market transactions. Proximity expands the variety of products sourced through contracts abroad rather than at home, but the range of generic imports is unchanged. A higher-quality foreign workforce raises the variety of contractual trade, but at the expense of generics. We confirm these predictions using data for ordinary versus processing exports from Chinese provinces to destination markets and also the predictions of an extended model that allows for multinational production.

ERTS image data compression technique evaluation

There are no author-identified significant results in this report

Zenithal bistable device: comparison of modeling and experiment

A comparative modeling and experimental study of the zenithal bistable liquid crystal device is presented. A dynamic Landau de Gennes theory of nematic liquid crystals is solved numerically to model the electric field induced latching of the device and the results are compared with experimental measurements and theoretical approximations. The study gives a clear insight into the latching mechanism dynamics and enables the dependence of the device latching on both material parameters and surface shape to be determined. Analytical approximation highlights a route to optimize material selection in terms of latching voltages and the numerical model, which includes an accurate surface representation, recovers the complex surface shape effects. Predictions of device performance are presented as a function of both surface anchoring strength and surface shape and grating pitch. A measurement of the homeotropic anchoring energy has been undertaken by comparing the voltage response as a function of cell gap; we find the homeotropic anchoring energies can be varied in the range 0.5 to 4 (10-44 J m-2)

Magmatic intrusions control Io's crustal thickness

Io, the most volcanically active body in the solar system, loses heat through eruptions of hot lava. Heat is supplied by tidal heating and is thought to be transferred through the mantle by magmatic segregation, a mode of transport that sets it apart from convecting terrestrial planets. We present a model that couples magmatic transport of tidal heat to the volcanic system in the crust, in order to determine the controls on crustal thickness, magmatic intrusions, and eruption rates. We demonstrate that magmatic intrusions are a key component of Io's crustal heat balance; around 80% of the magma delivered to the base of the crust must be emplaced and frozen as plutons to match rough estimates of crustal thickness. As magma ascends from a partially molten mantle into the crust, a decompacting boundary layer forms, which can explain inferred observations of a high-melt-fraction region.Comment: Accepted to JGR:Planets. 24 pages inc appendices and references. 7 figure

Photon induced secondary electron emission

Numerical models for predicting photon-induced secondary electron emission are presented. The results are compared with experimental measurements made using a Co-60 gamma ray source