Nonlinear electromagnetic wave equations for superdense magnetized plasmas

By using the quantum hydrodynamic and Maxwell equations, we derive the generalized nonlinear electron magnetohydrodynamic, the generalized nonlinear Hall-MHD (HMHD), and the generalized nonlinear dust HMHD equations in a self-gravitating dense magnetoplasma. Our nonlinear equations include the self-gravitating, the electromagnetic, the quantum statistical electron pressure, as well as the quantum electron tunneling and electron spin forces. They are useful for investigating a number of wave phenomena including linear and nonlinear electromagnetic waves, as well as three-dimensional electromagnetic wave turbulence spectra and structures arising from mode coupling processes at nanoscales in dense quantum magnetoplasmas

Spatially resolved monthly riverine fluxes of oxidised nitrogen (nitrate and nitrite) to the European shelf seas, 1960-2005

This report documents the methodology developed for statistically modelling the spatial and temporal patterns of oxidised nitrogen (nitrate plus nitrite) riverine fluxes into the coastal waters of northwestern Europe, over the period 1960-2005. The purpose of the study was to provide boundary data for a modelling study of new primary production in European waters. For the UK and Ireland, monthly freshwater discharges to a set of grid cells around the coastline were modelled from rainfall data and calibrated from detailed analyses performed for a subset of years with contrasting climatology. The mean and long-term trends in nitrate and nitrite content of the river discharges were modelled from Harmonised Monitoring Scheme data and flux estimates for each of the years of contrasting climateology. The product of the discharge rate and nitrogen content provided estimates of the monthly flux to each grid cell. Scandinavian inputs of nitrate and nitrite to the North Sea, Skagerrak and Kattegat were assembled from a composite of statistically modelled freshwater discharge, and recent estimates of nitrogen flux from national monitoring agencies. Fluxes of nitrate and nitrite from the rivers flowing into the North Sea from Germany, Netherlands and Belgium during 1960-2005 were assembled from previous analyses by researchers at the University of Hamburg. Nitrate and nitrite fluxes from French rivers flowing into the English Channel, in particular the Seine, were indirectly derived by correlation with the River Scheldt, calibrated from published estimates of annual fluxes. The results show the total oxidised nitrogen input to European shelf seas increasing from approximately 0.6Mt pa. in the 1960's to 1.2Mt pa. in the mid-1980's. Recent estimates of the annual flux since 2000 have been approximately 1.1Mt pa. Around 60-70% of the total annual flux to the northwest European shelf enters via the North Sea. Winter input rates are approximately twice those in the summer in all areas except the Skagerrak/Kattegat

Plastic anisotropy of soft reconstituted clays

The aim of the paper is to extend the experimental validation of the S-CLAY1 model, which is a recently proposed elastoplastic constitutive model that accounts for initial and plastic strain-induced anisotropy. Drained stress path controlled tests were performed on reconstituted samples of four Finnish clays to study the effects of anisotropy in the absence of the complexities of structure present in natural undisturbed clays. Each test involved several loading, unloading, and reloading stages with different values of stress ratio and, hence, induced noticeable changes in the fabric anisotropy. Comparisons between test results and model predictions with the S-CLAY1 model and the modified Cam clay model demonstrate that despite its simplicity, the S-CLAY1 model can provide excellent predictions of the behaviour of unstructured soil

Supporting reinterpretation in computer-aided conceptual design

This paper presents research that aims to inform the development of computational tools that better support design exploration and idea transformation - key objectives in conceptual design. Analyses of experimental data from two fields - product design and architecture - suggest that the interactions of designers with their sketches can be formalised according to a finite number of generalised shape rules defined within a shape grammar. Such rules can provide a basis for the generation of alternative design concepts and they have informed the development of a prototype shape synthesis system that supports dynamic reinterpretation of shapes in design activity. The notion of 'sub-shapes' is introduced and the significance of these to perception, recognition and the development of emergent structures is discussed. The paper concludes with some speculation on how such a system might find application in a range of design fields

Nonlinear multi-mode interactions in subsea risers undergoing vortex-induced vibrations

This paper investigates nonlinear multi-mode interactions in subsea risers undergoing vortex-induced vibrations based on a computationally efficient reduced-order fluid-structure interaction model. Cross-flow responses as a result of a steady uniform current are considered. The geometrically nonlinear equations of riser motion are coupled with nonlinear wake oscillators which have been modified to capture the effect of initial curvatures of curved cylinder and to approximate the space-time varying hydrodynamic lift forces. The main objectives are to provide new insights into the vortex-induced vibration characteristics of risers under external and internal resonances and to distinguish nonlinear dynamic behaviors between curved catenary and straight toptensioned risers. The analyses of multi-mode contributions, lock-in regimes, response amplitudes, resonant nonlinear modes and curvatures are carried out and several interesting aspects are highlighted

Vortex-induced vibration of catenary riser: reduced-order modeling and lock-in analysis using wake oscillator

A new reduced-order model capable of analyzing the vortex-induced vibration of catenary riser in the ocean current has been developed. This semi analytical-numerical approach is versatile and allows for a significant reduction in computational effort for the analysis of fluid-riser interactions. The incoming current flow is assumed to be steady, uniform, unidirectional and perpendicular to the riser plane of initial equilibrium curvatures

A community approach to road safety education using practical training methods : the Drumchapel project

Research shows that practical training methods, in which children receive guided experience of solving traffic problems in realistic traffic situations, are amongst the most effective in improving children's pedestrian competence. However, practical training is both time consuming and labour intensive, making it difficult to capitalise on the strengths of the method. The report describes a solution to this problem by adopting a community participation approach in which local volunteers carried out all roadside training, working in co-operation with schools and project staff. The project took place in an area of Glasgow known for its exceptionally high child pedestrian accident rate

Holding it all together? The management of supply cover in the teaching profession

There have for some years been concerns in Scotland about the availability of supply cover, the quality of supply teachers and the adequacy of support and development provided for them. This is a report of a study which focuses on the management of supply cover in Scotland. It presents an analysis of qualitative and quantitative data collected from education authorities, schools and supply teachers

The management of supply cover in the teaching profession

There have for some years been concerns in Scotland about the availability of supplycover, the quality of supply teachers, and the adequacy of support and developmentprovided for them. This Insighthighlights key findings from a study of the managementof supply cover in Scotland. The research was commissioned by the Scottish ExecutiveEducation Department in October 2002 to inform the development of guidelines

Europium doping of zincblende GaN by ion implantation

Eu was implanted into high quality cubic (zincblende) GaN (ZB-GaN) layers grown by molecular beam epitaxy. Detailed structural characterization before and after implantation was performed by x-ray diffraction (XRD) and Rutherford backscattering/channeling spectrometry. A low concentration ( direction, while a Ga substitutional site is observed for W-GaN:Eu. The implantation damage in ZB-GaN:Eu could partly be removed by thermal annealing, but an increase in the wurtzite phase fraction was observed at the same time. Cathodoluminescence, photoluminescence (PL), and PL excitation spectroscopy revealed several emission lines which can be attributed to distinct Eu-related optical centers in ZB-GaN and W-GaN inclusions