Percolation in soils at Different Bulk Densities: Porosity, Connectivity and Grey Threshold.

To improve percolation modelling on soils the geometrical properties of the pore space must be understood; this includes porosity, particle and pore size distribution and connectivity of the pores. A study was conducted with a soil at different bulk densities based on 3D grey images acquired by X-ray computed tomography. The objective was to analyze the effect in percolation of aspects of pore network geometry and discuss the influence of the grey threshold applied to the images. A model based on random walk algorithms was applied to the images, combining five bulk densities with up to six threshold values per density. This allowed for a dynamical perspective of soil structure in relation to water transport through the inclusion of percolation speed in the analyses. To evaluate separately connectivity and isolate the effect of the grey threshold, a critical value of 35% of porosity was selected for every density. This value was the smallest at which total-percolation walks appeared for the all images of the same porosity and may represent a situation of percolation comparable among bulks densities. This criterion avoided an arbitrary decision in grey thresholds. Besides, a random matrix simulation at 35% of porosity with real images was used to test the existence of pore connectivity as a consequence of a non-random soil structure.

An Hebrew grammar, collected chiefly from those of Mr. Israel Lyons, teacher of Hebrew in the University of Cambridge; and the Rev. Richard Grey, D.D. rector of Hinton, in Northamptonshire: To which is subjoined a praxis, taken from the sacred classics, and containing a specimen of the whole Hebrew language: with a sketch of the Hebrew poetry

as retrieved by Bishop Hare ...

Euro-enthusiasm, Euro-rejection, and various shades of grey: The 2014 European Parliament election campaign in the Netherlands. EPIN Commentary No. 18/29 April 2014

With less than a month to go to the European Parliament (EP) elections, campaigning has barely begun in the Netherlands. Whether the campaign will address concrete EU policies or the future of the European Union remains to be seen, but this author argues that the outcomes will probably have less to with the parties’ stance on Europe than with the unpopularity of the incumbent parties and the ‘second order’ character of EP elections.

Euro-enthusiasm, Euro-rejection, and various shades of grey: The 2014 European Parliament election campaign in the Netherlands. EPIN Commentary No. 18, 29 April 2014

With less than a month to go to the European Parliament (EP) election in the Netherlands on May 22nd, the campaign has barely kicked off. It remains to be seen whether the campaign will address concrete EU policies in a palatable way and whether all parties are able to present clear visions about the future of the European Union. The traditional mainstream parties (the Christian Democratic CDA, Liberal VVD and Social Democratic PvdA) all agree that EU membership is essentially beneficial to the Netherlands, but are careful to stress the shortcomings of the EU in its present form. The parties outside the traditional three that can be expected to do well adopt a more outspoken position on European integration. These include the pro-European Democrats 66 (D66), the Eurosceptic Socialist Party (SP), and the Euroreject Freedom Party (PVV). Yet, reasons for their success should probably not be sought mainlyin their positions on European integration, but rather more in the unpopularity of the incumbent parties and the „second order‟ character of EP elections.