A statistical model describing temperature dependent gettering of Cu in p-type Si

A model is proposed describing quantitatively the temperature dependent gettering of Cu atoms in p-type Si wafers by taking into account the densities and the binding energies of all types of occupying sites, including the gettering ones. Binding energy in this context is defined as the decrease of the formation energy from the reference energy of the Cu atom when it is located at the T-site through which Cu atoms wander through the silicon lattice. By using a statistical approach, the model allows to predict the thermal equilibrium concentration of Cu atoms in each part of a wafer structure. The calculated results show good agreement with reported experimental observations. This model can also be applied to calculate thermal equilibrium concentrations of any contaminant

Turbid wakes associated with offshore wind turbines observed with Landsat 8

In the last decade, the number of offshore wind farms has increased rapidly. Offshore wind farms are typically constructed in near-shore, shallow waters. These waters can be highly productive or provide nursery grounds for fish. EU legislation requires assessment of the environmental impact of the wind farms. The effects on hard and soft substrate fauna, seabirds and marine mammals are most frequently considered. Here we present Landsat-8 imagery that reveals the impact of offshore wind farms on suspended sediments. Turbid wakes of individual turbines are observed that are aligned with tidal currents. They are 30–150 m wide, and several km in length. The environmental impact of these wakes and the source of the suspended material are still unclear, but the wake size warrants further study. The underwater light field will be affected by increased suspended sediments and the turbid wakes could significantly impact sediment transport and downstream sedimentation. The question of whether such features can be detected by other remote sensors is addressed by a theoretical analysis of the signal:noise specification for the Operational Land Imager (OLI), the Enhanced Thematic Mapper Plus (ETM +), the Advanced Very High Resolution Radiometer (AVHRR/3), the Moderate-Resolution Imaging Spectroradiometer (MODIS), the Spinning Enhanced Visible and Infrared Imager (SEVIRI), the Flexible Combined Imager (FCI) and the Multispectral Instrument (MSI) and by a demonstration of the impact of processing OLI data for different spatial resolutions