Optical metallography, scanning electron microscopy, electron microprobe analysis, and transmission electron microscopy were used to characterize metallurgical grade silicon, produced in an electric are furnace. Coincidence fraction determinations were assumed to be Σ7 and Σ9 when grain boundaries are underlined by precipitated phases and Σ3 when they are not. The study of intergranular compounds was emphasized; ten compounds were found, the main ones being Si2Ca, Si8Al6Fe4Ca, Si2Al2Ca, Si2FeTi, and Si2.4Fe (α leboitc). The precipitation of these compounds was discussed according to the principal impurity concentrations in silicon. The crystalline structure of Si8Al6Fe4Ca was determined to be triclinic with a = 1.3923 nm, b = 1.3896 nm, c = 1.3900 nm and α = 92.4°, β = 110.3°, γ = 119.9°.

A web-based, non-expert daylighting analysis tool has been developed to support daylighting-related design decisions in peripheral private offices during an early design stage (http://buildwiz.com). The tool offers a comparative, reliable, and fast analysis of the annual amount of daylight in the offices (daylight factor and daylight autonomy) and the lighting energy performance of automated lighting controls (occupancy sensors, photocells) compared to standard on/off switches. Blinds are either manually or automatically controlled. During a simulation run, pre-calculated, RADIANCE-based daylight coefficients for over 600 office designs are coupled with weather data from 285 sites in North America to yield annual daylight illuminance profiles. The annual electric lighting energy use is subsequently predicted via a model that mimics occupancy and manual lighting and blinds control in private offices. A simulation run takes between 30 seconds to 3 minutes and yields a detailed report of the annual daylight availability and lighting energy use in the investigated office.