NANOCRYSTAL SIZE MODIFICATIONS IN POROUS SILICON BY PREANODIZATION ION-IMPLANTATION

A tuning of the nanocrystal sizes in porous silicon has been obtained by self-ion implantation in p-type silicon wafers before the anodization treatment. Sample porosity, luminescence spectra, Raman scattering, and transmission electron microscopy have been used to determine the structure of porous silicon samples. A porosity increase, a blue shift of the luminescence peak, a widening of the phonon resonance, and a decrease in the size features revealed by transmission electron microscopy (TEM) images are observed by increasing the ion implantation dose. It is suggested that this effect results from the increased resistivity of the Si wafer caused by the ion implantation damage

Assisting global rainwater harvesting practitioners: A decision support tool for tank sizing method selection under uncertainty

Rainwater harvesting (RWH) tank sizing can be an onerous task due to the range of available methods. This paper presents a simple, yet robust, end-user and design criteria-focused decision support tool, based on a comparison of 12 well established methods across four types (simplified, mass balance continuous simulation, cost-function and statistical). Each method was applied to two example households located in Bucaramanga, Colombia and considered uncertainty through integrated representation of demand variability, climate change, overflow and financial scenarios. Quantitative and qualitative criteria were used to assess the performance of each method. Based on the summation of these criteria, a diversified approach constituting mass balance simulation, cost-function and probabilistic methods was most suited to RWH tank sizing for houses in Bucaramanga. Global RWH practitioners now have a decision support tool to assist in selecting the best tank sizing approach for their context