Porous silicon layers were fabricated on p-type crystalline silicon wafers using electrochemical etching ECE process. An investigation of the dependence on applied current density to formed PS layer was made. Porosity of the porous silicon layer and thickness were determined gravimetrically. Increasing the etching current density led to increase the surface porosity and thickness.The porosity varies between 44and 77% for current densities between 25 and 85mA/2.The current density-voltage charact...

Nanometer Materials  Material Experiment  Fundamentals of Material Science 

Doi:10.4236/oalib.preprints.1200044

Abstract: The formation of ash and the transformation of minerals matter during coal combustion have been topics of intensive study by numerous research groups. The fact that toxic and heavy metal constituents are associated with pulverized coal ash has been known for many years. Coal combustion not only generates gaseous pollutants like SO2 and NOx but also toxic and heavy metals to the atmosphere. From the environmental point of view, the determination and speciation of trace toxic and heavy m...

Environmental Chemistry  Electrochemistry  Material Experiment  Analytical Chemistry  Environmental Sciences 

Doi:10.4236/oalib.preprints.1200004