This Phase II research will focus on the investigation of the refinement of the geometric and mathematical models used in conjunction with nondestructive evaluation (NDE) methods to quantify the biodegradation of wood at inaccessible locations. The emphasis will be on the prediction methodology for planes located at distances from the NDE excitation and output sensing planes. Additional research will include the quantification of the effects of geometric (shape, size, check, boundary conditions) and environmental (moisture content, temperature) factors on the NDE methodology. The data base used for model building and model verification will be greatly expanded to incorporate several species and product types.