Graphite epoxy composites are being used in aerospace industry and spacecraft applications for their light weight and high strength. As a matter of fact these materials also have some disadvantages like damage which is hazardous when used in cryogenic application. Composite materials IM7/977-2, IM7/5555 and IM7/5276-1 are of interest for the aerospace industry and this research concentrates on study of microcracking, delamination and other defects in the [0/90]s composite laminates of the above materials. These materials were uni-axially tested to pre-determined stress levels and the damages in the material were recorded in the form of microcrack density at different stress levels. In this research work the use of X-Ray Microtomography has proven to be an excellent tool to characterize the crack connectivity and damage information three dimensionally. Dye penetrant technique was also used in this work to enhance the visibility of the cracks.

Bisphosphonates (BPs) are used for the treatment of osteoporosis. This study evaluated changes in bone microdamage with BP treatment duration. Fifty-one iliac crest biopsies were obtained from Caucasian women, ages 41 to 87 years, who were previously diagnosed and treated for osteoporosis with oral BPs for 1-16 years duration. Patients diagnosed with any disease, drug, or substance abuse that may affect bone metabolism were excluded. Bone samples were sectioned, stained, and histologically examined using light and fluorescence microscopy. Bone area, number and length of microcracks were quantified. Following adjustment for age, BMD, BV/TV, trabecular thickness, and turnover, regression analysis revealed a relationship between microcrack density and treatment duration (p=0.018). No significant relationship was observed between microcrack length and treatment duration. This study provides novel data relating microdamage with varying BP treatment duration in human bone. Given information from other studies showing that microdamage amounts are related to changes in bone biomechanics, the BP treatment duration related changes in microdamage shown offer new information that may help optimize osteoporosis treatment.