In 1991, my newly formed researchgroupat Berkeley was working intensely in the area of continuum-level constitutive relationships that could be obtained in a deductive mannerfrom microstructuralinformationthroughthemethods of homogenization theory. Of particular interest was the application of such methods to structural problems in the blossoming field of micromechanical devices. In this context it was becoming evident that we needed to learn to navigate through the continuum/discrete interface. Such were the circumstances when Vladimir Granik came to visit us at Berkeley for the first time. It is probably not surprising that we received with great enthusiasm his offer to join forces and develop a mechanics .of solid structures that would be based on a discrete representation of matter. Vladimir had established the foundations for such an endeavor with his work at Moscow University in the late 1970s. Since that first meeting, and with ever-increasing enthusiasm, it has been a great privilege for me to collaborate with Vladimir. We first applied the formalism of what has become known as "doublet mechanics" to the microstructure-based theory of failure of solids and worked on the paral- lels and differences between the doublet approach and homogenization, to- gether with Kevin Mon and Derek Hansford. Plane elastodynamics followed after Francesco Maddalena had proposed doublet viscoelesticity. The consti- tutive relationships in doublet mechanics were laid on a firm thermodynami- cal foundation through the work of Kevin Mon, while Miqin Zhang analyzed free boundary effects on multi-scale plane elastic waves in discrete domains.

Deafness is the invisible disability and the most common human sensory defects. It leads to difficult speech development poor educational and employment prospects of childhood. Comprehensive otologic and audiological evaluations are very much essential for aetiological assessment of hearing impaired children and management efficacy. The aetiology of deaf Children was diverse. Infection was the predominationg aetiologial factor (38%). The infections were: Measles (31.5%), Pneumonia in (26.2%), Typhoid (21.5%), Maternal Rubella (5.2%), Varicella (5.2%), Mumps (5.2%) and Meningitis (5.2%). 48% of deaf child had a parental suspicion of deafness below the one year of age. 35% had a positive family history and 32% had history of consanguinal marriage. The deaf children were managed with hearing device, among them 89% with hearing aid and 11% with cochlear implant 42.7% of child used hearing aid in both ears. The results of aided audiogram showde that, the gain after using hearing aid within 31-60 dB were 80%.10% in right ear, 71.10% in left year and 70.00% in both ears, so average gain after using hearing aid was 74% within 31- 60 dB.

Fossil fuels are limited and are running out through extensive usage. Therefore alternative source of energy is more important now than ever before. Unlike traditional power plants, electricity generation using solar power systems provides an environment friendly way to harness energy, produces virtually no emission and consumes no fuel other than sunlight. The energy collection and conversion through solar panel depends on the amount of irradiance is decreased when the sun is not directly in front of the panels. Therefore, there is a decrease in the amount of energy absorbed by the collector. To make solar energy more viable, the efficiency of solar array system must be maximize. The existing solar panels have very low efficiency and are very expensive also. Due to the initial cost of the equipment solar energy conversion is still an expensive alternate. Therefore, enhancing the efficiency of solar panel or energy converting technology is the best way to reduce that cost. In this book authors have described about the efficient tracking of sun using double sun method which gives certain increase of power output and make solar panel much more efficient.