Excitation and Deexcitation of Benzene

This chapter contains sections titled: - Introduction; - The Nature of the Lower Excited States of Benzene; - Transitions Between Lower Energy States; - Excited State Geometry; - The Influence of the Environment on Electronic States; - The S1 ↔ S0 Radiative Transition; - The S1 ↔ Triplet Radiationless Transition; - The S1 → S0 Radiationless Transition; - The T1 → S0 Phosphorescence Transition; - The T1 → S0 Radiationless Transition; - Transitions from Higher (n > 1) Excited States; - Relevant Photochemical Reactions of Excited States of Benzene; - Benzene Excimer; - Conclusioninfo:eu-repo/semantics/publishedVersio

A Critical Evaluation of the Use of the Microbond Method for Determination of Composite Interfacial Properties

AbstractThe microbond method has been applied with increased frequency to characterize interfacial adhesion in fiber reinforced composites. Nevertheless, a number of serious questions remain regarding the interpretation of experimental data. This paper addresses material and experimental variables in the microbond test procedure including the cure behavior of thermoset test specimens, matrix heterogeneity, locus of failure in test specimens and load application techniques. The theoretical basis for the method is examined by viewing experimental results in terms of existing theoretical interpretations of interfacial failure. Conclusions are presented regarding the limitations and the potential of the microbond method for determining fiber/matrix adhesive bond strength.</jats:p

An Investigation of Optical Fiber Coating Performance in Embedded Sensing Applications

AbstractThe use of composite materials for aerospace applications has created an increased need for developing nondestructive methods for assessment of composite performance. Embedded optical fiber sensor technology provides the potential for monitoring parameters of interest during processing and testing of composite materials as well as the opportunity for tracking properties over the lifetime of composite parts in service. The successful development of this technology depends on designing optical fiber sensor systems suitable for embedding in composite structures.This paper focuses on the role played by optical fiber coatings in the design of embedded sensor systems. The performance of different optical fiber coatings under typical composite processing conditions will be discussed. Photomicrographs of test specimens containing embedded sensors will be presented which show delamination occurring at the coating/optical fiber interface in preference to the coating/epoxy resin interface. Coating performance criteria will be outlined for use in the selection of fiber optic sensors for composite applications.</jats:p