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We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta 2 O 5 and SiO 2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate(More)
Eddy current inspection is widely used in nondestructive evaluation to detect cracks in metal structures. The impedance plane measurement response collected using our motion controlled eddy current inspection system, are used in the analysis. A scalar reduction from the impedance plane response is used to minimize human-factor variation. We apply a noise(More)
A novel boundary integral equation (BIE) is developed for eddy-current nondestructive evaluation problems with surface crack under a uniform applied magnetic field. Once the field and its normal derivative are obtained for the structure in the absence of cracks, normal derivative of scattered field on the conductor surface can be calculated by solving this(More)
This paper reports on a study of the effects of cold work induced by surface enhancement treatment on conductivity profiles in nickel-base superalloys, as part of the on-going efforts aimed at evaluating the feasibility of characterizing near-surface residual stress profiles in peened engine components using a swept frequency eddy current (SFEC) technique.(More)
This paper reports on a feasibility study of using eddy current (EC) and magnetic flux leakage (MFL) methods to detect corrosion damage in rebars that anchor concrete barrier rails to the road deck of bridge structures. EC and MFL measurements were carried out on standalone rebars with and without artificial defects of 25% and 50% material loss, using a(More)