1. Method for inspecting a turbine component comprising a thermally insulating layer over a ceramic matrix composite material, the method comprising:
providing a distinguishing agent indicative of a remaining thickness of said thermally insulating layer, wherein the distinguishing agent comprises a non-luminescent colorant; and
monitoring visually perceptible color-changing effects of said distinguishing agent to determine a thickness range for said thermally insulating layer.
2. The method of claim 1, further comprising performing a corrective action on the turbine component based on the determined thickness range for said thermally insulating layer.
3. The method of claim 1, wherein said distinguishing agent is introduced into an interface layer disposed between the thermally insulating layer and the ceramic matrix composite material.
4. The method of claim 1, wherein said distinguishing agent is uniformly distributed throughout the thermally insulating layer.
5. The method of claim 1, wherein said distinguishing agent is varyingly distributed throughout the thermally insulating layer to form a distinguishing gradient in the thermally insulating layer.
6. The method of claim 1, wherein the thermally insulating layer comprises a stack of discrete layers, and the distinguishing agent is introduced to form distinctive adjacent layers in the stack of discrete layers.
7. The method of claim 1, wherein said distinguishing agent comprises a coloring agent.
8. The method of claim 7, wherein said coloring agent is selected from the group consisting of transition element oxides and rare earth element oxides.
9. The method of claim 7, wherein said coloring agent is perceptible in a range of an electromagnetic spectrum visible to human vision.
10. The method of claim 1, wherein said distinguishing agent is selected from the group consisting of infrared, ultraviolet, X-ray and visible electromagnetic spectrum.
11. The method of claim 1, wherein the distinguishing agent is introduced in a precursor form of said thermally insulating layer.
12. The method of claim 11, wherein said precursor form is selected from the group consisting of a fully densified body, a partially densified body, and a green body.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for filtering a communication channel, and comprising:
a differencer for differencing a pair of signal inputs and outputting a difference signal corresponding to the difference there between;
a pair of adaptive finite impulse response filters (FIR) each having a delay line input and an error signal input and an output and the delay line input of a first of the pair of FIR coupled to the communication channel and the outputs of the pair of FIR coupled to the pair of signal inputs of the difference;
a statistical sequence estimator with an input coupled to the differencer to alter the difference signal based on statistics therefore and to output an altered difference signal which includes both altered bits or symbols together with associated confidence or likelihood values; and
a blender with an inputs coupled to the differencer and the statistical sequence estimator and the blender responsive to the confidence or likelihood values in the altered difference signal to vary both a blend of different error signal sources forming a resultant error signal coupled to the error signal inputs of the pair of adaptive FIR as well as the blend of different input signal sources forming a resultant input signal coupled to the delay line input of a second of the pair of FIR, to stabilize the adaptive filtering performed by the pair of FIR.
2. The system of claim 1, wherein at least one of the pair of adaptive FIR further comprise:
a delay line with \u201cN\u201d taps to successive portions of the communication channel, and the delay line shifting the successive portions of the communication channel once in each symbol processing interval;
at least one tap processor subjecting each of the \u201cN\u201d taps to a first scaling utilizing first scaling coefficients associated with filtering the current symbol interval and further subjecting at least one of the \u201cN\u201d taps to a second scaling by a second scaling coefficient associated with filtering the prior symbol interval; and
at least one summer generating in each symbol interval a filtered output comprising a sum of the \u201cN\u201d scaled taps from the first scaling in the prior symbol interval and the second scaling of the at least one tap in the current symbol interval, thereby increasing an order of the FIR without corresponding increase in an order of the delay line.
3. A method for filtering a communication channel, comprising:
subjecting a first set of successive samples of the received communication channel to a first impulse response filtering using a first finite impulse response (FIR) filter that utilizes weighting coefficients which vary based on an error signal and which minimize at least one of frequency dependent and multi-path dependent variations in a resultant first filtered output;
subjecting a second set of successive samples to a second impulse response filtering using a second finite impulse response (FIR) filter that utilizes weighting coefficients which vary based on the error signal and which minimize at least one of frequency dependent and multi-path dependent variations in a resultant second filtered output;
generating a difference signal proportional to a difference between the first and second filtered outputs;
generating an altered difference signal, based on statistics for the difference signal, which altered difference signal includes both altered bits or symbols of the difference signal together with associated confidence or likelihood values; and
blending, responsive to the confidence or likelihood values in the altered difference signal, both different error signal sources to form the error signal as well as different input signal sources to form the second set of successive samples; thereby stabilizing the filtering performed.