A thermodynamic entropy based approach for fault detection and prognostics of samples subjected to corrosion-fatigue degradation mechanism

2015 ◽  
pp. 2063-2071
Author(s):  
A Imanian ◽  
M Modarres
Keyword(s):  
Fault Detection ◽  
Corrosion Fatigue ◽  
Degradation Mechanism ◽  
Thermodynamic Entropy

Corrosion-Fatigue Structural Integrity Assessment Using a Thermodynamic Entropy Based Damage Approach

2015 ◽  
Author(s):  
Anahita Imanian ◽  
Mohammad Modarres
Keyword(s):  
Entropy Generation ◽  
Corrosion Fatigue ◽  
Structural Integrity ◽  
Degradation Mechanism ◽  
Health Assessment ◽  
Irreversible Thermodynamics ◽  
Integrity Assessment ◽  
Thermodynamic Entropy ◽  
Equilibrium Processes ◽  
Thermodynamic Forces

Using fundamentals of irreversible thermodynamics, with specific focus on entropy generation, this paper studies the structural integrity of degraded materials. All damage mechanisms share a common feature namely energy dissipation. Dissipation, as a fundamental measure for irreversibility in a thermodynamic treatment of non-equilibrium processes, is quantified by entropy generation. Based on the theoretical relationship between entropy generation and generalized thermodynamic forces and fluxes, the entropic damage is measured during a corrosion-fatigue degradation experiment. Life estimation of components, which were subject to complex corrosion-fatigue degradation mechanism, was then estimated through a proposed entropic-based prognostic framework. The performance of predictions was evaluated and compared with previous predictions in terms of the influence of additional features on components health assessment.

scholarly journals Lithium-Ion Cell Fault Detection by Single-Point Impedance Diagnostic and Degradation Mechanism Validation for Series-Wired Batteries Cycled at 0 °C

Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 834 ◽  
Author(s):  
Corey Love ◽  
Matthieu Dubarry ◽  
Tatyana Reshetenko ◽  
Arnaud Devie ◽  
Neil Spinner ◽  
...  
Keyword(s):  
Fault Detection ◽  
Degradation Mechanism ◽  
Single Point ◽  
Lithium Ion ◽  
Lithium Ion Cell

Structures of c-di-GMP/cGAMP degrading phosphodiesterase VcEAL: identification of a novel conformational switch and its implication

2019 ◽  
Vol 476 (21) ◽  
pp. 3333-3353 ◽  
Author(s):  
Malti Yadav ◽  
Kamalendu Pal ◽  
Udayaditya Sen
Keyword(s):  
Active Site ◽  
Metal Binding ◽  
Metal Ion ◽  
Triosephosphate Isomerase ◽  
Catalytic Mechanism ◽  
Degradation Mechanism ◽  
Structural Basis ◽  
Conserved Residues ◽  
Phosphodiester Bond ◽  
Cyclic Dinucleotides

Cyclic dinucleotides (CDNs) have emerged as the central molecules that aid bacteria to adapt and thrive in changing environmental conditions. Therefore, tight regulation of intracellular CDN concentration by counteracting the action of dinucleotide cyclases and phosphodiesterases (PDEs) is critical. Here, we demonstrate that a putative stand-alone EAL domain PDE from Vibrio cholerae (VcEAL) is capable to degrade both the second messenger c-di-GMP and hybrid 3′3′-cyclic GMP–AMP (cGAMP). To unveil their degradation mechanism, we have determined high-resolution crystal structures of VcEAL with Ca2+, c-di-GMP-Ca2+, 5′-pGpG-Ca2+ and cGAMP-Ca2+, the latter provides the first structural basis of cGAMP hydrolysis. Structural studies reveal a typical triosephosphate isomerase barrel-fold with substrate c-di-GMP/cGAMP bound in an extended conformation. Highly conserved residues specifically bind the guanine base of c-di-GMP/cGAMP in the G2 site while the semi-conserved nature of residues at the G1 site could act as a specificity determinant. Two metal ions, co-ordinated with six stubbornly conserved residues and two non-bridging scissile phosphate oxygens of c-di-GMP/cGAMP, activate a water molecule for an in-line attack on the phosphodiester bond, supporting two-metal ion-based catalytic mechanism. PDE activity and biofilm assays of several prudently designed mutants collectively demonstrate that VcEAL active site is charge and size optimized. Intriguingly, in VcEAL-5′-pGpG-Ca2+ structure, β5–α5 loop adopts a novel conformation that along with conserved E131 creates a new metal-binding site. This novel conformation along with several subtle changes in the active site designate VcEAL-5′-pGpG-Ca2+ structure quite different from other 5′-pGpG bound structures reported earlier.

A Fault Detection Approach Based on Sound Signal Analysis for Equipment Monitoring

2020 ◽  
pp. 129-139
Author(s):  
Weihai Sun ◽  
Lemei Han
Keyword(s):  
Fault Detection ◽  
Signal Analysis ◽  
Energy Analysis ◽  
Detection Method ◽  
Sound Signal ◽  
Practical Significance ◽  
Time Frequency ◽  
Detection Approach ◽  
Machine Fault ◽  
Learning Data

Machine fault detection has great practical significance. Compared with the detection method that requires external sensors, the detection of machine fault by sound signal does not need to destroy its structure. The current popular audio-based fault detection often needs a lot of learning data and complex learning process, and needs the support of known fault database. The fault detection method based on audio proposed in this paper only needs to ensure that the machine works normally in the first second. Through the correlation coefficient calculation, energy analysis, EMD and other methods to carry out time-frequency analysis of the subsequent collected sound signals, we can detect whether the machine has fault.

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