The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
John R. Scully - One of the best experts on this subject based on the ideXlab platform.
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Measurement and Modeling of Hydrogen Environment-Assisted Cracking in Monel K-500
Metallurgical and Materials Transactions A, 2014Co-Authors: Richard P. Gangloff, James T. Burns, Hung M. Ha, John R. ScullyAbstract:Hydrogen environment-assisted cracking (HEAC) of Monel K-500 is quantified using slow-rising stress intensity loading with electrical potential monitoring of small crack propagation and elastoplastic J -integral analysis. For this loading, with concurrent crack tip plastic strain and H accumulation, aged Monel K-500 is susceptible to intergranular HEAC in NaCl solution when cathodically polarized at −800 mV_SCE ( E _A, vs saturated calomel) and lower. Intergranular cracking is eliminated by reduced cathodic polarization more positive than −750 mV_SCE. Crack tip diffusible H concentration rises, from near 0 wppm at E _A of −765 mV_SCE, with increasing cathodic polarization. This behavior is quantified by thermal desorption spectroscopy and barnacle cell measurements of hydrogen solubility vs overpotential for planar electrodes, plus measured-local crevice potential, and pH scaled to the crack tip. Using crack tip H concentration, excellent agreement is demonstrated between measurements and decohesion-based model predictions of the E _A dependencies of threshold stress intensity and Stage II growth rate. A critical level of cathodic polarization must be exceeded for HEAC to occur in aged Monel K-500. The damaging-cathodic potential regime likely shifts more negative for quasi-static loading or increasing metallurgical resistance to HEAC.
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Erratum to: Measurement and Modeling of Hydrogen Environment-Assisted Cracking in Monel K-500
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2014Co-Authors: Richard P. Gangloff, James T. Burns, Hung M. Ha, John R. ScullyAbstract:Fig. 17—(Color online) Model predicted (Eq. [2]) and measured Stage II crack growth rate (at elastic K = 50 MPa m, Table III; Fig. 9) vs crack tip CH-Diff (bottom axis) and stress enhanced CHr (top axis) for aged Monel K-500 (ATI Allvac, j; Table I) stressed in 3.5 pct NaCl at EA between 1100 and 700 mVSCE. The rH/rYS is 12.0 in Eq. [3]. Measured da/dtII are included for a Special Metals lot of Monel K-500 (m) using the corresponding H uptake law (Footnotes * and **). Fig. 18—(Color online) Model predicted (Eq. [2]) and measured Stage II crack growth rate (at elastic K = 50 MPa m, Table III; Fig. 9) vs applied cathodic potential for aged Monel K-500 (ATI Allvac, j; Table I) stressed in 3.5 pct NaCl. The rH/rYS equals 12.0 in Eq. [3]. Measured da/dtII values are included for a Special Metals lot of Monel K-500 (Footnote *, m).
K S Chaudhuri - One of the best experts on this subject based on the ideXlab platform.
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an imperfect production process for time varying demand with inflation and time value of money an emq model
Expert Systems With Applications, 2011Co-Authors: Biswajit Sarkar, Shib Sankar Sana, K S ChaudhuriAbstract:Abstract The paper deals with an economic manufacturing quantity (EMQ) model for time-dependent (quadratic) demand pattern. Every manufacturing sector wants to produce perfect quality items. But in long run process, there may arise different types of difficulties like labor problem, machinery capabilities problems, etc., due to that the machinery systems shift from in-control state to out-of-control state as a result the manufacturing systems produce imperfect quality items. The imperfect items are reworked at a cost to become the perfect one. The rework cost may be reduced by improvements in product reliability i.e., the production process depend on time and also the reliability parameter. We want to determine the optimal product reliability and production rate that achieves the biggest total integrated profit for an imperfect manufacturing process using Euler–Lagrange theory to build up the necessary and sufficient conditions for optimality of the dynamic variables. Finally, a numerical example is discussed to test the model which is illustrated graphically also.
Gabriel Fagan - One of the best experts on this subject based on the ideXlab platform.
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money growth and inflation a regime switching approach
Journal of International Money and Finance, 2013Co-Authors: Gianni Amisano, Gabriel FaganAbstract:We develop a Markov Switching model for inflation with time-varying transition probabilities. Inflation is characterized by two regimes (high and low inflation) and the probability of regime changes depends on money growth. Using Bayesian techniques, we apply the model to the euro area, Germany, the US, the UK and Canada for data from the 1960s up to the present. Our estimates suggest that a smoothed measure of broad money growth, corrected for real-time estimates of trend velocity and potential output growth, has important leading indicator properties for switches between inflation regimes. Thus money growth provides an important early warning indicator for risks to price stability.
Richard P. Gangloff - One of the best experts on this subject based on the ideXlab platform.
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Measurement and Modeling of Hydrogen Environment-Assisted Cracking in Monel K-500
Metallurgical and Materials Transactions A, 2014Co-Authors: Richard P. Gangloff, James T. Burns, Hung M. Ha, John R. ScullyAbstract:Hydrogen environment-assisted cracking (HEAC) of Monel K-500 is quantified using slow-rising stress intensity loading with electrical potential monitoring of small crack propagation and elastoplastic J -integral analysis. For this loading, with concurrent crack tip plastic strain and H accumulation, aged Monel K-500 is susceptible to intergranular HEAC in NaCl solution when cathodically polarized at −800 mV_SCE ( E _A, vs saturated calomel) and lower. Intergranular cracking is eliminated by reduced cathodic polarization more positive than −750 mV_SCE. Crack tip diffusible H concentration rises, from near 0 wppm at E _A of −765 mV_SCE, with increasing cathodic polarization. This behavior is quantified by thermal desorption spectroscopy and barnacle cell measurements of hydrogen solubility vs overpotential for planar electrodes, plus measured-local crevice potential, and pH scaled to the crack tip. Using crack tip H concentration, excellent agreement is demonstrated between measurements and decohesion-based model predictions of the E _A dependencies of threshold stress intensity and Stage II growth rate. A critical level of cathodic polarization must be exceeded for HEAC to occur in aged Monel K-500. The damaging-cathodic potential regime likely shifts more negative for quasi-static loading or increasing metallurgical resistance to HEAC.
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Erratum to: Measurement and Modeling of Hydrogen Environment-Assisted Cracking in Monel K-500
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2014Co-Authors: Richard P. Gangloff, James T. Burns, Hung M. Ha, John R. ScullyAbstract:Fig. 17—(Color online) Model predicted (Eq. [2]) and measured Stage II crack growth rate (at elastic K = 50 MPa m, Table III; Fig. 9) vs crack tip CH-Diff (bottom axis) and stress enhanced CHr (top axis) for aged Monel K-500 (ATI Allvac, j; Table I) stressed in 3.5 pct NaCl at EA between 1100 and 700 mVSCE. The rH/rYS is 12.0 in Eq. [3]. Measured da/dtII are included for a Special Metals lot of Monel K-500 (m) using the corresponding H uptake law (Footnotes * and **). Fig. 18—(Color online) Model predicted (Eq. [2]) and measured Stage II crack growth rate (at elastic K = 50 MPa m, Table III; Fig. 9) vs applied cathodic potential for aged Monel K-500 (ATI Allvac, j; Table I) stressed in 3.5 pct NaCl. The rH/rYS equals 12.0 in Eq. [3]. Measured da/dtII values are included for a Special Metals lot of Monel K-500 (Footnote *, m).
Biswajit Sarkar - One of the best experts on this subject based on the ideXlab platform.
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an imperfect production process for time varying demand with inflation and time value of money an emq model
Expert Systems With Applications, 2011Co-Authors: Biswajit Sarkar, Shib Sankar Sana, K S ChaudhuriAbstract:Abstract The paper deals with an economic manufacturing quantity (EMQ) model for time-dependent (quadratic) demand pattern. Every manufacturing sector wants to produce perfect quality items. But in long run process, there may arise different types of difficulties like labor problem, machinery capabilities problems, etc., due to that the machinery systems shift from in-control state to out-of-control state as a result the manufacturing systems produce imperfect quality items. The imperfect items are reworked at a cost to become the perfect one. The rework cost may be reduced by improvements in product reliability i.e., the production process depend on time and also the reliability parameter. We want to determine the optimal product reliability and production rate that achieves the biggest total integrated profit for an imperfect manufacturing process using Euler–Lagrange theory to build up the necessary and sufficient conditions for optimality of the dynamic variables. Finally, a numerical example is discussed to test the model which is illustrated graphically also.
