Determination of multiple deferred state repetitive group sampling plan for life time assurance under Birnbaum–Saunders distribution

2021 ◽  
pp. 1-14
Author(s):  
G. Kannan ◽  
P. Jeyadurga ◽  
S. Balamurali
Keyword(s):  
Life Time ◽  
Sampling Plan ◽  
Repetitive Group Sampling

Determination of cerebral glucose transport and metabolic kinetics by dynamic MR spectroscopy

1997 ◽  
Vol 273 (6) ◽  
pp. E1216-E1227 ◽  
Author(s):  
P. C. M. Van Zijl ◽  
D. Davis ◽  
S. M. Eleff ◽  
C. T. W. Moonen ◽  
R. J. Parker ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Kinetic Equations ◽  
Direct Determination ◽  
Life Time ◽  
Compartment Model ◽  
Brain Extract ◽  
Influx Rate ◽  
Positron Emission

A new in vivo nuclear magnetic resonance (NMR) spectroscopy method is introduced that dynamically measures cerebral utilization of magnetically labeled [1-13C]glucose from the change in total brain glucose signals on infusion. Kinetic equations are derived using a four-compartment model incorporating glucose transport and phosphorylation. Brain extract data show that the glucose 6-phosphate concentration is negligible relative to glucose, simplifying the kinetics to three compartments and allowing direct determination of the glucose-utilization half-life time [ t ½ = ln2/( k 2 + k 3)] from the time dependence of the NMR signal. Results on isofluorane ( n = 5)- and halothane ( n = 7)- anesthetized cats give a hyperglycemic t ½ = 5.10 ± 0.11 min−1 (SE). Using Michaelis-Menten kinetics and an assumed half-saturation constant Kt = 5 ± 1 mM, we determined a maximal transport rate T max = 0.83 ± 0.19 μmol ⋅ g−1 ⋅ min−1, a cerebral metabolic rate of glucose CMRGlc = 0.22 ± 0.03 μmol ⋅ g−1 ⋅ min−1, and a normoglycemic cerebral influx rate CIRGlc = 0.37 ± 0.05 μmol ⋅ g−1 ⋅ min−1. Possible extension of this approach to positron emission tomography and proton NMR is discussed.

Modeling of Gear Hobbing: Part II — A Computer Supported Experimental-Analytical Determination of the Wear Progress to Optimize the Tool Life Time

1999 ◽  
Author(s):  
Konstantinos D. Bouzakis ◽  
Spiros Kombogiannis ◽  
Aristomenis Antoniadis ◽  
Nectarios Vidakis
Keyword(s):  
Tool Wear ◽  
Prediction Models ◽  
Digital Simulation ◽  
Life Time ◽  
Analytical Determination ◽  
Tool Wear Prediction ◽  
Gear Hobbing ◽  
User Friendly ◽  
Continuous Enrichment

Abstract Tool wear prediction models for gear hobbing were presented in the first part of this paper. To determine the constants of the equations used in these models, fly hobbing experiments with uncoated and coated HSS tools were conducted. Hereby, it was necessary to modify the fly hobbing kinematics from continuous tangential feed to continuous axial feed. The experimental data were evaluated, and correlated to the analytical ones, elaborated through the described digital simulation of the cutting process. The determined constants of the wear laws for the investigated tools were used in a further developed user friendly software, enabling the prediction of the tool wear accomplishment in gear hobbing. On that account the wear development can be precisely foreseen and the tangential shift of the tool is optimized. The open and modular structure of the developed code enables the continuous enrichment of its database with other type of coating and workpiece materials. With the aid of the aforementioned techniques, the superiority of coated HSS tools in comparison to uncoated ones is also quantitatively exhibited.

X-Ray Diffraction Determination of Macro and Micro Stresses in SOFC Electrolyte and Evolution with Redox Cycling of the Anode

2011 ◽  
Vol 681 ◽  
pp. 25-30 ◽  
Author(s):  
Julie Villanova ◽  
Olivier Sicardy ◽  
Roland Fortunier ◽  
Jean Sebastien Micha ◽  
Pierre Bleuet
Keyword(s):  
High Performance ◽  
Life Time ◽  
Redox Cycling ◽  
European Synchrotron Radiation Facility ◽  
X Ray Diffraction ◽  
Compressive Stresses ◽  
Diffraction Determination ◽  
Local Measurements ◽  
Strain Stress

Solid Oxide Fuel Cell (SOFC) is a high-performance electrochemical device for energy conversion. Usually, the electrolyte is made of dense YSZ (Yttria Stabilized Zirconia) and the anode is a porous YSZ-Ni composite. The electrolyte is submitted to high stresses mainly due to the thermal expansion coefficient mismatch between components and the volume change associated with the redox cycling of Ni. Because the mechanical integrity of the cell is a major issue during its life time, it is proposed in this study to determine both micro and macro stresses in the electrolyte. Macro stresses in the 10 µm-thick electrolyte were measured using the sin²(Ψ) method after different treatments of the cell : (i) manufacturing, (ii) thermal cycle, (iii) reduction and (iv) re-oxidation of the anode layer. After manufacturing, the electrolyte is under strong biaxial compressive stresses (-690 MPa). These stresses decrease after reduction of the anode. They finally reach tensile stresses and induce the cracking of the electrolyte for full re-oxidation. Micro stresses determinations were performed using the micro-diffraction setup of the BM32 beam line at ESRF (European Synchrotron Radiation Facility). Complete strain-stress tensor and crystallographic orientation determinations have been achieved within 5 µm grains. The accuracy of the method has been improved and is now 2.4 10-4 for strain values. On an average, local measurements are found to be consistent with global ones. Both strain and stress heterogeneities between grains with various orientations have been evidenced.

Determination of Creep Parameters of Ti-6Al-4V with Bimodal and Equiaxed Microstructure

2012 ◽  
Vol 326-328 ◽  
pp. 520-524 ◽  
Author(s):  
L.A.N.S. Briguente ◽  
Antônio Augusto Couto ◽  
Nara Miranda Guimarães ◽  
Danieli A.P. Reis ◽  
Carlos de Moura Neto ◽  
...  
Keyword(s):  
Creep Resistance ◽  
Room Temperature ◽  
Life Time ◽  
Constant Load ◽  
Bimodal Microstructure ◽  
Creep Tests ◽  
Equiaxed Microstructure ◽  
Specific Strength ◽  
Heat Treated

Ti-6Al-4V is the most used of titanium alloy and presents some important properties as metallurgical stability, high specific strength, corrosion and creep resistance [. The aim of this study is to evaluate the creep behavior of Ti-6Al-4V alloy with equiaxed and bimodal microstructures and determine the creep parameters of Ti-6Al-4V in these conditions. It was used a Ti-6Al-4V alloy forged and annealed at 190°C for 6 hours and cooled in air. The material in this condition shows an equiaxed microstructure. For bimodal microstructure, the material was heat-treated at 950°C for 60 minutes and cooled in water until room temperature. After this the material was heat-treated at 600°C for 24 hours and cooled in air until room temperature. Creep tests were performed at 600°C in stress conditions of 125, 250 and 319 MPa at constant load. The alloy with Bimodal microstructure shows higher creep resistance with a longer life time in creep.

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