Comparison of experiment and the proposed general linear viscoelastic theory. 2. Stress relaxation line shape analysis

1986 ◽  
Vol 19 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Y. H. Lin
Keyword(s):  
Stress Relaxation ◽  
Shape Analysis ◽  
Line Shape ◽  
General Linear ◽  
Line Shape Analysis ◽  
Linear Viscoelastic ◽  
Viscoelastic Theory ◽  
Linear Viscoelastic Theory

Quasi-Linear Viscoelastic Theory is Insufficient to Comprehensively Describe the Time-Dependent Behavior of Human Cervical Spine Ligaments

2010 ◽  
Author(s):  
Kevin L. Troyer ◽  
Christian M. Puttlitz
Keyword(s):  
Cervical Spine ◽  
Stress Relaxation ◽  
Strain Range ◽  
Relaxation Curve ◽  
Physiological Strain ◽  
Dependent Behavior ◽  
Linear Viscoelastic ◽  
Viscoelastic Theory ◽  
Relaxation Experiments ◽  
Linear Viscoelastic Theory

Stress relaxation experiments were conducted on cervical spine ligaments at multiple strain magnitudes to determine the validity and applicability of the quasi-linear viscoelastic (QLV) theory to model their dynamic behavior. The results indicate that the shape of the stress relaxation curve is dependent upon the magnitude of the applied strain. Thus, a more general, nonlinear formulation is required to model these ligaments within the physiological strain range.

Determination of the Accurate Values of the Rate Constant and Thermodynamic Parameters for the Rotation About the C(sp2)-C(aryl) Bond; Adamantan-1-yl 3-Bromo-2,4,6-trimethylphenyl Ketone

1998 ◽  
Vol 63 (7) ◽  
pp. 955-966
Author(s):  
Eva Přibylová ◽  
Miroslav Holík
Keyword(s):  
Thermodynamic Parameters ◽  
Shape Analysis ◽  
Rate Constants ◽  
Line Shape ◽  
Microsoft Excel ◽  
Hindered Rotation ◽  
H Nmr ◽  
Line Shape Analysis ◽  
Coalescence Temperature

Four programs for the 1H NMR line shape analysis: two commercial - Winkubo (Bruker) and DNMR5 (QCPE 165) and two written in our laboratory - Newton (in Microsoft Excel) and Simtex (in Matlab) have been tested in order to get highly accurate rate constants of the hindered rotation about a single bond. For this purpose four testing criteria were used, two of them were also developed by us. As supplementary determinations the rate constants obtained for the coalescence temperature and for the thermal racemization of chromatographically separated enantiomers were used which fitted well the temperature dependence of the rate constants determined by the line shape analysis. As a test compound adamantan-1-yl 3-bromo-2,4,6-trimethylphenyl ketone was prepared and studied. It was shown that supermodified simplex method used in our algorithm (Simtex), though time consuming, gives the most accurate values of the rate constants and consequently the calculated thermodynamic parameters Ea, ∆H≠, and ∆S≠ lay in relatively narrow confidence intervals.

Cope rearrangement of 9-methylenebarbaralane. Complete line shape analysis

1973 ◽  
Vol 38 (6) ◽  
pp. 1210-1215 ◽  
Author(s):  
Linda G. Greifenstein ◽  
Joseph B. Lambert ◽  
Michael J. Broadhurst ◽  
Leo A. Paquette
Keyword(s):  
Shape Analysis ◽  
Line Shape ◽  
Cope Rearrangement ◽  
Line Shape Analysis
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