Articles Related to entropy

High entropy alloys (HEAs) are alloys that contains multiple elements, often five or more principal elements in equiatomic or near equiatomic ratio with or without minor elements. As felt from the name, high mixing entropy is the sole parameter to decide the solid solution alloy formation in HEAs but, the mutual interaction between elements are key parameters to predict the phase formation in HEAs as proposed by some researchers. In this review the guideline for alloy design in HEAs for the formation of solid solution phases are proposed on basis of atomic size difference (δ), mixing entropy (ΔSmix), mixing enthalpy (ΔHmix), valence electron concentration (VEC) and electronegativity difference (Δχ).

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Autonomic nervous system involvement in subjects practicing Yoga has rarely been studied and has shown conflicting results. Our main purpose was to assess the effect of Yoga on autonomic function of group of subjects practicing Yoga regularly in comparison with another group with normal control subjects by measuring the frequency gain response of the two groups. Other aim of this study was to determine wither the duration of Yoga practicing correlated with measures of heart rate variability signal (HRV) using approximate entropy index (ApEn).

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New analytic methods based on nonlinear system theory have been developed to characterize the nonlinear features in HR dynamics. It is known from long time series (24h ECG recordings) that patients with chronic heart failure or stable coronary heart disease have altered fractal organization in heartbeat dynamics. During such long-time series, many confounding could limit the assessment of autonomic functions.

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