scholarly journals Surprising Complexity of the [Gd(AAZTA)(H2O)2]− Chelate Revealed by NMR in the Frequency and Time Domains

2021 ◽  
Author(s):  
Daniela Lalli ◽  
Fabio Carniato ◽  
Lorenzo Tei ◽  
Carlos Platas-Iglesias ◽  
Mauro Botta
Keyword(s):  
Time Domains

scholarly journals Psychological and Physiological Features Associated with Swimming Performance

2021 ◽  
Vol 18 (9) ◽  
pp. 4561
Author(s):  
Vicente Javier Clemente-Suárez ◽  
Juan Pedro Fuentes-García ◽  
Ricardo J. Fernandes ◽  
João Paulo Vilas-Boas
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Swimming Performance ◽  
Aerobic Performance ◽  
Anaerobic Performance ◽  
Probe Characteristic ◽  
Time Domains ◽  
High Fatigue ◽  
Psychological Features ◽  
Aerobic And Anaerobic

Background: The aim of the present research was to study the psychological and physiological features associated with aerobic and anaerobic performance in trained swimmers. Methods: A correlation and stepwise regression analyses were conducted with the data obtained in a RESTQ-76 sport questionnaire, a heart rate variability test, and an anaerobic and aerobic swimming performance efforts of 20 swimmers. Results: Aerobic performance correlated, principally, with parameters related to parasympathetic modulation measured in the frequency and time domains of the heart rate variability (LF/HF r: −0.806, p < 0.001; NN50 r: 0.937, p < 0.001). Swimmers’ anaerobic performance correlated to psychological features (low stress r: 0.526, p: 0.025, and high fatigue r: −0.506, p: 0.032). Conclusion: Swimming performance presented different psychological and physiological features depending on the probe characteristic. Specifically, swimmers’ anaerobic performance was associated with psychological features (low stress and high fatigue perception) and aerobic performance with physiological features (high parasympathetic modulation). This information could help coaches to know the variables to control in their swimmers, depending on the probe in which they compete (anaerobic or aerobic).

A nonlinear stochastic growth model on discrete time domains

2016 ◽  
Vol 22 (11) ◽  
pp. 1732-1746 ◽  
Author(s):  
Ferhan M. Atıcı ◽  
Gang Cheng ◽  
Alex Lebedinsky
Keyword(s):  
Growth Model ◽  
Discrete Time ◽  
Stochastic Growth ◽  
Stochastic Growth Model ◽  
Time Domains

The Mechanics of the Secondary Flows of Viscoelastic Fluids in Non-Circular Straight Tubes and the Mean Transversal Field in Pulsating Flows

2000 ◽  
Author(s):  
Dennis A. Siginer ◽  
Mario F. Letelier
Keyword(s):  
Secondary Flow ◽  
Cross Sections ◽  
Viscoelastic Fluids ◽  
Secondary Flows ◽  
Novel Approach ◽  
Transversal Field ◽  
Time Domains ◽  
Viscoelastic Liquids ◽  
First Time ◽  
Secondary Flow Field

Abstract A survey of secondary flows of viscoelastic liquids in straight tubes is given including recent work pointing at striking analogies with transversal deformations associated with the simple shearing of solid materials. The importance and implications of secondary flows of viscoelastic fluids in heat transfer enhancement are explored together with the difficulties in detecting weak secondary flows (dilute, weakly viscoelastic solutions) in a laboratory setting. Recent new work by the author and colleagues which explores for the first time the structure of the secondary flow field in the pulsating flow of a constitutively nonlinear simple fluid, whose structure is defined by a series of nested integrals over semi-infinite time domains, in straight tubes of arbitrary cross-sections is summarized. The transversal field arises at the second order of the perturbation of the nonlinear constitutive structure, and is driven by first order terms which define the linearly viscoelastic longitudinal flow in the hierarchy of superposed linear flows stemming from the perturbation of the constitutive structure. Arbitrary conduit contours are obtained through a novel approach to the concept of domain perturbation. Time averaged, mean secondary flow streamline contours are presented for the first time for triangular, square and hexagonal pipes.

scholarly journals The offset-midpoint traveltime pyramid in 3D transversely isotropic media with a horizontal symmetry axis

Geophysics ◽  
2015 ◽  
Vol 80 (1) ◽  
pp. T51-T62 ◽  
Author(s):  
Qi Hao ◽  
Alexey Stovas ◽  
Tariq Alkhalifah
Keyword(s):  
Symmetry Axis ◽  
Transversely Isotropic ◽  
P Wave ◽  
Analytic Representation ◽  
Velocity Inversion ◽  
Transversely Isotropic Media ◽  
Horizontal Symmetry ◽  
Time Domains ◽  
Isotropic Media ◽  
Hti Media

Analytic representation of the offset-midpoint traveltime equation for anisotropy is very important for prestack Kirchhoff migration and velocity inversion in anisotropic media. For transversely isotropic media with a vertical symmetry axis, the offset-midpoint traveltime resembles the shape of a Cheops’ pyramid. This is also valid for homogeneous 3D transversely isotropic media with a horizontal symmetry axis (HTI). We extended the offset-midpoint traveltime pyramid to the case of homogeneous 3D HTI. Under the assumption of weak anellipticity of HTI media, we derived an analytic representation of the P-wave traveltime equation and used Shanks transformation to improve the accuracy of horizontal and vertical slownesses. The traveltime pyramid was derived in the depth and time domains. Numerical examples confirmed the accuracy of the proposed approximation for the traveltime function in 3D HTI media.

Photoexcitations of polycarbazolyldiacetylenes in different time domains

1997 ◽  
Author(s):  
Davide Comoretto ◽  
I. Moggio ◽  
Carla Cuniberti ◽  
Giovanna Dellepiane ◽  
Alessandro Borghesi ◽  
...  
Keyword(s):  
Time Domains

scholarly journals Ultrasonic-based monitoring of tapered roller bearings in frequency and time domains

2017 ◽  
Vol 25 (2) ◽  
pp. 235-241
Author(s):  
Jabid Quiroga Méndez ◽  
Omar Ardila Sánchez ◽  
Gustavo Andrés Martínez Gordillo
Keyword(s):  
Roller Bearings ◽  
Time Domains ◽  
Tapered Roller ◽  
Tapered Roller Bearings

Numerical Solution of the Coupled Nernst-Planck and Poisson Equations for Ion-Selective Membrane Potentials

2002 ◽  
Vol 752 ◽  
Author(s):  
Peter Lingenfelter ◽  
Tomasz Sokalski ◽  
Andrzej Lewenstam
Keyword(s):  
Electrical Potential ◽  
Membrane System ◽  
Contact Boundary ◽  
Poisson Equations ◽  
Space And Time ◽  
Boundary Potential ◽  
Time Domains ◽  
Selective Membrane ◽  
Linear Differential ◽  
And Migration

ABSTRACTA numerical model is presented for analyzing the propagation of ionic concentrations and electrical potential in space and time in the solution ion-exchanging membrane system. Diffusion and migration according to the Nernst-Planck (NP) flux equation govern the transport of ions, and the electrical interaction of the species is described by the Poisson (P) equation. These two equations and the continuity equation form a system of partial non-linear differential equations that is solved numerically. As a result of the physicochemical properties of the system, both the contact/boundary potential and the diffusion potential contribute to the overall membrane potential. It is shown that interpreting the electrical potential of ion-exchanging membranes exclusively in terms of boundary potential at steady-state is incorrect. The Nernst-Planck-Poisson (NPP) model is general and applies to ions of any charge in space and time domains.

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