relaxation time

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re·lax·a·tion time (τ),

the time required for the substrate in an enzymatic or chemical reaction to fall to 1/e of its initial value.
Farlex Partner Medical Dictionary © Farlex 2012

relaxation time

An MRI term for the post-excitation return of spins to their equilibrium distribution, in which there is no transverse magnetisation and the longitudinal magnetisation is at its maximum value and oriented in the direction of the static magnetic field. Transverse magnetisation decays toward zero after excitation at a characteristic time constant T2; longitudinal magnetisation returns toward equilibrium with a characteristic time constant T1.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

re·lax·a·tion time

(τ) (rē'lak-sā'shŭn tīm)
The time required for the substrate in an enzymatic or chemical reaction to fall to 1/e of its initial value.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
where [tau] is the relaxation time, [omega] is the angular frequency, and H (r) is the relaxation time spectrum.
The measured parameters compared between the two groups included T1, T2, T2* relaxation times, fat fraction (FF), and cross-sectional area (CSA) of the quadriceps femoris and the hamstring muscles.
At the new structure, we set the Fermi energy of graphene [E.sub.F] = 0.8 eV and the relaxation time of graphene [tau] = 1.5 ps; the constants of dielectric slab 1 and dielectric slab 2 are set as 11.9 and 3.84, respectively.
It is evident from Figure 7 that relaxation time increases with increase in concentration of polyvinyl alcohol in solution.
Figures 1(c) and 1(d) show that, under different storage conditions, the extension of storage time for all fresh wet noodles gradually decreased the relaxation time [T.sub.22] of the intermediate state water, and the water transformed from the combinative state to the intermediate state, for an overall decrease of total water content.
Here we will use the normalized time t by introducing the dimensionless time [??] = t/(L[square root of ([rho]/3[mu]))], [??] = c/(2[mu][L.sub.3]L[square root of ([rho]/3[mu])) and dimensionless relaxation time [??] = ([eta]/[[mu].sup.B])/(L[square root of ([rho]/3[mu])), and we may reduce (12) and (13) to the following form:
The amounts of proton nuclei, T1/ T2 relaxation times and the kinetics of molecules of water, are the most important parameters.18,20 The contrast of an MR image depends simultaneously on several considerations, e.g.
Samples (S )exponent factor Pure PANI 0.1423 0.5V Protonation PANI by HCl 0.3247 1V Protonation PANI by HCl 0.0536 1.5 V Protonation PANI by HCl 0.428 2V Protonation PANI by HCl 0.579 Table 3: polarizability and Relaxation time data for doped samples.
The combined phonon relaxation time r for impurity scattering and U scattering can be given by Matthiessen's formula, as in (5), and the possibility of boundary scattering is only dependent on its locations in the simulated physical model.
Relationship between the Capillary Pressure ([P.sub.C]) and the Nuclear Magnetic Transverse Relaxation Time ([T.sub.2]).
6, the relaxation time increase with temperature, it is characteristics time of the involved dynamics of the relaxing entities.