Background: Quantitative Magnetization Transfer Imaging (QMTI) is often used to quantify the myelin content in multiple sclerosis (MS) lesions and normal appearing brain tissues. Also, automated classifiers such as artificial neural networks (ANNs) can significantly improve the identification and classification processes of MS clinical datasets.Objective: We classified patients with relapsing-r...

We have measured the temperature dependence of the proton spin-lattice relaxation rate R at 8.50 and 22.5 MHz in solid 1,3,5-tri-ethyl-benzene and solid 1,2,4-tri-ethyl-benzene. Analysis of the data strongly suggests that we are studying amorphous states in these slowly solidified organic solids (that are liquids at room temperature). The ethyl groups are static on the Larmor frequency timescal...

spin-lattice relaxation time Ti and second moment M 2 have been studied as a function of temperature over the temperature range 445 to 77 K. A discontinuous change in Ti at 365 K, indicates the presence of a phase transition, while the slope change at 152 K, is attributed to a change in the TMA ion dynamics from tumbling to torsion. The 7i results could be explained in terms of inequivalent TMA...

Introduction Direct measurement of the longitudinal relaxation time T1 provides objective and quantitative diagnostic information. However, current T1 mapping methods are generally time consuming without the aid of fast imaging. The current study developed a model-based compressed sensing (CS) method for fast cardiac T1 mapping in small animals. Based on the physics of magnetization recovery, t...

for the time dependence of the macoscopic magnetisation M(t) of a sample under the influence of an external field H(t) where γ =μ / Ih is the gyromagnetic ratio of the nuclei under consideration with magnetic moment μ and spin I, i, j, and k are the usual triad of unit vectors along the Cartesian axes. The external field has the form H(t) = H0k + H1(t), where H0 is strong and constant while H1 ...

The relaxation mechanism of an initially straight flexible or stiff polymer chain of length N in a viscous solvent is studied through Brownian dynamics simulations covering a broad range of time scales. After the short-time free diffusion, the chain's longitudinal reduction R2(0)-R2 approximately Nt1/2 at early intermediate times is shown to constitute a universal behavior for any chain stiffne...

Hall angle in high-T c cuprates: Anomalous temperature dependence and anisotropic scattering Abstract. The anisotropy of the scattering rates, 1/τ tr ∝ T and 1/τ H ∝ T 2 , implied effectively by the anomalous temperature dependence of the normal-state in-plane Hall angle, cot θ ∝ T 2 , observed in the high-T c lay-ered cuprates is reasoned out to be a natural consequence of the semiclassical Bo...

Using a field cycling technique, the Larmor frequency (VL) dependence of the proton Zeeman spin-lattice relaxation time T I has been measured in the smectic A, smectic C, smectic B and smectic VII phases of terephtal-bis-butylaniline (TBBA) between VL = 90 MHz and V L = 0.14 MHz and a significant dispersion has been found. The observed c o i J 2 dispersion law in the smectic A phase and the dev...

The temperature dependence of the spin-lattice relaxation time Tx for the Re NQR in K R e0 4 , N H 4R e 0 4 and N D 4R e 0 4 has been measured between 77 K and 323 K. The relaxation is electric quadrupolar in all cases, and because of the large quadrupole moment of Re, 7i is short. In K R e0 4 Ti follows a T 2 dependence. In N H 4R e 0 4 , Ti decreases more rapidly than T ~ 2 above about 100 K;...

Chapter 7 presents a study of molecular dynamics as a function of molecular composition in novel binary liquid crystalline mixtures of nematic liquid crystals 8CN and 7BCB, which exhibit Induced Smectic Phase (ISP). Frequency and temperature dependent spin-lattice relaxation time measurements were carried out in pure systems and mixtures at specific compositions. This work is done in collaborat...