This paper studies the relaxation of the molecular spin angular velocity in the framework of generalized extended Navier-Stokes theory. Using molecular dynamics simulations, it is shown that for uncharged diatomic molecules the relaxation time decreases with increasing molecular moment of inertia per unit mass. In the regime of large moment of inertia the fast relaxation is wave-vector independ...

The alkali-antimonide compounds are of some technical importance because of their high photoelectric quantum efficiency in the visible region. For this reason the electronic properties of these semiconductors have been studied relatively intensively in the past — for comprehensive reviews see Ref. [1] and [2] —. However, the understanding of the nature of chemical bonding of these materials is ...

The stability of a moisture-sensitive drug in lyophilized products was investigated under conditions with varying water content and temperature using two model formulations: a formulation containing inositol (IF) as the excipient and a formulation containing mannitol (MF) as the excipient. IF showed better chemical stability (a lower hydrolysis rate) than MF when both formulations contained 2% ...

PURPOSE To determine whether a quantitative MR imaging method to map spin-lattice relaxation time (T1) can be used to characterize maturational changes in the normal human brain. METHODS An inversion-recovery technique was used to map T1 transversely at the level of the basal ganglia in a study population of 19 healthy children (4 to 10 years old) and 31 healthy adolescents (10 to 20 years ol...

Photoswitchable spiropyran has been conjugated to the crowned ring system DO3A, which improves its solubility in dipolar and polar media and stabilizes the merocyanine isomer. Adding the lanthanide ion gadolinium(III) to the macrocyclic ring system leads to a photoresponsive magnetic resonance imaging contrast agent that displays an increased spin-lattice relaxation time (T₁) upon visible light...

The osmotic changes in root cells of Zea mays L. under the effect of mannitol (concentration range 1-15%; range of osmotic pressures: -0.13 to -2.01 MPa) were studied by measuring time and concentration dependence of water self-diffusion constant (Deff) and proton spin-lattice relaxation time (T1) using proton NMR relaxation spectroscopy. In addition, in vivo uptake of Mn2+ by roots after their...

We report high resolution 15N NMR measurements of the paraelectric to antiferroelectric phase transition (TN = 216 K) of the model hydrogen-bonded antiferroelectric NH4H2AsO4 (ADA). We specifically examined whether the NH + 4 ions undergo a displacive or an order-disorder behavior at the phase transition. High resolution NMR measurements were made on 15N-enriched single crystals, using the CPMA...

A comprehensive tract-based characterisation of white matter should include the ability to quantify myelin and axonal attributes irrespective of the complexity of fibre organisation within the voxel. Recently, a new experimental framework that combines inversion recovery and diffusion MRI, called inversion recovery diffusion tensor imaging (IR-DTI), was introduced and applied in an animal study...

Longitudinal exchange experiments facilitate the quantification of the rates of interconversion between the exchanging species, along with their longitudinal relaxation rates, by analyzing the time-dependence of direct correlation and exchange cross peaks. Here we present a simple and robust alternative to this strategy, which is based on the combination of two complementary experiments, one wi...

This paper is concerned with propagation of thermoelastic longitudinal vibrations of an infinite circular cylinder, in the context of the linear theory of generalized thermoelasticity with two relaxation time parameters (Green and Lindsay theory). Three displacement potential functions are introduced to uncouple the equations of motion. The frequency equation, by using the traction free boundar...