Resistance relaxation studies of gas/metal reactions leading to simultaneous dissolution and gasification. The dissociated oxygen/tantalum system above 2000 K. Part 2.—Mechanism, kinetics and energetics of chemisorption, interface crossing and product desorption

1976 ◽  
Vol 72 (0) ◽  
pp. 858 ◽  
Author(s):  
D. E. Rosner ◽  
H. M. Chung ◽  
H. H. Feng
Keyword(s):  
Relaxation Studies ◽  
Simultaneous Dissolution ◽  
Resistance Relaxation

1H-NMR RELAXATION STUDIES ON THE NATURE OF THE SEMICONDUCTING STATE OF (TMTTF)2Br AND (TMTTF)2PF6: MAGNETISM

1983 ◽  
Vol 44 (C3) ◽  
pp. C3-1095-C3-1097
Author(s):  
T. Takahashi ◽  
F. Creuzet ◽  
D. Jérôme ◽  
J. M. Fabre
Keyword(s):  
1H Nmr ◽  
Nmr Relaxation ◽  
Relaxation Studies

Dielectric Relaxation Studies of Silver Nanoparticles dispersed Liquid Crystal

2015 ◽  
Vol 8 (3) ◽  
pp. 2176-2188 ◽  
Author(s):  
Keisham Nanao Singh
Keyword(s):  
Activation Energy ◽  
Silver Nanoparticles ◽  
Liquid Crystal ◽  
Dielectric Relaxation ◽  
Relaxation Process ◽  
Relaxation Times ◽  
Low Frequency ◽  
Bulk Liquid ◽  
Molecular Rearrangement ◽  
Relaxation Studies

This article reports on the Dielectric Relaxation Studies of two Liquid Crystalline compounds - 7O.4 and 7O.6 - doped with dodecanethiol capped Silver Nanoparticles. The liquid crystal molecules are aligned homeotropically using CTAB. The low frequency relaxation process occurring above 1 MHz is fitted to Cole-Cole formula using the software Dielectric Spectra fit. The effect of the Silver Nanoparticles on the molecular dipole dynamics are discussed in terms of the fitted relaxation times, Cole-Cole distribution parameter and activation energy. The study indicate a local molecular rearrangement of the liquid crystal molecules without affecting the order of the bulk liquid crystal molecules but these local molecules surrounding the Silver Nanoparticles do not contribute to the relaxation process in the studied frequency range. The observed effect on activation energy suggests a change in interaction between the nanoparticles/liquid crystal molecules.

scholarly journals Electron Spin Relaxation Studies of Polydopamine Radicals

2021 ◽  
Vol 125 (3) ◽  
pp. 841-849 ◽  
Author(s):  
Krzysztof Tadyszak ◽  
Radosław Mrówczyński ◽  
Raanan Carmieli
Keyword(s):  
Spin Relaxation ◽  
Electron Spin ◽  
Electron Spin Relaxation ◽  
Relaxation Studies

scholarly journals Co-Amorphous Formulations of Furosemide with Arginine and P-Glycoprotein Inhibitor Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 171
Author(s):  
Marika Ruponen ◽  
Konsta Kettunen ◽  
Monica Santiago Pires ◽  
Riikka Laitinen
Keyword(s):  
Storage Conditions ◽  
Scanning Calorimetry ◽  
Glycoprotein P ◽  
Molar Ratios ◽  
P Glycoprotein ◽  
Permeation Studies ◽  
Poorly Soluble ◽  
Biopharmaceutics Classification ◽  
Permeability Assay ◽  
Simultaneous Dissolution

In this study, the amino acid arginine (ARG) and P-glycoprotein (P-gp) inhibitors verapamil hydrochloride (VER), piperine (PIP) and quercetin (QRT) were used as co-formers for co-amorphous mixtures of a Biopharmaceutics classification system (BCS) class IV drug, furosemide (FUR). FUR mixtures with VER, PIP and QRT were prepared by solvent evaporation, and mixtures with ARG were prepared by spray drying in 1:1 and 1:2 molar ratios. The solid-state properties of the mixtures were characterized with X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in stability studies under different storage conditions. Simultaneous dissolution/permeation studies were conducted in side-by-side diffusion cells with a PAMPA (parallel artificial membrane permeability assay) membrane as a permeation barrier. It was observed with XRPD that ARG, VER and PIP formed co-amorphous mixtures with FUR at both molar ratios. DSC and FTIR revealed single glass transition values for the mixtures (except for FUR:VER 1:2), with the formation of intermolecular interactions between the components, especially salt formation between FUR and ARG. The co-amorphous mixtures were found to be stable for at least two months under an elevated temperature/humidity, except FUR:ARG 1:2, which was sensitive to humidity. The dissolution/permeation studies showed that only the co-amorphous FUR:ARG mixtures were able to enhance both the dissolution and permeation of FUR. Thus, it is concluded that formulating co-amorphous salts with ARG may be a promising option for poorly soluble/permeable FUR.

Dielectric Relaxation Studies by Time Domain Spectroscopy

Nature ◽  
1970 ◽  
Vol 228 (5270) ◽  
pp. 456-457 ◽  
Author(s):  
A. SUGGETT ◽  
P. A. MACKNESS ◽  
M. J. TAIT ◽  
H. W. LOEB ◽  
G. M. YOUNG
Keyword(s):  
Dielectric Relaxation ◽  
Time Domain ◽  
Time Domain Spectroscopy ◽  
Relaxation Studies
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