Particle-Size Effects on Nuclear Magnetic Resonance in Superconductors

1967 ◽  
Vol 163 (2) ◽  
pp. 420-431 ◽  
Author(s):  
Fulton Wright
2021 ◽  
Vol 63 (1) ◽  
pp. 43
Author(s):  
А.В. Чжан ◽  
С.А. Подорожняк ◽  
В.К. Мальцев ◽  
И.Н. Краюхин ◽  
Г.С. Патрин

The effect of the acidity of solutions on the crystal structure of cobalt during its chemical precipitation is reported. On the basis of structural, magnetic studies, as well as studies by nuclear magnetic resonance, it was shown that a change in the acidity of the working solution leads to the precipitation of cobalt in various allotropic modifications in the immediate environment: by the type of hcp in the region of small (up to ~ 8.5) and by the type of fcc in the region large (over ~ 8.5) pH values. The formation of these modifications of cobalt is associated with size effects, which are caused by a decrease in the size of its particles with increasing pH.


2013 ◽  
Vol 88 (14) ◽  
Author(s):  
W. A. MacFarlane ◽  
T. J. Parolin ◽  
T. I. Larkin ◽  
G. Richter ◽  
K. H. Chow ◽  
...  

2010 ◽  
Vol 56 (5) ◽  
pp. 789-798 ◽  
Author(s):  
Benoit J Arsenault ◽  
Isabelle Lemieux ◽  
Jean-Pierre Després ◽  
Nicholas J Wareham ◽  
Erik SG Stroes ◽  
...  

Abstract Background: Gradient gel electrophoresis (GGE) and nuclear magnetic resonance (NMR) spectroscopy are both widely accepted methods for measuring LDL and HDL particle size. However, whether or not GGE- or NMR-measured LDL or HDL particle size predicts coronary heart disease (CHD) risk to a similar extent is currently unknown. Methods: We used GGE and NMR to measure LDL and HDL particle size in a nested case-control study of 1025 incident cases of CHD and 1915 controls from the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study. The study sample included apparently healthy men and women age 45–79 years followed for an average of 6 years. Results: Pearson correlation coefficients showed that the overall agreement between NMR and GGE was better for the measurement of HDL size (r = 0.78) than for LDL size (r = 0.47). The odds ratio for future CHD among participants in the bottom tertile of LDL size (smallest LDL particles) was 1.35 (95% CI, 1.12–1.63) for GGE and 1.74 (1.41–2.15) for NMR. For HDL size, these respective odds ratios were 1.41 (1.16–1.72) and 1.85 (1.47–2.32). After adjustment for potential confounders, the relationship between small LDL or HDL particles and CHD was no longer significant, irrespective of the method. Conclusions: In this prospective population study, we found that the relationships between NMR-measured LDL and HDL sizes and CHD risk were slightly higher than those obtained with GGE.


Author(s):  
V. V. Terskikh ◽  
I. L. Moudrakovski ◽  
C. I. Ratcliffe ◽  
J. A. Ripmeester ◽  
C. J. Reinhold ◽  
...  

2020 ◽  
Vol 43 (3) ◽  
pp. 364-374
Author(s):  
A. A. Mezin ◽  
M. Y. Shumskayte ◽  
V. N. Glinskikh ◽  
N. A. Golikov ◽  
E. S. Chernova

The purpose of the study is to extend the use of nuclear magnetic resonance relaxometry and dielectric spectrometry methods. This is realized through a complex interpretation of the data by the above methods to timely provide additional petrophysical information about the drill cuttings pore space properties and structure. The relevance of the study is that the data on the drill cuttings obtained by the NMR method can be used as prior information in the logging data interpretation before a detailed petrophysical study of the core sample or in case of the core absence in the sampling interval. The objects of study are the drill cuttings samples from the fields of the West Siberian oil-and-gas province. The samples are saturated with different fluids, and their reservoir properties are determined by the nuclear magnetic resonance and dielectric spectrometry methods. As part of the experimental research, nuclear magnetic resonance investigations of the core samples of different discretization degrees have been carried out to determine the reservoir properties of the samples depending on the degree of their particle size reduction. It has been shown that the obtained results do not depend on the particle size of the measured sample and are consistent with the results of the standard petrophysical studies. The relationship between the porosity and the saturating fluid type has been established. Based on the data obtained by the dielectric spectroscopy method, the study has determined the value of the complex dielectric constant that shows how the degree of saturation changes depending on the fluid, and what happens in the pore space. The complex interpretation of the results obtained by the two methods provides additional information on the drill cuttings reservoir properties that can be used as a priori information on the formation properties.


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