The effect of magnetic field strength on the positron range and projected annihilation artifact in integrated PET/MR systems: a GATE Monte Carlo study

2021 ◽  
Author(s):  
Sepideh Barati ◽  
Milad Enferadi ◽  
Saeed Sarkar ◽  
Parham Geramifar

Author(s):  
Akira Satoh ◽  
Yasuhiro Sakuda

We have investigated aggregation phenomena of a colloidal dispersion composed of magnetic plate-like particles by means of Monte Carlo simulations. Such plate-like particles have been modeled as disk-like particles which have a magnetic moment normal to the particle axis at the particle center, with the section shape of a spherocylinder. The main objective of the present study is to clarify the influences of magnetic field strength and magnetic interactions between particles on particle aggregation phenomena. We have concentrated our attention on a quasi-2D system from an application point of view such as development of surface changing technology using such magnetic plate-like particles. A magnetic field was applied along a direction perpendicular to the plane of the monolayer. Internal structures of particle aggregates have been discussed quantitatively in terms of radial distribution and orientational pair correlation functions. The main results obtained here are summarized as follows. For the case of strong magnetic interactions between particles, the particles form long column-like clusters with their magnetic moments alternating in direction between the neighboring particles. These tendencies appear under circumstances of a weak applied magnetic field. However, as the magnetic field strength increases, the particles incline toward the magnetic field direction, so that the particles do not form such clusters.





1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.



1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-579-Pr2-582 ◽  
Author(s):  
S. Tumanski ◽  
M. Stabrowski


2014 ◽  
Vol 6 (2) ◽  
pp. 1178-1190
Author(s):  
A. JOHN PETER ◽  
Ada Vinolin

Simultaneous effects of magnetic field, pressure and temperature on the exciton binding energies are found in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot. Numerical calculations are carried out taking into consideration of spatial confinement effect. The cylindrical system is taken in the present problem with the strain effects. The electronic properties and the optical properties are found with the combined effects of magnetic field strength, hydrostatic pressure and temperature values. The exciton binding energies and the nonlinear optical properties are carried out taking into consideration of geometrical confinement and the external perturbations.Compact density approach is employed to obtain the nonlinear optical properties. The optical rectification coefficient is obtained with the photon energy in the presence of pressure, temperature and external magnetic field strength. Pressure and temperature dependence on nonlinear optical susceptibilities of generation of second and third order harmonics as a function of incident photon energy are brought out in the influence of magnetic field strength. The result shows that the electronic and nonlinear optical properties are significantly modified by the applications of external perturbations in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot.



1988 ◽  
Vol 12 (2) ◽  
pp. 89-96 ◽  
Author(s):  
R. Lufkin ◽  
M. Anselmo ◽  
J. Crues ◽  
W. Smoker ◽  
W. Hanafee


AIP Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 015008
Author(s):  
Yan-Hom Li ◽  
Cing-Hui Zeng ◽  
Yen-Ju Chen


2016 ◽  
Vol 69 (1) ◽  
pp. 7 ◽  
Author(s):  
Kosuke Namekata ◽  
Takahito Sakaue ◽  
Kyoko Watanabe ◽  
Ayumi Asai ◽  
Kazunari Shibata


Radiology ◽  
1984 ◽  
Vol 151 (1) ◽  
pp. 127-133 ◽  
Author(s):  
L E Crooks ◽  
M Arakawa ◽  
J Hoenninger ◽  
B McCarten ◽  
J Watts ◽  
...  


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