Computation of horizontal force normal to the axis of a spheroidal conducting particle in a field gradient

2016 ◽  
Vol 23 (3) ◽  
pp. 1649-1651 ◽  
Author(s):  
Steven A. Boggs ◽  
Kenichi Nojima ◽  
Takanori Yasuoka
Keyword(s):  
Field Gradient ◽  
Horizontal Force ◽  
Conducting Particle

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

Magnetic suspension mechanism using rotary permanent magnets

2020 ◽  
Vol 64 (1-4) ◽  
pp. 977-983
Author(s):  
Koichi Oka ◽  
Kentaro Yamamoto ◽  
Akinori Harada
Keyword(s):  
Permanent Magnets ◽  
Suspension System ◽  
Magnetic Suspension ◽  
Horizontal Force ◽  
Mechanical Contact ◽  
New Type ◽  
Magnetic Suspension System

This paper proposes a new type of noncontact magnetic suspension system using two permanent magnets driven by rotary actuators. The paper aims to explain the proposed concept, configuration of the suspension system, and basic analyses for feasibility by FEM analyses. Two bar-shaped permanent magnets are installed as they are driven by rotary actuators independently. Attractive forces of two magnets act on the iron ball which is located under the magnets. Control of the angles of two magnets can suspend the iron ball stably without mechanical contact and changes the position of the ball. FEM analyses have been carried out for the arrangement of two permanent magnets and forces are simulated for noncontact suspension. Hence, successfully the required enough force against the gravity of the iron ball can be generated and controlled. Control of the horizontal force is also confirmed by the rotation of the permanent magnets.

Fore-Aft Forces in Tire-Wheel Assemblies Generated by Unbalances and the Influence of Balancing

1991 ◽  
Vol 19 (3) ◽  
pp. 142-162 ◽  
Author(s):  
D. S. Stutts ◽  
W. Soedel ◽  
S. K. Jha
Keyword(s):  
Mathematical Model ◽  
Elastic Foundation ◽  
Torsional Oscillation ◽  
Vertical Direction ◽  
Torsional Stiffness ◽  
Rolling Motion ◽  
Vertical Force ◽  
Horizontal Force ◽  
Wheel Rim ◽  
Open Question

Abstract When measuring bearing forces of the tire-wheel assembly during drum tests, it was found that beyond certain speeds, the horizontal force variations or so-called fore-aft forces were larger than the force variations in the vertical direction. The explanation of this phenomenon is still somewhat an open question. One of the hypothetical models argues in favor of torsional oscillations caused by a changing rolling radius. But it appears that there is a simpler answer. In this paper, a mathematical model of a tire consisting of a rigid tread ring connected to a freely rotating wheel or hub through an elastic foundation which has radial and torsional stiffness was developed. This model shows that an unbalanced mass on the tread ring will cause an oscillatory rolling motion of the tread ring on the drum which is superimposed on the nominal rolling. This will indeed result in larger fore-aft than vertical force variations beyond certain speeds, which are a function of run-out. The rolling motion is in a certain sense a torsional oscillation, but postulation of a changing rolling radius is not necessary for its creation. The model also shows the limitation on balancing the tire-wheel assembly at the wheel rim if the unbalance occurs at the tread band.

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

2019 ◽  
Author(s):  
Benjamin Egleston ◽  
Konstantin V. Luzyanin ◽  
Michael C. Brand ◽  
Rob Clowes ◽  
Michael E. Briggs ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Synthesis ◽  
Field Gradient ◽  
Window Size ◽  
Standard Approach ◽  
Porous Solids ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Cage Molecules ◽  
Gas Selectivity

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH<sub>4</sub>-selective, which is understood using <sup>129</sup>Xe, <sup>1</sup>H, and pulsed-field gradient NMR spectroscopy.

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

2019 ◽  
Author(s):  
Benjamin Egleston ◽  
Konstantin V. Luzyanin ◽  
Michael C. Brand ◽  
Rob Clowes ◽  
Michael E. Briggs ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Synthesis ◽  
Field Gradient ◽  
Window Size ◽  
Standard Approach ◽  
Porous Solids ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Cage Molecules ◽  
Gas Selectivity

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH<sub>4</sub>-selective, which is understood using <sup>129</sup>Xe, <sup>1</sup>H, and pulsed-field gradient NMR spectroscopy.

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