scholarly journals Energy Based Calculation of the Second-Order Levitation in Magnetic Fluid

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2507
Author(s):  
Mislav Trbušić ◽  
Marko Jesenik ◽  
Mladen Trlep ◽  
Anton Hamler
Keyword(s):  
Permanent Magnet ◽  
Magnetic Fluid ◽  
Alternative Energy ◽  
Magnetic Levitation ◽  
Minimum Energy ◽  
Second Order ◽  
Surface Integral ◽  
Energy Principle ◽  
Minimum Energy Principle ◽  
The Difference

A permanent magnet immersed in magnetic fluid experiences magnetic levitation force which is of the buoyant type. This phenomenon commonly refers to self-levitation or second-order buoyancy. The stable levitation height of the permanent magnet can be attained by numerical evaluation of the force. Various authors have proposed different computational methods, but all of them rely on force formulation. This paper presents an alternative energy approach in the equilibrium height calculation, which was settled on the minimum energy principle. The problem, involving a cylindrical magnet suspended in a closed cylindrical container full of magnetic fluid, was considered in the study. The results accomplished by the proposed method were compared with those of the well-established surface integral method already verified by experiments. The difference in the results gained by both methods appears to be under 2.5%.

scholarly journals Meteoritic amino acids as chemical tracers of parent-body chemistries

2021 ◽  
Vol 502 (3) ◽  
pp. 4064-4073
Author(s):  
Y Ellinger ◽  
M Lattelais ◽  
F Pauzat ◽  
J-C Guillemin ◽  
B Zanda
Keyword(s):  
Amino Acids ◽  
Relative Stability ◽  
Density Functional ◽  
Minimum Energy ◽  
Protonated Form ◽  
Parent Body ◽  
Chemical Formula ◽  
Energy Principle ◽  
Chemical Tracers ◽  
Minimum Energy Principle

ABSTRACT The analysis of the organic matter of meteorites made it possible to identify over 70 amino acids (AA), including 8 of those found in living organisms. However, their relative abundances vary drastically with the type of the carbonaceous chondrite, even for isomers of same chemical formula. In this report, we address the question whether this difference may have its origin in the relative stability of these isomers according to the conditions they experienced when they were formed and after. To this end, we rely on the fact that for most of the species observed so far in the interstellar medium (ISM), the most abundant isomer of a given generic chemical formula is the most stable one (minimum energy principle, MEP). Using quantum density functional theory (DFT) simulations, we investigate the relative stability of the lowest energy isomers of alanine (Ala) and amino butyric acid (ABA) in the neutral, protonated, and zwitterionic structures together with corresponding nitrile precursors. It is shown that β-alanine and γ-ABA are the most stable in a protonated form, whereas α-AA are the most stable in the zwitterionic and nitrile structures. The different composition of the carbonaceous chondrites CIs and CMs could be linked to the chemical context of the aqueous alterations of the parent bodies.

scholarly journals Prediction of Permanent Displacement of Liquefied Ground by Means of Minimum Energy Principle

1992 ◽  
Vol 32 (3) ◽  
pp. 97-116 ◽  
Author(s):  
Ikuo Towhata ◽  
Yasushi Sasaki ◽  
Ken-Ichi Tokida ◽  
Hideo Matsumoto ◽  
Yukio Tamar ◽  
...  
Keyword(s):  
Minimum Energy ◽  
Permanent Displacement ◽  
Energy Principle ◽  
Minimum Energy Principle

Experimental Study on the Second-Order Buoyancy of Magnetic Fluid

2012 ◽  
Vol 512-515 ◽  
pp. 1464-1469 ◽  
Author(s):  
Xin Zhi He ◽  
De Cai Li ◽  
Wen Ming Yang ◽  
Hai Na Zhang
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Numerical Calculation ◽  
Permanent Magnet ◽  
Saturation Magnetization ◽  
Experimental Method ◽  
Magnetic Fluid ◽  
Second Order

The buoyancy principle of magnetic fluid is one of the most attractive effects of magnetic fluid statics. But it is too difficult to calculate the buoyancy directly due to the complexity of magnetic field. Moreover, numerical calculation employs too many assumptions. So in this paper the experimental method is adopted to measure the second-order buoyancy received by permanent magnet immersed in magnetic fluid, which depends on the distance between the magnet and the wall of vessel. The influence of the diameter of cylindrical vessels, the size of magnets and the saturation magnetization of magnetic fluid on the buoyancy is also analyzed qualitatively.

Sign in / Sign up

Export Citation Format

Share Document