Examination of Levitation of Thin Non-Magnetic Conductor by AC Electoromagnet Type Electro Dynamic Suspension
Because transportation by magnetic levitation has the advantage of not contacting, it has various good points. Conventional studies of electro dynamic suspension (EDS) are aimed on the large-scale applications, and use the non magnetic conductor of 1mm or more in thickness. However, in theoretical, it is possible that the thinner non magnetic conductor of less than 1mm in thickness levitate, using higher frequency or larger magnetomotive force. Therefore, applications to a smaller levitation model can be expected. In this paper, the relation between lift force and the temperature rise in the conductor is examined from the numerical analysis, when we consider a smaller levitation model. Skin effect and electromagnetic force between gaps are taken into account. These results are verified by experiments.
Electro-magnetic and electrodynamic sustentation comparison No . A 20110228-89
The aim of the present analysis is to compare electro-dynamic (EDS) and electromagnetic (EMS) sustentation systems. For the electro-dynamic solution, the simplified model will be a sine wave MMF generated by a DC conducting layer in front of a semi-infinite conducting space. For the electro-magnetic solution, an electromagnet in front of iron will be considered. In a second step a more precise model is presented, allowing a sensitivity analysis of the main design parameters: speed, air gap, conducting layer thickness, pole pitch, etc 1 SIMPLIFIED METHODOLOGY 1.1 Electro-dynamic sustentation The system is defined as two semi-infinite spaces air and conducting material with a sine tangential magnetic field moving at the surface (Fig 1). The main variables are: V r vector potential Such as for the magnetic flux density B: V t o r B r r r = [1] [1] In air : 0 = ΔV r r Laplace’s law [2] In a material with constant resistivity (ρ) and permeability (μ): t V V ∂ ∂ = Δ r r r ρ μ Poisson’s law [3] Figure 1. EDS semi-infinite spaces. Two half-spaces, air and conducting material, are separated by a plane. On the surface, on the air side, an ideal conducting layer creates an alternating magnetic field in the y direction at the level z = 0: τ π ' sin ˆ 0 0 ' y H H y = with τ = pole pitch If the excitation layer moves at the speed v in the y’ direction, it comes: vt y y + = ' ( ) ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + = + = t v y H vt y H H y τ π τ π τ π sin ˆ sin ˆ 0 0 0 ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + = t y H ω τ π sin ˆ 0 With τ π ω v = It is possible to associate complex numbers to sine expressions: Air ( ) Ω = = + 0 / 0 0 ˆ ˆ H e H H t y j y ω τ π [4] The vector potential is co-linear with the electric field E, in the x direction. By analogy, the vector potential can be written as: ) , , ( t z y V i V x = r Equation [3] becomes: Conducting material μ, ρ μ0, ρ x
Acetylation analysis of saccharides. 2. Microanalysis of neutral glycosphingolipids by means of acetylation with radioactive acetic anhydride.
Abstract The quantitative analysis of mixtures of glycosphingolipids by acetylation with radioactive acetic anhydride and separation by thin-layer chromatography is described. The method was primarily developed for screening of glycosphingolipid composition of tissues, cultured cells, and virus preparations. The sensitivity and linearity of the method is demonstrated. Although theoretically a much higher sensitivity is achievable, in practive about 10 −9 g of glycosphingolipid can be detected and tentatively identified. As an example, the acetylation pattern of lipids from a preparation of herpes simplex virus is demonstrated.