Magnetization of Ni-Fe-Mo Electrolytic films at low temperatures

H_{c), J_{s}, and Jrwere measured on Ni-Fe-Mo films at low temperatures. As the temperature dropped from 300 to 80°K, the Hccoercive field of Ni-Fe-Mo films with 0 percent content of Mo decreases from 1800 to 680 A/m. On the contrary, for the films with 5 and 10 percent Mo, the Hcincreases. The magnetization Jsvaries with temperature in the same sense as Hc. From the curvesJ = f(H/T)atT_{1} = 300degK andT_{2} = 80degK, it is found that the Ni-Fe-Mo electrolytic films with a concentration of over 10 percent Mo present properties characteristic of the superparamagnetic state.     

Preliminary Study on the Seizure Trend of a MOM-THP with Self-directed Balls

This work continues the approach of one of our topics relating to a MOM-THP （metal on metal-total hip prostheses） with self-directed movement balls. Experiments revealed a certain seizure in some strain conditions. Laboratory trials for balls/plane Hertzian contacts have been restarted in order to determine seizure behaviour depending on the roughness of the flat area. The trials have been carried out in BSF （body simulated fluid） lubrication conditions, much closer to the real operating conditions up against the initial tests with distilled water. Seizure burdens to different loadings and contact surfaces roughness influence over the seizure burden have been determined. Even though the minimum value of the wear must be the same with the minimum value of the surfaces roughness, given the experimental conditions, it came out from the trials results on wear that the lowest level of wear is acquired at a certain value of roughness, not at the lowest level of roughness.     

Sloshing effect on the dynamic behavior of horizontal cylindrical shells

The present study investigates the effect of free surface motion of a fluid on the dynamic behavior of thin-walled cylindrical shells. This paper outlines a semi-analytical approach to dynamic analysis of a fluid-filled horizontal cylindrical shell taking into account free surface motion; sloshing. The aim of the method is to provide a general approach that can be used for both analysis and synthesis of fluid/structure interaction problems in horizontal cylindrical shells focusing on the dynamic interaction between a flexible structure and incompressible and inviscid flow. The approach is very general; it allows dynamic analysis of both uniform and non-uniform cylindrical shells and considers the fluid forces and includes the sloshing effect exerted on the structure. The hybrid method developed in this work incorporates a combination of the classic finite element approach and thin shell theory to determine the specific displacement functions. Mass and stiffness matrices of the shell are determined by precise analytical integration. A potential function is applied to develop the dynamic pressure due to the fluid. The kinetic and potential energies are evaluated for a range of fluid heights to find the influence of the fluid on the dynamic responses of the structure. The influence of physical and geometrical parameters on the fluid-structure system has been considered in the numerical solutions. When these results are compared with corresponding results available in the literature, both theoretical and experimental, very good agreement is obtained.     

Sur la dispersion de l''anisotropie et de la stabilité dans le temps des couches électrolytiques de Ni-Fe-Mo avec anisotropie biaxiale

The angular and amplitude dispersions of the anisotropy in Ni-Fe-Mo films with biaxial anisotropy have been studied. The permalloy films had a thickness of 5000 Å and those of permalloy with 5% Mo a thickness of 5400 å. The films were deposited onto plane copper substrates. The angular and amplitude dispersions, measured by the resonance absorption method, decrease with an increase in the angle between the anisotropy axes, having values of 4° and 2.8 Oe, respectively, for the permalloy films with an angle of 5° between the axes, and 2° 30′ and 2 Oe for films with an angle of 22° between the axes. For the permalloy films with Mo the dispersions decrease from 7° 30′ and 3.2 Oe to 6° 30′ and 2.9 Oe for an increase of the angle between the anisotropy axes from 10° to 20°.

The time variation (over 1000 h) of the angle between the anisotropy axes is given. Decreases from 22° to 17° and from 10° to 7° respectively for permalloy and permalloy with 5% Mo are obtained.