Formation pratique à la conception d’un circuit intégré spécifique

We present an example of practical works in design methodology for realizing digitalASIC circuit, at the graduate level in the microelectronics engineering program (ISIM) of the University of Montpellier II. This training program is illustrated by the design of a small project from specification to silicon manufacturing files, using a CMOS standard cell approach with theCAD softwares system Hilo (Genrad) and Solo 1400(ES2).     

Influence of roasting temperature on reactions between ferruginous blende and copper(II) oxide

Thermal treatment in an oxidizing atmosphere of a mixture of raw blende (ZnS) and copper(II) oxide enhanced the formation of a mixed ferrite phase at temperature about 600°C. The composition established at 900°C was approximately (0.8 ZnO · 0.2 CuO)Fe₂O₃. For the mixture ZnS–CuO, with 5 to 15% CuO by weight, less than 15% copper was involved in the formation of the spinel phase. The increasing copper content in the mixture, roasted above 1000°C, favoured solubilization of iron, even in a weakly acid medium.     

A study of the durability of boundary films

The frictional properties of solid surfaces are modified by the adsorption of organic molecular films. The lifetime of a monomolecular film of a fatty acid which was deposited on a surface to form a solid/monolayer/air interface has been investigated.The continual presence of an agglomerate has been observed during frictional contact under boundary lubrication conditions. This agglomerate is composed of several substances resulting from the deterioration and recombination of fatty acid molecules with each other and/or the surrounding media.     

Influence de la structure sur les propriétés mécaniques dynamiques de quelques polytéréphtalates de polyméthylèneglycol. Relaxations β et γ

The influence of structure, cristallinity and orientation on the β- and γ-relaxation mechanisms of several poly(α,ω-alkandiolterephthalates) has been investigated. The γ-relaxation consists of two main components involving molecular motions in the amorphous phase, and motions of CH₂ groups (glycolic residue) in the gauche or trans form. A third component involves movements of bigger groups. The β-relaxation at low frequencies can be compared with the dilatometric glass transition.     

Comparison of the thermodynamic properties of particulate and monolithic columns of molecularly imprinted copolymers

A variety of polymerization techniques can be used to prepare molecularly imprinted copolymers (MIPs) for the purpose of the separation of enantiomers by HPLC. Unfortunately, the lack of thermodynamic and kinetic data characterizing the imprinted polymers prepared by these different techniques prevents the rational choice of the one most suited for a specific application. We investigated and compared the thermodynamic properties of copolymers imprinted for Fmoc-L-tryptophan and prepared by two different methods. The first was an in situ polymerization method that gives monolithic columns (monolithic MIPs), the second, a traditional method giving bulk MIPs. Examination of the thermodynamic properties on these two different MIPs showed that three types of binding sites coexist on their surface. The highest energy sites adsorb only the imprinted molecule or template. Most of the intermediate energy sites adsorb both the template and its antipode, although part of them may adsorb only the template. Finally, the lowest energy sites provide nonselective interactions of both the template and its antipode. On the nonimprinted copolymer, there are only two types of sites. The high-energy sites have a slightly lower energy that the intermediate sites of the MIPs, and the low-energy sites have properties close to those of the lowest energy sites on the MIPs. The monolithic MIPs have fewer nonselective sites than the bulk MIPs. However, the polar porogen that is needed to prepare the monolithic MIPs negatively affects the enantiomeric separation.     

Variation thermique de la susceptibilite magnetique et de l'aimantation du ferrite bicalcique Ca2Fe2O5

An investigation of the magnetic susceptibility and the magnetization vs temperature has been carried out for Ca₂Fe₂O₅. The weak ferromagnetism behaviour of this compound was confirmed. The value of the ferromagnetic component was determined; an estimate of the various magnetic couplings was given and the importance of the thermal variation of the molecular field at high temperature pointed out.     

Wear behaviour of carbonitrided steel

A pin and disk study of carbonitrided steel revealed different types of wear. The best results were with carbonitrided material rubbing on carbonitrided material. The effect of load and the role of brittleness on wear has been studied. Differences in structure, hardness and work-hardening of the various surface layers as well as debris in the interface caused the difference in wear behaviour of the layers.