The vibrational study of potassium and ammonium disulfates by Raman and Infrared spectroscopy gives supplementary informations about the structure of these two crystals and shows that there is strong and dissymetric hydrogen bonds in these salts.
M. Damak, A. Daoud, A. Novak
Pages 39-45
The cubic β-Na3PO4 phase stabilized by calcium shows an order-disorder phenomenon, which is studied by means of electronic paramagnetic resonance.
A.W. Kolsi, J. Livage, M. Quarton
Pages 47-50
The fact that mixed potential of aluminum in a 0.1 N NaOH solution at 60°C is more negative when the metal is purer can be readily explained by potential v s. time plots and volumetric measurements. these are consistent with impurities behaving as microcathodes which shift the mixed potential of pure aluminum towards higher potentials, the corrosion velocity being enhanced correlatively.
E. Triki
Pages 51-54
A modification of the Lumbroso Reverbori method for the determination of the pores volume of resin is described. The results are compared with those of previously published methods.
R. Catusse , M. Feki, H.F. Ayedi
Pages 55-58
Any thermodynamical investigation should be preceded by a precise definition of the "Thermodynamical System" (Material System) connected with this investigation. It is possible to extend the usual definition of a Thermodynamical system and to emphasize the fact that such a system is indeed a particular element in a well given set. These sets, we have called "Existence fields of Thermodynamical Systems", may be defined in a rigourous way by means of some conventions issued from an adapted terminology. Such a thermodynamical phenomena concept enables us to investigate, in an original manner, in-equilibrial material system and specially phase diagrams.
J. Belguith, J. L. Janier Dubry
Pages 59-63
The importance of recording Raman spectra in the vicinity of phase transitions of the studied materials led us to the design of this device. It is made of materials available and calibrated to allow temperature measurements with an accuracy of around 2°C.
M. Damak, A. Daoud
Pages 65-67
The study of sodium chloracetate monocondensation on certain primary and secondary amines with hydrocarbonus chains which are either linear or ramified or cyclic, has enabled us to synthesize nine α-aminoacids. We have purified those α-aminoacids by preparing their chlorhydrates.
F. M'henni, Z. Mighri
Pages 3-12
The reaction of oxygen with the surface of γFe2O3 has been studied by infrared spectroscopy method. It has been shown that a variety of forms of adsorbed oxygen is produced. The adsorption bands corresponding to the different forms of adsorbed oxygen lie in the 1600 - 800 cm-1 spectral range. Two species are clearly distinguished: one neutral molecular specie highly polarised which absorbs in the 1500-1540 cm-1 region and one charged specie O2n- with 0 < n < 1 which absorbs in the 1500 - 1200 cm-1 region. Their thermodesorption in vacum at 250°C is accompanied by sample reduction to Fe3O4 state. Hydrogen reacts selectively (according to temperature) with adsorbed molecular oxygen then lattice oxygen. With molecule interacts physically among hydrogen bonds with some O2n- species, however dipole-dipole interaction with polarized species is pointed out. At room temperature, propen adsorption leads to chemisorbed species obtained by a reaction with adsorbed oxygen.
H. Batis
Pages 13- 23