Use of isothermal microcalorimetry data for the determination of integral molar entropies of adsorption at the gas—solid interface by a quasi-equilibrium procedure

The aim of this paper is to describe the present position in the experimental determination of entropies of adsorption. After pointing out the limitations of the “isosteric” approach and after stressing the fact that the most interesting entropy to know is the integral molar entropy of adsorption, the authors show how the use of isothermal adsorption microcalorimetry, with a special quasi-reversible procedure, allows this entropy to be determined satisfactorily from the thermodynamic point of view.     

124Sn target residues in the interaction of heavy ions at intermediate energies

Cross sections, recoil energy distributions for residues produced by¹⁴N,²⁰Ne,⁴⁰Ar on¹²⁴Sn targets have been measured in the 10–70 MeV/u intermediate energy range. As the projectile energy increases, processes as complete fusion-evaporation, incomplete fusion-evaporation and intranuclear cascade-evaporation participate progressively in the nuclear collisions. Peculiar residues corresponding to a gain of 4, 5 or even 6 protons for the¹²⁴Sn target have been observed in the 30–50 MeV energy range.     

Synthese und Reaktionen des 5-[p-(Dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazolins

Synthesis and Reactions of 5-[p-(Dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline The title compound 8 has been synthesized in a one-pot reaction of 4′-(dimethylamino)benzoin ( 4 ) with 2-propanone and NH₃. The preparation of the intermediate 4 from 3 is the first example of an acid-catalyzed transformation of the stable benzoin 3 into the corresponding less stable benzoin 4 . Structures and yields of various by-products occurring under different reaction conditions during the synthesis of 8 from 4 are given. The O-atom of the 3-oxazoline ring in 8 could be replaced by S from P₂S₅ yielding the 3-thiazoline 14 . Separation of the enantiomers of the racemate 8 could only be performed by transforming them into the trimethylanilinium salts 8b and 8c of (−)- and (+)-10-camphorsulfonic acid, respectively. Solid NaOAc in boiling toluene caused the precipitation of the 10-camphorsulfonic acids from the quaternary ammonium salts as sodium salts and the removing of the third methyl group from the quaternary ammonium salts as AcOMe to give the enantiomers (−)-(5S)- 8 and (+)-(5R)- 8 . Their absolute configurations are deduced from an X-ray analysis of 8b .     

A Callan-Symanzik study of the λϕ34+gϕ36 theory

We investigate a $\text{L}{}_{\mathrm{<mtext>I</mtext>}}\text{=λ?}{}_3{}^4\text{+g?}{}_3{}^6$ theory using Callan-Symanzik equations. Logarithmic corrections to trivial fixed-point behaviour are obtained. The theory is shown to correspond to a model for tri-critical phenomena in ³He⁴He mixtures.     

Unexpected formation of rearrangement and fragmentation products during the thermal activation of pyrazolino diazepines

Ionic and radical mechanistic steps are postulated in order to explain the formation of the rearrangement-, the isomerization- and the fragmentation-products isolated during the thermal treatment of pyrazolo-diazepines.     

Excited levels of 233Pa by alpha decay of 237Np

α-spectrometry using Si(Au) detectors has been performed with thin samples of ²³⁷Np; αγ bi-parametric coincidences have permitted an analysis and unfolding of the spectrum and give data about the level scheme. Direct and α-coincident γ-spectra have been measured using Ge(Li) and Si(Li) detectors, obtaining the characteristic electromagnetic transitions in ²³³Pa. Nine new γ-transitions are found, relative to the most recent compilation made by Ellis. In the level scheme, the existence of a level at 306.1 keV is confirmed. A level at 257.1 keV, previously suggested, is evidenced. The level at 300.5 keV is proposed as the $\text{7}\text{2}{}^{\mathrm{?}}$ component of the $\text{5}\text{2}\text{(523)}$ band, hence proposing the 306.1 keV level as the $\text{7}\text{2}{}^{\mathrm{+}}$ term of the $\text{5}\text{2}\text{(642)}$ band.     

The electronic structure of sulphur chloride penta-fluoride

The electronic structure of SCIF₅ is computed within the framework of the CNDO/2 approximation on the basis of Kewley's microwave geometrical data and is compared with our previous results on SF₆. The charge distribution and the value of the dipole moment are discussed as a function of the F-S-F_ax angle and an inversion of the net charge on Cl is observed when passing through the 95° value for (F-S-F_ax) angle.     

Neutron activation cross sections at 14.7 MeV for isotopes of tungsten

Cross sections for (n, 2n), (n, p), (n, α) and [(n, n′p) + (n, pn)] reactions at 14.7 ± 0.3MeV on enriched ^{180, 182, 183, 184, 186}W isotopes have been measured by the activation technique using Ge(Li) detector γ-ray spectroscopy. Some systematic trends in the cross-section data have been analysed. The (n, 2n) reaction at this energy in this mass region is by far the most favoured reaction and accounts for > 80 % of the total inelastic cross section.