Etude de verres de chalcogenures contenant de l'europium divalent systeme EuSGa2S3GeS2

Existence of a very large glassy domain inside the ternary system EuSGa₂S₃GeS₂. Conditions of formation of the glassy products. Thermal properties : glass trarsition temperatures and crystallization temperatures. Existence in the ternary system of a large region of glass having a very small crystallization speed. Refractiv index. Magnetic moment. Structural study by Raman spectroscopy of crystalline compounds (GeS₂, EuGeS₃, Eu₂GeS₄, EuGa₂S₄) and of various glasses of this system.     

Pregnancy in chronic hemodialysis

Two successful pregnancies in our dialysis center bring us an opportunity to update the related treatment. The success rate of this rare event is more than 30% at the moment. Maternal morbidity is reduced through close follow up. From the second semester, it is necessary to adapt and intensify dialysis, which becomes daily. At the third quarter, full-time hospitalization, extended to a high risk pregnancy unit at first incident, must be provided. Delivery may be normal. The infant is not particularly at risk for malformation, but is 30 to 35 weeks premature; at short time, its psychomotor development seems normal. To our sense, to influence systematically on women a "voluntary" therapeutic pregnancy interruption might be qualified if, when duly informed, women wish to try and keep their child.     

Optimization of Extreme Load and Break-in Period in Plain ZDDP Oil with FeF3 Catalyst Using Design of Experiment and Fundamental Study under Different Speeds

The mechanism of tribofilm formation and breakdown was carefully followed and studied in 0.1 P% (percentage phosphorus content) plain zinc dialkyldithiophosphate (ZDDP) oil in the presence of iron fluoride (FeF₃) catalyst under extreme Hertzian contact pressure (3.0 GPa) and two different rotational speeds or variable speed with break in period (100 rpm for the first 5,000 revolutions and a 700 rpm until failure or 100,000 revolutions, whichever comes first). At the onset of large frictional fluctuations, the contact surface temperature increased significantly and reached 90°C ± 5°C. The present article describes an innovative method of reducing the surface temperature by using a break in period of 2 or 3 min and rerunning the test until failure. The two different rotational speeds or variable speed will be compared to a steady-state speed of 700 rpm.

Thermal decomposition of ZDDP is examined in the presence of powder and dispersed FeF₃ using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Surface analyses were carried out using scanning electron microscopy (SEM) coupled with X-ray of the wear tracks, transmission electron microscopy (TEM), and auger electron spectroscopy (AES). Results showed that submicrometer dispersed FeF₃ provided excellent wear protection when combined with ZDDP in the variable-speed test with break-in by forming a tribofilm that is amorphous in nature and rich in phosphorus, which was shown by the TEM and X-ray analyses.     

Cloud point and solvent extraction study of uranium(VI) by 8‐hydroxyquinoline

BACKGROUND: Cloud point extraction (CPE) is an attractive alternative to solvent extraction. However, comparisons between both techniques are lacking. In this paper, the extraction of uranium(VI) using 8‐hydroxyquinoline (HQ) as chelating agent was studied by CPE using Triton X‐114 as non‐ionic surfactant and by solvent extraction using CHCl₃ as diluent. RESULTS: Using CPE, a quantitative extraction was observed for pH higher than 4.5 with a HQ/U ratio of 10. Using solvent extraction an increase in the HQ/U ratio up to 50 is necessary to obtain a near quantitative extraction. Both extraction systems were then compared with respect to the nature of extracted species, and the extraction constants determined using log‐log analysis of the extraction data. In the solvent extraction system, the extracted species were identified as UO₂Q₂ and the corresponding extraction constant was found to be log k_ex = ? 3.6 ± 0.2 on the molar scale. Considering that UO₂Q₂ is also the extracted species in CPE, a slightly higher extraction constant, i.e. log k_ex = ? 2.5 ± 0.3, was found. CONCLUSION: Such a small difference in favour of the CPE system may arise from the combination of various phenomena, including effects of temperature and effects of ‘extractant environment’. However, a change in the nature of the extracted species, namely from UO₂Q₂ in the solvent extraction system to the formation of adducts, i.e. UO₂Q₂(HQ) and UO₂Q₂(HQ)₂ in the CPE system, due to higher HQ concentration in the surfactant‐rich phase compared with chloroform, cannot be precluded, but requires confirmation. Copyright © 2012 Society of Chemical Industry     

Sequence of a 17·1 kb DNA fragment from chromosome X of Saccharomyces cerevisiae includes the mitochondrial ribosomal protein L8

We have sequenced a continuous segment of 17 137 bp on chromosome X. Sequence analysis of this stretch revealed 14 open reading frames (ORFs) at least 100 amino acids long. One gene, encoding the mitochondrial 60S ribosomal protein L8, had already been sequenced. Four ORF products show weak homologies with known protein sequences. The nine remaining ORF products have no homologies with sequences in data banks. The nucleotide sequence of the 17·1 kb fragment is available through the EMBL data library under Accession Number Z34288.     

The use of an algorithmic approach for the assessment of research quality

Recent years have seen a growing interest in the use of quantitative parameters for assessing the quality of research carried out at universities. In the UK, university departments are now subject to regular investigations of their research standing. As part of these investigations, a considerable amount of quantitative (as well as qualitative) information is collected from each department. This is made available to the panels appointed to assess research quality in each subject area. One question that has been raised is whether the data can be combined in some way to provide an index which can help guide the panels' deliberations. This question is looked at here via a detailed examination of the returns from four universities for the most recent (1992) research assessment exercise. The results suggest that attempts to derive an algorithm are only likely to be helpful for a limited range of subjects.     

Nystatin and osmotica as chemical enhancers of the phenotypic adaptation to freeze-thaw stress in Geotrichum candidum ATCC 204307

Geotrichum candidum is a yeast-like fungus used as ripening starter in cheese making. The present study focused on chemical stress pretreatments affecting survival of G. candidum ATCC 204307 to freeze-thaw stress. Cryotolerance of G. candidum cells was induced by pretreatment with NaCl, CaCl2, or MgCl2, indicating heterologous phenotypic adaptation to freeze-thaw stress (- 20 to 25 degrees C) by osmotic stress. Furthermore, the nystatin, an antifungal compound, was shown to be a cryotolerance inducer.     

Etude des verres formes dans le ternaire EuAsS

From the glasses of the binary As-S system, a large region of ternary glasses is observed in the Eu-As-S system. The thermal behaviour, the magnetic susceptibility and the Raman and infrared absorption spectra show that europium is always in the divalent state, in contrast with the ternary phase diagram in which compounds of trivalent europium are present.