Structural characterisation of nickel-cobalt spinel-related oxides of NixCO3-xO4 (0≤x≤1.2) prepared by four different routes using XRD, FTIR, UV-VIS-NIR and XPS

AbstractFour analytical techniques, i.e. X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), ultraviolet-visible-near infrared reflectance spectroscopy (UV-vis-NIR), X-ray photoelectron spectroscopy (XPS) and four different synthesis methods, i.e the sol gel routes pechini and propionic acid route, thermal decomposition of nitrates and coprecipitation of hydoxides, have been used to characterise Ni – Co mixed oxides NixCo3-xO4 (0 ≤ x  ≤ 1.2). XRD patterns show that the oxides crystallise in cubic spinel phases with a unit lattice parameter, which increases with x and closely linked to the preparation method. The UV-vis-NIR reflectance patterns confirm the two mixed valence ionic distribution. IR spectra exhibit strong peak characteristics of pure spinel. XPS study shows that there are possibly structural differences as ions site occupation or types of spinel form in compounds prepared by different methods

L'acacia au Sénégal

La variabilité intra et interspécifique de la fixation biologique de l'azote a été étudiée chez les acacias. Cette variabilité se manifeste d'abord dans l'aptitude des espèces d'#Acacia à former des nodules avec des souches de #Rhizobium ou de #Bradyrhizobium. Ensuite, il a été mis en évidence une différence dans le potentiel fixateur d'azote entre les espèces d'#Acacia : #A. mangium, #A. seyal et #A. raddiana ont un potentiel élevé alors qu'#A. senegal, #A. pellita et #Faidherbia albida ont un potentiel faible. La variabilité intraspécifique des acacias à fixer l'azote a également été observée dans le cas de #F. albida : la provenance de Kabrousse a le potentiel fixateur le plus élevé ; les provenances de Merina et Dangalma ne fixent pas d'azote. Cette diversité traduit probablement l'existence d'une variabilité génétique chez #Acacia. (Résumé d'auteur

Imperforate hymen complicated by obstructive acute renal failure

Imperforate hymen is a rare malformation (1/ 1000 female births). It is diagnosed most often during puberty. Early diagnosis of hematocolpos and evacuation is necessary to avoid any consequences. We report a rare case of an imperforate hymen complicated with acute urinary retention,  hydronephrosis and renal failure in a 14-year-old girl to emphasize thepossible misdiagnosis and its possible consequences. This is the firstcase we encounter in our unit

Insecticidal effect of kaolin powder flavoured with essential oils of Lantana camara L. (Verbenaceae) and Annona senegalensis Pers. (Annonaceae) on Caryedon serratus Olivier (Coleoptera-Bruchidae), a groundnut stock pest

The groundnut weevil, Caryedon serratus, causes significant losses of groundnut stocks in Senegal by developing larvae in the seeds. Essential oils extracted from leaves of two plants that grow naturally in Senegal, i.e. the sugar apple (Annona senegalensis Pers.) and lantana (Lantana camara), were tested on adults of Caryedon serratus. Purified and pulverized kaolin was flavoured with essential oils of A. Senegalensis Pers. and L. camara (Lam) obtained through vapour distillation. Adults C. serratus aged 24 hrs at most were treated with 0.1 g of powder flavoured with increasing doses (12.5 to 50 ìl/g. of powder) of essential oil. Withincreasing doses (12.5 to 50 ìl/g of powder) of essential oil. The powder Aromatized with essential oil of A. senegalensis at concentration 25 ìl/g. induced 50% mortality after 36 hrs of contact at concentration 25 ìl/gand 100% after 48 hrs at 50 ìl/g. The powder mixed with the essential oil of L. camara induced after 12 hours of contact 22% mortality at the dose of 12.5 ìl/g, the mortality increased with dose duration of exposure andreached 97.22% after 36 hrs with 50ìl/g