Effect of mixed alkali-element substitution on structural and magnetic properties of praseodymium manganites Pr0.9(Na1-xKx)0.1MnO3

The effect of cationic size mismatch at the A site at constant manganese valence on the structural and magnetic properties of a perovskite-type rare-earth manganate was investigated in the Pr0.9(Na1-xKx)0.1MnO3 solid solution system (0 <= x < 1). All members of this solid solution series are orthorhombic at room temperature, space group Pbnm. Structural refinements using the Rietveld method show that the cell volume increases and the static Jahn-Teller distortion decreases with increasing potassium content x. Magnetic properties are characterized by strong positive \theta p values, and are ascribed to a canted ferromagnetic arrangement. The high Curie constant values in the paramagnetic regime can be explained by a magnetic cluster model of 2-3 Mn ions.Comment: Journal of Alloys and Compounds (2007) (accept\'e, sous presse

LA REVELATION DES FAITS DELICTUEUX ENTRE OBLIGATION ET APPLICATION : Cas de la Tunisie

International audienceThe revelation of fraud is one of the main characteristics of the profession of financial auditor in France but also in Tunisia. This obligation arises from a desire of governments to protect the market against any risk of fraud. The goal is to protect firms and their economic and social environment. In this perspective, this qualitative research on the Tunisian audit market tries to analyze the behavior of auditors facing this legal aspect of their profession. It suggests that the revelation of fraud by the auditor depends on its independence towards his client and the degree of aversion to risk.La révélation des faits délictueux est l'une des principales spécificités du métier de l'auditeur légal en France mais aussi en Tunisie. Cette obligation résulte d'une volonté des pouvoirs publics de protéger le marché contre tout risque de fraude et s'inscrit dans un souci de protection des entreprises et de leur environnement économique et social. Dans cette perspective, cette recherche tente à partir d'une étude qualitative menée sur le marché d'audit tunisien, d'analyser le comportement des auditeurs légaux face à cet aspect juridique de leur métier. Elle suggère que la révélation des faits délictueux par l'auditeur dépend de son indépendance vis-à-vis de son client mais aussi de son degré d'aversion face à un risque à double tranchant : un risque économique et un risque pénal

Inter-organizaional issues toward a "greener" supply chain

Cahier de recherche du CERAG 2011-01 E5Recent changes in environmental legislation have focused company thinking on business practices, particularly concerning the importance of integrating environmental concerns like outsourcing and procurement in supply chain networks. Supply chain partners are becoming progressively more accountable not only for their internal practices, but also for their suppliers' behavior because implementing a "greener" supply chain is far from an individual strategy. The objective of this paper is to study the difficulties that may be encountered by a focal firm with its partners from the perspective of implementing environmental practice issues, or improving these practices if they already exist. In this paper we develop an integrative conceptual framework to show the role of relationship types, contract design and clauses to coordinate the relationship between a focal firm and its supplier in the implementation of a green supply chain

Structural and magnetic properties in the ruthenate Bi2.67Pr0.33Ru3O11

An unreported praseodymium substituted phase of the Bi-Ru-O system with formula Bi2.67Pr0.33Ru3O11was prepared. Its crystal structure and magnetic properties were investigated. Pr substituted occurs only on one of the two Bi sites. The magnetism of the compound is essentially dominated by a Pr3+ contribution. A non linear variation of the reciprocal magnetic susceptibility is observed that appears to account for crystal electric field interactions on the Pr3+ ions

Spirituality: A Multidimentional Construct and Its Implications for Marketing

The present paper deals with the spiritual value that controls the brain activity of many thinkers as well as with the various definitions and characteristics tied up with it. The ultimate scope throughout this essay is to point out the multi-facets aspect of spirituality. Indeed, spirituality encompasses a personal, interpersonal, and transpersonal context. It revealed thus to be a multidimensional construct, entailing four dimensions namely meaningfulness of life (the goal of one’s living), interconnectedness with people (the various relationships that one nourishes with others), transcendence (feeling of an inexplicable supernatural and divine power) and self-renewal (the relationship with one’s self

Variation of chemical composition of essential oils in wild populations of Thymus algeriensis Boiss. et Reut., a North African endemic Species

<p>Abstract</p> <p>Background</p> <p><it>Thymus algeriensis </it>is an endemic aromatic plant to Tunisia largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by the geographical location and the phase of the plant development. Therefore, the aim of the present work is to provide more information on the variation of essential oil composition of <it>T. algeriensis </it>collected during the vegetative and the flowering phases and from eight different geographical regions. Besides, influence of population location and phenological stage on yield and metal chelating activity of essential oils is also assessed.</p> <p>Methods</p> <p>The essential oil composition of <it>Thymus algeriensis </it>was determined mainly by GC/FID and GC/MS. The chemical differentiation among populations performed on all compounds was assessed by linear discriminate analysis and cluster analysis based on Euclidean distance.</p> <p>Results</p> <p>A total of 71 compounds, representing 88.99 to 99.76% of the total oil, were identified. A significant effect of the population location on the chemical composition variability of <it>T. algeriensis </it>oil was observed. Only 18 out of 71 compounds showed a statistically significant variation among population locations and phenological stages. Chemical differentiation among populations was high. Minor compounds play an important role to distinguish between chemical groups. Five chemotypes according to the major compounds have been distinguished. Chemotypes distribution is linked to the population location and not to bioclimate, indicating that local selective environmental factors acted on the chemotype diversity.</p> <p>Conclusions</p> <p>The major compounds at the species level were α-pinene (7.41-13.94%), 1,8-cineole (7.55-22.07%), <it>cis</it>-sabinene hydrate (0.10-12.95%), camphor (6.8-19.93%), 4-terpineol (1.55-11.86%), terpenyl acetate (0-14.92%) and viridiflorol (0-11.49%). Based on major compounds, the populations were represented by (α-pinene/1,8-cineole/<it>cis</it>-sabinene hydrate/camphor/viridiflorol), (1,8-cineole/camphor/terpenyl acetate), (α-pinene/1,8-cineole/camphor), (1,8-cineole/camphor/4-terpineol) and (α-pinene/1,8-cineole/<it>cis</it>-sabinene hydrate/camphor/4-terpineol) chemotypes. Variation of phenological stage did not have a statistically significant effect on the yield and metal chelating activity of the essential oil. These results can be used to investigate the geographical location and the harvesting time of this plant for relevant industries.</p