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International audience; One of the most elaborate community initiatives for the management of groundwater consists of managed aquifer recharge and use. In the oases in the M’zab valley in the Algerian Sahara, the collective action that upholds these initiatives has been challenged in past decades by the development of intensive groundwater use with individual pumps in new agricultural areas. However, faced with water shortage and inspired by the more circular irrigation practices in oases, farmers are increasingly creating local use loops in these extension areas by installing recharge devices and using water more carefully. This study analyzes the functioning of the circular managed aquifer recharge and use system in Beni Isguen oasis, and how farmers have reinvented it in agricultural extensions, creatively combining it with modern technologies to engage in market-oriented agriculture. Reinventing circular practices in new agricultural extensions can contribute to more environmentally sustainable forms of agriculture.

Background Interferon regulatory factor 5 (IRF5) is a transcription factor regulating interferon secretion and was proved to be implicated in the pathogenesis of systemic lupus erythematosus (SLE) in several studies. The purpose of this case-control study was to investigate whether IRF5 gene polymorphism is involved in the genetic predisposition to SLE in the Algerian population. Methods IRF5 rs729302 (A/C) polymorphism was analyzed in 120 SLE patients and 98 age and sex matched controls by real time- polymerase chain reaction. Results Significant association was observed for AA and AC genotypes of IRF5 between patients and healthy subjects (60% vs 73%; 40% vs 27%, p =0.025, respectively). Patients with SLE had more frequent C allele compared to controls (20% vs 13%, P = 0.041). However, the allele and genotype frequencies did not show any difference in patients with nephritis in comparison to those without nephritis. Conclusion The rs729302 C allele and AC genotype can be considered as risk factors for the development of SLE in Algerian patients.

Co spinel ferrite nanoparticles were successfully prepared using a solvothermal route. Their structure, morphology and cationic distribution were studied by X-ray diffraction, Transmission Electron Microscopy and 57Fe Mossbauer Spectrometry. Though, their electric conductivity and dielectric relaxation were studied on nanostructured pellets resulting from the compaction of nanoparticles, by complex impedance spectroscopy in the frequency range 1–106 Hz from 25 up to 250 °C. The dielectric properties are investigated in detail. The presence of two thermally activated relaxation peaks in the modulus loss spectra confirms the contribution of grains and grain boundaries to the electrical behavior of the material. The main dielectric relaxation comportment and the conduction process are governed by the grain boundaries. Ac-conductivity, which deviates from the usual Universal Dielectric Response, can be described by a double power-law evidenced by a Nearly Constant Loss trend followed by a Super-Linear Power Law that decreases with increasing temperature. The change in the cationic distribution in CoFe2O4, deduced from the 57Fe Mossbauer spectra, may explain the observed trend in conductivity. The classical dielectric relaxation behavior is observed and very low values of permittivity are estimated. This compound can therefore be classified as an ultra-low-k dielectric.

An easy method based on the chemical charge neutrality and low temperature magnetic measurements is proposed to estimate the cationic distribution of Co x Fe 3-x O 4 (0 3+ cations located in the octahedral B sites has been quantified and found to be increased with x (about 30% for x = 1.5). The results have been compared to the literature and found to be accurate with advance techniques as Neutron powder diffraction and in-field Mossbauer spectroscopy. The validity of our method is discussed: when the grain size is less than 6 nm and when the nanoparticles are in a core-shell structure the method cannot be applied. Furthermore, the dependence of the magnetocrystalline anisotropy on the cobalt content x is related to the evolution of the Co 3+ cations. Our method offers the possibility to calculate the cationic distribution of spinel ferrite systems ones they have the suitable physico-chemical properties.

In this paper, we report on self-assembled Co nanoparticles deposited in and on porous silicon (PS) matrix by using UHV evaporation. Four samples were prepared by varying the Co deposited thickness (t = 3, 5, 7 and 10 nm). All samples have been investigated by means of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Physical Properties Measurement System (PPMS). The increase of t has induced an increase of the nanoparticle diameter from 3 nm to about 150 nm. Referring to the magnetic characterizations, this increase has been followed by a single to multi-domain transition. Therefore, this has been evidenced by a switching from superparamagnetism to purely ferromagnetism accompanied by a change in the magnetic reversal dynamics. Thus, by performing micromagnetic calculation, we have shown that a transition from the uniform rotation to vortex state occurs at a critical diameter of about 55 nm.

International audience; In this work, we present a correlation between High Resolution Transmission Electron Microscopy (HRTEM) and in-field Mössbauer spectrometry to point out exchange coupling behavior, surface effects and chemical disorder in CoxFe3-xO4 cobalt ferrite nanoparticles. The samples were synthesized by a solvothermal chemical route. The hysteresis loops, recorded by using Vibrating Sample Magnetometer (VSM), suggest a jump-like behavior nearby zero applied magnetic fields. The HRTEM micrographs illustrate the presence of faceted nanoparticles for x

Cobalt ferrites nanoparticles Co x Fe 3-x O 4 (1≤ x B ) range from 294 to 240 K. Kneller's law fitting of the coercive field dependence on the temperature exhibits a non-neglected interparticle interaction and a wide size distribution according to the difference found between T B and the Kneller transition temperature T BK .

International audience; In this work, we report on magnetic nanoparticles of CoxFe3-XO4 (x 0) gives spinel structure of space group Fd-3m for all samples. Magnetization curves, recorded by a Vibrating Sample Magnetometer (VSM), are the sign of two exchange-coupled magnetic phases (x > 0). This was in disagreement with XRD and SAED analyses which showed only one structural phase. Large (similar to 250 nm and less) rectangular and small spheroidal nanoparticles have been found by Transmission Electron Microscopy (TEM). The increase of cobalt content favors the formation of monodisperse nanoparticles. Following a subsequent heat treatment, a fraction of the as prepared samples (depending on x) has been transformed into hematite phase with a disappearance of the exchange-coupling behavior. In situ Micro-Raman analyses were necessary to investigate on the growing of the nanoparticles and the ferrite-hematite transformation. We have also deduced, that the synthesized phase with the cobalt ferrite one (till x < 1) was the magnetite Fe3O4. Then, we have pointed out the effect of performing local spectroscopy and the effect of having mixed ferrites on the structural and the physical properties. (C) 2016 Elsevier B.V. All rights reserved.

The urbanization of information systems (IS) is a key concern of IT professionals. This is largely due to changes in business, organizations and institutions, the need for coexistence between old and new systems, the necessary restructuring of architectures and business process reengineering needs. The main objective of this work is to provide an urbanization approach based on the objectives of the organization and in our case it is an approach that will be applied to the information system of the University of Manouba. In fact a process that must take into account the objectives and contexts must have a guiding model can guide the process of urbanization. The model advocated guide must be scalable, situational, adaptive, interactive, directed by the objectives and context. These characteristics point us to the goal-oriented models and especially to the model of the card as a model guide to adopt given the consideration of the context and the evolving strategic needs and it offers is one of these specificities. This article is organized into three parts. The first part will present a brief state of the art of the main approaches used to urbanization, the second part will present the specific context of the University of Manouba, and the third part will present the approach advocated and adopted model guide.