Growth of homopolymer chain

Thermodynamic and kinetic properties of an homopolymer chain, in two dimensional square lattice, are studied by the use of chain growth algorithm based on the self avoiding walks process. Which is in accord with what happen in nature. All monomers are considered to be hydrophobic. In the thermodynamical study we examine the critical behaviour of the chain by following the evolution of the chain geometry with temperature. This is done by studying the behaviour of the mean distance R chosen to describe the homopolymer structure. Moreover, we give the behaviour of thermodynamic quantities such as conformational energy and specific heat. The effect of a force applied, in a fixed direction, on the chain when it is growing is also investigated. Finally, in a kinetic study, we analyse the evolution with temperature of the mean time necessarily for a given conformation to reach its native state.Thermodynamic and kinetic properties of an homopolymer chain, in two dimensional square lattice, are studied by the use of chain growth algorithm based on the self avoiding walks process. Which is in accord with what happen in nature. All monomers are considered to be hydrophobic. In the thermodynamical study we examine the critical behaviour of the chain by following the evolution of the chain geometry with temperature. This is done by studying the behaviour of the mean distance R chosen to describe the homopolymer structure. Moreover, we give the behaviour of thermodynamic quantities such as conformational energy and specific heat. The effect of a force applied, in a fixed direction, on the chain when it is growing is also investigated. Finally, in a kinetic study, we analyse the evolution with temperature of the mean time necessarily for a given conformation to reach its native state

“Authentic Islam” : the religious profile of Taqī al-Dīn al-Hilālī (1893-1987) as reflected in his fatwas

This study is an examination of the religious profile of Taqī al-Dīn Al-Hilālī (1894-1987) as it evolved throughout the various periods of his life. The study commences with an introduction, beginning with a discussion of the Origins of the Salafiyya in Morocco. The first chapter offers a brief sketch of the formative period of Al-Hilālī’s life. In the second chapter, Al-Hilālī’s attitudes are examined in the light of his early missionary work in Egypt and elsewhere. Chapter Three deals with the first steps in Al-Hilālī’s international preaching. Chapter Four discusses Al-Hilālī's activities during the time he spent in Germany. Chapter Five begins with a discussion of the reason for Al-Hilālī’s departure from Germany in 1942 and his vicissitudes thereafter in Spanish Morocco. Chapter Six discusses Al-Hilālī time in Iraq, where he had settled from 1947 to 1959. Chapter Seven shows how Al-Hilālī was able to lead an active intellectual and religious life in Morocco after Independence. In Chapter Eight, the extent to which Al-Hilālī’s religious profile was affected by his time in Saudi Arabia is examined and assessed. Chapter Nine offers a brief sketch of the final phase in Al-Hilālī’s life and his religious profile based on the unpublished fatwasReligious Studie

Computational Analysis of Subcooled Flow Boiling in a Vertical Minichannel with Two Different Shapes under Various Mass Fluxes

In the current research project, two-dimensional numerical simulations are conducted to analyze the effects of geometrical configuration on flow structures and the thermal performances of subcooled flow boiling. The CFD simulations are carried out in two different configurations (straight and periodic constriction expansion) in a minichannel mounted vertically at four mass fluxes (500 kg/m2s; 836.64 kg/m2s; 1170 kg/m2s; and 2535 kg/m2s). The present predicted results exhibit excellent accordance with the previous experiments, with mean errors of 6.39% and 9.78%, demonstrating the efficiency of the present numerical study. The simulation results show that the periodic constriction expansion design provides good mixing between the layers, leading to a 43.11% mean enhancement of the thermal transfer, which is more important than the slight pressure drop penalty of 4.32 for a mass flux of 500 kg/m2s due to the combined pressure drop along the minichannel that resulted from the periodic constriction and expansion regions. Furthermore, the visualization of flow patterns shows that the bubbly flow is the dominant flow regime in the periodic constriction-expansion configuration

Mean field theory and Monte Carlo simulation of Phase transitions and Magnetic Properties of a tridimensional Fe7S8 Compound

The structural, electronic and magnetic properties of Fe7S8 material have been studied within the framework of the ab-initio calculations, the mean field approximation (MFA) and Monte Carlo simulation (MCS). Our study shows that two forms of the iron atoms, Fe2+ with spin S=2, and Fe3+ with spin {\sigma}=5/2 are the most probable configurations. A mixed Ising model with ferromagnetic spin coupling between Fe2+ and Fe3+ ions and between Fe3+ and Fe3+ ions, and with antiferromagnetic spin coupling between Fe2+ ions of adjacent layers has been used to study the magnetic properties of this compound. We demonstrated that the magnetic phase transition can be either of the first or of the second order, depending on the value of the exchange interaction and crystal field. The presence of vacancies in every second iron layer leads to incomplete cancellation of magnetic moments, hence to the emergence of the ferrimagnetism. Anomalies in the magnetization behavior have been found and compared with the experimental results.Comment: 18 pages, 14 Figures, 4 Table

Modélisation multicritère pour la valorisation de la réserve foncière

The country land reserve is not unlimited, its use is generally permanent and long-lasting. The valuation of the resource currently is a strategic issue of local and national governance, as it remains a priority that meets the economic and social issues and environmental challenges. The proposed decision mapping is part of a reflection process which aims to improve the land use understanding mechanism. Its aim is the presentation of a process, based on a combined use of geographic information systems (GIS) and the hierarchical multi-criteria analysis (AHP) which has demonstrated its relevance to understand complex spatial problems. The new approach is an information reference to the construction of multi-criteria decision maps. It operates as a territorial GIS business intelligence tool for data production, management and the crossing of land data with a base of predefined indicators. Also, it implements the AHP method to selected criteria (georeferenced, quantitative and qualitative) to model the phenomenon in a participatory manner, determine the weight of importance relating to the evaluation criteria and aggregate different evaluation indexes. Key words: modeling, mapping, land assets, decision, multi-criteria, AHP, GISpérenne dans le temps. La valorisation de cette ressource constitue actuellement une question stratégique de gouvernance locale et nationale, de même, elle demeure une priorité qui permet de répondre aux enjeux économiques et sociaux et aux défis environnementaux. La modélisation décisionnelle proposée s'inscrit dans une démarche de réflexion qui vise à améliorer la compréhension du mécanisme d’utilisation du patrimoine foncier. Il a pour objectif la présentation d’un processus, basé sur une utilisation combinée des systèmes d'information géographiques (SIG) et de l’analyse hiérarchique multicritères (AMC) qui a démontré sa pertinence pour appréhender les problèmes spatiaux complexes. La nouvelle approche constitue une référence d’informations à la construction multicritère des cartes décisionnelle. Elle exploite les SIG comme outil de veille stratégique territoriale permettant la production des données, la gestion et le croisement des données foncières avec une base d’indicateurs spatialisables prédéfinis. Aussi, elle met en œuvre la méthode AHP aux critères choisis (géoréférencés, quantitatifs et qualitatifs) pour modéliser de façon participative le phénomène, déterminer les poids d'importance relatifs aux critères d’appréciation et agréger les différents indices d’évaluation. Mots clés: modélisation, cartographie, foncier, décision, multicritère, AHP, SI

Elaboration and characterization by XRD and SEM of the glass-ceramics in BaTiO3 – NaPO3 system

There is a strong need for low cost glass-ceramic materials whose high chemical stability and dielectric properties can be engineered flexibly in bulk and fiber forms. Therefore we have manufactured transparent ferroelectric glass-ceramics consisting of barium titanate (BT) crystallites in a chain metaphosphate glass matrix. Several glass compositions, in the series (1-x) NaPO3 – x BaTiO3 have been prepared by a conventional melt quenching method. The compositions have been selected on the basis of chemical stability. X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate the formation of small particle size of BaTiO3 in the glass network when its amount is above 4 mol%.There is a strong need for low cost glass-ceramic materials whose high chemical stability and dielectric properties can be engineered flexibly in bulk and fiber forms. Therefore we have manufactured transparent ferroelectric glass-ceramics consisting of barium titanate (BT) crystallites in a chain metaphosphate glass matrix. Several glass compositions, in the series (1-x) NaPO3 – x BaTiO3 have been prepared by a conventional melt quenching method. The compositions have been selected on the basis of chemical stability. X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate the formation of small particle size of BaTiO3 in the glass network when its amount is above 4 mol%

Invagination intestinale aiguë consécutive à un lipome grèlique: à propos d’un cas et revue de la littérature

L’invagination intestinale aiguë est une pathologie du nourrisson et du petit enfant. Sa survenue chez l’adulte est très inhabituelle. Elle estd’étiologie diverse. Dans l’immense majorité des cas, elle est secondaire à une tumeur qui peut être bénigne ou maligne. L’invagination intestinalesur lipome est exceptionnelle. Nous rapportons un cas d’invagination intestinale grêlo-grêlique sur lipome.Key words: Invagination, grele, lipom

APPORT DE L’IMAGERIE DANS L’ABDOMEN AIGU NON FEBRILE

The non febrile abdominal pains are very frequent and their causes are multiple. The imaging is important in the diagnosis, the complete physical examination, the follow-up and the treatment of the abdominopelvic lesions. The abdominal negatives without preparation are still used for the search of intestinal occlusion, acute intestinal ischemia. The echography is indicated particularly in the abdominal traumatisms, pelvic pain in the woman and for the search of lithiasis in the case of biliary ileus. The echo-doppler is indicated mainly in the vascular pathology. The computerized tomography is still the preferable examination in the diagnosis of the non febrile acute abdomens. The angiography is necessary if there is suspicion of mesenteric ischemia, digestive hemorrhage and particularly in an interventional gesture.Les douleurs abdominales aiguës non fébriles sont très fréquentes et relèvent de causes multiples. L’imagerie prend une place importante dans le diagnostic, le bilan, le suivi et le traitement des lésions abdomino-pelviennes. Les clichés d’abdomen sans préparation gardent leur indication à la recherche d’une occlusion intestinale, d’une ischémie intestinale aiguë. L’échographie est indiquée surtout dans les traumatismes abdominaux, douleurs pelviennes chez la femme et  à la recherche de lithiase en cas d’iléus biliaire. L’écho-doppler est indiquée principalement dans la pathologie vasculaire. La TDM reste l’examen de choix dans le diagnostic des abdomens aigus non fébriles. L’angiographie est justifiée en cas de suspicion d’une ischémie mésentérique, d’une hémorragie digestive et surtout dans un geste interventionnel