On the Hilbert 22-class field tower of some abelian 22-extensions over the field of rational numbers

summary:It is well known by results of Golod and Shafarevich that the Hilbert $2$-class field tower of any real quadratic number field, in which the discriminant is not a sum of two squares and divisible by eight primes, is infinite. The aim of this article is to extend this result to any real abelian $2$-extension over the field of rational numbers. So using genus theory, units of biquadratic number fields and norm residue symbol, we prove that for every real abelian $2$-extension over $\mathbb Q$ in which eight primes ramify and one of theses primes $\equiv -1\pmod 4$, the Hilbert $2$-class field tower is infinite

Коммуникативные стратегии в современной массовой литературе

Рассматривается массовая литература как один из компонентов современной коммуникации. На примере романов А. А. Бушкова показано, какие коммуникативные стратегии используются писателем с целью активизации читательского интереса

Phase diagram of the mixed spin Ising model with four-spin interaction and nextnearest neighbor couplings

The phase diagrams of the ferromagnetic two-dimensional mixed spin-1 and spin-1/2 Ising model with four-spin interaction J4 and next-nearest couplings J’ are investigated by the use of the finite cluster approximation based on single-site cluster theory. The state equations are derived for the two-dimensional square lattice. The phase diagram is qualitatively and quantitatively different from that obtained when the interaction J’ is ignored. In fact, the system exhibits a variety of interesting features resulting from the introduction of the next-nearest neighbor interaction (NNN). It undergoes two kinds of behavior according to the negative and the positive value of J’. In particular, for J4/J2=-4, the system keeps the coexistence of the two ground state up to J’-dependent finite temperature

Evaluation and Improvement of Nuclear Security Measures at a Radiological Facility in Morocco

Nuclear security combines both concepts of physical security and security culture within a nuclear facility to protect people, property, society and the environment from harmful effects of ionization radiation. Physical security means prevention, detection, and response to unauthorized removal, sabotage, and/or illegal transfer involving radioactive sources and nuclear material. Nuclear security culture is the human factor within the nuclear field which is considered a principal means to support and enhance nuclear security system. This paper presents a study of nuclear security system already established within a radiological facility considering concepts such as: deter, detect, delay, and response layers. This study focuses on nuclear security culture in order to assess, improve, and complement existing nuclear security practices

On the role of selective nucleation and growth to recrystallization texture development in a Mg-Gd-Zn alloy

One of the main material properties altered by rare earth additions in magnesium alloys is texture, which can be specifically adjusted to enhance ductility and formability. The current study aims at illuminating the texture selection process in a Mg-0.073at%Gd-0.165at%Zn alloy by investigating recrystallization nucleation and early nucleus growth during static recrystallization. An as-cast sample of the investigated alloy was deformed in uniaxial compression at 200{\deg}C till 40% strain and was then cut into two halves for subsequent microstructure characterization via ex-situ and quasi in-situ EBSD investigations. In order to gain insights into the evolution of texture during recrystallization, the contributions from dynamic and static recrystallization were initially separated and the origin of the non-basal orientation of recrystallization nuclei was traced back to several potential nucleation sites within the deformed matrix. Considering the significant role of double-twin band recrystallization in determining the recrystallization texture, this type of recrystallization nucleation was further investigated via quasi-in-situ EBSD on a deformed sample, annealed at 400{\deg} for different annealing times. With progressive annealing a noticeable trend was observed, in which the basal nuclei gradually diminished and eventually vanished from the annealed microstructure. In contrast, the off-basal nuclei exhibited continuous growth, ultimately becoming the dominant contributors to the recrystallization texture. The study therefore emphasizes the importance of particular nucleation sites that generate favorably oriented off-basal nuclei, which over the course of recrystallization outcompete the neighboring basal-oriented nuclei in terms of growth, and thereby dominate the recrystallization texture

Essai de traction sur un toron avec 3 fils artificiellement endommagés et prédiction de sa durée de vie

Les câbles métalliques de levage sont exposés à divers processus de dégradation une fois déployé au service. Par conséquent, ils doivent répondre aux critères de sécurité les plus strictes au cours de leur utilisation En effet, les moindres défaillances entraînent des dégâts matériels et immatériel. C'est la raison pour laquelle une surveillance préventive, un entretien régulier et une évaluation de la fiabilité s'avèrent d'une haute importance pour assurer une durée de vie maximale. Tout au long de la vie utile d'un câble métallique, les fils et les torons qui composent ce câble sont soumis à des sollicitations mécaniques élevées indiquant une perte de la force originale, ce qui mène à des dégradations parfois très rapides conduisant à la rupture brutale. L'objectif principal de cette étude consiste à prédire l'évolution du dommage d'un toron constituant un câble métallique , en se basant sur un essai expérimental de traction d'un toron contenant 4 fils endommagés artificiellement et par la suite déterminer les différents stades d'endommagement qui permettent de prévoir l'instant du dommage critique et donc d'intervenir à temps pour une maintenance prédictive du système

Une méthode de tri multicritère multi-périodes pour la sélection de projet en contexte d'incertitude

RÉSUMÉ: Dans les dernières années, le gouvernement du Québec a souligné l'importance de la prise de décision dans un contexte de développement durable et de lutte contre les changements climatiques. L'évaluation des projets dans ce contexte devrait prendre en considération l'équilibre entre les critères économiques, sociaux et environnementaux à court, moyen et long terme. De plus, ces évaluations peuvent être imprécises et tâchées d'incertitude. Les problèmes de décision dans ce contexte sont complexes et caractérisés par les trois aspects suivants, à savoir l'aspect multicritère, l'aspect temporel et l'incertitude. Or, la plupart des méthodes multicritères sont statiques et seules quelques rares méthodes traitent l'aspect temporel des évaluations. En effet, des recherches récentes ont développé des méthodes multicritères multi-périodes de rangement mais au meilleur de notre connaissance, aucune méthode de tri multicritère multi-périodes ne fut développée à date. L'objectif de ce mémoire est de proposer une méthode de tri multicritère multi-périodes dans un contexte d'incertitude pour l'évaluation de la durabilité des projets. La méthode proposée est constituée de deux phases d'agrégation multicritère et d'agrégation multi-périodes. La première phase consiste à conduire les simulations Monte Carlo et à appliquer la méthode SMAA-Tri pour affecter à chaque période le projet à une des catégories prédéfinies. Ensuite, la phase d'agrégation multi-périodes propose d'agréger les résultats obtenus dans chaque période pour arriver à une affectation à la fois multicritère et multi-périodes. La méthode proposée a été appliquée dans le contexte d'aménagement forestier durable. Un projet d'aménagement spécifique qui consiste à implanter un plan de protection spécifique pour l'habitat du caribou a été trié selon un ensemble de critères évalués sur l'horizon de régénération de la forêt de 150 ans. L'incertitude a été simulée par 10000 simulations Monte Carlo à chacune des 30 périodes. Les résultats de cette application démontrent que la méthode proposée permet de généraliser la méthode SMAA Tri au contexte multi-périodes et aboutit à des résultats intéressants. -- Mot(s) clé(s) en français : Sélection de projet, Méthodes de tri multicritère, évaluations multi-périodes, Monte Carlo, incertitude, développement durable. -- ABSTRACT: In the last years, the government of Quebec emphasized sustainable and robust decision making in the context of climate change. Projects evaluation in this context must take into consideration the balance between economic, social and environmental criteria, over the short, medium and long term. Furthermore, decision criteria may be imprecise or uncertain. Decision-making problems in this context are complex and characterized by multi-criteria, temporal and uncertainty aspects. Yet, the majority of the multi-criteria methods are static and only few methods deal with temporal evaluations. In fact, recent studies proposed multi-criteria multi-period ranking methods but to the best of our knowledge, there is no multi-criteria multi-period sorting method proposed yet. The general objective of this research is to propose a multi-criteria multi-period sorting method in the context of uncertainty to be used for sustainability evaluations of projects. The proposed method is composed of two phases, the multi-criteria aggregation phase, and the multi-period aggregation phase. The aggregation phase consists of conducting the Monte-Carlo Simulations and applying the SMAA-TRI method at each period in order to sort the project in one of the predefined categories. Then, the multi-period aggregation proposes to aggregate the results obtained at each period in order to get a global sorting result. The proposed method is applied in the context of sustainable forest management. A particular project of forest management, that aims to implement a specific protection plan for the caribou habitat, is sorted according to a set of criteria evaluated over the regeneration forest horizon of 150 years. Uncertainty has been simulated with 10 000 Monte-Carlo simulations over 30 periods. The results of this application show that the proposed method generalizes the SMAA-TRI method to the multi-period context and provides interesting results. -- Mot(s) clé(s) en anglais : Project selection, multi-criteria sorting methods, multi-period evaluations, Monte Carlo, uncertainty, sustainable development

Application of Mutagenic Radiation and Research the Optimal doses of Induction of bud break and Vegetative Growth in the Grapevine (Vitis vinifera (L.)

The demand of grape in Morocco is fulfilled through import from foreign countries. The fruits of local cultivars of grapes offer a low yield. Development of seedless grape varieties having increased sweetness, higher yield with better nutritional quality is necessary to reduce the import dependency. The present research activities are the part of a grape improvement project. A pot experiment was conducted at the National Institute of Agronomic Research (INRA), Center Tangier (Morocco), during February to November 2017 to determine the suitable gamma irradiation doses on growth, leaf area and content of chlorophyll of grape seedling. One hundred vegetative bud cutting and three doses of gamma irradiation 20, 30, and 40 Gy were used as treatment. Different irradiation doses and vegetative cutting showed significant variations in respect of plant growth characters, leaf area and Chlorophyll Content. Higher doses of gamma irradiation had showed detrimental effect on grape saplings. Generally, increased in irradiation doses showed decreased and detrimental effects on most of the parameters under study. Maximum numbers of growing bud, leaf area and content of chlorophyll were found at 20 Gy irradiation dose. All parameters showed best results in 20 Gy with bud cutting initiation

Numerical Study of Internal Radius Effect on Mechanical Behavior of P265GH Material

In metallic structures, cracks are mostly initiated at geometric discontinuities of notches or defects. The geometric parameters and discontinuities govern cracks initiation or propagation and therefore affect the resistance of structures during their use. In industry, for economic or security reasons it is seek to know the degree of defects harmfulness and residual life time of structures; This requires the development of models based on fracture mechanics.The objective of this paper is to establish a numerical finite element modeling for a bent specimen using CASTEM2013 computer code. The studied material is P265GH steel commonly used in sheet form in boilers and pressure vessels.The results show that the propagation velocity of crack and stress concentration coefficient increases by increasing the length of the crack and the diameter of the structure

Evaluation of potential drug-drug interactions and adverse drug reactions among chronic kidney disease patients: An experience from United Arab Emirates

Purpose: To determine the prevalence and assessing nature of potential drug-drug interactions (pDDIs) and adverse drug reactions (ADRs) among chronic kidney disease (CKD) patients.Methods: This was a prospective observational study involving adult CKD patients. Occurrence of pDDIs was evaluated using Micromedex database 2.0. Suspected ADRs during the study period were documented and assessed.Results: Overall prevalence of pDDIs was found to be 85.3 %. A total of 811 pDDIs with 225 different pairs of interacting drugs were identified. Majority of the patients had ≥ 3 pDDIs regardless of type of severity. Thirty-five ADRs were identified in 25 CKD patients. Hyperkalemia was the most-commonly suspected ADR. Logistic regression analysis revealed that age (OR: 1.04, 95 % CI: 1.01 - 107), length of hospital stay (OR: 1.15, 95 % CI: 1.0 - 1.32), presence of comorbidity like diabetes (OR: 9.1, 95 % CI: 3.2 - 25.3) and number of drugs prescribed (OR: 6.88, 95 % CI: 1.5 - 30.0) were positively correlated with occurrence of pDDIs. Length of hospital stay (OR: 1.05, 95 % CI: 0.99 - 1.06) and number of drugs (OR: 0.16, 95 % CI 0.03 - 0.84) were identified as independent predictors of occurrence of ADRs.Conclusion: Prevalence of pDDIs was high in the study population. A majority of the pDDIs were of major severity type, fair documentation grade, and of unspecified onset. A majority of suspected ADRs were probably of moderate in severity and not preventable type