496 research outputs found

    Kinetic Modeling of Photodegradation of Water-Soluble Polymers in Batch Photochemical Reactor

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    Synthetic water-soluble polymers, well-known refractory pollutants, are abundant in wastewater effluents since they are extensively used in industry in a wide range of applications. These polymers can be effectively degraded by advanced oxidation processes (AOPs). This entry thoroughly covers the development of the photochemical kinetic model of the polyvinyl alcohol (PVA) degradation in UV/H2O2 advanced oxidation batch process that describes the disintegration of the polymer chains in which the statistical moment approach is considered. The reaction mechanism used to describe the photo-degradation of polymers comprises photolysis, polymer chain scission, and mineralization reactions. The impact of operating conditions on the process performance is evaluated. Characterization of the polymer average molecular weights, total organic carbon, and hydrogen peroxide concentrations as essential factors in developing a reliable photochemical model of the UV/H2O2 process is discussed. The statistical moment approach is applied to model the molar population balance of live and dead polymer chains taking into account the probabilistic chain scissions of the polymer. The photochemical kinetic model provides a comprehensive understanding of the impact of the design and operational variables

    La cartographie des sonorités environnementales d'un territoire

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    Sur un territoire, des sources sonores émettent des sons qui peuvent être d’origines anthropophoniques (i.e. le bruit des véhicules), biophoniques (i.e. les sons émis par les oiseaux), ainsi que géophoniques (i.e. le bruit du vent). Ceci permet de décrire un paysage sonore des lieux tout en alimentant des besoins particuliers propres à la cartographie de l’environnement sonore tels que les propriétés acoustiques des territoires, nécessaires à la compréhension de l’environne me nt sonore. Au-delà des travaux de recherches qui étudient et analysent les propriétés acoustiques de l’environnement, l’état de l’existant se concentre sur deux types de cartes sonores : les cartes d’inventaire de sons et les cartes de bruit. Deux approches méthodologiques sont à l’origine de la production de ces cartes. La première est basée sur des enregistrements sonores mesurés et géoréférencées sur le territoire à l’aide de sonomètres, ou d’applications installées sur des tablettes/téléphones intelligents. La deuxième sert à modéliser la propagation de l’onde acoustique en lien avec les objets présents sur le territoire (i.e. bâtiments, arbres, etc.). Bien que cette deuxième approche considère les différents facteurs environnementaux qui peuvent affaiblir l’onde acoustique comme l’absorption atmosphérique (causée par le vent, la température, etc.), la divergence géométrique et la nature de la couverture des sols, on constate qu’elle est peu documentée dans la littérature scientifique, lorsqu’aucun capteur sonore n’est utilisé pour produire des cartes sonores. L’objectif principal est de définir une méthode générique de modélisation de la propagation acoustique du son pour territoire à l’aide de données géospatiales multi-sources, dont des images à très haute résolution. Ainsi à l’aide des outils géomatiques, il est possible de représenter l’interaction qui existe entre l’onde sonore et les objets environnementaux composant ce territoire. Il est alors possible à partir d’une source sonore et des points récepteurs du son de réaliser des cartes dites spatio-phoniques. Mots clés : environnement sonore, modélisation, géomatique, propagation, données géospatiales, cartographieOn a territory, sound sources emit sounds that can be of anthropophonic origins (i.e. vehicle noise), biophonic origins (i.e. sounds emitted by birds), as well as geophonic origins (i.e. wind noise). This makes it possible to describe a soundscape of the places while feeding particular needs specific to the mapping of the sound environment such as the acoustic properties of the territories, necessary to the understanding of the sound environment. Beyond the research work that studies and analyzes the acoustic properties of the environment, the state of the existing focuses on two types of sound cards: sound inventory cards and noise maps. Two methodological approaches are behind the production of these cards. The first is based on sound recordings measured and georeferenced on the territory using sound level meters, or applications installed on tablets/smartphones. The second is used to model the propagation of the acoustic wave in relation to the objects present on the territory (i.e. buildings, trees, etc.). Although this second approach considers the different environmental factors that can weaken the acoustic wave like atmospheric absorption (caused by wind, temperature, etc.), the geometric divergence and the nature of the cover of soil, it is found that it is poorly documented in the scientific literature, when no sound sensor is used to produce sound cards. The main objective is to define a generic method for modeling the acoustic propagation of a territory using multi-source geospatial data including very high resolution images. Thus, using geomatic tools, it is possible to represent the interaction that exists between the sound wave and the environmenta l objects that make up this territory. It is then possible from a sound source and sound receiving points to make so-called spatio-phonic card

    Etude et résolution de problèmes d'ordonnancement de projets multi-compétences : intégration à un ERP libre

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    The work presented in this thesis deals with multi-skill project scheduling problems.We have studied two models of project scheduling which are defined in collaboration with project management experts in Néréide company.In the first model, a task is defined by a set of required skills, the load needed for each skill as well as the possibility of preemption. To build a predictive planning witch respects all problem constraints and minimize the project completion time (makespan), we propose heuristics and meta-heuristis methods. A mixed integer mathematical linear programming model and lower bounds are also proposed. From a predefined planning, we propose an exact method based on a mathematical program as well as a genetic algorithm of type NSGA-II allowing to deal with disruptions occurred during the project realization. It is, therefore, a reactive approach in which we look for feasible solutions minimizing both the project completion date and the maximum number of resources assignment changes.In the second studied model, we focus on a case where a task exactly requires one skill with preemption possibility only in case of resources unavailability. In this model, a task is also characterized by its release and due date. A cost per person/skill is given. It is,therefore, a bi-objective problem in which the computed solutions must minimize boththe maximum tardiness and the project global cost. Heuristics and meta-heuristics are proposed for solving this problem.Some proposed methods are integrated in the framework OFBiz as add-ons.Les travaux de cette thèse réalisée sous contrat CIFRE portent sur des problématiques d’ordonnancement de projets multi-compétences définis en collaboration avec des experts de gestion de projet au sein de la société Néréide, deux modèles d’ordonnancement de projet font l'objet de cette étude.Dans le premier modèle, une tâche est définie par l'ensemble des compétences dont elle a besoin, la charge nécessaire de chaque compétence ainsi que la possibilité d'être interrompue ou non. Pour l'élaboration d'un planning prédictif respectant toutes les contraintes et minimisant la date de n du pro jet, nous proposons des heuristiques de liste et métaheuristiques. Un modèle mathématique linéaire en nombres entiers ainsi que des bornes inférieures sont également développés. Dans un second temps, nous proposons, à partir d'un planning prédéfini, des méthodes pour ajuster le planning et répondre aux aléas survenus lors du déroulement du pro jet. Pour résoudre ce problème réatif, nous proposons une approche exacte itérative basée sur une formulation linéaire en nombres entiers ainsiqu'un algorithme génétique de type NSGA-II. Il s'agit donc d'une approche réactive bi-critère où les solutions calculées doivent minimiser à la fois la date d'achèvement du projet et le nombre maximum de changements d'aaffectation de tâches aux employés. Dans le deuxième modèle, un cas particulier du modèle préemptif précédent est étudié.Nous nous intéressons au cas où une tâche nécessite une seule compétence avec possibilité depréemption seulement si les ressources ne sont pas disponibles (absence, congés, et.). Dans ce modèle, une tâche est définie également par sa date de disponibilité et une date de nsouhaitée. Un coût d'utilisation personne/compétence est introduit. Pour ce dernier modèle,il s'agit d'un problème d'ordonnancement de projet bi-critère, pour lequel les solutions calculées doivent minimiser le retard maximum et le coût global d'affectation des personnes aux tâches. Des heuristiques et métaheuristiques sont proposées pour ce modèle.Certaines méthodes de résolution proposées ont été implémentées sous forme d'add-onsintégrables au framework OFBiz

    Evaluating the MSG satellite Multi-Sensor Precipitation Estimate for extreme rainfall monitoring over northern Tunisia

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    Knowledge and evaluation of extreme precipitation is important for water resources and flood risk management, soil and land degradation, and other environmental issues. Due to the high potential threat to local infrastructure, such as buildings, roads and power supplies, heavy precipitation can have an important social and economic impact on society. At present, satellite derived precipitation estimates are becoming more readily available. This paper aims to investigate the potential use of the Meteosat Second Generation (MSG) Multi-Sensor Precipitation Estimate (MPE) for extreme rainfall assessment in Tunisia. The MSGMPE data combine microwave rain rate estimations with SEVIRI thermal infrared channel data, using an EUMETSAT production chain in near real time mode. The MPE data can therefore be used in a now-casting mode, and are potentially useful for extreme weather early warning and monitoring. Daily precipitation observed across an in situ gauge network in the north of Tunisia were used during the period 2007–2009 for validation of the MPE extreme event data. As a first test of the MSGMPE product's performance, very light to moderate rainfall classes, occurring between January and October 2007, were evaluated. Extreme rainfall events were then selected, using a threshold criterion for large rainfall depth (>50 mm/day) occurring at least at one ground station. Spatial interpolation methods were applied to generate rainfall maps for the drier summer season (from May to October) and the wet winter season (from November to April). Interpolated gauge rainfall maps were then compared to MSGMPE data available from the EUMETSAT UMARF archive or from the GEONETCast direct dissemination system. The summation of the MPE data at 5 and/or 15 min time intervals over a 24 h period, provided a basis for comparison. The MSGMPE product was not very effective in the detection of very light and light rain events. Better results were obtained for the slightly more moderate and moderate rain event classes in terms of percentage of detected events, correlation coefficient, and ratio bias. The results for extreme events were mixed, with high pixel correlations of R=0.75 achieved for some events, while for other events the correlation between satellite and ground observation was rather weak. MPE data for northern Tunisia seem more reliable during the summer season and for larger event scales. The MSGMPE data have demonstrated to be very informative for early warning purposes, but need to be combined with other near real time data or information to give reliable and quantitative estimates of extreme rainfall

    Portable system for monitoring and controlling driver behavior and the use of a mobile phone while driving

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    There is an utmost requirement for technology to control a driver's phone while driving, which will prevent the driver from being distracted and thus saving the driver's and passenger;s lives. Information from recent studies has shown that 70% of the young and aware drivers are used to texting while driving. There are many different technologies used to control mobile phones while driving, including electronic device control, global positioning system (GPS), onboard diagnostics (OBD)-II-based devices, mobile phone applications or apps, etc. These devices acquire the vehicle information such as the car speed and use the information to control the driver's phone such as preventing them from making or receiving calls at specific speed limits. The information from the devices is interfaced via Bluetooth and can later be used to control mobile phone applications. The main aim of this paper is to propose the design of a portable system for monitoring the use of a mobile phone while driving and for controlling a driver's mobile phone, if necessary, when the vehicle reaches a specific speed limit (>10 km/h). A paperbased self-reported questionnaire survey was carried out among 600 teenage drivers from different nationalities to see the driving behavior of young drivers in Qatar. Finally, a mobile application was developed to monitor the mobile usage of a driver and an OBD-II module-based portable system was designed to acquire data from the vehicle to identify drivers' behavior with respect to phone usage, sudden lane changes, and abrupt breaking/sharp speeding. This information was used in a mobile application to control the driver's mobile usage as well as to report the driving behavior while driving. The application of such a system can significantly improve drivers' behavior all over the world.Author Contributions: Experiments were designed by A.K., M.C.; Experiments were performed by A.D.,M.M.; Results were analyzed by A.K.,M.C.,R.D.,N.E. and D.M.; All authors were involved in interpretation of data and paper writing. Funding: The publication of this article was funded by the Qatar National Library. Conflicts of Interest: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the resultsScopu

    Etude et résolution de problèmes d'ordonnancement de projets multi-compétences (Intégration à un progiciel intégré libre)

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    Les travaux de cette thèse réalisée sous contrat CIFRE portent sur des problématiques d ordonnancement de projets mufti-compétences. Définis en collaboration avec des experts de gestion de projet au sein de la société Néréide, deux modèles d ordonnancement de projet font l objet de cette étude. Dans le premier modèle, une tâche est définie par l ensemble des compétences dont elle a besoin, la charge nécessaire de chaque compétence ainsi que la possibilité d être interrompue ou non. Pour l élaboration d un planning prédictif respectant toutes les contraintes et minimisant la date de fin du projet, nous proposons des heuristiques de liste et métaheuristiques. Un modèle mathématique linéaire en nombres entiers ainsi que des bornes inférieures sont également développés. Dans un second temps, nous proposons, à partir d un planning prédéfini, des méthodes pour ajuster le planning et répondre aux aléas survenus lors du déroulement du projet. Pour résoudre ce problème réactif, nous proposons une approche exacte itérative basée sur une formulation linéaire en nombres entiers ainsi qu un algorithme génétique de type NSGA-II. Il s agit donc d une approche réactive bicritère où les solutions calculées doivent minimiser à la fois la date d achèvement du projet et le nombre maximum de changements d affectation de tâches aux employés. Dans le deuxième modèle, un cas particulier du modèle préemptif précédent est étudié. Nous nous intéressons au cas où une tâche nécessite une seule compétence avec possibilité de préemption seulement si les ressources ne sont pas disponibles (absence, congés, etc.). Dans ce modèle, une tâche est définie également par sa date de disponibilité et une date de fin souhaitée. Un coût d utilisation personne/compétence est introduit. Pour ce dernier modèle, il s agit d un problème d ordonnancement de projet bicritère, pour lequel les solutions calculées doivent minimiser le retard maximum et le coût global d affectation des personnes aux tâches. Des heuristiques et métaheuristiques sont proposées pour ce modèle. Certaines méthodes de résolution proposées ont été implémentées sous forme d add-ons intégrables au framework OFBiz.The work presented in this thesis deals with multi-skill project scheduling problems. We have studied two models of project scheduling which are defined in collaboration with project management experts in Néréide company. In the first model, a task is defined by a set of required skills, the load needed for each skill as welI as the possibility of preemption. To build a predictive planning which respects aIl problem constraints and minimize the project completion time (makespan), we propose heuristics and meta-heuristics methods. A mixed integer mathematical linear programming model and lower bounds are also proposed. From a predefined planning, we propose an exact method based on a mathematical program as weIl as a genetic algorithm of type NSGA-II allowing to deal with disruptions occurred during the project realization. It is, therefore, a reactive approach in which we look for feasible solutions minimizing both the project completion date and the maximum number of resources assignment changes. In the second studied model, we focus on a case where a task exactly requires one skill with preemption possibility only in case of resources unavailability. In this model, a task is also characterized by its release and due date. A cost per person/skill is given. It is, therefore, a bi-objective problem in which the computed solutions must minimize both the maximum tardiness and the project global cost. Heuristics and meta-heuristics are proposed for solving this problem. Some proposed methods are integrated in the framework OFBiz as add-ons.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

    Brain health: time matters in multiple sclerosis

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    publisher: Elsevier articletitle: Brain health: time matters in multiple sclerosis journaltitle: Multiple Sclerosis and Related Disorders articlelink: http://dx.doi.org/10.1016/j.msard.2016.07.003 content_type: article copyright: © 2016 Oxford PharmaGenesis Ltd. Published by Elsevier B.V

    Polyneuropathy Associated with IgA Paraproteinemia and Amyloidosis: A Case Report and Literature Review

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    Paraproteinemia potentially causes peripheral neuropathy via an unknown underlying pathogenetic mechanism. We report a case of pathologically proven amyloid neuropathy with AL amyloidosis with an IgA kappa light chain, which was initially diagnosed as neuropathy associated with monoclonal gammopathy of undetermined significance. This case indicates that in cases of neuropathy with paraproteinemia, the other potential causes should be excluded by appropriate means, especially pathological evaluations

    Blockchain Technology for Intelligent Transportation Systems: A Systematic Literature Review

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    The use of Blockchain technology has recently become widespread. It has emerged as an essential tool in various academic and industrial fields, such as healthcare, transportation, finance, cybersecurity, and supply chain management. It is regarded as a decentralized, trustworthy, secure, transparent, and immutable solution that innovates data sharing and management. This survey aims to provide a systematic review of Blockchain application to intelligent transportation systems in general and the Internet of Vehicles (IoV) in particular. The survey is divided into four main parts. First, the Blockchain technology including its opportunities, relative taxonomies, and applications is introduced; basic cryptography is also discussed. Next, the evolution of Blockchain is presented, starting from the primary phase of pre-Bitcoin (fundamentally characterized by classic cryptography systems), followed by the Blockchain 1.0 phase, (characterized by Bitcoin implementation and common consensus protocols), and finally, the Blockchain 2.0 phase (characterized by the implementation of smart contracts, Ethereum, and Hyperledger). We compared and identified the strengths and limitations of each of these implementations. Then, the state of the art of Blockchain-based IoV solutions (BIoV) is explored by referring to a large and trusted source database from the Scopus data bank. For a well-structured and clear discussion, the reviewed literature is classified according to the research direction and implemented IoV layer. Useful tables, statistics, and analysis are also presented. Finally, the open problems and future directions in BIoV research are summarized
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