Caractérisation de mousses de polyuréthanes au cours du procédé de fabrication

Les mousses flexibles polyuréthanes sont très utilisées dans l’industrie. Afin d’éviter l’apparition de défauts, les conditions de mise en œuvre doivent être mieux contrôlées. La qualité de ces mousses thermodurcissables dépend principalement des cinétiques de deux réactions chimiques concomitantes: la première crée du CO2 dissout dans la matrice fluide et la seconde conduit à la polymérisation de la mousse. Le moussage est modélisé comme l’expansion d’un fluide rhéofluidifiant compressible dans lequel une phase gazeuse est mélangée. Son comportement thermomécanique dépend du taux de gaz et des propriétés rhéologiques de la matrice polymère, qui sont corrélés aux degrés d’avancement des deux réactions chimiques. Une méthode éléments finis mixtes avec une approche multidomaine est utilisée pour simuler l’expansion de la mousse dans un moule cylindrique. Une approche expérimentale (RhéoFoam) est proposée afin d’identifier les paramètres du modèle

Ba(H2PO3)2.0.5H2O: Synthesis, crystal structure optimization, vibrational study, DFT computation and application as a corrosion inhibitor

This investigation involved the synthesis of barium phosphite Ba(H2PO3)2.0.5H2O by reacting barium chloride with phosphorous acid. The physical characteristics, FT-IR spectra, and X-ray diffraction were employed to validate the composition of the synthesized substance, and powder X-ray diffraction (PXRD) was used to determine the phase purity. The optimal molecular geometry, infrared intensities were calculated using density functional theory (DFT/B3LYP) methods with the LanL2DZ basis set. The HOMO-LUMO properties and geometries of this compound have been determined and discussed. The computational structural parameters are generally in agreement with the experimental investigations. The theoretical infrared for the title compound has been constructed. Additionally, the anti-corrosion properties of this compound were investigated in an acidic solution using weight loss and electrochemical techniques. The results showed good effectiveness, indicating the formation of a protective film on the C38 surface

Removal of methylene blue with a highly effective hydroxyapatite-silica nanocomposite

Two Hydroxyapatite-silica nanocomposite adsorbent (HApS220 and HApS230) were successfully synthesized using sol-gel technique. The samples were characterized by powder X-ray diffraction (XRD), Infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), which confirmed the formation of a Hydroxyapatite-silica nanocomposite. The synthesized powders were then used for adsorption of methylene blue (MB). Both compounds possessed high absorption capacities, the adsorption equilibrium time is around 10 min. HApS230 sample shows higher adsorption capacity compared to HApS220. Furthermore, isotherm studies show that the adsorption used is an ion exchange process and that Temkin isotherm describes the adsorption better compared to the Langmuir and Freundlich and Dubinin-Radushkevich isotherms. Kinetics studies confirm that the adsorption follow the pseudo-second order model and chemisorption mechanism. Thermodynamics’ studies confirm that the adsorption of MB on HApS samples is a spontaneous endothermic process. The average removal effectiveness of MB reached about 89.02% (6.389 mg/g adsorption capacity) and 91.36% (6.55 mg/g adsorption capacity) for HApS220 and HApS230 respectivel

Generating multimedia presentations: from plain text to screenplay

In many Natural Language Generation (NLG) applications, the output is limited to plain text – i.e., a string of words with punctuation and paragraph breaks, but no indications for layout, or pictures, or dialogue. In several projects, we have begun to explore NLG applications in which these extra media are brought into play. This paper gives an informal account of what we have learned. For coherence, we focus on the domain of patient information leaflets, and follow an example in which the same content is expressed first in plain text, then in formatted text, then in text with pictures, and finally in a dialogue script that can be performed by two animated agents. We show how the same meaning can be mapped to realisation patterns in different media, and how the expanded options for expressing meaning are related to the perceived style and tone of the presentation. Throughout, we stress that the extra media are not simple added to plain text, but integrated with it: thus the use of formatting, or pictures, or dialogue, may require radical rewording of the text itself

Traitement peu invasif d’une breche osteo meningee associee a une hypertension intracranienne benigne

Description L’hypertension intracrânienne bénigne (HTICB) est une augmentation anormale de la pression intracrânienne non associée à un processus occupant de l’espace intracrânien, une thrombose des veinescérébrales ou une hydrocéphalie. Caractérisée par des céphalées invalidantes, des acouphènes pulsatiles, elle peut avoir une évolution péjorative et irréversible entraînant une cécité. La survenue d’une rhinorrhée spontanée dans un contexte d’HTICB a été décrite dans la littérature mais demeure peu fréquente. Objectif et cas cliniqueNous rapportons le cas d’une femme obèse âgée de 40 ans, qui a été admise pour rhinorrhée droite spontanée. Les explorations neuroradiologiques ont permis d’évoquer une hypertension intracrânienne bénigne sur une brèche ethmoïdale antérieure. Le monitoring de la pression a confirmé le diagnostic. Elle abénéficié d’une dérivation ventriculo péritonéale. L’évolution est favorable (disparition des symptômes) avec un delai de recul de 16 mois . Conclusion L’HTICB est une pathologie avec des conséquences irréversibles si le traitement n’est pas adéquat et rapide. En cas de rhinorrhée isolée dans le cadre de l’hypertension intracrânienne bénigne la dérivation ventriculo péritonéale est une attitude thérapeutique simple mais efficace

A model for verbalising relations with roles in multiple languages

Natural language renderings of ontologies facilitate communication with domain experts. While for ontologies with terms in English this is fairly straightforward, it is problematic for grammatically richer languages due to conjugation of verbs, an article that may be dependent on the preposition, or a preposition that modifies the noun. There is no systematic way to deal with such `complex' names of OWL object properties, or their verbalisation with existing language models for annotating ontologies. The modifications occur only when the object performs some {\em role} in a relation, so we propose a conceptual model that can handle this. This requires reconciling the standard view with relational expressions to a positionalist view, which is included in the model and in the formalisation of the mapping between the two. This eases verbalisation and it allows for a more precise representation of the knowledge, yet is still compatible with existing technologies. We have implemented it as a Prot\'eg\'e plugin and validated its adequacy with several languages that need it, such as German and isiZulu

A classification of grammar-infused templates for ontology and model verbalisation

Involving domain-experts in the development, maintenance, and use of knowledge organisation systems can be made easier through the introduction of easy-to-use interfaces that are based on natural language. Well resourced languages make use of natural language generation techniques to provide such interfaces. In particular, they often make use of templates combined with computational grammar rules to generate grammatically complex text. However, there is no model of pairing templates and computational grammar rules to ensure suitability for less-resourced languages. These languages require a modular design that ensures grammar detachability so as to allow grammar re-use across domains and applications. In this paper, we present a model and classification scheme for grammar-infused templates suited for less-resourced languages and classify existing systems that make use of them. We have found that of the 15 systems that pair templates and grammar rules, and their 11 distinct template types, 13 have support for detachable grammars

Investigating International Time Trends in the Incidence and Prevalence of Atopic Eczema 1990-2010: A Systematic Review of Epidemiological Studies

The prevalence of atopic eczema has been found to have increased greatly in some parts of the world. Building on a systematic review of global disease trends in asthma, our objective was to study trends in incidence and prevalence of atopic eczema. Disease trends are important for health service planning and for generating hypotheses regarding the aetiology of chronic disorders. We conducted a systematic search for high quality reports of cohort, repeated cross-sectional and routine healthcare database-based studies in seven electronic databases. Studies were required to report on at least two measures of the incidence and/or prevalence of atopic eczema between 1990 and 2010 and needed to use comparable methods at all assessment points. We retrieved 2,464 citations, from which we included 69 reports. Assessing global trends was complicated by the use of a range of outcome measures across studies and possible changes in diagnostic criteria over time. Notwithstanding these difficulties, there was evidence suggesting that the prevalence of atopic eczema was increasing in Africa, eastern Asia, western Europe and parts of northern Europe (i.e. the UK). No clear trends were identified in other regions. There was inadequate study coverage worldwide, particularly for repeated measures of atopic eczema incidence. Further epidemiological work is needed to investigate trends in what is now one of the most common long-term disorders globally. A range of relevant measures of incidence and prevalence, careful use of definitions and description of diagnostic criteria, improved study design, more comprehensive reporting and appropriate interpretation of these data are all essential to ensure that this important field of epidemiological enquiry progresses in a scientifically robust manner