Study of deterioration mechanisms and protective treatments for the Egyptian limestone of the Ayyubid city wall of Cairo

The al-Azhar project of the Aga Kahn Trust for Culture will create one of the largest urban parks in Cairo. This has brought attention to the eastern portion of the Ayyubid city wall which would border the western edge of the park. Partially buried during centuries, the stone wall presents different forms of deterioration, including flaking and disaggregation as well as large areas of salt crusts on the stone surface requiring a comprehensive conservation treatment. .

Dessalement de matériaux poreux modèles par la méthode des compresses

Poultices, wet adhesive pastes applied to porous materials to draw out salts, are used in the in situ conservation of built heritage. This study aims to better understand the mechanisms of water and ion transport during desalination to improve its efficiency. Sodium chloride crystallization in laboratory-made model porous samples (sintered glass beads) was carried out to master the artificial salting process. Poultices made of kaolin, cellulose, aggregates, and water were characterized to investigate the relationship between their formulation and their properties. Finally, desalination experiments were conducted. Nuclear magnetic resonance imaging was used throughout the studies to obtain the spatial distribution of water in the different elements non-destructively. Desalination efficiency is related to the system drying behavior which, in turn, depends partly on the material microstructure. Drying of the material before the poultice seems to lead to greater desalination efficiency.Les compresses, pâtes humides appliquées sur un matériau poreux pour éliminer les sels, sont utilisées pour conserver le patrimoine architectural. Les mécanismes de transport de l'eau et des ions lors du dessalement ont été étudiés pour améliorer son efficacité. La cristallisation de chlorure de sodium dans des échantillons poreux modèles (frittés de billes de verre) a été entreprise pour maîtriser le processus de salage artificiel. Des compresses de kaolin, cellulose, granulat et eau ont été caractérisées pour étudier la relation entre formulation et propriétés. Des expériences de dessalement ont finalement été menées. L'imagerie par résonance magnétique nucléaire a permis d'obtenir la distribution spatiale de l'eau dans les différents éléments de manière non destructive. L'efficacité du dessalement est liée au comportement au séchage des systèmes qui dépend en partie de la microstructure du matériau. Le séchage du matériau avant la compresse semble conduire à la meilleure efficacité

Fertilité et contraception : quel est le délai moyen d’attente entre l’arrêt de la contraception et la procréation ?

Objective: The main goal of the study was to determine the effect of contraception type, duration of contraception use, lifestyle (age, smoking, parity, BMI, coital frequency, cycle control) on time to conception.Material and Methods: Retrospective study was performed from 14/07 to 15/03 on 220 couples consulting in Ile de France. Anonymous answers to questionnaire inquiring about personal and medical histories, contraception use, age and lifestyle characteristics of either partner. All data were analysed with Excel and R softwares: T test for continue data and Fisher test for binary data.Results and conclusions: The time to conception (TTC) in this population was 8 ± 0.7 months. The various parameters were involved in TTC: duration of contraception use for more than 5 years induced TTC increase by 4.4 months, women older than 35 years old had a TTC extended to 3 months and cycle control raised by 4 months the TTC. Even if the contraception types didn’t show significantly effect, TTC was higher when women used progestatif and oestro-progestatif pills. Other factors like father’s age, couple’s BMI, smoking, parity and coital frequency had not impact on TTC.Objectifs : L'objectif principal de l'étude était de faire un état des lieux du Délai Nécessaire à Concevoir (DNC) et de voir l'impact du type de contraceptifs, de la durée de prise du contraceptif, des caractères individuels du couple (âge, IMC, tabac, parité, la surveillance des cycles). Matériel et méthodes : Étude rétrospective de juillet 2014 à mars 2015 auprès de 219 couples consultant dans la région d’Ile de France. Réponse anonyme à un questionnaire comportant : antécédents personnels de la mère et du père, moyen de contraception, antécédents médicaux et obstétricaux de la mère, fréquence des rapports sexuels. L’ensemble des données a été analysé à l’aide d’Excel et du logiciel R : test de Student pour les variables continues et test de Fisher pour les variables binaires. Résultats : Le DNC de la population de cette étude était de 8 ± 0.7 mois. Les différents paramètres modulant le DNC sont : une durée de contraception supérieure à 5 ans majore de 4.4 mois le DNC, l’âge maternel, à partir de 35 ans le DNC s’allonge d’environ 3 mois et, la surveillance des cycles conduit à une augmentation significative de 4 mois du DNC. Même si l’analyse des types de contraceptifs n’a pas montré d’impact significatif, on remarque que le DNC est plus élevé en cas de pilule progestatif et oestro-progestatif. Les autres facteurs comme l’âge du père, l’IMC du couple, la consommation de tabac, la parité et la fréquence des rapports sexuels n’ont pas montré d’impact sur le DNC

The disturbing 'rise' of global income inequality

We use aggregate GDP data and within-country income shares for the period 1970-1998 to assign a level of income to each person in the world. We then estimate the gaussian kernel density function for the worldwide distribution of income. We compute world poverty rates by integrating the density function below the poverty lines. The $1/day poverty rate has fallen from 20The$2/day rate has fallen from 44% to 18%. There are between 300 and 500 million less poor people in 1998 than there were in the 70s. We estimate global income inequality using seven different popular indexes: the Gini coefficient, the variance of log-income, two of Atkinson s indexes, the Mean Logarithmic Deviation, the Theil index and the coefficient of variation. All indexes show a reduction in global income inequality between 1980 and 1998. We also find that most global disparities can be accounted for by across-country, not within-country, inequalities. Within-country disparities have increased slightly during the sample period, but not nearly enough to offset the substantial reduction in across-country disparities. The across-country reductions in inequality are driven mainly, but not fully, by the large growth rate of the incomes of the 1.2 billion Chinese citizens. Unless Africa starts growing in the near future, we project that income inequalities will start rising again. If Africa does not start growing, then China, India, the OECD and the rest of middle-income and rich countries diverge away from it, and global inequality will rise. Thus, the aggregate GDP growth of the African continent should be the priority of anyone concerned with increasing global income inequality

Aesthetic compatibility assessment of consolidants for wall paintings by means of multivariate analysis of colorimetric data

Abstract Background and methods Wall paintings and architectural surfaces in outdoor environments are exposed to several physical, chemical and biological agents, hence they are often treated with different products to prevent or slow down their deterioration. Among the factors that have to be taken into account in the selection of the most suitable treatment for decorated surfaces, the aesthetic compatibility with the substrate is of great importance in the cultural heritage field; minimizing colour variation after treatment application is a crucial issue in particular for painted surfaces. In the framework of the European Project Nanomatch the color variation induced on wall painting mock-ups by the two innovative consolidants (calcium alkoxides) developed was evaluated using colorimetry in comparison with two traditional products. In this work these innovative consolidants have been also tested in combination with two commercial biocides and the results of colorimetric measurements discussed. Moreover, as the univariate approach didn’t allow to draw clear conclusions on the relation between the different sources of data variability, multivariate analysis was performed on colorimetric data. Results Principal Component Analysis and multi-way Parallel Factor Analysis (PARAFAC) were successfully applied to colorimetric data to investigate the short-term effects of the application of different consolidants on wall painting surfaces, making it possible to study at the same time the different sources of data variability, i.e. treatments, painting techniques, pigments. Finally, a ranking list of the treatments under study in terms of colour variation induced on the surface was established, in function of the painting technique and pigment, taking also in consideration the combination consolidant/biocide. In particular, given the true multi-way nature of the data, PARAFAC model turned out to be extremely useful in the study of the dependence of colour variation on pigments, a critical issue for painted surfaces, that was not clear using univariate approach. Conclusions Multivariate approach to colorimetric data and especially 3-way PARAFAC method resulted a powerful technique to evaluate in short-term the color compatibility of consolidants for wall paintings, improving data interpretation and visualization, and thus outperforming the univariate statistical analysis

L'évolution du métier d'enseignant de langue de spécialité

Les treize contributions publiées dans ce volume des Cahiers de l’APLIUT mettent l’accent sur les mutations qui ont, le temps d’une carrière de baby boomer, transformé radicalement le métier d’enseignant. Les travaux des didacticiens et les recherches croisées entre les disciplines de référence ont bouleversé le regard sur l’apprentissage et les comportements. L’élaboration du Cadre européen commun de référence pour les langues (souvent abrégé en Cadre ou CECRL) transcrit cette vision nouvelle de l’enseignement/apprentissage désormais centré sur l’apprenant et sur le processus cognitif. Parallèlement, la révolution technologique a ouvert le champ des possibles et permis de développer l’apprentissage en autonomie et de redéfinir le rôle de l’enseignant. Enfin, l’intérêt pour les langues de spécialité n’a cessé de croître, élargissant le champ des recherches