Silicone Joint Dimensioning Calculation Methods

Historically, silicone joint dimensioning is calculated with a simplified equation implemented in various standards for structural glazing. This equation assumes homogeneous stress distribution along the sealant bite whilst high local stress peaks, structure deformation or material ageing are included in a global safety factor. Safeguards such as a maximum authorized deflection (1%) and aspect ratio to respect (between 1 and 3) have been given to ensure the validity of the used equations. However new trends in commercial buildings such as the use of large dimensions glass panes or stronger engineering performance requirements such as high windloads above 5000Pa lead to the non-respect of these guidelines and the impossibility to use the simplified equation. An improved mathematical relationship making a direct correspondence between a joint included in a façade system and the behavior of a test piece was recently proposed by the authors. The goal of this article is to further validate the proposed relationship by confronting predictions with physical measurements on various test samples and the results from FEA modeling. The domain of validity of the simplified equation and the improved equation will be developed

Study of copper nitrate-based patinas

Artificial patination is mostly based on empirical recipes for which the result is difficult to forecast. Little is known about the final corrosion compound formed on the patinated object. Therefore, different patinas based on copper nitrate - an ingredient recurrent in numerous references - were realized according to traditional recipes. Their characteristics of morphology and molecular composition were studied using various methods such as scanning electron microscopy (SEM)-energy dispersive X-ray analysis (EDX), X-ray diffraction analysis (XRD) and Raman spectroscopy (RS). A better understanding of artificial patinas will not only allow developing appropriate methods of conservation and restoration, but also differentiating between natural and artificial patinas. An example of a patina present on an ancient artifact is discussed and compared with the studied artificial patinas. Copyright © 2006 John Wiley & Sons, Ltd.SCOPUS: cp.jFLWINinfo:eu-repo/semantics/publishe

2,6-Quinolinyl derivatives as potent VLA-4 antagonists

International audienc

Offices, écrits et papauté (XIIIe-XVIIe siècles)

La papauté connaît, entre XIIIe et XVIIe siècle, des évolutions remarquables qui coïncident avec l’affirmation de l’État en Europe occidentale. L’écrit, qui permet à toute autorité politique d’immuniser, de statuer, d’informer, de conserver, est un des principaux instruments de sa construction. Ce volume, second écho d’une recherche collective internationale, tente de croiser les questionnements diffus portant sur ces deux objets historiographiques. Sans prétendre offrir une analyse globale de la culture écrite des organes du pouvoir, dans et hors de la curie, ni proposer une véritable histoire documentaire de l’institution pontificale, les études présentées ici permettent de cerner les structures d’évolution de la documentation dans divers secteurs d’intervention de la papauté. Elles appréhendent les interrogations que les mécanismes de rédaction, de transmission et de conservation des informations suscitent. Elles soulèvent avec acuité des questions économiques fondamentales que les registres occultent, voire tentent de celer. De Rome en Avignon, par Pérouse, Bologne et la Savoie, des cours provinciales aux familles cardinalices, de l’armée à la Pénitencerie, du maçon à l’artiste, des premières ébauches de l’écrit à l’évasion du secret d’archives, la richesse des thèmes étudiés, des analyses apportées et des interprétations historiques parcourues approfondissent de manière déterminante nos connaissances de cette forme de pouvoir unique qu’est la papauté médiévale et de l’âge moderne

Impacts of alien invasive plants on soil nutrients are correlated with initial site conditions in NW Europe.

Alien invasive plants are capable of modifying ecosystem function. However, it is difficult to make generalisations because impacts often appear to be species- and site-specific. In this study, we examined the impacts of seven highly invasive plant species in NW Europe (Fallopia japonica, Heracleum mantegazzianum, Impatiens glandulifera, Prunus serotina, Rosa rugosa, Senecio inaequidens, Solidago gigantea) on nutrient pools in the topsoil and the standing biomass. We tested if the impacts follow predictable patterns, across species and sites or, alternatively, if they are entirely idiosyncratic. To that end, we compared invaded and adjacent uninvaded plots in a total of 36 sites with widely divergent soil chemistry and vegetation composition. For all species, invaded plots had increased aboveground biomass and nutrient stocks in standing biomass compared to uninvaded vegetation. This suggests that enhanced nutrient uptake may be a key trait of highly invasive plant species. The magnitude and direction of the impact on topsoil chemical properties were strongly site-specific. A striking finding is that the direction of change in soil properties followed a predictable pattern. Thus, strong positive impacts (higher topsoil nutrient concentrations in invaded plots compared to uninvaded ones) were most often found in sites with initially low nutrient concentrations in the topsoil, while negative impacts were generally found under the opposite conditions. This pattern was significant for potassium, magnesium, phosphorus, manganese and nitrogen. The particular site-specific pattern in the impacts that we observed provides the first evidence that alien invasive species may contribute to a homogenisation of soil conditions in invaded landscapes. © 2008 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe