Search results for "Pact"
showing 10 items of 2355 documents
Preparation of synthetic sandstones with variable cementation for studying the physical properties of granular rocks
1997
In this article, we report a new set of procedures to fabricate synthetic analogues of granular rocks. These procedures permit accurate control of the most important structural parameters (i.e., grain size, porosity, cement content). We were thus able to prepare two varieties of synthetic sandstones in which only the cement content significantly varied. Our procedures were also particularly successful in producing materials that were very similar to natural rocks. To demonstrate this similarity, we compared the microstructure, the mechanical properties (i.e., strength, elastic moduli) and the mechanical behaviour (i.e., brittle or ductile) of the synthetic materials to those of various natu…
Experimental Investigation on Water Loss and Stiffness of CBTM Using Different RA Sources
2021
Cold recycling of reclaimed asphalt (RA) is a promising technique to build or to maintain roads, combining performance and environmental advantages. Although this technique has been extensively used worldwide, there is no unique and internationally-shared method to characterize cold recycled mixtures. The previous work of the RILEM TC 237-SIB TG6 successfully attempted to characterize different RA sources with both traditional parameters (gradation, bitumen content and geometrical properties) and non-conventional properties (fragmentation and strength testing). The current RILEM TC 264-RAP TG1 mainly focuses on the influence of different RA sources on physical and mechanical characteristics…
Pumice powder as filler of self-compacting concrete
2015
Abstract An experimental study on the rheological and mechanical properties of self-compacting concrete with pumice powder used as filler additive is presented. Self-compacting concrete (SCC) shows its peculiar characteristics in the fresh state and many researches have been developed with reference to its rheological characteristics paying attention to the techniques of self-compacting properties assessment. One of the most important aspect in concrete mix-design is the type and the amount of fillers with respect to water and cement: this amount has great influence not only on self-compacting properties (fluidity, segregation, etc.), but also on the mechanical properties of the mixture. Vo…
Etiological factors in second mandibular molar impaction.
2013
Objectives: The impaction of the second mandibular molar (MM2) has recently become more prevalent. Several etiological hypothesis have been proposed to investigate the association between skeletal features and impaction of MM2. The aims of this study were to analyze the skeletal features in patients with MM2 impaction and the association between arrested eruption of MM2 and the presence of the third mandibular molar (MM3). Study Design: In this retrospective study 48 subjects from 3,530 Caucasian orthodontic patients with MM2 impaction were included in a study group (SG) and compared to a control group (CG) of 200 subjects without MM2 impaction. Panoramic radiographs evaluated the presence …
Erosion en milieu sableux cultivé au Niger : dynamique actuelle et passée en liaison avec la pression anthropique et les changements climatiques
2011
Sahelian ecosystems, especially those installed on sandy soils react very quickly and intensely to small climatic changes. In this semi-arid area, wind erosion which occurs mainly on cultivated millet fields and is threatening the sustainable use of land resources. Furthermore, the rapid population growth and the severe droughts of the twentieth century have had important impacts on ecosystems. To better manage this fragile environment, it is important first to understand how it works. This thesis was included in the framework of the AMMA project (African Monsoon Multidisciplinary Analyses) and was in the heart of a CORUS 2 (Coopération pour la Recherche Universitaire et Scientifique) progr…
Changement climatique en Bourgogne et ses impacts sur la ressource en eau
2018
International audience
Novel Version of PageRank, CheiRank and 2DRank for Wikipedia in Multilingual Network Using Social Impact
2020
International audience; Nowadays, information describing navigation behaviour of internet users are used in several fields, e-commerce, economy, sociology and data science. Such information can be extracted from different knowledge bases, including business-oriented ones. In this paper, we propose a new model for the PageRank, CheiRank and 2DRank algorithm based on the use of clickstream and pageviews data in the google matrix construction. We used data from Wikipedia and analysed links between over 20 million articles from 11 language editions. We extracted over 1.4 billion source-destination pairs of articles from SQL dumps and more than 700 million pairs from XML dumps. Additionally, we …
Pollutants in indoor environments
2014
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Solitary Rectal Ulcer
1979
Solitary ulcers of the rectum may be traumatic in origin and caused by thermometers, occasionally by digital removal of a fecal impaction, or by deviate sexual behavior. Solitary rectal ulcers may also be a manifestation of Crohn’s disease. Very rarely, ectopic gastric mucosa is their cause. For the vast majority of solitary rectal ulcers, the explanation remains unknown. Occasionally, the ulcers are accompanied by localized inflammation of the mucosa within the distal segment of the rectum with edema, erythema, and circumscribed whitish flecks in a thickened bowel wall covered by excessive secretions. The changes are found predominantly in the ventral portion of the rectum, and in contrast…
Optimized Multipactor-Resistant Wedge-Shaped Waveguide Bandpass Filters
2013
[EN] Wedge-shaped waveguides present a certain advantage with respect to rectangular waveguides regarding their resistance to multipactor discharges. In this paper, the optimal configuration for the wedge geometry is investigated based on theoretical results, on a precise multipactor prediction tool, and on previous experience. In addition, design rules are presented, which allow us to achieve for wedge-shaped filters electrical performances comparable to the ones of rectangular waveguide filters, while at the same time improving the multipactor-free power range. As a proof of concept, two three-pole bandpass filters with equivalent electrical characteristic of 150-MHz bandwidth, centered a…