994 resultados para composite media


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Joyce Tam de l'Université McGill est récipiendaire du 3ème prix du concours de la bourse d'initiation à la recherche offerte par le Regroupement Droit et changements aux étudiants du baccalauréat en droit.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bien que la souveraineté apparaisse aujourd'hui comme un concept juridique autonome, cela ne fut pas toujours le cas. Comme le souligne l’auteur de ce texte, notre société est passée d'une souveraineté mystique, celle de l'Église, à une souveraineté laïque, celle de l'État, pour aboutir, aujourd'hui, à une souveraineté plurielle ou composite. L'avènement d'un réseau de masse, comme l'Internet, vient encore une fois changer la donne. Ainsi, le concept de souveraineté informationnelle, discuté à la fin des années 70, semble aujourd’hui suranné, voire obsolète, à la lumière des nouveaux environnements électroniques. Conscient de cette évolution et de ses conséquence, l’auteur propose une réflexion historique et conceptuelle du principe de souveraineté afin de réévaluer les critères de territorialité et d'espace physique en tant que pivots autour desquels s'articule le concept de souveraineté nationale. L'État d'aujourd'hui ne pouvant aspirer seul à réglementer les transactions économiques transnationales, cet article nous pousse à nous questionner sur le sens que doit prendre le terme « souveraineté » à l’aube de l’ère numérique.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: An interprofessional steering committee was created at Université de Montréal’s Faculty of Medicine to examine how social media are integrated in medical and health professional education in universities across the globe, and to propose a strategic plan for integrating social media in the Faculty’s various curricula. This presentation will summarize the steering committee’s work and describe the librarian’s contribution. Methods: The Committee’s project leader first conducted a literature search on best practices of social media in medical and health professional curricula. A reference website was then created (mse.med.umontreal.ca) to provide easy access to a large number of the articles and resources reviewed. A steering committee was constituted and 11 meetings were held over a 9-month period. The Committee comprised 18 members and included assistant deans, academic program directors, professors, communication advisors, undergraduate and graduate students and a librarian. An online survey on social media use by students and professors of the Faculty was conducted, ten pilot projects were put forward and a three-year strategic plan was proposed. Results: A total of 1508 students and 565 professors participated in the survey. Results showed that both groups had a strong interest in learning how social media could be integrated in academic and professional activities. Participants reported concern with risks associated with social media use and expressed the need for a Faculty policy and guidelines. The librarian’s contribution to the steering committee included: writing posts on the website’s internal blog, assisting in the design of the survey questionnaires and writing the final report’s survey results chapter. She also proposed two pilot projects: creating a social media learning portal and an altmetrics workshop. Conclusions: Based on the literature review and the survey results, the Committee affirmed the importance of integrating social media in the various study programs of the Faculty of Medicine. Despite the restricted timeline, this interprofessional steering committee was able to carry out its mandate because of the leadership and expertise of each of its members. As the librarian had the most experience with the use of social media in a professional context, her knowledge was instrumental in assisting the project leader in a group mainly composed of social media non-users.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Polymer materials find application in optical storage technology, namely in the development of high information density and fast access type memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized and its comparison with methylene blue sensitized PVA in methanol and complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented. The optical absorption spectra of the thin films of these polymers showed a strong and broad absorption region at 670-650 nm, matching the wavelength of the laser used. A very slow recovery of the dye on irradiation was observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pHof 3.8 and a sensitizer concentration of 4.67 10 5 g/ml were used. A diffraction efficiency of up to 20% was observed for the MBPVA/alcohol system and an energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films with a spatial frequency of 588 lines/mm.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Polymer materials find application in optical storage technology, namely in the development of high information density and fast access type memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized and its comparison with methylene blue sensitized PVA in methanol and complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented. The optical absorption spectra of the thin films of these polymers showed a strong and broad absorption region at 670-650 nm, matching the wavelength of the laser used. A very slow recovery of the dye on irradiation was observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pHof 3.8 and a sensitizer concentration of 4.67 10 5 g/ml were used. A diffraction efficiency of up to 20% was observed for the MBPVA/alcohol system and an energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films with a spatial frequency of 588 lines/mm.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of various processing parameters, such as nip gap, friction ratio and roll temperature, on the tensile properties of short Kevlar aramid fibre-thermoplastic polyurethane composite has been investigated and the tensile and tear fracture surfaces have been characterised using a scanning electron microscope. A nip gap of 0.45 mm, a friction ratio of 1.15 and a roll temperature of 62°C was found to give optimum mechanical properties. Scanning electron microscopy study revealed a higher extent of fibre orientation in the milling direction in the above condition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tear and wear properties of short kevlar fiber, thermoplastic polcurethane (TPU) composite with respect to fiber loading-and fiber onentation has been studied and the fracture surfaces were examined under scanning electron microscope (SEM). Tear strength first decreased up to 20 phr fiber loading and then gradually increased with increasing fiber loading. Anisotropy in tear strength was evident beyond a fiber loading of 20 phr. Tear fracture surface of unfilled TPU showed sinusoidal folding characteristics of high strength matrix. At low fiber loading the tear failure was mainly due to fibermatrix failure whereas at higher fiber loading the failure occurred by fiber breakage. Abrasion loss shows a continuous rise with increasing fiber loading, the loss in the transverse orientation of fibers being higher than that in the longitudinal orientation. The abraded surface showed lone cracks and ridges parallel to the direction of abrasion indicating an abrasive wear mechanism. In the presence of fber the abrasion loss was mainly due to fiber low.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The self adhesion behaviour of thermoplastic polyurethane (TPU) in itself and its composite with short Kevlar fibre with respect to contact time, temperature, pressure, and fibre loading has been studied. The adhesion strength showed two linear increments of different slopes with respect to the square root of time: with temperature and pressure of contact, the adhesion strength was improved. The maximum strength was obtained with 20 phr of short fibre in only one of the mating substrates in the peel test sample. The duration for wetting and diffusion was shifted to longer time intervals with fibres loaded in both the substrates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The flammability of short Kevlar aramide fiber-thermoplastic polyurethane (TPU) has been investigated with respect to fiber loading and various flame retardant additives such as halogen containing polymers, antimony oxide/chlorine donor combination, zinc borate, and aluminum hydroxide. Smoke generation was reduced drastically, while the oxygen index was reduced marginally in the presence of short fibers. The best improvement in the oxygen index was obtained with antimony oxide/chlorinated paraffin wax combination, in the weight ratio 1:6. A 70 phr loading of aluminum hydroxide improved LOI and reduced smoke generation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The thermal degradation of short nylon-6 fiber reinforced acrylonitrile butadiene rubber (NBR) composites with and without epoxy-based bonding agent has been studied by thermogravimetric analysis (TGA). It was found that the onset of degradation shifted from 330.5 to 336.1°C in the presence of short nylon fiber, the optimum fiber loading being 20 phr. The maximum rate of degradation of the composites was lower than that of the unfilled rubber compound, and it decreased with increase in fiber concentration. The presence of epoxy resin-based bonding agent in the virgin elastomer and the composites improved the thermal stability. Results of kinetic studies showed that the degradation of NBR and the short nylon fiber reinforced composites followed first-order kinetics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The thermal properties of short Nylon-6 fiber-reinforced Styrene butadiene rubber (SBR) composites were studied by Thermogravimetric Analysis (TGA). The effect of epoxy-based bonding agent on thermal degradation of the gum and the composites was also studied. The thermal stability of the SBR was enhanced in the presence of Nylon-6 fibers and the stability of the composites increased in the presence of bonding agent. The epoxy resin did not significantly change the thermal stability of SBR gum vulcanizate. Results of kinetic studies showed that the degradation of SBR and the short nylon fiber-reinforced composites with and without bonding agents followed first-order kinetics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of diphenylmethane diisocyanate (MDI) -polyethyleneglycol (PEG) resin on the cure characteristics and mechanical properties of nitrile rubber/whole tyre eclaim-short nylon fiber composite-was studied. At a constant loading of 5 phr, the resin composition was varied. The minimum torque .,id (maximum - minimum) torque increased with isocyanate concentration. Scorch time and cure time showed a reduction on introduction of bonding agent. Properties like tensile strength, tear strength, and abrasion resistance increased with increase in MDI/PEG ratio, and these properties are higher in the longitudinal direction of fiber orientation. Compression set increased with isocyanate concentration and the resilience remain unchanged.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The cure characteristics and mechanical properties of short nylon fiber- styrene /whole tyre reclaim (SBR/WTR) composites with and without an interfacial bonding agent based on 4,4 diphenyl methane diisocyanate and polyethylene glycol (MDI/PEG) have been studied. An 80:40 blend of SBR/ WTR reinforced with 20 phr of short nylon fiber has been selected and the MDI/ PEG ratio has been changed from 0.67:1 to 2:1. The minimum and maximum torques increased with isocyanate concentration. The scorch time and cure time showed an initial reduction. The cure rate showed an initial improvement. Tensile strength, tear strength and abrasion resistance increased with MDI/PEG ratio, these values were higher in longitudinal direction. Resilience and compression set increased with isocyanate concentration.