L’avenir des services de référence des bibliothèques universitaires

Le texte qui suit présente d’abord une « petite histoire de la référence », une rétrospective des pratiques de services de référence dans les bibliothèques universitaires depuis les années 1970, et ce à partir de l’expérience des bibliothèques universitaires de l’Université de Montréal. Par la suite, les auteurs font une analyse de l’impact des nouvelles technologies sur les services de référence à une époque de rationalisation du travail et de coupures de personnel. Une réflexion est ensuite proposée sur ce que sera l’avenir des professionnels de la référence dans un contexte de travail plus exigeant marqué par l’augmentation de la charge de travail, l’importance de plus en plus grande des qualités pédagogiques et la spécialisation des tâches, sans oublier le fait que le bibliothécaire de référence, en bâtissant des collections et des portails dans sa discipline de spécialisation, deviendra sans doute de plus en plus un gestionnaire de l’information

La modification des attitudes d'étudiants du secondaire à l'égard des handicapés physiques

Québec Université Laval, Bibliothèque 201

Étude par éléments finis du comportement thermo-chimio-mécanique de la pâte monolithique

L’industrie de l’aluminium fait aujourd’hui l’objet d’une compétition internationale féroce obligeant les producteurs d’aluminium de première fusion à améliorer l’efficacité et la longévité des cuves d’électrolyse. En ce sens, la sélection ainsi que la qualité des matériaux composant ladite cuve deviennent donc des facteurs de toute première importance. La pâte monolithique, qui entre dans la préparation du plan cathodique des cuves, est un matériau qui est mis en place dans les joints par vibro-compaction et ce, afin d’assurer son scellement. Il s’agit là d’un matériau thermoréactif fort complexe dont les propriétés évoluent selon le niveau de cuisson. Le but du présent projet est donc de proposer une loi de comportement thermo-chimio-mécanique (TCM) pour la pâte monolithique et assurer son implémentation dans le logiciel d’analyse par éléments finis ANSYS®. Pour ce faire, un modèle de comportement a été choisi à partir des lois existantes dans la littérature. Celui-ci est dépendant de la pression hydrostatique et possède un mécanisme d’écrouissage et d’adoucissement en plus de prendre en compte l’effet de cuisson du matériau. Une validation de l’approche a été menée en comparant les résultats numériques obtenus avec l’outil FESh++, outil possédant une loi de comportement TCM pour les matériaux à base de carbone considérée comme une des plus représentatives à ce jour. Finalement, une validation du banc d’essai thermomécanique BERTA (Banc d’essai de résistance thermomécanique ALCAN) a été effectuée dans l’optique de son utilisation pour la validation expérimentale de la loi de comportement sur un montage à plus grande échelle. Il a cependant été conclu que le banc d’essai BERTA ne possède actuellement pas la capacité de suivre efficacement le comportement déformationnel d’un matériau tel que celui à l’étude. Au terme de ce projet, l’outil prédictif développé aura permis d’assurer une meilleure compréhension du comportement des cuves d’électrolyses lors de leur mise en service, et ce, via la simulation réaliste de l’effet de la cuisson de la pâte monolithique sur son comportement durant cette période critique. Aluminum industry is in a fierce international competition requiring the constant improvement of the electrolysis cell effectiveness and longevity. The selection of the cell’s materials components becomes an important factor to increase the cell’s life. The ramming paste, used to seal the cathode lining, is compacted in the joints between the cathode and the side wall of the cell. It is a complex thermo-chemo-reactive material whose proprieties change with the evolution of his baking level. Therefore, the objective of this project is to propose a thermo-chemo-mechanical constitutive law for the ramming paste and implement it in the finite element software ANSYS®. A constitutive model was first chosen from the available literature on the subject. It is a pressure dependent model that uses hardening, softening and baking mechanisms in its definition to mimic the behavior of carbon-based materials. Subsequently, the numerical tool was validated using the finite element toolbox FESh++, which contains the most representative carbon-based thermo-chimio-mechanical material constitutive law at this time. Finally, a validation of the experimental setup BERTA (Banc d’essai de résistance thermomécanique ALCAN) was made in prevision of a larger scale experimental validation of the constitutive law in a near future. However, the analysis of the results shows that BERTA is not suited to adequately measure the mechanical deformation of such kind of material. Following this project, the numerical tool will be used in numerical simulation to introduce the various effects of the baking of the ramming paste during the cell startup. This new tool will help the industrial partner to enhance the understanding of Hall-Héroult cell start-up and optimize this critical step

SPHERE IRDIS and IFS astrometric strategy and calibration

We present the current results of the astrometric characterization of the VLT planet finder SPHERE over 2 years of on-sky operations. We first describe the criteria for the selection of the astrometric fields used for calibrating the science data: binaries, multiple systems, and stellar clusters. The analysis includes measurements of the pixel scale and the position angle with respect to the North for both near-infrared subsystems, the camera IRDIS and the integral field spectrometer IFS, as well as the distortion for the IRDIS camera. The IRDIS distortion is shown to be dominated by an anamorphism of 0.60+/-0.02% between the horizontal and vertical directions of the detector, i.e. 6 mas at 1". The anamorphism is produced by the cylindrical mirrors in the common path structure hence common to all three SPHERE science subsystems (IRDIS, IFS, and ZIMPOL), except for the relative orientation of their field of view. The current estimates of the pixel scale and North angle for IRDIS are 12.255+/-0.009 milliarcseconds/pixel for H2 coronagraphic images and -1.75+/-0.08 deg. Analyses of the IFS data indicate a pixel scale of 7.46+/-0.02 milliarcseconds/pixel and a North angle of -102.18+/-0.13 deg. We finally discuss plans for providing astrometric calibration to the SPHERE users outside the instrument consortium.Comment: 12 pages, 6 figures, 3 table

Polymérisation par plasma à pression atmosphérique : caractérisation des dépôts et leurs applications en biotechnologies

Les plasmas, les polymères plasma et leurs applications biomédicales -- Physico-chimie des plasmas et de la polymérisation par plasma -- Les fonctionnalisations de surfaces polymériques par plasma et procédés analogues -- Application biomédicales des polymères plasma -- Applications biomédicales des PP:N -- Méthodologie expérimentale -- Dépôts de couches minces riches en azote -- Stratégie de caractérisation des matériaux -- Cultures cellulaires -- Dépôt et caractérisation chimique de polymères plasma riches en azote déposés par décharge à barrière diélectrique à pression atmosphérique -- Atmospheric pressure deposition of micropatterned nitrogen-rich plasma-polymer films for tissue engineering -- Chemical characterisation of nitrogen-rich plasma-polymer films deposited in dielectric barrier discharges at atmospheric pressure -- Adhésion de monocytes humaines U937 sur des couches minces organiques riches en azote : Étude des mécanismes d'adhédion cellulaire164

Comparing Statistical Methods for Constructing Large Scale Gene Networks

The gene regulatory network (GRN) reveals the regulatory relationships among genes and can provide a systematic understanding of molecular mechanisms underlying biological processes. The importance of computer simulations in understanding cellular processes is now widely accepted; a variety of algorithms have been developed to study these biological networks. The goal of this study is to provide a comprehensive evaluation and a practical guide to aid in choosing statistical methods for constructing large scale GRNs. Using both simulation studies and a real application in E. coli data, we compare different methods in terms of sensitivity and specificity in identifying the true connections and the hub genes, the ease of use, and computational speed. Our results show that these algorithms performed reasonably well, and each method has its own advantages: (1) GeneNet, WGCNA (Weighted Correlation Network Analysis), and ARACNE (Algorithm for the Reconstruction of Accurate Cellular Networks) performed well in constructing the global network structure; (2) GeneNet and SPACE (Sparse PArtial Correlation Estimation) performed well in identifying a few connections with high specificity

Industrial Cu-Ni alloys for HTS coated conductor tape

Copper rich Cu-Ni alloys have been textured with the RABiTS method in order to get non-magnetic and cost efficient substrates for coated conductor wires. The study is focused on two industrial compositions: Cu55Ni45 (Constantan) and Cu70Ni30. Studies on surface roughness have been done. The effects of annealing conditions (temperature and atmosphere) on the grain boundaries deepness were analyzed. Electrolytic polishing was also applied to improve the surface quality. RX pole figures and micro hardness measurements have been achieved on samples annealed up to 950°C. Attention has been paid to the rolling texture and to the annealing processes. The rolling texture has been found to be mainly copper-type (C, S and B contributions). Beginning of recrystallization occurred between 400°C and 600°C and stabilized between 900°C to 950°C, depending on the nickel content of the alloy. Finally both samples, rolled and annealed under the appropriate conditions, have been characterized. Pole figure measurements gave the global in plane and out of plane disorientations of our samples which are in-plane 7.4° and out-plane (RD) 4.3° for both samples. EBSD maps have shown the details of the distribution and have allowed us to quantify the ratio between cubic {100} and twined {122} orientations

VUV Photodeposition of Thiol-Terminated Films: A Wavelength-Dependent Study

Photoinitiated chemical vapor deposition (PICVD) has become attractive for selective and specific surface functionalization, because it relies on a single energy source, the photons, to carry out (photo-) chemistry. In the present wavelength (λ)-dependent study, thiol (SH)-terminated thin film deposits have been prepared from gas mixtures of acetylene (C2H2) and hydrogen sulfide (H2S) via PICVD using four different vacuum-ultraviolet (VUV) sources, namely, KrL (λpeak = 123.6 nm), XeL (λpeak = 147.0 nm), XeE (λpeak = 172.0 nm), and Hg (λ = 184.9 nm) lamps. Different λ influence the deposition kinetics and film composition, reflecting that photolytic reactions are governed by the gases’ absorption coefficients, k(λ). Thiol concentrations, [SH], up to ∼7.7%, were obtained with the XeL source, the highest reported in the literature so far. Furthermore, all films showed islandlike surface morphology, regardless of λ

Liquid Mirror Telescopes: A progress report

We review the present status of liquid mirror telescopes. Interferometric tests of liquid mirrors (the largest one having a diameter of 2.5 meters ) show excellent optical qualities. The basic technology is now sufficiently reliable that it can be put to work. Indeed, a handful of liquid mirrors have now been built that are used for scientific work. A 3.7-m diameter LMT is presently being built in the new Laval upgraded testing facilities. Construction of the mirror can be followed on the Web site: http://astrosun.phy.ulaval.ca/lmt/lmt- home.html. Finally we address the issue of the field accessible to LMTs equipped with novel optical correctors. Optical design work, and some exploratory laboratory work, indicate that a single LMT should be able to access, with excellent images, small regions anywhere inside fields as large as 45 degrees.Comment: To appear in the SPIE conference proceedings 'Optical Telescopes of Today and Tomorrow', May 29 - June1, Landskrona/Hven, Sweden, Additional info on LMs at: http://astrosun.phy.ulaval.ca/lmt/lmt-home.htm