1,965 research outputs found

    Experimental Study of Heat Pump Thermodynamic Cycles Using CO 2 Based Mixtures -Methodology and First Results

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    The aim of this work is to study heat pump cycles, using CO 2 based mixtures as working fluids. Since adding other chemicals to CO 2 moves the critical point and generally equilibrium lines, it is expected that lower operating pressures as well as higher global efficiencies may be reached. A simple stage pure CO 2 cycle is used as reference, with fixed external conditions. Two scenarios are considered: water is heated from 10 {\textdegree}C to 65 {\textdegree}C for Domestic Hot Water scenario and from 30 {\textdegree}C to 35 {\textdegree}C for Central Heating scenario. In both cases, water at the evaporator inlet is set at 7 {\textdegree}C to account for such outdoor temperature conditions. In order to understand the dynamic behaviour of thermodynamic cycles with mixtures, it is essential to measure the fluid circulating composition. To this end, we have developed a non intrusive method. Online optical flow cells allow the recording of infrared spectra by means of a Fourier Transform Infra Red spectrometer. A careful calibration is performed by measuring a statistically significant number of spectra for samples of known composition. Then, a statistical model is constructed to relate spectra to compositions. After calibration, compositions are obtained by recording the spectrum in few seconds, thus allowing for a dynamic analysis. This article will describe the experimental setup and the composition measurement techniques. Then a first account of results with pure CO 2 , and with the addition of propane or R-1234yf will be given

    Election Campaign Finance Rules in Canadian Municipalities: An Overview

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    The Money and Local Democracy Project explores the effects of campaign finance rules on municipal election campaigns and election outcomes in Canada. Governments around the world regulate election campaign financing to ensure that elections are fair and competitive, although they do so in different ways. Funded by a Western University Undergraduate Student Research Internship (UWO) grant, research assistant Brittany Bouteiller was tasked with conducting preliminary research on 65 municipalities across Canada to determine the availability of campaign finance data from local and provincial governments and to identify clusters or trends. This research bulletin summarizes her findings.https://ir.lib.uwo.ca/urbancentre-reports/1006/thumbnail.jp

    Adhesion and non-linear rheology of adhesives with supramolecular crosslinking points

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    Soft supramolecular materials are promising for the design of innovative and highly tunable adhesives. These materials are composed of polymer chains functionalized by strongly interacting moieties, sometimes called "stickers". In order to systematically investigate the effect of the presence of associative groups on the debonding properties of a supramolecular adhesive, a series of supramolecular model systems has been characterized by probe-tack tests. These model materials, composed of linear and low dispersity poly(butylacrylate) chains functionalized in the middle by a single tri-urea sticker, are able to self-associate by six hydrogen bonds and range in molecular weight (M n) between 5 and 85 kg/mol. The linear rheology and the nanostructure of the same materials (called "PnBA3U") was the object of a previous study 1,2. At room temperature, the association of polymers via hydrogen bonds induces the formation of rod-like aggregates structured into bundles for M n \textless{} 40kg/mol and the behavior of a soft elastic material was observed (G'\textgreater{}\textgreater{}G "and G'~ω\omega 0). For higher M n , the filaments were randomly oriented and polymers displayed a crossover towards viscous behavior although terminal relaxation was not reached in the experimental frequency window. All these materials show however similar adhesive properties characterized by a cohesive mode of failure and low debonding energies (W adh \textless{}40J/m 2 for a debonding speed of 100μ\mum/s). The debonding mechanisms observed during the adhesion tests have been investigated in detail with an Image tools analysis developed by our group 3. The measure of the projected area covered by cavities growing in the adhesive layer during debonding can be used to estimate the true stress in the walls of the cavities and thus, to characterize the in-situ large strain deformation of the thin layer during the adhesion test itself. This analysis revealed in particular that the PnBA3U materials with M n \textless{} 40 kg/mol soften very markedly at large deformation like yield stress fluids, explaining the low adhesion energies measured for these viscoelastic gels.

    Money and Local Democracy: Local Campaign Finance Regimes in Canada

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    Prof. Zack Taylor plans to apply for a major research grant to research the effects of campaign finance regimes. To provide a comprehensive assessment and to lay the groundwork for the grant application, I collected data on 65 municipalities across Canada, which together comprise 50% of the national population, to determine their campaign donation and spending limits, candidate disclosure requirements, and availability of disclosure statements over the last 3 election cycles. As well, I looked at the number of candidates and offices available in each of the municipalities for the last 3 election cycles

    Le temps du travail dans le temps de l'emploi: Biographies professionnelles et bibliographies familiales d'infirmières de plus de 40 ans

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    Post-enquête "Conditions et organisation du travail dans les établissements de santé"La recherche ici présentée est l'une des « post-enquêtes » financées par la DREES dans la foulée de sa vaste enquête sur les « conditions et l'organisation du travail auprès des actifs des établissements de santé », interrogeant 5000 personnes par questionnaire téléphonique au premier semestre de l'année 2003. C'est donc l'une des « post enquêtes » ou enquêtes qualitatives destinées à tester la validité et la fiabilité des résultats de cette enquête quantitative. La DREES souhaitait en effet « étudier d'éventuelles distorsions potentielles entre le sens des questions pour le statisticien et l'enquêté » ; approfondir certains aspects des conditions de travail, dans l'optique notamment de “proposer de nouveaux questionnements pour la prochaine enquête”

    Etudier le travail des cadres : un bilan de 10 ans d'expérience de recherches

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    http://gdr-cadres.cnrs.fr/cahier/Cahier6.pdfSans résumé

    Réflexions croisées sur la gestion des compétences en France et en Amérique du Nord

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    Si la gestion des compétences est encore un sujet d’actualité à la fois pour les gestionnaires de ressources humaines et pour bon nombre de responsables d’entreprise, c’est que l’objet même de cette gestion ne cesse de prendre de l’importante au sein des nouveaux systèmes productifs et face aux nouvelles contraintes de l’environnement. Pourtant, ces nouvelles approches, dont on parle beaucoup, sont peu et mal connues, et ne sont que très rarement mises en perspective au plan international. Il peut donc être intéressant, partant d’un enjeu « théoriquement » similaire — la compétence — de voir de quelle façon ces logiques et ces modes de gestion ont été conceptualisés, instrumentés et implantés de chaque côté de l’Atlantique. L’analyse conduit à observer que si les deux systèmes se sont constitués de façon contingente, et que certains facteurs lourds leur sont encore associés aujourd’hui, d’autres forces poussent vers une certaine standardisation, pour ne pas dire universalisation des approches dans ce domaine désormais central de la gestion des ressources humaines.As a management style that is still in its infancy, the phenomenon of competency management has gradually grown in importance to the point that it is now a well-established practice in full development on both sides of the Atlantic. However, what is called “competency management” covers a wide range of practices in different countries, and is positioned differently, particularly as concerns France and North America. As well, this approach has not yet been well documented from a comparative standpoint.The comparison of these two national contexts shows that we are clearly faced with two distinct systems, each with its own history, its pace, and its practical details in structuring, its means of organization and of leading and also, doubtlessly, having its own structuring effects on the environments in which it is established. Competency management will thus have given rise to, under the combined effect of a number of historical, economic or structural, legislative and cultural factors, specific developments, and dependant on each of these environments. In this way, managing competencies, in its French form does not cover the same reality as does managing competencies in the American style. Several differentiating elements stand out between the two systems. The conceptual work from which skills management has developed appears more multidisciplinary in nature, more intensive, and at the same time, richer in the French context (sociology, education, ergonomics, cognitive psychology, adult education, etc.) than on the American side, where psychology is the key consideration. The centrality of performance in the debate and in the instrumentation is also clearly evident in the North American context. The key skills are first identified and measured through discriminating behaviours among the most productive workers, then these skills are defined, calibrated, and measured with a view to a certain performance level which is to be attained. What is even more significant, perhaps, is that competency management does not target the same employee categories: middle and upper management, non-unionized, on the North American side, and operators and technicians, often unionized, on the French side. As a corollary of the preferred targets, we often find reference points strongly centered on “soft” and generic skills on the American side, while more specialized knowledge and skills are given center stage on the French side. Instruments for evaluation do exist in the French context, but these seem more “rustic,” and, in a certain way, cut off from academic sources which would make it possible to render the process objective. Finally, if the American style of skills management certainly aims to upgrade internal competency capital, this aim is in parallel with a turn towards mobilization and “cultural control” in trying to promote certain values, and in ascertaining that behaviour sufficiently aligns with strategic priorities. Overall, if the system’s goals are perhaps less “strategic” and if the instrumentation in France is less noticeable, this is doubtless in favour of a more marked goal of social regulation. Competencies do not escape the legislator’s notice, and continue to be a point of collective negotiation between social partners. On the North American side, skills are found to be part of the employer initiative, and their application is strictly reserved for management.Nevertheless, analysis shows that the competency management instrumentation presents certain important similarities between North America and France. As conceptualized by both sides, one may say that, competency management is not yet truly operationalized and is far from being completely implemented in businesses, thus confirming a significant gap between popular management discourse, and the reality of practices. When it does exist, several observations are clear: (1) A “competence,” as considered as an operational variable, is mostly a shared issue. In both cases, it is an uncertainty whose optimized control has become indispensable to achieving performance; (2) the fields of competence included in a frame of reference only cover, at best, a portion of reality. A more cross-sectional and corporate approach on the one hand, a tendency more towards trade and specialization on the other, the reference points remain strategic and dependant constructs; (3) competency management only covers a small part of the personnel in place (in North American, upper management and hierarchical lines; in France, primarily operators) while competence is each time announced as an issue and as a field of organizational management; (4) only a portion of competencies is actually taken into consideration—the more generic (soft competencies) in North America, the more specialized (skills) in France—leaving aside for the most part (for the time being at least) the other constituents; (5) the linkage of competency management with other human resources sub-systems, that is to say, its purpose is only very partially guaranteed and often called into question in its final implementation; and finally, (6) this means of management, which by definition is supposed to be forward-looking and minimally projected into the future of employees and of the organization is most often guided by the logic of short-term adaptation.Based on these observations, the hypothesis of convergence for French and North American approaches can be expressed in the short or in the long term. This convergence could be promoted by several “heavy” factors: (1) internationalization of businesses, and of consulting practices, exchanges between managers, consultants and researchers, combined with a broadened publication of knowledge as to the factors for success in competency management etc.; (2) the implantation of centralized systems for similar management so as to standardize approaches by skill; (3) the unifying influence of new concepts popular with managers (“the learning organization,” “the intelligent enterprise,” “knowledge management,” etc.). On the other hand, certain characteristics of each of the two systems seem inevitably to depend on other limitations, whether these are due to legislative, statutory or conventional limitations, due to cultural pressure, through management tradition or due to a purely strategic choice. The idea of a “convergence by means of slow sedimentation” between the two systems cannot therefore be put forward at the conclusion of this article. Competency management systems are, without a doubt, decisional processes involving too many vital company elements so as to be able to easily allow a shift towards universality. But paradoxically, these systems must deal with a resource and with the criteria for using and mobilizing this resource, and these are tending to become so “universal” that their management systems may no longer remain totally centered on local or national realities.Si la gestión de competencias es aún un sujeto de actualidad para los directores de recursos humanos y para numerosos responsables de empresa, es porque el objeto mismo de esta gestión no cesa de tomar importancia en los nuevos sistemas productivos y frente a las nuevas exigencias del entorno. Sin embargo, estos nuevos enfoques, sobre los cuales se ha hablado bastante, son poco o mal conocidos y son raramente vistos desde una perspectiva internacional. Puede ser entonces interesante, partiendo de un desafío “teóricamente” semejante ‑ la competencia –, de ver de qué manera esas lógicas y esos modelos de gestión han sido conceptualizados, instrumentados e implantados de cada lado del Atlántico. El análisis de los autores conduce a observar que si los dos sistemas se han constituido de manera contingente y que ciertos factores fuertes siguen hasta ahora asociados a ellos, otros factores llevan a cierta estandardización, por no decir universalización de los enfoques en el campo – de ahora en adelante central – de la gestión de recursos humanos
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