919 resultados para Plate Library
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The objective of the present work is the experimental determination of pressure drop coefficients (loss coefficients) for elliptic and circular sections in one, two and three-row arrangements of plate fin and tube heat exchangers. The experiments permitted to correlate the dimensionless loss coefficient with the flow Reynolds number in the rectangular channel formed by the plate fins. The experimental technique consisted of the measurement of the longitudinal pressure distribution along the flow channel, for several values of air mass flow rate. The total number of data runs, each one characterized by the flow Reynolds number, was 216. The present geometry is used in compact heat exchangers for air conditioning systems, heaters, radiators, and others. Also, it is verified the influence of the utilization of elliptic tubes, instead of circular ones, in the pressure drop. The measurements were performed for Reynolds numbers ranging from 200 to 1900.
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The Shadow Moiré fringe patterns are level lines of equal depth generated by interference between a master grid and its shadow projected on the surface. In simplistic approach, the minimum error is about the order of the master grid pitch, that is, always larger than 0,1 mm, resulting in an experimental technique of low precision. The use of a phase shift increases the accuracy of the Shadow Moiré technique. The current work uses the phase shifting method to determine the surfaces three-dimensional shape using isothamic fringe patterns and digital image processing. The current study presents the method and applies it to images obtained by simulation for error evaluation, as well as to a buckled plate, obtaining excellent results. The method hands itself particularly useful to decrease the errors in the interpretation of the Moiré fringes that can adversely affect the calculations of displacements in pieces containing many concave and convex regions in relatively small areas.
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This paper deals with the use of the conjugate gradient method of function estimation for the simultaneous identification of two unknown boundary heat fluxes in parallel plate channels. The fluid flow is assumed to be laminar and hydrodynamically developed. Temperature measurements taken inside the channel are used in the inverse analysis. The accuracy of the present solution approach is examined by using simulated measurements containing random errors, for strict cases involving functional forms with discontinuities and sharp-corners for the unknown functions. Three different types of inverse problems are addressed in the paper, involving the estimation of: (i) Spatially dependent heat fluxes; (ii) Time-dependent heat fluxes; and (iii) Time and spatially dependent heat fluxes.
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Kristiina Hormia-Poutasen esitys CBUC-konferenssissa Barcelonassa 12.4.2013.
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Kristiina Hormia-Poutasen esitys Liber-konferenssissa Münchenissa, Saksassa 27.6.2013.
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Kristiina Hormia-Poutasen esitys KRE-konferenssissa 2013.
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Kristiina Hormia-Poutasen esitys KOBV-konferenssissa Berliinissä, Saksassa kesäkuussa 2013.
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The collections policy of the National Library of Finland guides the formation and development of collections. The policy also outlines the National Library’s collection, its national and international significance, and the guidelines for acquisition, selection, donation and disposal.
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Jussi-Pekka Hakkaraisen esitys 24. Kansainvälisessä tieteen-, teknologian ja lääketieteen historian kongressissa (24th International Congress of History of Science, Technology and Medicine) Manchesterissa 26.7.2013
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Social media has become a part of many people’s everyday lives. In the library field the adoption of social media has been widespread and discussions of the development of “Library 2.0” began at an early stage. The aim with this thesis is to study the interface between public libraries, social media, and users, focusing on information activities. The main research question is: How is the interface between public libraries and social media perceived and acted upon by its main stakeholders (library professionals and users)? The background of Library 2.0 is strongly associated with the development of the Web and social media, as well as with the public libraries and their user-centered and information technological development. The theoretical framework builds on the research within the area of Library and Information Science concerning information behavior, information practice, and information activities. Earlier research on social media and public libraries is also highlighted in this thesis. The methods survey and content analysis were applied to map the interface between social media and public libraries. A questionnaire was handed out to the users and another questionnaire was sent out to the library professionals. The results were statistically analyzed. In the content analysis public library Facebook pages were studied. All the empirical investigations were conducted in the area of Finland Proper. An integrated analysis of the results deepens the understanding of the key elements of the social media and public library context. These elements are interactivity, information activities, perceptions, and stakeholders. In this context seven information activities were distinguished: reading, seeking, creating, communicating, informing, mediating, and contributing. This thesis contributes to develop the research concerning information activities and draws a realistic picture of the challenges and opportunities in the social media and public library context. It also contributes with knowledge on library professionals and library users, and the existing differences in their perceptions of the interface between libraries and social media.