1,721,014 research outputs found
Numerical investigation of particle distribution in a floor heated room with different air change rates
No full textAirborne particles have a significant effect on human health in enclosed volumes like rooms and office areas. Particle distribution in these spaces should be well known to understand how heating systems may harm to human regarding to respirable particles. In this study, being a major low temperature system aiming energy efficiency, the floor heating system was examined in terms of on particle distribution in a room numerically. When particle concentration come into question, floor heating systems should be evaluated and compared with other heating choices. The effects of five different air change rates on five different particle size were investigated by finite volume method using Eulerian-Lagrangian model. In this study, the effect of drag, lift, thermophoretic and Brownian forces were considered. It is found that, air change rate is a critical factor to obtain desired indoor air quality but outdoor air conditions may worsen the indoor quality due to air pollution
Numerical investigation of air conditioners' control unit position on temperature distribution and energy consumptions of a room
No full textMinimum temperature difference should be achieved in conditioned rooms to meet comfort criteria. It is desired that the temperature set by a user from the control unit, should be the same in the entire room. Therefore, the position of the control unit plays a significant role in order to achieve a homogeneous temperature distribution in the room. In this study, the effect of control unit positioning on temperature and velocity distributions in a room, where a cassette type indoor unit was applied, was numerically investigated. Blowing temperature and speed of the indoor unit has been adjusted by the temperature value that measured by a control unit which was placed at five different locations, in order to examine positioning effects of the control unit. Predicted percentage dissatisfied (PPD) values were calculated, and uncomfortable zones were determined by 2-dimensional analyses. Cooling loads, as well as energy consumptions, were calculated and their variations according to the position of control unit was figured out in steady state conditions. The results showed that control unit positioning not only influences the comfort levels or temperature distributions in a room but also energy consumptions
Particle concentration comparison of radiator and floor heating systems under zero air change rate condition
No full textAs a result of isolating doors and windows very well to reduce heating energy costs, some environments' air change rate becomes zero. Two different heating systems (radiator and floor heating systems) widely used in residential applications were compared for a room where the air change rate is zero, using numerical methods in terms of particle concentrations. 3D dimensional CFD simulations show that the floor heating system performs better in removing the pollutants dispersed homogeneously in the room, while the radiator system is more effective in removing the pollutants emitted from a source close to the floor. It was concluded that special care should be taken not to have a source of pollutants close to the ground surface in the environments where a floor heating system is used
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Polymer nanofiber-carbon nanotube network generating circuits
No full textThe polymer nanofiber carbon nanotube (CNT) based devices attracts attention since they promise high performance for next generation devices such as wearable electronics, ultra-light weighted appliances and foldable devices. This abstract describes the utilization of polymer nanofibers and CNT as major component of low cost foldable photo-resistor. We use polymer nanofiber as template guiding CNTs to generate nanocircuits and conductive sensing network. The controlled combination of CNTs and polymer nanofibers provide opportunities for device miniaturization without loss of performance. The nanofiber-CNT network based photo-resistor exhibits broad band response 400 to 1600 nm that holding promises for ultra-thin devices and new sensing platforms.Center for Materials Research in IZTECH, TUBITAK-215054
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