1,730,403 research outputs found
Effects of window-to-wall ratio on energy consumption: Application of numerical and ann approaches
Full text linkBuildings account for a major part of Total Energy
Consumption (TEC) in comparison to that of industry and
other sections. The opening and envelope material can affect
their TEC. Accordingly, this paper aims to study the effects
of the window to external wall ratio (WWR) and the
application of recycled panels as the building envelope on
the total energy consumption in a one-floor residential
building located in Iran and characterized by a semi-arid
climate. To follow the sustainability criterion, we designed
two concrete panels for the external walls’ envelope
including a porous concrete panel and recycled ash concrete
panel. The WWR varies between 5% to 95% and the optimal
WWRs are separately presented for all the months. To
develop the models, we used Design Builder software which
its simulations are validated via field observations. For all
the panels, the least energy consumption is obtained when
the WWR is 5%. However, due to lighting issues, the most
optimal WWR is calculated as 45-55% based on the results
of the numerical simulations. Further, it is proved that the
recycled ash concrete panel outperforms the porous concrete
panel in terms of minimum energy consumption. Hence, it is
recommended to use eco-friendly material as the external
walls envelop with the WWR below 50%. The numerical
simulations provided 240 data points for each panel which is
exploited to develop an ANN model. The results suggested
that the ANN models predict the TEC based on the month
and WWR with high accuracy
Lotic ecosystems as important but tricky refugia for charophytes in warm climates – implications for biodiversity and conservation
No full textCharophytes are an ecological and evolutionary important group of macroalgae characterizing the benthic vegetation of lakes and wetlands, where they exert crucial control over community and ecosystem dynamics. In spite of their widespread distribution, they are amongst the most endangered macrophytes in aquatic ecosystems, threatened by habitat loss and various forms of environmental alterations. The increasing ephemeral nature of many water bodies in Mediterranean and warmer climates further restricts the range of suitable habitats and acts as an
environmental filter affecting biodiversity. In this context, lotic environments may represent suitable refugia, but their highly dynamical nature poses further challenges for the persistence of charophyte populations.
With a view to investigate the ecological niche breadth of charophytes and the role of lotic refugia on their distribution and diversity, the present research investigated 23 populations belonging to the genera Chara, Nitella and Tolypella from southern Italy and northern Egypt. Results show that charophytes increasingly colonize lotic ecosystems in warmer climates, with morphological adaptations to mechanical stresses, but also that populations are likely to undergo local extinction events, dramatically shaping metapopulation dynamics. By shedding light on charophyte ecology, our findings contribute to understanding their dynamics and devising suitable conservation
strategies
Effects of surface and bulk transverse fields on the critical behaviour of ferromagnetic films
No full textThe influence of surface and bulk transverse fields on the critical behaviour of ferromagnetic Ising films is studied by using effective field theory based on a single-site cluster method. Surface exchange enhancement is considered and a critical value is obtained. The,dependence of the critical uniform transverse field on the film thickness, the phase diagrams in the fields, the critical surface transverse field versus the bulk one, and the exchange coupling ratio is presented
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Effects of brace-viscous damper system on the dynamic response of steel frames
Full text linkIn this study, the effects of three different viscous damper configurations, chevron, diagonal and toggle, as well as brace stiffness on the performance of brace-viscous damper system in various steel frams under different earthquake records were investigated. A finite element software, ANSYS, is exploited to develop the numerical models. To verify the numerical simulations, their results were compared with those of the experimental studies in the literature. The results show the reduction in the base shear force given by the toggle configuration is larger than that due to the chevron and diagonal configurations. Regarding the brace stiffness (area), for a reference damping coefficient of 500 N.m/s, a 54% increase in the brace area (from 42 to 91.8 mm2) results in a 21.26, 38.61, and 17.57% reduction in the structure displacement response for the diagonal, chevron, and toggle configurations, respectively. Further, using the results of the numerical simulations, we proposed the spatially-optimized distribution of the brace-viscous damper system
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