1,720,985 research outputs found
Isothermal (Vapour + Liquid) Equilibrium Measurements and Correlation of the Binary Mixture {3,3,3-Trifluoropropene (HFO-1243zf) + 2,3,3,3-tetrafluoropropene (HFO-1234yf)} at Temperatures from 283.15 K to 323.15 K
Full text linkThe many constrains introduced by the F-gas Regulation and the Kigali Amendment to the Montreal Protocol have resulted in an intense search for alternatives to fluorinated greenhouses gases for air conditioning and refrigeration purposes (Mota-Babiloni A, Makhnatch P, in Int J Refrig 127:101–110, 2021). With respect to the urge of new low-GWP and low-ODP refrigerants, blends composed of hydrofluoroolefins (HFO) are considered promising possible substitutes to hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) for HVAC&R applications (Sovacool et al., in Renew Sustain Energy Rev 141:110759), but thermophysical properties data for these blends are still scarce (Bell et al., in: J Chem Eng Data, 2021). In the present study, the vapor–liquid equilibrium (VLE) for the binary system (HFO-1243zf + HFO-1234yf), for which just one set of data on the VLE is available to date in literature, has been experimentally studied by means of a vapor recirculation apparatus. The measurements have been performed at isothermal conditions in the range of temperatures between 283.15 K and 323.15 K, while the composition of both the phases in equilibrium has been measured by gas-chromatographic analysis. The experimental VLE data have been correlated by two different equations of state (EoS): the Peng-Robinson (PR) EoS combined with Mathias–Copeman (MC) alpha function and van der Waals (vdW) mixing rules, and the Helmoltz EoS with dedicated binary interaction parameters. Correlated results showed a good agreement with the experimental data for the binary system
HCFO refrigerant cis-1-chloro-2,3,3,3 tetrafluoropropene [R1224yd(Z)]: Experimental assessment and correlation of the liquid density
No full textIn the search for substitutes for high global warming potential (GWP) refrigerants, measurements of thermodynamic properties for refrigerants belonging to new halogenated olefins group (HFO) is of strict actuality, due to their GWP, close to that of natural refrigerants, and the lack of information on their properties. One of the most interesting HFOs is cis-1-chloro-2,3,3,3-tetrafluoropropene (R1224yd(Z)), suitable, for its relatively high NBP (287.15 K) and its low vapour pressure, to be used in applications such as Organic Rankine Cycles (ORC), industrial high temperature heat pumps or centrifugal chillers. The paper presents 90 experimental compressed liquid density data for R1224yd(Z) in a range of temperatures and pressures varying from 283.15 K and 363.15 K and from close to saturation pressure up to 35 MPa, respectively. The data were measured by means of a vibrating tube densimeter at isothermal conditions. By extrapolating the isothermal compressed liquid density data at the saturated pressure, 10 saturated liquid density values have also been obtained. A Tait correlation for the compressed liquid density data and a dedicated correlation for the saturated liquid density are presented. Both correlations well represent the experimental data, with a percentage absolute average deviation (AAD%) of 0.1% in both cases. Experimental liquid density data have been compared to literature through the most updated version of the fundamental equation of state proposed by (Akasaka et al., 2017). The equation shows a very good agreement with the present data, considering that most of the data are in the extrapolation areas of the equation
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
grasshoppers (Orthoptera: Acrididae)
No full textCastillo, Elio Rodrigo D, Celeste Scattolini, M, Palacios-Gimenez, Octavio M, Martí, Dardo A, Cabral-De-Mello, Diogo C, Cigliano, María M (2023): Karyotype evolution in Ronderosia grasshoppers (Orthoptera: Acrididae). Zoological Journal of the Linnean Society 198 (2): 351-367, DOI: 10.1093/zoolinnean/zlac090, URL: https://academic.oup.com/zoolinnean/article/198/2/351/704129
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
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