1,720,957 research outputs found
Measurement of gas temperature profile using spectral intensity from CO2 4 3 mu m band
No full textSpectral remote sensing (SRS) method for determining the temperature profile along a line-of-sight is investigated experimentally Quartz tube, within which combustion gas flows, is used as the test section The inversion procedure is carried out with a line-by line (LBL) method and a CK-based WNB model, The optimal gas temperature profile that minimizes the error between the measured narrow band intensities around the CO2 4 3 mum band and the calculated ones is obtained as the result of the inversion process The gas temperature is also measured with a shielded thermocouple and corrected for the error The results show that the front center and back temperatures are within errors of 1% 4% and 12%, respectively SRS technique shows poor performance in measuring cold gas temperatures behind a hot layer The reconstructed temperature profile in the front region is however in good agreement with the thermocouple reading The potential applicability of SRS is positively demonstrated and current technical limitations are also discussed (C) 2002 Editions scientifiques et medicales Elsevier SAS All rights reserved.This work has been supported by the Critical Technology 21 Project of theMinistry of Science and Technology,Korea and also by a grant from Korea Science and Engineering Foundation (grant No. KOSEF 995-1000-013-2)
The analytic function expansion nodal method refined with transverse gradient basis functions and interface flux moments
No full textA refinement of the analytic function expansion nodal (AFEN) method is described. By increasing the number of flux expansion terms in the way that the original basic functions are combined with the transverse-direction linear functions, the refined AFEN method can describe the flux shape in the nodes more accurately, since the added flux expansion terms still satisfy the diffusion equation. The additional nodal unknowns introduced are the interface flux moments,, and the additional constraints required are provided by the continuity conditions of the interface flux moments and the interface current moments. Also presented is an algebraically exact method for removing the numerical singularity that can occur in any analytic nodal method when the core contains nearly no-net-leakage nodes. The refined AFEN method was tested on the Organization for Economic Cooperation and Development (OECD)-L336 mixed-oxide benchmark problem in rectangular geometry, and the VVER-440 benchmark problem and a nearly no-net-leakage node embedded core problem, both in hexagonal geometry. The results show that the method improves not only the accuracy in predicting the flux distribution but also the computing time, and that it can replace the corner-point fluxes with the interface flux moments without accuracy degradation, unless the problem consists of strongly dissimilar nodes. The possibility of excluding the corner-point fluxes increases the flexibility in implementing this method into the existing codes that do have the corner-point fluxes scheme and may make it fit better for the nonlinear scheme based on two-node problems
PREVENTION OF SUPERCOOLING AND STABILIZATION OF INORGANIC SALT HYDRATES AS LATENT-HEAT STORAGE MATERIALS
No full textVarious inorganic salt hydrates have been studied as a latent heat storage medium. A super-absorbent polymer (SAP) made from an acrylic acid copolymer is proposed as an effective thickener to prevent undesirable phase separation of the high hydrate inorganic salts (Na2SO4. 10H2O, Na2HPO4 . 12H2O, Na2CO3 . 10H2O). Most of these materials can be stabilized by the addition of 3 to 5 wt% SAP as a thickener. For the low hydrate inorganic salts (CH3COONa. 3H2O, Na2S2O3.5H2O), carboxymethyl cellulose (CMC) is found to be an effective thickener. Similarly, the phase separation of the low hydrate salts can be prevented by the addition of 2 to 4 wt% thickener. To overcome the supercooling of the thickened phase change materials, various potential nucleators have been evaluated. For the thickened Glauber's salt, borax reduces supercooling of the salt from 15 to 3-4-degrees-C. Three different powders of carbon (1.5-6.7-mu-m), copper (1.5-2.5-mu-m) and titanium oxide (2-200-mu-m) are found to reduce the supercooling of thickened Na2HPO4 . 12H2O. Also, the supercooling of thickened CH3COONa . 3H2O is reduced from 20 to 2-3-degrees-C by adding 2 wt% potassium sulfate. New compositions for preventing supercooling and phase separation of PCMs are developed in the temperature range 30-60-degrees-C: Glauber's salt/SAP/borax (94/3/3 wt%, T(m) = 32-degrees-C), Na2CO3 . 10H2O/SAP/Sr(OH)2 (93/3/4 wt%, T(m) = 32-degrees-C), Na2HPO4 . 12H2O (92.8/3.5/3.7 wt%, Tm = 35-degrees-C), Na2S2O3 . 5H2O/CMC/SrSO4 (92/3/5 wt%, T(m) = 48-degrees-C), CH3COONa . 3H2O/CMC/K2SO4 (95/3/2 wt%, T(m) = 58-degrees-C).Ministry of Engergy and Resources of Kore
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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