1,721,265 research outputs found
Engineering of a FGM Interlayer to Reduce the Thermal Stresses Inside the PFCs
Full text linkFeatured Application: Thermomechanical design of a plasma-facing component with an engineered interlayer made with a functionally graded material, able to reduce the thermal stresses due to the mismatch of the coefficient of thermal expansion between the armor and the heat sink material. A substantial contribution of the stresses that arise inside the Plasma-Facing Components (PFCs) when a heat load is applied is caused by the mismatch of the Coefficient of Thermal Expansion (CTE) between the armor, usually made of tungsten (W), and the heat sink. A potential way to reduce such contribution to the secondary stresses is the use of an interlayer made with a Functionally Graded Material (FGM), to be interposed between the two sub-components. By tailoring the W concentration in the volume of the FGM, one can engineer the CTE in such a way that the thermal stresses are reduced inside the PFC. To minimize and, theoretically, reduce to zero the stresses due to the CTE mismatch, the FGM should ensure kinematic continuity between the armor and the heat sink, in a configuration where they deform into exactly the shape they would assume if they were detached from each other. We will show how this condition occurs when the mean thermal strain of each sub-component is the same. This work provides a methodology to determine the thickness and the spatial concentration function of the FGM able to ensure the necessary kinematic continuity between the two sub-components subjected to a generic temperature field monotonously varying in the thickness, while remaining stress-free itself. A method for the stratification of such ideal FGM is also presented. Additionally, it will be shown that the bending of the PFC, if allowed by the kinematic boundary conditions, does not permit, at least generally, the coupling of the expansion of the armor and of the heat sink. As an example of our methodology, a study case of the thermomechanical design of a steel-based PFC with an engineered W/steel FGM interlayer is presented. In such an exercise, we show that our procedure of engineering a FGM interlayer is able to reduce the linearized secondary stress of more than 24% in the most critical section of the heat sink, satisfying all the design criteria
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
ColdPeak - Sistema prototipale di accumulo frigorifero con materiale a cambiamento di fase
Full text linkViene presentata una soluzione innovativa (brevettata) per stoccare energia frigo-rifera in forma di calore latente di solidificazione di materiali a cambio di fase (PCM). Un innovativo sistema di scambio termico implementato nell’unità di stoccaggio per-mette di migliorare la dinamica di accumulo e rilascio di energia, garantendo il raggiun-gimento di elevati valori di potenza specifica sia nella fase di carica che in scarica. Gra-zie a questa soluzione il dimensionamento in potenza del sistema di accumulo è sostan-zialmente indipendente da quello in energia (legato alla quantità di PCM stoccata).
A dimostrazione delle potenzialità della tecnologia, è stato sviluppato e testato un prototipo da 5 kWh di energia frigorifera e 5 kW di potenza media, che viene qui pre-sentato unitamente ad alcuni risultati sperimentali.
Il sistema prototipale di stoccaggio frigorifero è adatto ad applicazioni residenziali (temperature in/out tipiche per il circuito primario pari a 7-12 °C) in quanto il freddo viene stoccato a 5,5 °C. Modificando il tipo di PCM utilizzato è però possibile lavorare in altri range di temperatura realizzando anche accumuli caldi.An innovative (patented) solution to store cold energy by means of the solidifica-tion latent heat of PCMs is presented. An innovative heat exchanger system implement-ed in the storage unit allows the increase of energy charge/release dynamics and, there-fore, leads to high specific power both in charge and release phases. Thanks to this solu-tion, in the design of the storage system, the power can be considered substantially un-connected to the energy (which is related to the amount of PCM stored)
The 5 kWh (and 5 kW of mean power) prototype developed and tested is illustrat-ed, together with some experimental results, demonstrating the technology application potentialities.
The cold storage prototype system is suitable for residential application (typical in/out primary circuit temperature = 7-12°C) since it stores cold energy at 5.5°C; never-theless, modifying the PCM adopted, it is possible to vary the temperature working range (e.g. also hot storage systems can be implemented)
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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