1,721,334 research outputs found
Supplementary material - Supplemental material for Identification of Anti-<i>Helicobacter pylori</i> Compounds From <i>Usnea undulata</i>
No full textSupplemental material, Supplementary material, for Identification of Anti-Helicobacter pylori Compounds From Usnea undulata by Trung Do, Trang T.H. Nguyen, Thai N. Ha, Nguyen T.H. Nhu, Nguyen Van Lam, Nguyen T.T. Tram, and Yen Pham in Natural Product Communications</p
First-order phase transitions and giant magnetocaloric effect
No full textModern society relies on cooling technology for food safety, comfort and medical applications. The solid-state cooling technology known as magnetic refrigeration is one of the most promising techniques to replace the current vapor-compression cooling technology. To date, the search for suitable materials with a large magnetocaloric effect (MCE) for domestic applications of magnetic refrigeration is still in progress. This thesis describes a study focused on magnetocaloric materials that can be used in magnetic refrigerators operating at room temperature. Understanding of the phase transition in these materials is of great important to create better materials. As a refrigerator is expected to operate at rather high cycle frequencies, large thermal hysteresis (?Thys) at the magnetic phase transition is the main obstacle to use a material for applications. We have been successful in tuning ?Thys of MnFe(P1-xGex) and related compounds to very small values, while maintaining a large MCE in a large range of working temperatures. These low-cost materials can be used as refrigerants working at high frequencies. This brings the use of practical magnetic cooling a step closer. On the other hand, we have discovered a near room-temperature giant MCE in a new class of magnetic materials based on the intermetallic MnCoGe alloy. The mechanism of manipulating the first-order magnetic phase transition in the MnCoGe-based alloys opens up new possibilities for searching novel magnetic refrigerants for room-temperature applications.Radiation Radionuclides ReactorsApplied Science
A Fourier-series-based virtual fields method for the identification of 2-D stiffness and traction distributions
Full text linkThe virtual fields method (VFM) allows spatial distributions of material properties to be calculated from experimentally determined strain fields. A numerically efficient Fourier-series-based extension to the VFM (the F-VFM) has recently been developed, in which the unknown stiffness distribution is parameterised in the spatial frequency domain rather than in the spatial domain as used in the classical VFM. However, the boundary conditions for the F-VFM are assumed to be well-defined, whereas in practice, the traction distributions on the perimeter of the region of interest are rarely known to any degree of accuracy. In the current paper, we therefore consider how the F-VFM theory can be extended to deal with the case of unknown boundary conditions. Three different approaches are proposed; their ability to reconstruct normalised stiffness distributions and traction distributions around the perimeter from noisy input strain fields is assessed through simulations based on a forward finite element analysis. Finally, a practical example is given involving experimental strain fields from a diametral compression test on an aluminium disc
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
A Fourier-series-based virtual fields method for the identification of 2-D stiffness distributions
Full text linkThe virtual fields method (VFM) is a powerful technique for the calculation of spatial distributions of material properties from experimentally determined displacement fields. A Fourier-series-based extension to the VFM (the F-VFM) is presented here, in which the unknown stiffness distribution is parameterised in the spatial frequency domain rather than in the spatial domain as used in the classical VFM. We present in this paper the theory of the F-VFM for the case of elastic isotropic thin structures with known boundary conditions. An efficient numerical algorithm based on the two-dimensional Fast Fourier Transform (FFT) is presented, which reduces the computation time by three to four orders of magnitude compared with a direct implementation of the F-VFM for typical experimental dataset sizes. Artefacts specific to the F-VFM (ringing at the highest spatial frequency near to modulus discontinuities) can be largely removed through the use of appropriate filtering strategies. Reconstruction of stiffness distributions with the F-VFM has been validated on three stiffness distribution scenarios under varying levels of noise in the input displacement fields. Robust reconstructions are achieved even when the displacement noise is higher than in typical experimental field
Highway Traffic Congestion Patterns: Feature extraction and Pattern retrieval
No full textTraffic congestion occurs daily, which can have negative effects on not only the quality of mobility, but also other important aspects of life like economic growth, health and environment. Both understanding and efficiently managing traffic are therefore crucially important tasks. Vast amounts of data are collected daily to gain insights into the dynamics of traffic. However, these data are typically stored in the form of raw measurements, that might hamper their potential benefits to both researchers and practitioners. A more informative and compact way to store traffic data is in the form of spatio-temporal maps, which have been shown to have advantage in intuitively observing traffic states. However, collecting, managing and retrieving such 2D patterns of congested traffic on large networks are challenging tasks. Accordingly, this dissertation is dedicated to developing methodologies and tools to advance the utilisation of traffic data, in particular, congestion patterns. A conceptual framework for an intelligent search engine for congestion patterns (socalled CoSI) is designed. It covers the entire requirements necessary to develop such a system, ranging from processing raw data to searching through the resulting database of congestion patterns. Overall, the framework consists of two parts: database construction and search application (or so-called pattern retrieval). Their designs and relations are comprehensively presented in this research. The database construction is responsible for preparing a database of patterns of congested traffic which is carefully designed for the conveniences of a search application. Its conceptual design consists of three layers (or phases): pattern collection, feature extraction and pattern annotation. Regarding the search application, several possibilities for retrieving patterns are identified in association with the aforementioned steps of constructing the underlying database.TRAIL Thesis Series no. T2021/22, the Netherlands Research School TRAILTransport and Plannin
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
- …
