1,720,982 research outputs found
The effect of wire drawing speed on the dislocation substructures and mechanical properties in aluminum
No full textAbstract not availabl
Virtual 3D microstructures with specified characteristics of state variable distributions
No full textFor a wide variety of model calculations a hypothetical 3D microstructure is required as input. Although experimental data are frequently used to this purpose, 3D microstructures are difficult to measure experimentally. In order to circumvent these difficulties, a virtual microstructure generator to simulate a specific 3D material microstructure is proposed. Such a virtual microstructure could serve as input for different types of models, would allow a faster model prototyping, would help to explore the boundary conditions of models and reduces the number of unnecessary experimental measurements. In the current paper, the method to generate and to control the grain size distribution as well as texture are discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
X-ray diffraction for the determination of residual stress of crystalline material: an overview
Get PDFThough there are a variety of experimental techniques available for residual stress measurements, diffraction-based measurements have the unique advantage of estimating the individual components of the residual strain matrix in a crystalline material. This is then converted to residual stresses with appropriate continuum elasticity model(s) and X-ray elastic constants. In particular, measurements based on electron or neutron diffractions have their complexities or availability issues. The laboratory X-ray diffraction, on the other hand, may provide an easy resource and an effective tool. Such measurements range from two tilt methods to more extended d-sin2ψ measurements and multiple {hkil} grazing incident X-ray diffraction. Measurements can even be conducted on single crystals with micro-Laue diffraction and extended to stress ODF (orientation distribution function) calculations. These techniques are unquestionably extremely specialized, where measurement uncertainty plays an important role in the effectiveness plus reproducibility of the data. Unfortunately, standard textbooks or review articles typically describe some, but not all, of the techniques. In this overview, different techniques of X-ray diffraction for the determination of residual stresses in crystalline material have been summarized. It is hoped that potential users may benefit from the deliberations
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Microstructural and Mechanistic Insights into the Tension-Compression Asymmetry of Rapidly Solidified Fe-Cr Alloys: A Phase Field and Strain Gradient Plasticity Study
Get PDFRapid solidification in Additively Manufactured (AM) metallic materials
results in the development of significant microscale internal stresses, which
are attributed to the printing induced dislocation substructures. The resulting
backstress due to the Geometrically Necessary Dislocations (GNDs) is
responsible for the observed Tension-Compression (TC) asymmetry. We propose a
combined Phase Field (PF)-Strain Gradient Plasticity (SGP) framework to
investigate the TC asymmetry in such microstructures. The proposed PF model is
an extension of Kobayashi's dendritic growth framework, modified to account for
the orientation-based anisotropy and multi-grain interaction effects. The SGP
model has consideration for anisotropic temperature-dependent elasticity,
dislocation strengthening, solid solution strengthening, along with GND-induced
directional backstress. This model is employed to predict the solute
segregation, dislocation substructure and backstress development during
solidification and the post-solidification anisotropic mechanical properties in
terms of the TC asymmetry of rapidly solidified Fe-Cr alloys. It is observed
that higher thermal gradients (and hence, cooling rates) lead to higher
magnitudes of solute segregation, GND density, and backstress. This also
correlates with a corresponding increase in the predicted TC asymmetry. The
results presented in this study point to the microstructural factors, such as
dislocation substructure and solute segregation, and mechanistic factors, such
as backstress, which may contribute to the development of TC asymmetry in
rapidly solidified microstructures.Comment: 30 pages, 12 figure
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