1,720,978 research outputs found
High strength brown parts produced by fast microwave-assisted debinding
No full textThe binder removal from 430L-steel MIM parts was performed in a two-step procedure using chemical and thermal debinding. During the first step, almost 80% of the binder is removed and a porous structure is created, which then favours the subsequent step. The second step was performed in a multi-mode microwave applicator, at 2.45 GHz ISM frequency. Numerical simulation allowed to optimise the microwave applicator loading conditions, in terms of heating homogeneity and efficiency. Experimental validation confirmed that using microwaves it is possible to reduce conventional debinding times by a factor of 3, and that the resulting brown parts possess a 4 times higher compressive strength. This phenomenon can be ascribed to local over-heating of the regions surrounding neighbouring metal particles, triggered by the high frequency electric field. This promotes the formation of necks among the particles, leading to pre-sintering, despite the overall measured samples temperature, which never exceeded 600°C
An integrated mass spectrometric and molecular imaging analytical approach to identify and localise constituents in paintings applied to gilded multilayer structures from 14th to 16th C works of art
No full textA multi-anal. approach is presented to det. the org. and inorg. compn. of gilding samples that have a multi-material and multi-layered structure. The effectiveness of the combination of mass spectrometric methods to identify org. materials and mol. imaging to localize org. and inorg. constituents is explored by a detailed characterization of the materials used in three different gilded decorations on wall paintings. The results are interpreted in the art tech. and historical context of gilding
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
Real time Vehicle Color Recognition on a budget: an investigation on the usage of CNN architectures
No full textIn this work, we consider the problem of vehicle color recognition and target scenarios with limited computational resources. Indeed, in real traffic monitoring systems running on the field, algorithms must be light in terms of inference time and memory, but also accurate and robust to the scene variability. We employ end-to-end Convolutional Neural Networks to investigate under which conditions the use of such methodologies- that are state-of-the-art in a multitude of vision-based tasks but often lead to a significant computational burden- can provide us a good compromise between efficiency and effectiveness. We reason on the structure and size of the networks, while monitoring the performance in terms of color classification accuracy and computational effort. We provide an extensive experimental analysis comparing the methods using a benchmark and a private dataset acquired on the field, with almost 20K of images covering a variety of scene conditions
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
Role of mitochondria in serum withdrawal-induced apoptosis of immortalized neuronal precursors
No full textAbstract
The intracellular mechanisms controlling apoptosis in immature neurons are still largely unknown. Taking immortalized hippocampal
neuronal precursors (mouse cell line HN9.10e) as a model, we have analyzed the cellular events associated to apoptosis induced by serum
deprivation. We observed translocation of Bax from cytosol to mitochondria after 1 h of serum withdrawal followed, 2 h later, by
cytochrome c release from mitochondria. These events occurred without mitochondrial membrane potential loss nor mitochondrial
calcium raise. As calcium is implicated in several cell death pathways, we analyzed intracellular calcium levels after longer periods of
21 21 serum deprivation. After 6 h, an increase of cytosolic Ca was detected in HN9.10e cells loaded with the Ca indicator Fluo3-AM. This
increase of calcium preceded morphological signs of apoptosis such as cell shrinkage and nuclear fragmentation, and was followed by a
more pronounced raise that persisted until the terminal phases of the apoptotic process. Cells serum-deprived for 4 h and then grown in
complete medium for 20 h fully recovered viability. Summarizing, in HN9.10e cells, calcium deregulation occurs in the late phases of
apoptosis; earlier events involve translocation of Bax, release of cytochrome c, and maintenance of mitochondrial functionality. This
allows an enlargement of the temporal window in which commitment to death is reversible
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
- …
