1,721,011 research outputs found
ESTRA-FitEXA: A software package for EXAFS data analysis
No full text""ESTRA and FitEXA are two programs for processing X-ray absorption spectroscopy data, extraction of extended X-ray absorption fine structure (EXAFS) signal, and EXAFS data analysis via least square refinement procedure (shell fitting). ESTRA and FitEXA propose useful options such as the analysis of the noise on the raw χ(k) data and a high flexibility in the choice of the model distribution function: harmonic, anharmonic (cumulants) and hard sphere models. The minimization routines underneath the FitEXA code allow ample choice\\\/control of the non-linear minimization procedure and check of the correlation among the parameters."
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
The Impact of Test Voltage Waveform in Determining the Repetitive Partial Discharge Inception Voltage of Type i Turn/Turn Insulation Used in Inverter-Fed Induction Motors
No full textThe reliability of induction motors stators realized using Type I insulation systems is ensured only when the partial discharge inception voltage (PDIV) is larger than the operating voltage. The concept of Repetitive PDIV (RPDIV) has been proposed as a replacement of PDIV for tests performed under surges or repetitive square waves. RPDIV estimates exceed the PDIV level. The difference might depend on the surge repetition frequency, possibly providing contradicting results using different high voltage sources. Thus, the industry is concerned about the use of RPDIV in place of PDIV and the possible implications for the quality of the stators. Also, little has been discussed about the randomness of measurements and how to treat data using appropriate statistical tools. In this paper, we shall show results of PDIV and RPDIV tests performed on twisted pairs subjected to AC sinusoidal voltages, surges from a commercial surge generator, and unipolar square waves from a high voltage MOSFET. Tests are performed on ten twisted pairs to derive the distribution of RPDIV estimates and compare the differences using statistical tools. Different types of wire are considered to carry out a comparative analysis
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
Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues
No full textInsights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy e energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed
that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed
by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process is easily decomposed
forming more stable compounds such as antimony mixed oxidic forms. Sb redox speciation, in particular and well studied circumstances, may enhance the potential and selectivity of this element as a tracer of
motor vehicle emissions in apportioning studies.Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy - energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process i..
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