1,720,964 research outputs found
Experimental data on the reliability of flowmetrs for pressure pipes
No full textThis paper summarizes the results of a large number of tests carried out about the reliability of discharge measurements given by flowmeters for pressure pipes of different kinds (electromagnetic, ultrasonic and turbine flowmeters), on the basis of the experimental data collected at Laboratorio di Idraulica “G. Fantoli” of Politecnico di Milano.
In fact, since 2002, this laboratory is the seat of the Settore Portate of Centro SIT n. 104, that is a structure of Politecnico di Milano accredited for flowmeters calibration in the discharge range from 3 l/s to 80 l/s, with a so-called “best measurement capability” (BMC) equal to 0.2 %.
During these years, a lot of calibrations of different flowmeters have been carried out (61 flowmeters were tested so far: 44 electromagnetic, 9 ultrasonic, 8 turbine flowmeters). So, the tested flowmeters are supposed to give a relevant sample of experimental data, and therefore it seems interesting to carry out some statistical analyses about their performances and reliability. Of course no general consideration can be inferred about the general performances and reliability of other similar instruments not tested
Statistical analysis on experimental calibration data for flowmeters in pressure pipes
Full text linkThis paper shows a statistical analysis on experimental calibration data for flowmeters (i.e.: electromagnetic, ultrasonic, turbine flowmeters) in pressure pipes. The experimental calibration data set consists of the whole archive of the calibration tests carried out on 246 flowmeters from January 2001 to October 2015 at Settore Portate of Laboratorio di Idraulica "G. Fantoli" of Politecnico di Milano, that is accredited as LAT 104 for a flow range between 3 l/s and 80 l/s, with a certified Calibration and Measurement Capability (CMC) - formerly known as Best Measurement Capability (BMC) - equal to 0.2%. The data set is split into three subsets, respectively consisting in: 94 electromagnetic, 83 ultrasonic and 69 turbine flowmeters; each subset is analysed separately from the others, but then a final comparison is carried out. In particular, the main focus of the statistical analysis is the correction C, that is the difference between the flow rate Q measured by the calibration facility (through the accredited procedures and the certified reference specimen) minus the flow rate QMcontemporarily recorded by the flowmeter under calibration, expressed as a percentage of the same QM
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
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
Takotsubo syndrome in a patient with metastatic renal cell carcinoma treated with pembrolizumab plus axitinib
No full textWe report the case of a patient with metastatic renal cell carcinoma who developed Takotsubo syndrome (TTS) 6 days after starting pembrolizumab plus axitinib as first-line treatment. Coronary angiogram was negative for obstructive coronary artery disease and echocardiogram revealed a depressed left ventricular ejection fraction with apical akinesis. Axitinib was discontinued and myocardial contractile function fully recovered 23 days after the initial presentation. The treatment was safely resumed and granted a partial response of disease. A literature review regarding TTS in patients receiving VEGFR tyrosine kinase inhibitors and/or immune checkpoint inhibitors was performed. TTS is reported as a rare adverse event and the possible causal relationship between TTS and antineoplastic therapy is still unclear. Further research is warranted to better understand cardiotoxicity mechanisms and their management
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