1,720,957 research outputs found
CFD approach for the induced effects of free wake past rivulets on cables of stayed bridges
No full textLarge-amplitude oscillations of stayed bridge cables appear under the combined effects of crosswind and rain. "Wave-like" oscillations along the whole cable length are born with large amplitudes even under low-speed wind and only the presence of the rain rivulet motion on the cable cross-section which guarantees an "all-or-none" amplification of the dynamic response of the cable. Even though this peculiar behavior has been studied, in a recent past, through dynamic and structural approaches, the phenomenon is not yet quite well understood, i.e., the quasi-cyclic oscillations seem to be activated to events (rain rivulets motion along the cables) compromising the circumferential geometry shape of the cable cross-section and the frequency of the vortex shedding of the leaving wake past the cable. The aim of the present work is to apply a Computational Fluid Dynamic (CFD) approach having in mind that the unsteady wake interaction with the cable dynamics could be useful to explain and predict how the cable fluctuates in an oscillatory fashion and its time-dependent evolution with the leaving vortex frequency under the combined actions of wind and rain.
Due to the available computational resources, the K-epsilon turbulent model simulations of an unsteady and viscous wake flow past the cables is here employed with emphasis on capturing the time-dependent flow structures representing the wave-like nature of the aerodynamic loads under the above mentioned atmospheric conditions in which both the (in-phased) cable and rivulet cross-sections are considered to have the same azimuthal frequency and embedded in a free-stream with constant velocity.
In this paper, the rivulet movement on the cable surface has been taken into account while a rigid translatory motion of the cable cross section is disregarded, being the aim of the current computational method to find (and predict) the inception mechanism of the elastic vibrations of the cable. As widely accepted and adopted in the current literature, in this initial computational step, the natural frequency of the cable has been fixed being that the only one a priori hypothesis
Adjuvant intravesical therapy in intermediate risk non-muscle invasive bladder cancer (NMIBC) recurring after first cycle of intravesical treatment.
No full textIntroduction and objectives
The therapeutic management of intermediate risk NMI-BC recurring after intravesical therapy (IT) is not established. Cystectomy will be offered to patients at higher risk of progression but the majority will be retreated by IT. Although some Authors suggest BCG when intravesical chemotherapy (ICH) fails, some patients are retreated by ICH and some others repeat BCG adopted as first-line treatment. Not many studies have been published on this issue. The response to retreatment by intravesical therapy in terms of recurrence-free rate (RFR) and recurrence-free survival (RFS) is analyzed in 179 intermediate-risk patients.
Materials and methods
Only intermediate-risk tumours (EORTC Risk Tables recurrence-risk score 5-9) in absence of TIS were selected. The patients not receiving at least 6 instillations of BCG or ICH after the first diagnosis and again after the TUR of the first recurrence, were excluded. Only BCG, mitomycin c and epirubicin were accepted. All patients were submitted to cytology and cystoscopy 3-monthly for the first 2-years and then 6-monthly. A statistical analysis was performed for RFR and RFS and progression, considering first line IT (BCG versus ICH), previous recurrence free interval, T-category, G-grade, multiplicity, second line IT (BCG versus ICH) and maintenance regimen.
Results
The study included 179 patients. The first-line IT was ICH in 131 (73.2%) and BCG in 48 (26.8%) patients. The median recurrence free interval was 16 months. Intravesical therapy at recurrence was BCG in 83 (46.4%) and ICH in 96 (53.6%) patients. Maintenance of at least 12 months was given in 31.3% and 38.5% of patients respectively. Of the 48 patients previously treated by BCG, 40 (83.3%) repeated it, while of the 131 previously treated by ICH, 88 (67.2%) received ICH again and 43 (32.8%) BCG. Thus, only 8 patients received ICH after BCG. At a median follow-up of 29 months, 65 (36.3%) patients recurred, 25 (30.1%) and 40 (41.7%) after BCG and ICH respectively. No statistical difference emerged in terms of RFS between BCG and ICH (p=0.97). Thirteen patients showed progression at a median interval of 19 months. At multivariate analysis no statistically significant correlation was detected among the considered parameters. Surprisingly, no statistical difference emerged in terms of recurrence free interval between first and second line IT (16 versus 15 months, Mann Whitney U-Test p=0.38), and between patients receiving BCG or ICH as second line therapy after ICH (=0.28).
Conclusions
Intravesical re-treatment by chemotherapy or BCG did not show any reduction in terms of RFS when compared with the first line therapy. Moreover, in patients recurring after intravesical chemotherapy, chemotherapy and BCG resulted equally effective in terms of RFR and RFS
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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