1,721,058 research outputs found
An impedance probe for the measurements of liquid hold-up and mixing time in two/three-phase stirred tank reactors
No full textA new probe based on the measurement of the electrical impedance has been developed to measure liquid hold-up in gas/liquid, solid/liquid and gas/solid/liquid stirred tank reactors. It allows measurements of liquid hold-up and mixing time to be made in stirred tanks. The main advantage of the new probe is that it is absolutely non-intrusive, because it uses the shaft and the baffles' support as electrodes, and that it can be used both for laboratory scale reactors as well as for industrial stirred tank reactors. The relation between impedance and liquid hold-up under loading conditions closely follows the predictions made by means of the Bruggeman model. Therefore, the new probe does not need any calibration, in that the liquid hold-up can be theoretically computed by the measurement of impedance
Time-series analysis approach for the identification of flooding/loading transition in gas-liquid stirred tank reactors
No full textThis work provides a simple method for the objective, quantitative and non-intrusive detection of flooding/loading transition in gas/liquid systems in agitated vessels starting from the time-series analysis of conductance fluctuations along a generic cross section of the vessel. The conductance probe is designed in order to introduce minimal perturbations of the flow field within the vessel. A thorough statistical characterization of the time series collected by the probe provides deeper insight into the fluid dynamics of gas-liquid systems in stirred vessels as well as a simple, objective way to detect flooding/loading transitions
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
A study of Reynolds stresses, triple products and turbulence states in a radially stirred tank with 3-D laser anemometry
No full textDecrease of thyroid-hormones in patients with familial hypercholesterolemia during dextran sulfate low-density-lipoprotein apheresis
No full textTracer dispersion in stirred tank reactors: Asymptotic properties and mixing characterization
No full textThis article addresses the characterization of dispersion and homogenization phenomena in stirred vessels through the analysis of dispersion curves that can be obtained experimentally by means of conductivity measurements. New insights on mixing conditions can be achieved from the analysis of the qualitative and asymptotic properties of tracer dispersion curves. The results obtained are interpreted in the context of the spectral approach to the advection-diffusion equation. It is shown that any flow model aimed at reproducing the experimentally determined dispersion curves must be at least two-dimensional. Convection-enhanced dispersion associated with the spectral structure of the advection-diffusion equation is addressed
Problemi di Epidemiologia e Profilassi dell'Idatidosi in Sardegna alla Luce della Casistica della Clinica Chirurgica dell'Università di Cagliari nel Periodo 1972-1982.
No full textLa diffusione dell'echinococco in Sardegna riveste notevole importanza igienico sanitaria non soltanto per l'indubbio "peso epidemiologico" sulla situazione generale delle parassitosi nel territorio italiano, ma anche per le preziose occasioni di studio che essa offre in rapporto alla peculiarità delle condizioni agro-pastorali dell'isola particolarmente favorenti all'estrinsecarsi del ciclo biologico del parassita. In questo lavoro si documenta l'attività svolta dalla Clinica Chirurgia Pediatrica dell'Università di Cagliari nel periodo 1972-1982 in relazione a 115 casi di idatidosi operata in età pediatrica al di sotto di 12 anni presso tutti i nosocomi cagliaritani. Vengono anche presi in rassegna gli schemi di intervento profilattici modulati in aderenza alla realtà economico-sociale ed alle caratteristiche agro-pastorali dell'Isola
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
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