1,721,120 research outputs found
Fluid dynamic efficiency and scale-up of a retreated blade impeller CSTR
No full textNumerical simulations are used to characterize the fluid dynamic behavior of an industrial-size reactor. First, we focused on an experimental replica (∼440:1 volume ratio) of the full-scale reactor and evaluated the reliability of fully three-dimensional, time-dependent numerical computations of the flow field. An experiment was planned to obtain power data, which were compared with computer simulations for the scaled model, giving good agreement. Next, we examined the full-scale industrial reactor by exploiting the available macroscopic experimental observations and original computer simulations. We verified the scale-up of the two reactors by comparing the power number, discharge flow number, and pumping efficiency. Finally, by examining the power and stirring capability for different operating conditions, we found the operating conditions that ensured the optimum fluid dynamic efficiency
Automated calibration of the EPA-SWMM model for a small suburban catchment using PEST: a case study
Full text linkRainfall-runoff models must be calibrated and validated before they can be used for urban stormwater management. Manual calibration is very difficult and time-consuming due to the large number of model parameters that must be estimated concurrently. Automatic calibration offers as a promising alternative, ideally supporting a user-independent and time-efficient approach to model parameters estimation. In this article, we test the use of a state-of-the-art standard package (PEST, Parameter ESTimation, http://www.pesthomepage.org/) for the automatic calibration of a rainfall-runoff EPA-SWMM (Storm Water Management Model) model developed for a small suburban catchment. Results reported in the paper demonstrate that the performance of automatically calibrated models still depends on a number of user-dependent choices (the level of catchment discretization, the selection of significant parameters, the optimization techniques adopted). Through a systematic analysis of the results, we try to identify the guidelines for the effective use of automatic calibration procedures based on modeling assumptions and target of the analysis
First electrosurgical excision of fibrosarcoma in goldfish (Carrassius auratus auratus)
No full textA Carrassius auratus auratus presented for a mass diagnosed as a fibrosarcoma. It was anaesthetised and an electrosurgical device was used and the mass was ablated. There is no previous documentation for electrocautery use in fish oncology. This note provides a safe protocol for electrosurgical excision of neoplasia in fish
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
Weight-Based Discrimination in the Italian Labor Market: an Analysis of the Interaction with Gender and Ethnicity
Full text linkAccess to the Italian job market is undermined by several kinds of discrimination influencing the opportunities for individuals to obtain a job. In this study, we analyze together the impact of three of the most relevant kinds of discrimination operating in the Italian labor market: gender, race, and weight. Our aim is to assess whether gender and race either increase or decrease the impact of weight-based discrimination. In this respect, we submit a set of fictitious résumés including photos of either obese or thin applicants in response to real online job offers. Our results indicate that the strongest kind of discrimination operating in the Italian labor market is the one connected to the candidate’s geographical origin. Moreover, we find discrimination based on body weight to be more relevant within immigrants than within natives, and gender gap appears to be higher within the obese candidates’ group compared to the normal-weight candidates’ one. This last result is particularly relevant, as the growing rates of obesity forecasted for the next years could in turn produce an increase in the gender gap, which in Italy is already massive
Comparison of novel ladle slag treatment and handling systems based on resource-efficiency metrics
No full textLadle slag is a by-product common to electric and basic oxygen steelmaking furnaces which is gaining increasing attention as a secondary material. Its main recycling path is internal to steelmaking process, since it can replace the lime used to remove impurities. However, storing and handling slag for internal recycling is problematic because cooled ladle slag soon becomes extremely dusty, determining harsh environmental conditions at the plant. Recently, a novel solution based on granulation of ladle slag was presented on the market, which could be integrated in the steelmaking process using diverse handling and storage systems. The implementation of such systems requires resources, specifically energy, but may produce benefits such as lower pollution from particulate emissions and easier storage, leading to lower material losses, reduced landfill disposal and savings of primary mineral resources. In this paper, three alternative treatment and handling systems are analyzed and ranked using ad hoc defined first level resource efficiency metrics. Results show that the best alternative in terms of carbon emission intensity is the more advanced configuration, which includes granulation within a casing and automatic transport with apron conveyors; however, open granulation with current handling systems apparently minimizes primary energy intensity. A possible cause for this discrepancy is that emission factors and primary energy consumption factors obtained from official sources refer to different years, and hence to a different electric energy generation mix. A clear ranking between the basic and the most advanced configuration cannot be obtained, but the resource efficiency evaluation leads to exclude the intermediate configuration (granulation within a casing and traditional materials handling) which is apparently dominated by the remaining alternatives
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