1,720,960 research outputs found
Analytical Evaluation of the Effects on the Electromagnetic Field Induced by a Moving Dielectric Slab
No full textA simple one-dimensional electromagnetic problem in the presence of moving objects is studied. The analytical solution is used to investigate the effects of motion on the electromagnetic field. The results show that for this class of one-dimensional problems the effects of motion are weaker than expected. For this reason the simple problem considered in this work could be of interest for investigating the reliability of inverse scattering procedures or for testing numerical methods
Recovery of lactose from acid whey by nanofiltration: An experimental study
Full text linkThe flowsheet of an overall process to recover valuable products from raw acid whey is proposed. It considers typical pretreatments, an ultrafiltration step to remove proteins, a decalcification step to remove calcium and magnesium by precipitation, and a nanofiltration/diafiltration step for demineralization and deacidification of lactose. The performance of each step is evaluated and the characteristics of the main streams are estimated. The feasibility of lactose recovery after the decalcification step by nanofiltration is demonstrated by using a spiral wound module. Membrane characterization was performed at pH 4 and 50 °C, with an artificial solution containing lactose, lactic acid and sodium chloride, prepared to mimic the clarified supernatant from the decalcification unit. The feasibility of the simultaneous concentration and deacidification of lactose is finally validated by processing a real solution. With the real solution, the maximum removal of lactic acid, close to 87%, is obtained by operating with a nanofiltration (NF) step (at a concentration factor of 3.5) followed by a NF step operated in diafiltration mode (DF) at constant volume (at a dilution factor of 1.8). A lactic acid/lactose ratio of 0.018 g/g is achieved, with an overall lactose purity and yield of 93.6% and 98.2%, respectively, when operating at low pressure values (up to 12-14 bar). A preliminary process simulation is finally performed to identify the premises for process optimization of the NF+DF configuration. The success of the integrated NF+DF process is contingent upon the correct balance between the choice of the membrane and the operating conditions, which ensure lactose rejections exceeding 98.5 % and lactic acid rejections falling below 20-30 %, while maintaining transmembrane fluxes between 8 and 15 dm3/(hm2)
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
Ion-exchange membrane chromatography
No full textChromatography is a powerful separation technique that has become an important unit operation when high levels of purity are required. The selectivity of the separation process depends on the interactions between the stationary phase and the mobile phase components. This gives the process great flexibility, as several functionalities can be incorporated into the stationary phase and stationary phases of different types and formats are possible. The focus of this volume is on ion-exchange chromatography, which is the most widely used process chromatography technique, and in this chapter, we will focus on ion-exchange membrane chromatography. Transport phenomena in membrane chromatography are discussed in detail highlighting the differences from packed column resin chromatography. We will then present different ways of stacking membranes into units and the limitations of existing module designs, finally we will present membrane adsorbers currently on the market and conclude with some application examples
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
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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