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Modelling students' behaviours has reached a status that can only be overcome by improving the ability of predicting the results on teamwork. Indeed, teamwork is an important piece on the learning process, but understanding their mechanisms and predicting the results achieved is far from being solved by traditional classifiers. In this paper, we address the problem of predicting teamwork results, and propose a recommender system that suggests new teams, in the context of a given curricular unit. Any student, who is looking for a team, may use the system; in particular, he may ask for the best team to join, either considering all available colleagues or just the set of his previous teammates. Our system makes use of social network analysis and classification methods as the algorithmic core of the decision‐making process. System evaluation is presented through a set of experimental results, which report the performance of social network analysis and classification algorithms over real datasets. 相似文献
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Dbora Drummond Hauss Monteiro Henrique Limboro Rodrigo Guimares Porto Allyson Nogueira Moreira Wagner Nunes Rodrigues Cludia Silami de Magalhes 《Microscopy research and technique》2020,83(6):597-603
The MeX? software is a useful tool for tridimensional data collection for surface evaluation and could be relevant to evaluate the same specimen in different phases of the study, assuming repeated measures of dental enamel roughness. The aim of this study was to evaluate the influence of sample metallization for dental enamel roughness analysis with 3D images reconstructed using MeX? software from Scanning Electron Microscopy (SEM) images. The influence of 74.98% (%mol/mol) argon?oxygen plasma for carbon layer removal on surface roughness of the metallized specimen was also evaluated. Dental enamel specimens were prepared for SEM analysis with and without carbon metallization using conventional or environmental modes. Argon?oxygen plasma for carbon layer removal was used and surface roughness was re‐evaluated. Roughness obtained by SEM and MeX? reconstructed images, with or without metallization, did not differ. No significant alteration on surface roughness after carbon layer removal using plasma was found. SEM baseline evaluation using conventional mode without sample preparation and in environmental mode were not comparable. Roughness of enamel 3D images reconstructed with MeX? software from SEM images, with or without metallization was similar. The 74.98% (%mol/mol) argon?oxygen plasma removed the carbon layer with no effect on enamel roughness. 相似文献
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Marta Oliveira Susana Casal Simone Morais Cláudia Alves Filipa Dias Sandra Ramos Eulália Mendes Cristina Delerue-Matos M. Beatriz P.P. Oliveira 《Food chemistry》2012,130(3):702-709
The present paper reports the amount and estimated daily mineral intake of nine elements (Ca, Mg, K, Na, P, Fe, Mn, Cr and Ni) in commercial instant coffees and coffee substitutes (n = 49). Elements were quantified by high-resolution continuum source flame (HR-CS-FAAS) and graphite furnace (HR-CS-GFAAS) atomic absorption spectrometry, while phosphorous was evaluated by a standard vanadomolybdophosphoric acid colorimetric method.Instant coffees and coffee substitutes are rich in K, Mg and P (>100 mg/100 g dw), contain Na, Ca and Fe in moderate amounts (>1 mg/100 g), and trace levels of Cr and Ni. Among the samples analysed, plain instant coffees are richer in minerals (p < 0.001), except for Na and Cr. Blends of coffee substitutes (barley, malt, chicory and rye) with coffee (20–66%) present intermediate amounts, while lower quantities are found in substitutes without coffee, particularly in barley.From a nutritional point of view the results indicate that the mean ingestion of two instant beverages per day (total of 4 g instant powder), either with or without coffee, cannot be regarded as important sources of minerals to the human diet, although providing a supplementation of some minerals, particularly Mg and Mn in instant coffees. Additionally, and for authentication purposes, the correlations observed between some elements and the coffee percentage in the blends, with particular significance for Mg amounts, provides a potential tool for the estimation of coffee in substitute blends. 相似文献
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Manuel Portugal Ferreira Cláudia Frias Pinto Fernando Ribeiro Serra 《Scientometrics》2014,98(3):1899-1922
Transaction costs theory (TCT) has long been an important conceptual lens for examining International Business (IB) phenomena and perhaps especially relevant for the study of multinational corporations, entry mode choices and location selection. In this paper we examine the extent to which TCT been used and has impacted IB research. Methodologically, we conduct a bibliometric study of the articles published on nine top journals for publishing IB-related research. We use Jean-François Hennart’s research as the key marker for TCT in IB research given that Hennart’s work has been a hallmark in the discipline. On a sample of 377 articles published between 1982 and 2010, and using the works rather than the authors as the unit of analysis, we analyze citations, co-citations and a spatial visualization of the intellectual research themes delved into. Our analyses provide insights on the influence of Hennart but more broadly of TCT on IB research over the past three decades. We conclude that the TCT has a pervasive influence on a large array of IB research and that Hennart’s work is boundary-spanning, connecting several research themes. 相似文献
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Vanessa Migliorini Urban Ana Lucia Machado Carlos Eduardo Vergani Eunice Teresinha Giampaolo Ana Cláudia Pavarina Quezia Bezerra Cass 《应用聚合物科学杂志》2012,123(2):732-739
The effect of a post‐polymerization treatment on the leaching of methacrylic acid (MA) and benzoic acid (BA) from the reline resins [Kooliner (K), New Truliner (N), Ufi Gel hard (U), and Tokuso Rebase Fast (T)] was evaluated. Specimens of each material were divided into two groups: Group C (control) – left untreated; Group WB (water‐bath) – immersion in water at 55 ± 1°C for 10 min. Specimens were placed in artificial saliva at 37 ± 1°C and, after 1‐, 3‐, 5‐, 24‐h and 3‐, 7‐, 14‐, and 30‐day intervals, aliquots were removed and analyzed using high performance liquid chromatography. Data were analyzed by using Wilcoxon, Mann–Whitney or Kruskal–Wallis tests (α = 0.05). At 1 h, the concentration of MA released from U control specimens was higher than those of the other ones, and decreased after 3 h. WB specimens released lower amounts of MA than control specimens only for material U, at the 1‐ and 3‐h periods. For all control specimens, concentrations of leached BA progressively decreased within 5 h and from 24 h to the end. WB specimens released significantly lower amounts of BA than did the control groups. The highest concentration of MA was leached from control specimens of Ufi Gel hard. Water‐bath post‐polymerization treatment caused a significant reduction in elution of BA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Optimization of alcohol‐free beer production by lager and cachaça yeast strains using response surface methodology 下载免费PDF全文
Cláudia Puerari Jan Strejc Angélica C. Souza Marcel Karabín Rosane F. Schwan Tomáš Brányik 《Journal of the Institute of Brewing》2016,122(1):69-75
Alcohol‐free beers (AFBs) are an attractive segment of the beer market both for the brewing industry and for consumers. While AFBs produced by arrested/limited fermentation often suffer from a lack of volatile compounds, beer flavour can be improved by yeast selection and optimization of fermentation conditions. The yeast selection strategy was demonstrated by comparing traditional lager yeast with selected cachaça yeast strains. Correspondingly, response surface methodology was used to enhance the formation of the flavour‐active volatile compounds by optimization of the fermentation conditions (original wort extract, fermentation temperature, pitching rate). Statistical analysis of the experimental data revealed the relative significance of process variables and their interactions. The developed quadratic model describing the responses of total esters and higher alcohols to changes in process variables was used to predict the ideal fermentation conditions in terms of flavour formation. The predicted conditions were experimentally verified and alternative strategies of AFB production are suggested. Copyright © 2016 The Institute of Brewing & Distilling 相似文献
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Cláudia Nunes Conceição Santos Glória Pinto Sónia Silva José A. Lopes-da-Silva Jorge A. Saraiva Manuel A. Coimbra 《Food chemistry》2009
The plums used to produce a traditional candied product, “Ameixa d’Elvas”, were obtained from two orchards, Vila Viçosa (VV) and Cano (CA). These orchards were selected because the fruits were behaving differently: (1) The day of harvesting for candying, established by the total soluble solids and titratable acidity, was one week earlier in VV; (2) VV yielded candied plums with good texture properties whereas CA gave poor processed fruits. In order to understand the origin of these differences, fruits from both orchards were harvested on the day established as the harvesting day for VV (day 1) and for CA (day 8). Comparable texture properties were obtained in firmness, rigidity and deformation work between the VV fresh plums harvested on day 1 and the CA plums harvested on day 8 but these were lower in CA when the flesh was analysed separately, in accordance with the activities of pectin methyl esterase (PME), polygalacturonase (PG) and cellulase (Cel). The increase of the intercellular area of parenchyma cells and the decrease in cell area caused by boiling, which resulted in a pronounced loss of textural properties, were partially recovered after the immersion of the fruits in sucrose syrup. The CA plums harvested on day 8 had a more pronounced degradation with boiling and lower recovery of cell shape, size and textural characteristics than had those of VV harvested on day 1. Upon candying, similar properties were observed for the fruits harvested on the same day: good candied products were observed for VV and CA fruits harvested on day 1 and poor candied products were observed for VV and CA fruits harvested on day 8. This work shows that the characteristics of the flesh of the fresh fruits are key parameters in defining the textural properties of the candied plum. The establishment of the harvesting moment for candying should take into account the changes that occur in the flesh of the plums during ripening. 相似文献
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Cludia E.B. Marino Sonia R. Biaggio Romeu C. Rocha-Filho Nerilso Bocchi 《Electrochimica acta》2006,51(28):6580-6583
The biocompatibility and mechanical integrity of Ti and Ti6Al4V alloy can be affected by corrosion processes. This paper presents studies on the stability of anodic oxide films on Ti6Al4V and Ti in chloride medium. The oxides were grown potentiodynamically up to 8.0 V in the phosphate buffer saline (PBS) solution (pH 6.8) at 25 and 37 °C. The morphology of the obtained anodic oxides and the type of corrosion that occurred were analyzed by SEM–EDS. The Ti6Al4V alloy presented less corrosion resistance than pure Ti. Elemental analyses showed that the decrease of the alloy corrosion resistance is due mainly to the corrosion of Al. 相似文献
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Mariana S. Silveira Cláudia P. M. L. Fontes Alexandre A. Guilherme Fabiano A. N. Fernandes Sueli Rodrigues 《Food and Bioprocess Technology》2012,5(3):947-953
The aim of the present work was to investigate the use of cashew apple juice as a low cost substrate for Lactobacillus casei B-442 cultivation and lactic acid production. Ammonium sulfate was employed as the only exogenous nitrogen source. The effect
of cashew apple juice reducing sugars and ammonium sulfate concentration and the fermentation pH and temperature on biomass
formation, lactic acid production, and productivity were evaluated. The highest productivity (2.36 g/L.h) was obtained applying
50 g/L of reducing sugar from the cashew apple juice supplemented with 6 g/L of ammonium sulfate. The process yield was about
95% when fermentation was carried out at 37 °C with pH controlled at pH 6.5 using NaOH (120 g/L). 相似文献