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961.
Patrícia Cruz Carolina Silva Fernando Rocha António Ferreira 《American Institute of Chemical Engineers》2019,65(9):e16683
The planar oscillatory flow crystallizer (planar-OFC) was designed with a rectangular cross-section to improve the flow and suspension of solids of conventional OFCs. Residence time distribution experiments with liquid and solid tracers were performed to assess the effect of the net flow rate, Q , the frequency, f , and the amplitude of oscillation, x0 , on the axial dispersion of liquids, , and solids, , in three planar-OFCs with different geometries. It was found that Q and f have in general positive effects on and , and x0 has negative effects. Furthermore, identical values of and were obtained in each crystallizer. It was also found that the interaction between Q and x0 is the most significant one in all systems. These results show that the three crystallizers have similar axial dispersion performances with liquids and solids. This is of paramount importance for multiphase systems such as crystallization. 相似文献
962.
Carolina Galleguillos Brian McFee Gert R. G. Lanckriet 《International Journal of Computer Vision》2014,108(1-2):115-132
The goal of an object category discovery system is to annotate a pool of unlabeled image data, where the set of labels is initially unknown to the system, and must therefore be discovered over time by querying a human annotator. The annotated data is then used to train object detectors in a standard supervised learning setting, possibly in conjunction with category discovery itself. Category discovery systems can be evaluated in terms of both accuracy of the resulting object detectors, and the efficiency with which they discover categories and annotate the training data. To improve the accuracy and efficiency of category discovery, we propose an iterative framework which alternates between optimizing nearest neighbor classification for known categories with multiple kernel metric learning, and detecting clusters of unlabeled image regions likely to belong to a novel, unknown categories. Experimental results on the MSRC and PASCAL VOC2007 data sets show that the proposed method improves clustering for category discovery, and efficiently annotates image regions belonging to the discovered classes. 相似文献
963.
José J. Castro José R. Jiménez Carolina Ortiz Miriam Casares-López Sonia Ortiz-Peregrina 《Journal of Modern Optics》2017,64(13):1307-1314
The study of the visual function and optical quality of the eye has become a fundamental aim in the characterization of visual performance, especially in binocular vision, as this is our natural state of visual perception and because of its importance in clinical applications. Interocular asymmetry affects visual performance, and therefore its effect on different visual functions and stereopsis is of interest. In this work, we analyse interocular differences in optical quality (higher order aberrations and Strehl ratio) on the maximum disparity (the total range of stereoscopic perception) under mesopic conditions. We also analyse the relationship between the maximum disparity and the visual-discrimination capacity (halo perception) or binocular summation. The results in normal observers show a deterioration of the range of stereoscopic perception with the interocular differences in optical quality and with a higher perception of halos. Regarding the binocular summation for the visual functions studied, a positive correlation with the maximum disparity is found. 相似文献
964.
Electroconductive Biohybrid Collagen/Pristine Graphene Composite Biomaterials with Enhanced Biological Activity
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Alan J. Ryan Cathal J. Kearney Nian Shen Umar Khan Adam G. Kelly Christopher Probst Eva Brauchle Sonia Biccai Carolina D. Garciarena Victor Vega‐Mayoral Peter Loskill Steve W. Kerrigan Daniel J. Kelly Katja Schenke‐Layland Jonathan N. Coleman Fergal J. O'Brien 《Advanced materials (Deerfield Beach, Fla.)》2018,30(15)
Electroconductive substrates are emerging as promising functional materials for biomedical applications. Here, the development of biohybrids of collagen and pristine graphene that effectively harness both the biofunctionality of the protein component and the increased stiffness and enhanced electrical conductivity (matching native cardiac tissue) obtainable with pristine graphene is reported. As well as improving substrate physical properties, the addition of pristine graphene also enhances human cardiac fibroblast growth while simultaneously inhibiting bacterial attachment (Staphylococcus aureus). When embryonic‐stem‐cell‐derived cardiomyocytes (ESC‐CMs) are cultured on the substrates, biohybrids containing 32 wt% graphene significantly increase metabolic activity and cross‐striated sarcomeric structures, indicative of the improved substrate suitability. By then applying electrical stimulation to these conductive biohybrid substrates, an enhancement of the alignment and maturation of the ESC‐CMs is achieved. While this in vitro work has clearly shown the potential of these materials to be translated for cardiac applications, it is proposed that these graphene‐based biohybrid platforms have potential for a myriad of other applications—particularly in electrically sensitive tissues, such as neural and neural and musculoskeletal tissues. 相似文献
965.
Beatriz Mora Nastassia Soriano Carolina Redondo Alberto Arteche David Navas Rafael Morales 《Nano Research》2016,9(8):2347-2353
Top-down lithography techniques allow the fabrication of nanostructured elements with novel spin configurations,which provide a new route to engineer and manipulate the magnetic response of sensors and electronic devices and understand the role of fundamental interactions in materials science.In this study, shallow nanostructure-pattemed thin films were designed to present inverse magnetization curves,i.e.,an anomalous magnetic mechanism characterized by a negative coercivity and negative remanence.This procedure involved a method for manipulating the spin configuration that yielded a negative coercivity after the patterning of a single material layer.Patterned NiFe thin films with trench depths between 15%-25% of the total film thickness exhibited inverse hysteresis loops for a wide angular range of the applied field and the trench axis.A model based on two exchange-coupled subsystems accounts for the experimental results and thus predicts the conditions for the appearance of this magnetic behavior.The findings of the study not only advance our understanding of patterning effects and confined magnetic systems but also enable the local design and control of the magnetic response of thin materials with potential use in sensor engineering. 相似文献
966.
Carolina Fonseca Couto Wagner Guadagnin Moravia Miriam Cristina Santos Amaral 《Clean Technologies and Environmental Policy》2017,19(8):2057-2073
This study investigates the application of a hybrid microfiltration–nanofiltration (MF–NF) process for textile wastewater reclamation. Indigo blue dye was efficiently retained by an MF membrane, allowing its recovery from the concentrated stream. NF technology was successfully applied to polish textile effluent. The NF membrane was evaluated under different transmembrane pressure (8–15 bars), crossflow velocities (0.21–0.84 cm s?1), pH (7–11), and feed temperature (20–40 °C). The best NF performance was provided at a pressure of 12 bar and a crossflow rate of 0.63 cm s?1. The NF performance (in terms of COD, conductivity, colour, and nitrogen removal) was not influenced by pH; however, higher feed pH values resulted in increased membrane fouling. The principal cause of flux decline was due to concentration polarization. Membrane chemical cleaning was sufficient to regain the initial permeability. The NF permeate met the quality requirements for all water demands within the textile industry, while the NF concentrate could be used to wash equipment, print work screens, print paste containers, and floors. The total capital cost (CapEx) of the MF–NF system was estimated at 58,362.50 US dollars and the total operational cost (OpEx) at 0.31 US dollars per cubic metre of effluent. 相似文献
967.
Oran Ana Carolina Santos Gleison Gadelha Bruno Conte Tayana 《Requirements Engineering》2021,26(4):481-508
Requirements Engineering - Requirements specifications are essential to properly communicate requirements among the software development team members. However, each role in the team has different... 相似文献
968.
969.
Carolina Valenzuela Lilian Abugoch Cristian Tapia Alexander Gamboa 《International Journal of Food Science & Technology》2013,48(4):843-849
It is important to produce hydrophobic edible protein films for use in foods. The aim of this study was to evaluate the effect of alkaline extraction of quinoa proteins (QP) on the structure and their film‐forming ability without plasticiser. QP were extracted between pH 8 to 12, and their structure was evaluated by PAGE‐SDS, size‐exclusion HPLC light scattering, fluorescence spectroscopy and SH and SS. Film was characterised by FTIR, SEM, tensile strength, barrier and colour. Structural changes of QP showing that alkalinisation over pH 10 produce significant denaturation/aggregation/dissociation structural changes in QP. pH 12 was the condition to form a film (film12). FTIR showed hydrogen bonds and hydrophobic film interactions. Film12 had 16.6 ± 3.8% elongation and 15.7 ± 1.1 MPa tensile strength, and water vapour permeability was 5.18 ± 0.38 g mm m?2 day?1 kPa?1. Film12 had a brownish colour. A high degree of denaturation/aggregation/dissociation of QP structure is required to form a film without plasticiser. 相似文献
970.
The levels of free and total tryptophan and of 5-hydroxytryptophan (5-HTP) were investigated in green and roasted grains and beverages of Coffea arabica L. (Arabica) and Coffea canephora Pierre var. robusta (Robusta). Grains were light, medium and dark roasted. Free and protein tryptophan were extracted before and after hydrolysis. The levels of tryptophan and 5-HTP were quantified simultaneously by ion-pair HPLC and fluorimetric detection after derivatisation with o-phthalaldehyde. Robusta green coffee had higher total and protein tryptophan, whereas Arabica had higher free tryptophan levels. 5-HTP was not detected in the samples before and after roasting. Free tryptophan was completely degraded during roasting. Roasting significantly affected protein tryptophan. The rate of loss was smaller in Arabica compared to Robusta at every roasting degree. A beverage prepared the Brazilian way with a medium-roasted coffee provided 1.4–2.5 mg tryptophan/50 ml cup. 相似文献