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João Lameu da Silva Júnior Victória Anselmo Haddad Osvaldir Pereira Taranto Harrson Silva Santana 《化学工程与技术》2020,43(7):1249-1259
Four passive micromixer designs (G1, G2, G3, and G4) based on distillation columns trays are proposed. The performance of the devices is assessed by numerical simulations. The mixing performance is investigated for different Reynolds numbers and channel heights for oil/ethanol flow. G1 and G4 designs provided a high mixing index. The G1 device achieved superior mixing performance with a moderate pressure drop due to the induced flow recirculation pattern for a relatively high flow rate, highlighting the potential use of such microdevice for scale-up and numbering-up of microdevices in modular chemical plant processing. 相似文献
3.
Lucia Padalino Marcella Mastromatteo Lucia Lecce Sara Spinelli Francesco Contò Matteo Alessandro Del Nobile 《International Journal of Food Science & Technology》2014,49(6):1544-1556
The goal of the study was to obtain spaghetti enriched with pea flour with sensory properties close to conventional pasta. To this aim, the study has been organised in two subsequent trials. In the first, the pea flour amount added to the spaghetti was continuously increased until the overall sensory quality reached its threshold value (pea flour concentration = 15%). In fact, the spaghetti samples supplemented with 15% pea flour (15%S‐P) showed less elasticity, unpleasant colour and higher firmness compared to the control sample (CTRL). The second step was aimed to improve the overall sensory quality of the 15%S‐P spaghetti by means of guar gum (GUAR). The sample with GUAR (15%S‐P/GUAR) showed a pleasant colour, odour and taste. Furthermore, the 15%S‐P/GUAR sample recorded a low starch digestibility value (i.e. 54) and a higher soluble fibre content with respect to the 15%S‐P sample. 相似文献
4.
Marcella Favale 《Information & Communications Technology Law》2014,23(2):117-135
The paper reviews copyright philosophical, economic and social justification confronted by the dematerialization of creative outputs. Digital Rights Management (DRM) is the tool implemented by copyright owners to adjust to the advent of the Digital Era. The claim is that DRM effectively addresses digital threats and market failures. If this is true, what is left of the role of copyright law in the digital environment? This review suggests an argument for traditional copyright justifications to resist in the digital environment. As a consequence, digital tools such as DRM need to be engineered according to these justifications, in order to preserve the balance between law and technology. 相似文献
5.
Marcella Feitosa de FigueirêdoBrenda Pontual Guedes João Manzi Monteiro de AraújoLuís Gonzaga Sales Vasconcelos Romildo Pereira Brito 《Chemical Engineering Research and Design》2011,89(3):341-346
The separation of binary mixtures which form azeotropes is not possible through conventional distillation and they are usually separated by extractive or azeotropic distillation. The optimization of extractive distillation columns is usually performed using a process simulator; however, normally, the result is only obtained after several simulations and the simultaneous analysis of several graphs. This paper sets out to present a systematic procedure, using a process simulator (Aspen Plus®), in order to obtain the optimum condition for extractive distillation columns. The optimization achieved is characterized by the fact that it is not necessary to perform various simulations, and it also avoids the simultaneous analysis of dozens of curves. The dehydration of aqueous mixtures of ethanol using ethylene glycol as solvent was the system chosen as a case study. 相似文献
6.
Carla D. Souza Maria Elisa C.M. Rostelato Carlos A. Zeituni João A. Moura Eduardo S. Moura Kátia Fonseca Anselmo Feher 《Progress in Nuclear Energy》2011,53(1):66-72
The estimates for the year 2009 predict that 466,730 new cancer cases would occur in Brazil. Prostate cancer is the second most incident in our country, with almost 50,000 new cases in 2009. Brachytherapy, a type of radiotherapy, with iodine-125 sources is an important form of treatment for this kind of cancer. The “Instituto de Pesquisas Energéticas e Nucleares” (Institute for Nuclear and Energy Research - IPEN) created a project to produce a national prototype of these sources and develop a facility for local production. Manufacturing seeds locally will diminish the overall treatment cost making such treatment available to a larger number of patients. While the laboratory is under development, the IPEN imports and distributes seeds. This work aims to present and evaluate the radiological protection procedures applied to imported sources in order to assist in the setup of the new laboratory. Although iodine-125 presents low energy photons, around 29 keV, local and personal dosimeters are used during the separation and distribution process of seeds as described in CNEN NN 3.01 standard “Diretrizes Básicas de Proteção Radiológica” (Radiological Protection Basic Guidelines). All testing has demonstrated that there is no area contamination and very low exposure, suggesting that the application of the standards outlined in CNEN NN 3.01 has been effective. As a result of this work, a new dosimeter should be installed and evaluated in a future study. 相似文献
7.
Marcella Roba Christoph Bruhin Urs Ebneter Roman Ehrbar Rowena Crockett Nicholas D. Spencer 《Tribology Letters》2010,38(3):267-273
Latex versus glass has frequently been used as a model system for the investigation of natural lubrication mechanisms, despite
its significant differences from articular cartilage pairings. The differences in surface chemistry account for its different
behavior in terms of protein adsorption and lubrication. While cartilage is well known for its protein resistance, most proteins
present in synovial fluid can non-specifically adsorb onto latex or glass. We have investigated latex-versus-glass lubrication
by means of pin-on-disk tribometry in the presence of synovial-fluid proteins and glycoproteins, focusing on the influence
of the glass-cleaning procedure on friction. In order to simulate the effects of possible contamination of glass in previous
studies, both hydrophilic and hydrophobic glass substrates were tested. Albumin was shown to impair lubrication (in comparison
to PBS) when latex was slid against both types of glass surface, whereas bovine synovial fluid (BSF) and alpha-1-acid glycoprotein
(AGP) impaired the lubrication of latex versus hydrophilic glass and improved the lubrication of latex versus hydrophobic
glass. Protein adsorption on the surfaces was monitored by means of fluorescence imaging and optical waveguide lightmode spectroscopy
(OWLS), which revealed a faster and greater amount of adsorption of AGP on hydrophobic surfaces than on hydrophilic ones.
The influence of surface chemistry on the friction behavior of BSF and on the adsorption of AGP suggests that it plays a role
in determining the relative amounts of adsorbed synovial fluid proteins. When BSF is used as a lubricant in the latex-versus-hydrophobic-glass
system, more of the AGP, relative to albumin, appears to adsorb on both surfaces, counteracting the negative effect of albumin
on friction. It therefore seems that latex on glass, while displaying nominal similarities to cartilage on cartilage under
certain conditions, is not a useful model system. Moreover, surface contamination of the glass can play a major role in determining
the results. 相似文献
8.
Fractal fragmentation of rocks within sturzstroms: insight derived from physical experiments within the ETH geotechnical drum centrifuge 总被引:1,自引:0,他引:1
An investigation of the behaviour and energy budget of sturzstroms has been carried out using physical, analytical and numerical
modelling techniques. Sturzstroms are rock slides of very large volume and extreme run out, which display intensive fragmentation
of blocks of rock due to inter-particle collisions within a collisional flow. Results from centrifugal model experiments provide
strong arguments to allow the micro-mechanics and energy budget of sturzstroms to be described quantitatively by a fractal
comminution model. A numerical experiment using a distinct element method (DEM) indicates rock mass and boundary conditions,
which allow an alternating fragmenting and dilating dispersive regime to evolve and to sustain for long enough to replicate
the spreading and run out of sturzstroms without needing to resort to peculiar mechanism. The fragmenting spreading model
supported here is able to explain the run out of a fluid-absent granular flow beyond the travel distance predicted by a Coulomb
frictional sliding model. This, and its strong relation to internal fragmentation, suggests that a sturzstrom constitutes
a landslide category of its own. This study provides a novel framework for the understanding the physics of such sturzstroms. 相似文献
9.
Fábio G. Melchiades Bruna T. Rego Silvia M. Higa Helton J. Alves Anselmo O. Boschi 《Journal of the European Ceramic Society》2010,30(12):2443-2449
Transparency is an extremely important optical property of several glazes used in the ceramic tile sector. The present work aimed to identify the causes of loss of transparency presented by some ceramic glazes composed of frits with chemical compositions typical of optically transparent glasses. After identifying the causes of low transparency presented by several ceramic glazes based on microstructural analyses, X-ray diffraction and scanning electron microscopy, attempts were made to increase the transparency of these glazes by altering their chemical compositions. The results suggest that the addition of alumina – through distinct mineral sources – may be an interesting alternative to prevent the crystallization of calcium silicates, which reduce the transparency of glazes used in the ceramic tile sector. 相似文献
10.