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排序方式: 共有390条查询结果,搜索用时 15 毫秒
41.
Cristiano Maio Cliff Schexnayder Kraig Knutson Sandra Weber 《Canadian Metallurgical Quarterly》2000,126(4):285-292
The need for reliable simulation systems has been discussed and recognized by many researchers. At the same time researchers have recognized that the quality of a simulation model's results are strictly related to the quality of the input probability distribution functions. The data used in this research were acquired from the Atkinson-Washington-Zachry joint venture on the Eastside Reservoir Project in California. The data were analyzed using BestFit software to obtain the parameters of the theoretical distribution functions that best described the field data set. The research validated previous warnings about the influence of the class interval decision on the selection of a distribution function when the chi-square fitting test is utilized. A second issue of importance that was encountered was the reliability of goodness-of-fit tests when dealing with large data sets. 相似文献
42.
Gabriele Landucci Benedetta NucciLuigi Pelagagge Cristiano Nicolella 《Journal of food engineering》2011,105(1):105-111
This work presents a methodology for the assessment of hazards due to the formation of flammable mixtures in edible oil refineries, with particular focus on storage tanks. Safety issues in these plants are due to the presence of residual volatile flammable solvents deriving from the extraction processes, which may accumulate in the storage tanks and generate flammable vapour mixtures. The methodology, based on the application of a thermodynamic model for the estimation of vapour phase composition in oil storage tanks as a function of operating conditions (i.e. temperature and residual solvent content), allows the identification of potential hazards due to formation of flammable mixtures inside the tanks. The model was first validated using available experimental data and then extended to case-studies representative of state-of-the-art industrial storage applications. The results of the case-studies were then used to calculate specific hazard indexes, providing a quick tool for preliminary assessment of hazards due to the formation of flammable mixtures in edible oil storage plants. 相似文献
43.
Rodrigo R. Oliveira Felipe C. Noguez Cristiano A. Costa Jorge L. Barbosa Mario P. Prado 《Expert systems with applications》2013,40(6):2023-2031
Logistics represent the biggest cost for transportation companies. Companies are investing in monitoring and tracking systems aiming at improving services, reducing costs and ensuring the safety in cargos transports. This article presents an intelligent model to obtain the position of vehicles, using off-the-shelf mobile devices named SWTRACK. The proposal allows distributors companies to track loads and to have real-time information about their whereabouts during a travel. SWTRACK presents an automatic travel management to initialize and finish travels without user interaction. Furthermore, it provides a mechanism to monitor detours in planned routes and to send alarms notification through mobile devices. To build that mechanism, we studied the Geofence concept and existing techniques to prepare two solutions based on continuous monitoring. Those solutions were compared and discussed. We also conducted a model evaluation using off-the-shelf mobile devices. Moreover, we provide an impact analysis regarding GPS precision and battery power consumption. In the end, we show that the proposed model generates a reliable system for tracking vehicles. 相似文献
44.
Cristiano Nicolella Antonio Bertei Massimo Viviani Antonio Barbucci 《Journal of Applied Electrochemistry》2009,39(4):503-511
This paper presents a mathematical model of mass and charge transport and electrochemical reaction in porous composite cathodes
for application in solid oxide fuel cells. The model describes a porous composite cathode as a continuum, and characterises
charge and mass transfer and electrochemical kinetics using effective parameters (i.e. conductivity, diffusivity, exchange
current) related to morphology and material properties by percolation theory. The model accounts for the distribution of morphological
properties (i.e. porosity, tortuosity, density of contacts among particles) along cathode thickness, as experimentally observed
on scanning electron microscope images of LSM/YSZ cathodes of varying thickness. This feature allows the model to reproduce
the dependence of polarisation resistance on thickness, as determined by impedance spectroscopy on LSM/YSZ cathodes of varying
thickness. Polarisation resistance in these cathodes is almost constant for thin cathodes (up to 10 μm thickness), it sharply
decreases for intermediate thickness, to reach a minimum value for about 50 μm thickness, then it slightly increases in thicker
cathodes. 相似文献
45.
46.
Sandra Balan Mendoza Jaime Sylvio Alves Ortiz Tiago Bassani Dantas Cristiano Ferreira Damasceno 《Packaging Technology and Science》2002,15(4):225-230
The mechanical performance of lightweight glass packages produced by the NNPB (narrow neck press and blow) process was evaluated by comparison with the same glass packages (regular weight) produced by the conventional process (blow and blow). The temper number (annealing process evaluation), thickness distribution behaviour and mechanical performance (impact, vertical load and thermal shock strength) were analysed before and after line simulation, applied in optimized conditions in the laboratory. The performance of lightweight glass packages under transport simulation (truck envelope) in relation to the regular weight bottles was also evaluated. Both bottles presented residual stress values within the specified limits. The lightweight glass bottles had a more homogenous thickness distribution in comparison with the regular weight bottles and a better performance (about 33% improvement) in relation to the impact strength, especially in the heel, even when evaluated after line simulation. As to the vertical load strength, the lightweight glass bottle also indicated a superior performance to the regular weight bottle, both before and after line simulation. Both bottles withstood the temperature difference of 42°C that such packages are supposed to resist according to thermal shock specification. Due to the better thickness distribution of lightweight glass packages, they withstood a maximum temperature difference (progressive thermal shock) of 5–10°C higher than the regular weight bottles. No restrictions of the lightweight glass packages submitted to the transport simulation were found. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
47.
Barreiro Gabriela; Guimaraes Cristiano Ruch Werneck; de Alencastro Ricardo Bicca 《Protein engineering, design & selection : PEDS》2003,16(3):209-215
To understand the mechanisms of Na+/Li+ permeation at submicromolarCa2+ concentrations, Na+/Li+ blocking at higher Ca2+ concentrations(10-610-4 M) and Ca2+ permeation at millimolar Ca2+ concentrations,we used our recently described L-type calcium channel model.For this purpose, we obtained potential of mean force (pmf)curves for the position change of one Na+ and one Ca2+ ion insidethe channel and for the position change of a second Ca2+ ionwhen the EEEE locus is coordinated to Ca2+. The pmf curves suggestthat (i) at submicromolar Ca2+ concentrations, because of thelow velocity of Ca2+ entry in the channel, monovalent ion fluxoccurs; (ii) at Ca2+ concentrations between 10-6 and 10-4 M,thermodynamic equilibrium between the channel and Ca2+ is achieved;as the coordination of Ca2+ with the locus is more favorablethan the coordination of Na+, the monovalent ion flux is blocked;and (iii) to put a second Ca2+ ion inside the channel at anappropriate rate, the Ca2+ concentration should reach millimolarlevels. Nevertheless, the entry of a second Ca2+ is thermodynamicallyunfavorable, indicating that the competition of two Ca2+ ionsfor the locus leads to Ca2+ permeation. 相似文献
48.
Cristiano Araujo Millena Gomes Edna Barros Sandro Rigo Rodolfo Azevedo Guido Araujo 《Design Automation for Embedded Systems》2005,10(4):253-283
This paper[3.5pc] presents the Platform Designer (PD) framework, a set of SystemC based tools that provide support for modeling,
simulation and analysis of multiprocessor SoC platforms (MPSoC), at different abstraction levels. PD provides mechanisms for
interconnection specification, process synchronization and communication, thus allowing the modeling of a complete platform,
in a unified environment. To do that it uses an extension of the ArchC ADL and acsys, a tool that enables the automatic generation
of a SystemC simulator of the platform. The main advantages of this approach are twofold. First, designers have more flexibility
since they can integrate and configure different processors to the platform, using a single environment. Second, it enables
a faster design space exploration, given that it automatically generates SystemC simulators of whole platforms at distinct
abstraction levels. A number of platform variations can be tried out with minor design changes, thus reducing design time.
Experimental results show the suitability of the platform simulator for design space exploration. Real applications (with
medium complexity) run in the platform in few minutes. Combined with the facility to generate platforms with minor changes,
this feature allows an improvement of the design space exploration. 相似文献
49.
Janicy Arantes Carvalho Cristiano Ceron Jayme Flávia Sayuri Matsuo Antonio Claudio Tedesco 《应用聚合物科学杂志》2024,141(8):e54978
Extensive injuries to bone tissue are still considered a significant clinical challenge; therefore, developing new bone tissue engineering (BTE) strategies is still necessary. This work aims to construct and characterize a chitosan-gelatin/hydroxyapatite-based (CG/H) scaffold to provide well-design support for mesenchymal stem cell (MSC) growth and differentiation to osteoblasts. First, the CG/H scaffolds are construct by freeze-drying. Then, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, x-ray diffraction, water uptake, and degradation profiles evaluate the material's surface. In addition, the CG/H morphological, biochemical, and MSC adhesion processes and growth behavior are also assess, indicating reasonable adhesion rates to the surface, low material cytotoxicity, and excellent alkaline phosphatase activity compared to control on the cellular framework. Based on these results, we obtain a highly biocompatible scaffold and that can support osteoblast differentiation. Finally, the in vivo studies demonstrate the CG/H scaffold with MSC adhere is capable of differentiating into osteoblasts, and the application of this scaffold is able to significantly enhance the closure of the bone lesion. Therefore, the CG/H scaffold has potential clinical application for bone regeneration. 相似文献
50.
Joo Neves Joo Monteiro Bruno Sousa Cristiano Soares Susana Pereira Fernanda Fidalgo Jos Pissarra Cludia Pereira 《International journal of molecular sciences》2023,24(1)
Plants must adapt to cope with adverse environmental conditions that affect their growth and development. To overcome these constraints, they can alter their developmental patterns by modulating cellular processes and activating stress-responsive signals. Alongside the activation of the antioxidant (AOX) system, a high number of genes are expressed, and proteins must be distributed to the correct locations within the cell. The endomembrane system and associated vesicles thus play an important role. Several pathways have been associated with adverse environmental conditions, which is the case for the exocyst-positive organelle—EXPO. The present work, using Arabidopsis mutants with T-DNA insertions in the gene EXO70, essential for EXPO vesicles formation, was designed to characterise the anatomical (morphology and root length), biochemical (quantification of stress markers and antioxidant system components), and molecular responses (gene expression) to abiotic stresses (saline, drought, oxidative, and metal-induced toxicity). The results obtained showed that mutant plants behave differently from the wild type (WT) plants. Therefore, in the exo70 mutant, morphological changes were more noticeable in plants under stress, and the non-enzymatic component of the antioxidant system was activated, with no alterations to the enzymatic component. Furthermore, other defence strategies, such as autophagy, did not show important changes. These results confirmed the EXPO as an important structure for tolerance/adaptation to stress. 相似文献