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11.
Fabrício José Pontes Anderson Paulo de Paiva Pedro Paulo Balestrassi João Roberto Ferreira Messias Borges da Silva 《Expert systems with applications》2012,39(9):7776-7787
This work presents a study on the applicability of radial base function (RBF) neural networks for prediction of Roughness Average (Ra) in the turning process of SAE 52100 hardened steel, with the use of Taguchi’s orthogonal arrays as a tool to design parameters of the network. Experiments were conducted with training sets of different sizes to make possible to compare the performance of the best network obtained from each experiment. The following design factors were considered: (i) number of radial units, (ii) algorithm for selection of radial centers and (iii) algorithm for selection of the spread factor of the radial function. Artificial neural networks (ANN) models obtained proved capable to predict surface roughness in accurate, precise and affordable way. Results pointed significant factors for network design have significant influence on network performance for the task proposed. The work concludes that the design of experiments (DOE) methodology constitutes a better approach to the design of RBF networks for roughness prediction than the most common trial and error approach. 相似文献
12.
Fabrícia Castagna Patrícia Rizzon Ricardo Abreu da Rosa Manuela Favarin Santini Mirela Sangoi Barreto Marco Antônio Húngaro Duarte Marcus Vinícius Reis Só 《Microscopy research and technique》2013,76(5):496-502
This study sought to evaluate the efficacy of passive ultrasonic irrigation (PUI) on removing the smear layer and debris from root dentin using scanning electron microscopy (SEM). Twenty‐five bovine incisors were manually prepared and divided into three groups according to the final irrigation protocol: EDTA, final irrigation with 12 mL of 17% EDTA for 3 minutes followed by 5 mL of 2.5% NaOCl; EDTA/PUI, final flush with 4 mL of 17% EDTA and PUI for 30 seconds. These procedures were repeated three times to standardize the volume of the irrigant. Control group, after preparation, the specimens were irrigated only with 17 mL of 2.5% NaOCl. The roots were fractured and analyzed using SEM. The intragroup analysis revealed that the EDTA/PUI protocol removed a higher amount of debris at the cervical third (P = 0.03). The intergroup analysis revealed that EDTA/PUI presented the lowest amount of debris at the cervical third (P = 0.007). Smear layer scores were higher in the control group compared with the EDTA and EDTA/PUI groups, but only at the cervical third (P = 0.02). None of the final irrigant protocols completely removed the smear layer and debris. EDTA/PUI only improved the removal of debris at the cervical third. Microsc. Res. Tech. 76:496–502, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
13.
Molecular Mechanism of Action of 2‐Ferrocenyl‐1,1‐diphenylbut‐1‐ene on HL‐60 Leukemia Cells 下载免费PDF全文
Dr. Alane Cabral de Oliveira Emanuella Gomes da Silva Dr. Danilo Damasceno Rocha Dr. Elizabeth A. Hillard Dr. Pascal Pigeon Prof. Gérard Jaouen Felipe A. R. Rodrigues Prof. Fabiane C. de Abreu Dr. Fabrícia da Rocha Ferreira Prof. Marilia O. F. Goulart Prof. Letícia V. Costa‐Lotufo 《ChemMedChem》2014,9(11):2580-2586
The aim of this work was to investigate the mechanism of action of 2‐ferrocenyl‐1,1‐diphenylbut‐1‐ene ( 1 ) on HL‐60 human leukemia cells. While inactive against noncancerous cells, 1 provoked a concentration‐dependent decrease in viable tumor cells, primarily via apoptosis, as evidenced by analysis of cell morphology, activation of caspases 3 and 7, increased DNA fragmentation, and externalization of phosphatidylserine. Necrosis was observed only at the highest tested concentration (4 μM ). Compound 1 interfered with the cell cycle, causing an accumulation of cells in the G1/G0 phase. Interaction of 1 with dsDNA and ssDNA was observed by differential pulse voltammetry and confirmed by hyperchromicity in the UV/Vis spectra of dsDNA, with an interaction constant of 2×104 M ?1. Both the organic analogue 1,1,2‐triphenylbut‐1‐ene ( 2 ) and ferrocene were inactive against cancer and noncancer cell lines and did not react with DNA. These results reinforce the idea that the hybrid strategy of conjugating ferrocene to the structure of tamoxifen derivatives is advantageous in finding new substances with antineoplastic activity. 相似文献
14.
Teixeira Elizabeth C. da Silva Victor E. L. Fabré Nidia N. Batista Vandick S. 《Scientometrics》2020,122(1):591-606
Scientometrics - Marine shrimp fishing is an economic activity of global importance due to its high profitability, but it also presents several environmental and socioeconomic problems. In a... 相似文献
15.
Fabrício Ravanello Mariosi Sabrina Arcaro Janio Venturini Rubens Camaratta Fernando Machado Machado Leandro Gómez-Plata Luiz Fernando Rodrigues Junior 《International Journal of Applied Ceramic Technology》2021,18(3):838-849
In this work, discarded glass bottles (GB) and eggshells (ES) were used to produce foam glass designed for thermal insulation. The literature on the thermal conductivity of foam glasses produced with eggshells is sparse. This material was used as pore-forming agent at 3% and 5% weight fractions to obtain a foam glass with low thermal conductivity. Homogenized powders were uniaxially pressed, and the compacts were fired at three temperatures (800, 850, and 900°C). Raw materials were characterized by chemical analysis and particle size distribution. The foam glasses were characterized by their porosity, phases, compressive strength, and thermal conductivity. The best insulating properties were obtained for the composition containing 5 wt% ES fired at 800°C. This sample displayed a porosity of 91.4% while its thermal conductivity was of 0.037 W/m.K, with a compressive strength of 1.12 ± 0.38 MPa. Crystalline phases were observed in samples fired at 850 and 900°C as a result of the devitrification process. The final properties of the materials are comparable to those of commercial foam glasses obtained from non-renewable, more expensive raw materials, a great indicator that the studied compositions could be used as an environmentally friendly substitute. 相似文献
16.
Fabrício?EnembreckEmail author Jean-Paul?Brathès 《Autonomous Agents and Multi-Agent Systems》2005,10(3):215-248
In this paper we discuss a new incremental learning approach used to implement adaptive behavior in autonomous agents. Adaptive agents must increase their performance based on experience using some learning approach. Often, incremental learning techniques like memory-based reasoning (MBR) are used. However, traditional MBR algorithms require an adequate (generally complex) measure of similarity, need much data and spend much time for computing similarities between examples. Such problems are unacceptable for autonomous agents that live in very dynamic environments, because they have little time to make decisions. Our approach does not use similarity measures between examples, classifies examples very fast and can compact data. We represent data as a concept graph (CG), each node representing a partition of the data. We propose an algorithm that uses the partitions to classify new examples. We compare our results with other techniques and conclude that the method performs quite well. Finally, we apply the approach to an application of adaptive agents for personalizing web search.This research was funded by Région Picardie in France. We thank Emerson Paraiso and Cesar Tacla for comments and time spent with the discussions. 相似文献
17.
Barros MA Nero LA Silva LC d'Ovidio L Monteiro FA Tamanini R Fagnani R Hofer E Beloti V 《Meat science》2007,76(4):591-596
This study aimed to establish the occurrence of Listeria spp., especially L. monocytogenes and its main serotypes, in beef and processing plants. A total of 443 samples were obtained from equipment, installations and products from 11 meat processing establishments from Paraná state, Brazil. All samples were analyzed using USDA methodology for Listeria spp. detection, followed by species identification. The occurrence of Listeria spp. in the samples was 38.1% of which 51.4% were from equipment, 35.4% from installations and 30.2% from products. The identified species were: L. monocytogenes (12.6%), L. innocua (78.4%), L. seeligeri (1.2%), L. welshimeri (7.2%) and L. grayi (0.6%). The identified serotypes of L. monocytogenes were 1/2a and 4b. The results demonstrate the significance of equipment and installations as sources of contamination by Listeria spp. and L. monocytogenes in the processing of beef and meat products. 相似文献
18.
D. Fabrègue A. Deschamps M. Suéry W. J. Poole 《Metallurgical and Materials Transactions A》2006,37(5):1459-1467
This work investigates the mechanical behavior of two aluminum alloys in the mushy state, the alloy AA6056 and an alloy based
on mixing AA6056 and AA4047. These alloys have been studied to give insight into the susceptibility to hot tearing, which
occurs during laser welding of AA6056 with 4047 filler wire. Two types of isothermal tensile tests have been conducted: (1)
tests during partial remelting and (2) tests after partial solidification at a high cooling rate. Results show that the maximum
tensile stress increases with increasing solid volume fraction. Both materials exhibit visco-plastic behavior for solid fractions
in the range 0.9 to 0.99, except for a critical solid fraction of 0.97, where the semisolid material also shows minimum ductility.
The stress levels observed for the remelting experiments are larger than those found for partial solidification experiments
at the same solid fraction due to the influence of the microstructure. The influence of temperature and strain rate on the
maximum stress is described by using a constitutive law that takes into account the fraction of grain boundaries wetted by
the liquid. 相似文献
19.
AbstractOxide dispersion strengthened steels are new generation alloys that are usually processed by hot isostatic pressing (HIP). In this study, spark plasma sintering (SPS) was studied as an alternative consolidation technique. The influence of the processing parameters on the microstructure was quantified. The homogeneity of the SPSed materials was characterised by electron microprobe and microhardness. A combination of limited grain growth and minimised porosity can be achieved on semi-industrial compact. Excellent tensile properties were obtained compared to the literature. 相似文献