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31.
The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters (1994). It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level. 相似文献
32.
Paiva Pedro Yuri Arbs Moreno Camila Castro Smith-Miles Kate Valeriano Maria Gabriela Lorena Ana Carolina 《Machine Learning》2022,111(8):3085-3123
Machine Learning - Machine Learning studies often involve a series of computational experiments in which the predictive performance of multiple models are compared across one or more datasets. The... 相似文献
33.
Demétrius Paiva Arçari Juliana Carvalho Santos Alessandra Gambero Lucio Fábio Caldas Ferraz Marcelo Lima Ribeiro 《Molecular nutrition & food research》2013,57(10):1882-1885
The aim of this study was to evaluate the effects of yerba maté (YM) extract on the phosphatidylinositol 3‐kinase (PI3K)‐AKT signaling pathway in vivo. The mice were introduced to either standard‐ or high‐fat diet (HFD). After 8 weeks on an HFD, mice were randomly assigned to one of the two treatment conditions, water or yerba maté extract at 1.0 g/kg. After treatment, glucose blood level and hepatic insulin response were evaluated. Liver tissue was examined to determine the mRNA levels using the PI3K‐AKT PCR array. The nuclear translocation of forkhead box O1 (FOXO1) was determined by an electrophoretic mobility‐shift assay. Our data demonstrated that yerba maté extract significantly decreased the final body weight, glucose blood levels, and insulin resistance of mice. Molecular analysis demonstrated that an HFD downregulated Akt2, Irs1, Irs2, Pi3kca, Pi3kcg, and Pdk1; after yerba maté treatment, the levels of those genes returned to baseline. In addition, an HFD upregulated Pepck and G6pc and increased FOXO1 nuclear translocation. The intervention downregulated these genes by decreasing FOXO1 nuclear translocation. The results obtained demonstrate for the first time the specific action of yerba maté on the PI3K‐AKT pathway, which contributed to the observed improvement in hepatic insulin signaling. 相似文献
34.
Tereza Neuma de Castro Dantas Leocadia Terezinha Cordeiro Beltrame Afonso Avelino Dantas Neto Maria Carlenise Paiva de Alencar Moura 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(6):645-650
One of the major environmental problems in the textile dyeing industry is the removal of color from effluents. The present study deals with color removal from effluents using microemulsions. The wastewater used in this study was the reactive exhausted dye liquor from a dyeing house containing Procion Yellow H‐E4R (CI Reactive Yellow 84), Procion Blue H‐ERD (CI Reactive Blue 160) and Procion Red H‐E3B (CI Reactive Red 120). Color removal was determined by CIE L*a*b* (CIELAB) color space, CIE L*a*b* color difference, ΔE*ab, and absorbance. Color removal greater than 95% was achieved, attaining values lower than the consent requirements established by the Environmental Agency. It was observed that pH is an important parameter in color removal and effluent pH correction from 10.44 to 9 before extraction improved results. The results obtained were modeled using the Scheffé net method and evaluated through the construction of isoresponse diagrams by correlation graphics between experimental values and those obtained through use of model equations, providing an experimental error of less than 2%. The optimized method very efficiently removed all dyes contained in the effluent. The same microemulsion phase recovered after the extraction process can be used at least a further 14 times and all the extractions gave good color removal. Copyright © 2004 Society of Chemical Industry 相似文献
35.
This paper presents a new microwave device - a non-radiative dielectric (NRD) waveguide with a dielectric pseudochiral Ω-slab - the Ω-NRD waveguide. A rigorous full-wave analysis is presented and the modal equations for the longitudinal-section magnetic (LSM) and longitudinal-section electric (LSE) modes are derived. The dispersion curves and operational diagrams for the first hybrid LSM modes are presented. The effect of the pseudochiral Ω-medium is discussed. New interesting modal features are revealed, showing that the propagation characteristics may differ considerably from the common isotropic case 相似文献
36.
F Brand?o MQ Paiva A Albino-Teixeira P Serr?o S Guimar?es 《Canadian Metallurgical Quarterly》1996,353(5):579-583
In incubation experiments it was shown that exogenous adrenaline or noradrenaline does not distribute homogeneously into the adrenergic varicosities of the rat vas deferens (wall with thick and compact muscle layer) but does distribute homogeneously in the rat spleen capsule (thin and loose muscle layer, containing more extracellular space than the vas deferens). To circumvent any hypothetical role of the muscular layer in the distribution of the amine, 100 micrograms.kg-1.h-1 adrenaline was administered to rats in vivo either i.v. (during 90 min) or i.p. (under pentobarbital anaesthesia, an Alzet minipump was implanted which delivered that dose during 6 days). The rats also received 100 mg.kg-1 pargyline (to inhibit MAO) and 100 mg.kg-1 tropolone (to inhibit COMT). At the end of adrenaline administration, vasa deferentia and spleen capsule were removed, washed and then exposed to 100 mumol.l-1 tyramine for 20 min. At the end of this exposure, the ratio noradrenaline/adrenaline in the tissue and in the medium was compared. In the vas deferens both after i.v. and i.p. administration of adrenaline, the ratio noradrenaline/adrenaline was about 3 times higher in the medium than in the tissue, while in the spleen capsule the ratio noradrenaline/adrenaline was not significantly different in the medium and in the tissue. We conclude that, even when the amine reaches the storage sites from the blood, it distributes homogeneously in the spleen capsule and heterogeneously in the vas deferens, perhaps because there are more than one kind of storage vesicles in the vas deferens. 相似文献
37.
Silva JE Soares D Paiva AP Labrincha JA Castro F 《Journal of hazardous materials》2005,121(1-3):195-202
Leaching studies of a sludge produced by the physico-chemical treatment of wastewaters generated by a Ni/Cr plating plant were carried out in both sulphuric acid and ammoniacal media aiming to decide which of them would be the best treatment for this kind of waste material. The dissolution behaviour of some metals (Cu, Ni, Cr and Zn) was studied in order to assure the best metal recovery conditions in subsequent processes by the use of some separation methods such as solvent extraction and precipitation techniques. Therefore, the study here presented deals with the first chemical stage of an integrated treatment process. For the sulphuric acid leaching, maximal conversions obtained were 88.6% Cu, 98.0% Ni and 99.2% Zn for the following experimental conditions: a 100 g L(-1) acid concentration, a 5:1 liquid-to-solid ratio (L/S), a particle size less than 1 mm, a digestion time of 1h, a stirring speed of 700 rpm (all at room temperature and under atmospheric pressure). As expected, no selectivity was achieved for the sulphuric acid leaching, despite this option yielding much higher metal ion dissolution when compared with that reached by ammoniacal leaching. The use of this latter medium allowed the extraction of Cu and Ni without Cr species, but rates of conversion were only about 70% for Cu and 50% for Ni, much lower than those obtained for sulphuric acid leaching. 相似文献
38.
The physical environment affects people’s behavior and wellbeing. Some effects can be easily noticed through observation, whereas others require an in-depth study to be understood and measured. Although many alterations can be positive, some can also negatively influence wellbeing, decision-making, and mental and physical health. Some of these effects are not easily associated with physical space. Thus, people may be unaware of the real triggers for changes in behavior, mood, and wellbeing. Although many studies have been performed on environmental psychology, detailed research to understand the impacts of architecture on the brain using neuroscience is limited. Some difficulties experienced by researchers in this field are on the isolation of each stimulus to understand its effects individually and measurement of brain changes in people interacting with the environment because some brain scans, such as fMRI, require people to be inside the machine. Nonetheless, the several ways a space can impact its users should be discussed to understand how architecture influences individuals and to help architects and urban planners in designing efficient and healthy spaces. This study aims to describe and analyze the results of previous research works and propose a way of organizing them to facilitate further investigation on this field. 相似文献
39.
40.
Linhares Claudio D. G. Ponciano Jean R. Pereira Fabíola S. F. Rocha Luis E. C. Paiva Jose Gustavo S. Travençolo Bruno A. N. 《Multimedia Tools and Applications》2020,79(25-26):17645-17667
Multimedia Tools and Applications - Networks are often used to model the structure of interactions between parts of a system. One important characteristic of a network is the so-called network... 相似文献