38 resultados para Longitudinal proximity effect
Resumo:
As técnicas do plantio direto são complementares às atuais técnicas de conservação do solo, que envolvem menor mobilização e permanência de cobertura vegetal na superfície do solo. O trabalho foi realizado na UNESP - Jaboticabal, de novembro de 2003 a março de 2004, e teve como objetivo avaliar o efeito de culturas, manejos e marchas do trator na semeadura da soja no plantio direto. O delineamento utilizado para instalação do experimento foi em blocos ao acaso, no esquema de parcelas subsubdivididas, com quatro repetições. Foram analisados: estande inicial, distribuição longitudinal de plantas, resistência mecânica à penetração, densidade e teor de água no solo. O estande inicial não foi influenciado pelos tratamentos. A distribuição longitudinal das plantas foi afetada pela marcha do trator. A resistência do solo à penetração sofreu efeito apenas na camada de 0,20 a 0,25 m na interação culturas, manejos e marchas do trator. A interação culturas e manejos na camada de 0,10 a 0,20 m para densidade indicou a presença de resistência maior do que 0 a 0,10 m e de 0,20 a 0,30 m. O teor de água no solo foi menor nas camadas superficiais do solo, influenciado pelos manejos.
Resumo:
The objective of this work was to evaluate the Nelore beef cattle, growth curve parameters using the Von Bertalanffy function in a nested Bayesian procedure that allowed estimation of the joint posterior distribution of growth curve parameters, their (co)variance components, and the environmental and additive genetic components affecting them. A hierarchical model was applied; each individual had a growth trajectory described by the nonlinear function, and each parameter of this function was considered to be affected by genetic and environmental effects that were described by an animal model. Random samples of the posterior distributions were drawn using Gibbs sampling and Metropolis-Hastings algorithms. The data set consisted of a total of 145,961 BW recorded from 15,386 animals. Even though the curve parameters were estimated for animals with few records, given that the information from related animals and the structure of systematic effects were considered in the curve fitting, all mature BW predicted were suitable. A large additive genetic variance for mature BW was observed. The parameter a of growth curves, which represents asymptotic adult BW, could be used as a selection criterion to control increases in adult BW when selecting for growth rate. The effect of maternal environment on growth was carried through to maturity and should be considered when evaluating adult BW. Other growth curve parameters showed small additive genetic and maternal effects. Mature BW and parameter k, related to the slope of the curve, presented a large, positive genetic correlation. The results indicated that selection for growth rate would increase adult BW without substantially changing the shape of the growth curve. Selection to change the slope of the growth curve without modifying adult BW would be inefficient because their genetic correlation is large. However, adult BW could be considered in a selection index with its corresponding economic weight to improve the overall efficiency of beef cattle production.
Resumo:
In this article, it is represented by state variables phase a transmission line which parameters are considered frequency independently and frequency dependent. Based on previous analyses, it is used the reasonable number of p circuits and the number of blocks composed by parallel resistor and inductor for reduction of numerical oscillations. It is analyzed the influence of the increase of the RL parallel blocks in the obtained results. The RL parallel blocks are used for inclusion of the frequency influence in the transmission line longitudinal parameter. It is a simple model that is been used by undergraduate students for simulation of traveling wave phenomena in transmission lines. Considering the model without frequency influence, it is included a representation of the corona effect. Some simulations are carried considering the corona effect and they are compared to the results without this phenomenon.
Resumo:
The inclusion of the corona effect in a frequency dependent transmission line model is proposed in this paper. The transmission line is represented through a cascade of π circuits and the frequency dependence of the longitudinal parameters is synthesized with series and parallel resistors and inductors. The corona effect will be represented using the Gary and Skilling-Umoto models. The currents and voltages along the line are calculated by using state-space technique. To demonstrate the accuracy and validity of the proposed frequency dependent line model, time domain simulations of a 10 km length single-phase line response under energization procedure will be presented. ©2008 IEEE.
Resumo:
The study was performed in a greenhouse with the aim of evaluating the production of butterhead lettuce cultivars with and without plastic film mulch in the summer. The cultivars studied were 'Elisa', 'Lídia', 'Herman' and 'Luísa'. The experimental design was a split plot, in which the main plot was plastic film mulch (with or without black polyethylene film) and the subplots were the cultivars, with three repetitions. The seedlings were grown in Styrofoam trays of 288 cells and transplanted 25 days after seeding in a space of 25 × 25 cm. Harvests were carried out 45 days after transplanting and the following variables were determined: fresh and dry weights of the aerial part, number of leaves per plant, plant height and the longitudinal and transverse diameters of the plant. Significant differences were found only among the cultivars for the characteristics studied, with no cover × cultivar interaction. Fresh weight of the aerial part of 'Lídia' (270.9 g) was greater than that of 'Herman' (142.5 g), but did not differ from those of 'Luísa' (229.8 g) or 'Elisa' (204.8). The dry weight of the aerial part of 'Lídia' (12.4 g) differed statistically only with respect to that of 'Herman' (7.9 g). The cultivars 'Luísa' and 'Elisa' had an aerial part dry weight of 11.4 and 11.2 g, respectively. The number of leaves per plant of the cultivars 'Luísa' (45.1) and 'Elisa' (43.0) was higher than for 'Herman' (24.05), but did not differ from that of the cultivar 'Lídia' (39.5). The mean transverse and longitudinal diameters, as well as the mean height of the plants, showed that 'Lídia', 'Elisa' and 'Luísa' had the greatest values. The cultivars 'Lídia', 'Elisa' and 'Luísa' were the most productive and plastic film mulch had no effect on lettuce production under protected cultivation.
Resumo:
This study evaluated bond strength to dentin as a result of storage time for conventional adhesive systems (with or without collagen) that had been deproteinized with 10% sodium hypochlorite (NaOCl). For this study, 72 human molars were sectioned in a mesiodistal axial plane and embedded in acrylic resin; at that point, the vestibular and lingual surfaces were worn down with abrasive paper. Acid etching was performed for 15 seconds (using 37% phosphoric acid) and the specimens were divided into 12 groups (n = 6), depending on the adhesive system used, the dentin treatment performed, and the length of evaluation (24 hours or six months). A resin composite was inserted over the prepared area with the aid of a metal matrix. Following a mechanical shear test, fractured surfaces were analyzed by stereomicroscope and the data were submitted to ANOVA and Tukey's test. It was concluded that the dentin deproteinization treatment with 10% NaOCI improved the bond strength in five of the six groups. The bond strength after 24 hours was significantly higher than the bond strength measured after six months. Of the three adhesive systems tested in this study, DenTASTIC UNO demonstrated the lowest bond strength.
Resumo:
Background: The time course of mild cardiotoxicity induced by anthracycline remains unknown. The aim of this study was to evaluate the long-term evolution of decreased myocardial reserve in children previously treated with a cumulative dose of anthracycline up to 100mg/m 2. Patients and Methods: Twenty-seven asymptomatic cancer survival patients (25 with lymphoblastic leukemia), in continuous remission and off treatment for >12 months with no alterations in conventional echocardiograms were evaluated by exercise echocardiography at 37±15.4 months (T1) and 101±24 months (T2) after finishing treatment (ADRIA group). This group was compared with 25 healthy individuals (control group) similar to the ADRIA group with respect to age and body surface area (BSA). All individuals underwent treadmill exercise testing according to Bruce protocol. Echocardiograms were performed before and immediately after exercise. Results: The groups were similar regarding cardiac structure and left ventricular (LV) systolic function at rest at T1 and T2. The growth of LV posterior wall thickness related to BSA was lower in the ADRIA group at T2. Post exercise, smaller LV ejection indexes and attenuated changes in the afterload in ADRIA group were observed at T1 and T2. Conclusion: The decreased systolic reserve induced by a low dose of anthracycline in asymptomatic children and adolescents remains unaffected over a 5-year period, suggesting that positive outcomes in chronic cardiotoxicity would be expected in patients with mild impairment after anthracycline treatment. © 2011 Wiley Periodicals, Inc.
Resumo:
Composite films made of lead zirconate titanate ceramic particles coated with polyaniline and poly(vinylidene fluoride) - PZT-PAni/PVDF were produced by hot pressing the powder mixtures in the desired ceramic volume fraction. The ceramic particles were coated during the polyaniline synthesis and the conductivity of the conductor polymer was controlled by different degrees of protonation. Composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ac and dc electrical measurements, the longitudinal d33 piezo coefficient and the photopyroelectric response. Results showed that the presence of PAni increased the dielectric permittivity of the composite and allowed better efficiency in the poling process, which increased the piezo- and pyroelectric activities of the composite film and reduced both the poling time and the poling electric field. The thermal sensing of the material was also analyzed, showing that this composite can be used as pyroelectric sensor. © 2013 IOP Publishing Ltd.
Resumo:
Purpose: This longitudinal clinic study evaluated the effect of a glass ionomer sealant (GIS) and a fluoride varnish (FV) in the prevention of dental decay on newly erupted permanent molars of children with and without caries experience. Materials and methods: Eighty children, aged 6-8 years, with all four newly erupted first permanent molars, were divided into two groups. Group 1 consisted of 53 children without caries experience and group 2 consisted of 27 children with dental caries experience. Permanent molars of the right side were sealed with GIS and the fluoride varnish was applied on the other two permanent first molars. Evaluation of GIS retention and the effectiveness of both materials in the prevention of dental caries were performed after 6, 12 and 18 months. Results: After 18 months, of the 299 teeth, 271 (91%) showed no caries lesions and 28 presented caries lesions (9%). Teeth sealed with GIS had more carious lesions (15) than teeth with fluoride varnish (13). Most of the teeth (70%) that presented carious lesions were in group 2. Of the 138 sealed teeth, only one showed GIS to be totally present, 95 were partially present and 42 teeth were absent. Conclusion: The caries-preventive effect was very similar between both treatments. The presence of dental caries prevailed in the children with caries experience. © 2013 Informa Healthcare.
Resumo:
Pós-graduação em Estudos Linguísticos - IBILCE
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Pós-graduação em Agronomia (Ciência do Solo) - FCAV
Resumo:
Pós-graduação em Odontologia - FOA
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)