Correlação linear e espacial da produtividade de forragem de milho com atributos físicos de um latossolo vermelho distrófico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Construção de um interferômetro de Bath para análise do comportamento da superfície de vidros usados na confecção de espelhos côncavos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Construção de um inclinômetro para avaliar o efeito da declividade lateral no desempenho de tratores agrícolas

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Establishing erosion susceptibility: analytical hierarchical process and traditional approaches

This study evaluated alternatives for producing erosion susceptibility maps, considering different weight combinations for an environment's attributes, according to four different points of views. The attributes considered were landform, steepness, soils, rocks and land occupation. Considered alternatives were: (1) equal weights, more traditional approach, (2) different weights, according to a previous study in the area, (3) different weights, based on other works in the literature, and (4) different weights based on the analytical hierarchical process. The area studied included the Prosa Basin located in Campo Grande-Mato Grosso do Sul State, Brazil. The results showed that the assessed alternatives can be used together or in different stages of studies aiming at urban planning and decision-making on the interventions to be applied.

An integrable evolution equation for surface waves in deep water

In order to describe the dynamics of monochromatic surface waves in deep water, we derive a nonlinear and dispersive system of equations for the free surface elevation and the free surface velocity from the Euler equations in infinite depth. From it, and using a multiscale perturbative method, an asymptotic model for small wave steepness ratio is derived. The model is shown to be completely integrable. The Lax pair, the first conserved quantities as well as the symmetries are exhibited. Theoretical and numerical studies reveal that it supports periodic progressive Stokes waves which peak and break in finite time. Comparison between the limiting wave solution of the asymptotic model and classical results is performed.

Lensometry by two-laser holography with photorefractive Bi12TiO20

Refractive and profilometric measurements of lenses were performed through holography with a photorefractive Bi12TiO20 crystal as the recording medium. Two properly aligned diode lasers emitting in the red region were employed as light sources. Both lasers were tuned in order to provide millimetric and sub-millimetric synthetic wavelengths. The surfaces of the test lens were covered by a 25-μm opaque plastic tape in order to allow the lens profilometry upon illuminating them with a collimated beam. The resulting holographic images appear covered by interference fringes corresponding to the wavefront geometry of the wave scattered by the lens. For refractive index measurement a diffusely scattering flat surface was positioned behind the uncovered lens which was also illuminated by a plane wave. The resulting contour interferogram describes the form of the wavefront after the beam traveled back and forth through the lens. The fringe quantitative evaluation was carried out through the four-stepping technique and the resulting phase map and the Branch-cut method was employed for phase unwrapping. The only non-optical procedure for lens characterization was the thickness measurement, made by a dial caliper. Exact ray tracing calculation was performed in order to establish a relation between the output wavefront geometry and the lens parameters like radii of curvature, thickness and refractive index. By quantitatively comparing the theoretical wavefront geometry with the experimental results relative uncertainties bellow 3% for refractive index and 1 % for focal length were obtained. © 2008 American Institute of Physics.

Capacidad de uso de la tierra en la cuenca de la Corriente del Lobo, Itatinga, São Paulo, Brasil

The objective of the research was to define the classes of use capacity of 2403.25 ha in the basin of the Corriente del Lobo - Itatinga (SP), (22°03'56" to 22°59'12" of latitude S and 48°38'47" to 48°41'25" of longitude W Gr.). The soil use capacity was obtained by using the SIG IDRISI 32 crossing the documents of steepness and soils and the document of judgment of classes of soil use capacity and of the utilitarian rising of the physical milieu. The classes and subclasses areas of use capacity presented the following values: IIIa - 68.60 ha (2.85%), IIIe,s - 1919.15 ha (79.86%); IIIe - 210.60 ha (8.76%); IVe - 3.38ha (0.14%); IVe,s - 157.42 ha (6.55%) and VIe,s - 44.10 ha (1.84%). The lands of the basin were distributed in three classes (III, IV and VI) and six subclasses but the biggest extension (79.9%) belonged to the subclass IIIe,s. The modules of the IDRISI allowed to discriminate, mapping and to quantify quickly the soil use capacity of the areas of classes and subclasses in the basin.

Agrupamentos de amostras circulares em função das unidades de solo

The objective of the study was to analyze the features of the relief through the variables: maximum altitude (HM); mean altitude (Hmd); minimum altitude (Hm); altitude range (H); average slope length (CVm); minimum length of run-off (Cd) and average steepness of circular samples (I) of the Capivara River Watershed – Botucatu (SP). A total of 4 circular samples were obtained per unit of soil (Quartzipsamment alfisol oxisol - RQ, Udox - LVA and Udorthent - RL). Multivariable analysis and aerial color photographs of 2000, Brazilian Chart and Soil Chart of Botucatu city-SP were used for data analyses. Soil differentiation was performed using the Student-t Test for analyzes of orthogonal contrasts among means of the three soils and analysis of groupings and major components. The grouping analysis of the variables of relief differentiated 75% of LVA and 100% of RL and RQ soil circular samples. The most efficient parameters of relief for differentiation of soils according to their order of importance were as follows: HM, Hm, Hmd and H.