Argilas bentoníticas da península de Santa Elena, Equador: pilarização, ativação ácida e seu uso como descolorante de óleo de soja

Two samples of calcic bentonite of the Santa Elena Peninsula, Ecuador, were pillared with Al13 ions in the ratio of 10, 15 and 20 meq of Al g-1 of clay, calcinated at 573, 723 and 873 ºK and acid activated with 4, 6 and 8 mol L-1 H2SO4. Analyses by X-ray diffraction, X-ray fluorescence, differential and gravimetric thermal, density, surface area and porosity, were applied in order to study the modifications occurred in the crystalline structure of the montmorillonite. The 8 mol L-1 H2SO4 acid-activated 15 meq of Al g-1 of clay at 573 ºK Al-pillared samples indicated the best results in the bleaching of the soybean oil measured by UV-visible spectrophotometer.

Snow products for assimilation and verification

Snow is an important component of the land surface, and the choice of products for assimilation or verification can have a large impact on the surface analysis. This paper introduces the many sources of snow data that are currently available, both in situ and from remote sensing from space, along with some recent developments. Snow extent products are derived from the biggest range of sensors and are the most widely used, while information on snow mass from space is still too error-prone to be used successfully in assimilation schemes.

Microphysical properties of cold frontal rainbands

Observations have been obtained within an intense (precipitation rates > 50 mm h−1 ) narrow cold-frontal rainband (NCFR) embedded within a broader region of stratiform precipitation. In situ data were obtained from an aircraft which flew near a steerable dual-polarisation Doppler radar. The observations were obtained to characterise the microphysical properties of cold frontal clouds, with an emphasis on ice and precipitation formation and development. Primary ice nucleation near cloud top (−55◦ C) appeared to be enhanced by convective features. However, ice multiplication led to the largest ice particle number concentrations being observed at relatively high temperatures (> −10◦ C). The multiplication process (most likely rime splintering) occurs when stratiform precipitation interacts with supercooled water generated in the NCFR. Graupel was notably absent in the data obtained. Ice multiplication processes are known to have a strong impact in glaciating isolated convective clouds, but have rarely been studied within larger organised convective systems such as NCFRs. Secondary ice particles will impact on precipitation formation and cloud dynamics due to their relatively small size and high number density. Further modelling studies are required to quantify the effects of rime splintering on precipitation and dynamics in frontal rainbands. Available parametrizations used to diagnose the particle size distributions do not account for the influence of ice multiplication. This deficiency in parametrizations is likely to be important in some cases for modelling the evolution of cloud systems and the precipitation formation. Ice multiplication has significant impact on artefact removal from in situ particle imaging probes.

An ASIFT-based local registration method for satellite imagery

Imagery registration is a fundamental step, which greatly affects later processes in image mosaic, multi-spectral image fusion, digital surface modelling, etc., where the final solution needs blending of pixel information from more than one images. It is highly desired to find a way to identify registration regions among input stereo image pairs with high accuracy, particularly in remote sensing applications in which ground control points (GCPs) are not always available, such as in selecting a landing zone on an outer space planet. In this paper, a framework for localization in image registration is developed. It strengthened the local registration accuracy from two aspects: less reprojection error and better feature point distribution. Affine scale-invariant feature transform (ASIFT) was used for acquiring feature points and correspondences on the input images. Then, a homography matrix was estimated as the transformation model by an improved random sample consensus (IM-RANSAC) algorithm. In order to identify a registration region with a better spatial distribution of feature points, the Euclidean distance between the feature points is applied (named the S criterion). Finally, the parameters of the homography matrix were optimized by the Levenberg–Marquardt (LM) algorithm with selective feature points from the chosen registration region. In the experiment section, the Chang’E-2 satellite remote sensing imagery was used for evaluating the performance of the proposed method. The experiment result demonstrates that the proposed method can automatically locate a specific region with high registration accuracy between input images by achieving lower root mean square error (RMSE) and better distribution of feature points.

Compactação do solo no crescimento radicular e produtividade da cultura do milho

As modificações estruturais causadas no solo pelos diferentes sistemas de manejo podem resultar em maior ou menor compactação, que poderá interferir na resistência mecânica à penetração, densidade e porosidade do solo, influenciando o crescimento radicular e, por fim, a produtividade das culturas. O objetivo deste trabalho foi avaliar os efeitos da compactação sobre determinadas características de um Latossolo Vermelho textura média e associá-las ao crescimento radicular e à produtividade da cultura do milho. Os tratamentos principais foram constituídos por seis níveis de compactação, proporcionados pelo tráfego controlado de tratores, e duas camadas, como subtratamentos, com quatro repetições. Foram coletadas amostras indeformadas do solo nas camadas de 0-0,10 e 0,10-0,20 m, para determinação da resistência do solo à penetração, densidade e porosidade do solo. Para determinação de densidade, superfície, diâmetro e massa seca das raízes, foram retiradas amostras do solo nas camadas de 0-0,10 e 0,10-0,20 m, em cada parcela. O tráfego de tratores sobre o solo provocou maiores níveis de compactação na camada superficial, proporcionando maior densidade e superfície radicular. O diâmetro radicular e a massa seca das raízes aumentaram linearmente com o aumento da resistência à penetração do solo. Verificou-se que valores de resistência à penetração variando entre 1,03 e 5,69 MPa provocaram alterações na morfologia do sistema radicular do milho, reduzindo a produtividade da cultura em 2,581 Mg ha-1, mas não foram impeditivos ao enraizamento.

Propriedades nanoestruturais de géis de sílica preparados com adiçoes de surfactante anionico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese de aerogéis e xerogéis de sílica com troca de solvente e secagem a pressão ambiente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relações entre as propriedades físicas de combustíveis sólidos e sua reatividade

Pós-graduação em Física - IGCE

Caracterização funcional de adjuvantes em soluções aquosas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da segregação de dopantes no contorno de grão e sua influência nas propriedades elétricas de cerâmicas à base de 'SN''O IND.2'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação do teor alcoólico de vodcas: uma abordagem multidisciplinar no ensino da física, química e matemática

In this paper, it is proposed an experimental activity to be developed with high school students, addressing the concepts of density and surface tension from a multidisciplinary approach among Physics, Chemistry and Mathematics. In this proposal, students are challenged to determine the alcohol content of vodkas from intensive physical properties of liquids. Two calibration curves were obtained, one for density and another for surface tension as a function of ethanol concentration in water. The alcohol levels obtained from these properties were very close to the values given by manufacturers, due the similarity of these beverages with ethanol-water binary mixtures.

Taking account of dependent species in management of the Southern Ocean krill fishery: estimating crabeater seal abundance off east Antarctica

1. The crabeater seal Lobodon carcinophaga is considered to be a key species in the krill-based food web of the Southern Ocean. Reliable estimates of the abundance of this species are necessary to allow the development of multispecies, predator–prey models as a basis for management of the krill fishery in the Southern Ocean. 2. A survey of crabeater seal abundance was undertaken in 1500 000 km2 of pack-ice off east Antarctica between longitudes 64–150° E during the austral summer of 1999/2000. Sighting surveys, using double observer line transect methods, were conducted from an icebreaker and two helicopters to estimate the density of seals hauled out on the ice in survey strips. Satellite-linked dive recorders were deployed on a sample of seals to estimate the probability of seals being hauled out on the ice at the times of day when sighting surveys were conducted. Model-based inference, involving fitting a density surface, was used to infer densities in the entire survey region from estimates in the surveyed areas. 3. Crabeater seal abundance was estimated to be between 0.7 and 1.4 million animals (with 95% confidence), with the most likely estimate slightly less than 1 million. 4. Synthesis and applications. The estimation of crabeater seal abundance in Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) management areas off east Antarctic where krill biomass has also been estimated recently provides the data necessary to begin extending from single-species to multispecies management of the krill fishery. Incorporation of all major sources of uncertainty allows a precautionary interpretation of crabeater abundance and demand for krill in keeping with CCAMLR’s precautionary approach to management. While this study focuses on the crabeater seal and management of living resources in the Southern Ocean, it has also led to technical and theoretical developments in survey methodology that have widespread potential application in ecological and resource management studies, and will contribute to a more fundamental understanding of the structure and function of the Southern Ocean ecosystem.

Distance software: design and analysis of distance sampling surveys for estimating population size

1. Distance sampling is a widely used technique for estimating the size or density of biological populations. Many distance sampling designs and most analyses use the software Distance. 2. We briefly review distance sampling and its assumptions, outline the history, structure and capabilities of Distance, and provide hints on its use. 3. Good survey design is a crucial prerequisite for obtaining reliable results. Distance has a survey design engine, with a built-in geographic information system, that allows properties of different proposed designs to be examined via simulation, and survey plans to be generated. 4. A first step in analysis of distance sampling data is modeling the probability of detection. Distance contains three increasingly sophisticated analysis engines for this: conventional distance sampling, which models detection probability as a function of distance from the transect and assumes all objects at zero distance are detected; multiple-covariate distance sampling, which allows covariates in addition to distance; and mark–recapture distance sampling, which relaxes the assumption of certain detection at zero distance. 5. All three engines allow estimation of density or abundance, stratified if required, with associated measures of precision calculated either analytically or via the bootstrap. 6. Advanced analysis topics covered include the use of multipliers to allow analysis of indirect surveys (such as dung or nest surveys), the density surface modeling analysis engine for spatial and habitat-modeling, and information about accessing the analysis engines directly from other software. 7. Synthesis and applications. Distance sampling is a key method for producing abundance and density estimates in challenging field conditions. The theory underlying the methods continues to expand to cope with realistic estimation situations. In step with theoretical developments, state-of- the-art software that implements these methods is described that makes the methods accessible to practicing ecologists.

The Effects Of Reinforcement Inclusions On Wear Tolerance, Playing Quality And Physical Properties In A Silt Loam And Sand Rootzone Matrix

Reinforcement inclusions have been advocated to alleviate wear, compaction, and unstable surfaces in sports fields, but little research on the effects of these materials has been conducted in the USA. Experiments were established on a native silt loam and a sand rootzone matrix, seeded with a Kentucky bluegrass (Poa pratensis L.) blend, at the Joseph Troll Turf Research Center, University of Massachusetts, Amherst, USA to determine the effects of reinforcement inclusions on wear, surface hardness, traction, ball roll, ball bounce resilience, water infiltration rate, soil bulk density, air porosity, total porosity, and root weights. Three types of reinforcement inclusions (Sportgrass, Netlon, Turfgrids) were tested along with a non-reinforced control in a three year study. The treatments were set out in a randomized complete block design with four replications in both soils. No inclusion provided less wear or greater infiltration or air-filled porosity relative to the control. Reinforcement inclusions showed significant differences, however, in surface hardness, traction, and ball roll relative to the control, although this varied with the time of year. Infiltration rates, airfilled porosity, total pore space, bulk density, hardness, traction, ball roll, and ball rebound were greater on the sand rootzone than on the silt loam. Significant correlations were present between soil bulk density, surface hardness, traction, and ball roll. Based on our study, the use of reinforcement inclusions to provide better wear tolerance for sand or native soil athletic fields is not warranted. Certain playing surface characteristics, however, may be slightly improved with the use of reinforcement inclusions. The use of sands for sports surfaces is justified based upon the improvement in playing quality characteristics and soil physical properties important to a good playing surface.

Wetland maps including open water extent dynamics based on ENVISAT ASAR WS for Siberia, 2007 and 2008, links to GeoTIFFs

Wetlands store large amounts of carbon, and depending on their status and type, they release specific amounts of methane gas to the atmosphere. The connection between wetland type and methane emission has been investigated in various studies and utilized in climate change monitoring and modelling. For improved estimation of methane emissions, land surface models require information such as the wetland fraction and its dynamics over large areas. Existing datasets of wetland dynamics present the total amount of wetland (fraction) for each model grid cell, but do not discriminate the different wetland types like permanent lakes, periodically inundated areas or peatlands. Wetland types differently influence methane fluxes and thus their contribution to the total wetland fraction should be quantified. Especially wetlands of permafrost regions are expected to have a strong impact on future climate due to soil thawing. In this study ENIVSAT ASAR Wide Swath data was tested for operational monitoring of the distribution of areas with a long-term SW near 1 (hSW) in northern Russia (SW = degree of saturation with water, 1 = saturated), which is a specific characteristic of peatlands. For the whole northern Russia, areas with hSW were delineated and discriminated from dynamic and open water bodies for the years 2007 and 2008. The area identified with this method amounts to approximately 300,000 km**2 in northern Siberia in 2007. It overlaps with zones of high carbon storage. Comparison with a range of related datasets (static and dynamic) showed that hSW represents not only peatlands but also temporary wetlands associated with post-forest fire conditions in permafrost regions. Annual long-term monitoring of change in boreal and tundra environments is possible with the presented approach. Sentinel-1, the successor of ENVISAT ASAR, will provide data that may allow continuous monitoring of these wetland dynamics in the future complementing global observations of wetland fraction.