Mineração de dados para inferência de relações solo-paisagem em mapeamentos digitais de solo

The objective of this work was to develop a methodology for digital soil mapping at a 1:100,000 scale by applying data mining techniques to preexisting relief descriptors and data from pedological and geological maps. A digital database was created from topographic and thematic maps, and allowed the generation of a digital elevation model (DEM) of the Dois Córregos (SP, Brazil) sheet (1:50,000 scale). The slope gradient, slope profile, contour profile, basin contributing area, and diagonal distance to drainage geomorphometric parameters were extracted from the DEM. The matrix which associated this georeferred data was analyzed by means of decision trees within the Weka machine-learning environment, and a model for soil mapping unit prediction was generated. The overall model accuracy increased from 54 to 61% when soil classes with no chances of being predicted were excluded. The association of data mining techniques with geographical information systems produced digital soil maps feasible to be used in studies requiring less detail than those made with the original reference soil maps.O objetivo deste trabalho foi desenvolver uma metodologia para mapeamento digital de solos na escala 1:100.000 com a aplicação de técnicas de mineração de dados a descritores de relevo e a dados de mapas geológico e pedológico preexistentes. Foi criada uma base de dados digitais a partir de cartas topográficas e temáticas, que permitiu elaboração do modelo digital de elevação (MDE) da folha Dois Córregos, SP (escala 1:50.000). A partir do MDE, foram calculados os parâmetros geomorfométricos declividade, curvaturas em planta e perfil, área de contribuição e distância diagonal de drenagem. A matriz que associou esses dados georreferenciados foi analisada por meio de árvores de decisão, no ambiente de aprendizado de máquina Weka, o que gerou um modelo de predição de unidades de mapeamento de solos. A acurácia geral do modelo aumentou de 54 para 61% com a eliminação das classes com probabilidade nula de ocorrência. A associação da mineração de dados com sistemas de informações geográficas permite a elaboração de mapas digitais passíveis de uso em estudos que requeiram menor detalhamento que aqueles realizados com o mapa original

Performance of calves fed silage transition milk

O objetivo deste trabalho foi avaliar o desempenho de bezerros da raça Holandesa, aleitados com leite ou silagem de leite de transição diluída em água ou misturada ao leite, bem como realizar análise econômica das dietas. Foram utilizados 18 animais, com peso corporal inicial médio de 36,50±4,03 kg, alojados individualmente em baias. Os animais receberam quatro litros de dieta líquida por dia, durante 54 dias. Os dados de consumo, ganho de peso diário, medidas de crescimento e conversão alimentar foram analisados em parcelas subdivididas; e o peso corporal final, o ganho total e a ocorrência de diarreia foram analisados em delineamento inteiramente casualizado. A silagem de leite de transição não alterou o consumo de concentrado e o total de matéria seca, nem a ocorrência de diarreia. O desempenho dos animais foi reduzido, quando a silagem foi diluída em água, o que resultou em menor peso final e menor ganho total de peso. Os animais tratados com silagem misturada ao leite tiveram desempenho similar aos tratados com leite, o que possibilita menor custo por quilograma de ganho de peso total e se mostra como opção viável para o aleitamento de bezerros leiteiros.The objective of this work was to evaluate the performance of Holstein calves fed with milk or transition milk silage diluted on water or mixed with whole milk, as well as to determine the economic viability of the diets. Eighteen calves, with an average initial body weight of 36.50±4.03 kg, were individually housed in stalls. The animals were fed four liters of the liquid diet a day, during 54 days. Consumption data, daily weight gain, growth measurements, and feed conversion were analyzed in split plots. Final body weight, total weight gain, and occurrence of diarrhea were analyzed in a completely randomized design. Transition milk silage did not affect concentrate intake, total dry matter intake and the occurrence of diarrhea. Animal performance was reduced when silage was diluted on water, resulting in lower final weight and lower total weight gain. Animals treated with transition milk silage mixed with whole milk had a similar performance to the ones treated with whole milk, which allows a lower cost per kilogram of total weight gain, and shows to be a viable option for the feeding of milking calves

The effect of beryllium oxide on retention in JET ITER-like wall tiles

Preliminary results investigating the microstructure, bonding and effect of beryllium oxide formation on retention in the JET ITER-like wall beryllium tiles, are presented. The tiles have been investigated by several techniques: Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray (EDX), Transmission Electron microscopy (TEM) equipped with EDX and Electron Energy Loss Spectroscopy (EELS), Raman Spectroscopy and Thermal Desorption Spectroscopy (TDS). This paper focuses on results from melted materials of the dump plate tiles in JET. From our results and the literature, it is concluded, beryllium can form micron deep oxide islands contrary to the nanometric oxides predicted under vacuum conditions. The deepest oxides analyzed were up to 2-micron thicknesses. The beryllium Deuteroxide (BeOxDy) bond was found with Raman Spectroscopy. Application of EELS confirmed the oxide presence and stoichiometry. Literature suggests these oxides form at temperatures greater than 700 °C where self-diffusion of beryllium ions through the surface oxide layer can occur. Further oxidation is made possible between oxygen plasma impurities and the beryllium ions now present at the wall surface. Under Ultra High Vacuum (UHV) nanometric Beryllium oxide layers are formed and passivate at room temperature. After continual cyclic heating (to the point of melt formation) in the presence of oxygen impurities from the plasma, oxide growth to the levels seen experimentally (approximately two microns) is proposed. This retention mechanism is not considered to contribute dramatically to overall retention in JET, due to low levels of melt formation. However, this mechanism, thought the result of operation environment and melt formation, could be of wider concern to ITER, dependent on wall temperatures

Modelling of tungsten erosion and deposition in the divertor of JET-ILW in comparison to experimental findings

The erosion, transport and deposition of tungsten in the outer divertor of JET-ILW has been studied for an HMode discharge with low frequency ELMs. For this specific case with an inter-ELM electron temperature at the strike point of about 20 eV, tungsten sputtering between ELMs is almost exclusively due to beryllium impurity and self-sputtering. However, during ELMs tungsten sputtering due to deuterium becomes important and even dominates. The amount of simulated local deposition of tungsten relative to the amount of sputtered tungsten in between ELMs is very high and reaches values of 99% for an electron density of 5E13 cm$^{-3}$ at the strike point and electron temperatures between 10 and 30 eV. Smaller deposition values are simulated with reduced electron density. The direction of the B-field significantly influences the local deposition and leads to a reduction if the E×B drift directs towards the scrape-off-layer. Also, the thermal force can reduce the tungsten deposition, however, an ion temperature gradient of about 0.1 eV/mm or larger is needed for a significant effect. The tungsten deposition simulated during ELMs reaches values of about 98% assuming ELM parameters according to free-streaming model. The measured WI emission profiles in between and within ELMs have been reproduced by the simulation. The contribution to the overall net tungsten erosion during ELMs is about 5 times larger than the one in between ELMs for the studied case. However, this is due to the rather low electron temperature in between ELMs, which leads to deuterium impact energies below the sputtering threshold for tungsten

Impact of fast ions on density peaking in JET : fluid and gyrokinetic modeling

The effect of fast ions on turbulent particle transport, driven by ion temperature gradient (ITG)/trapped electron mode turbulence, is studied. Two neutral beam injection (NBI) heated JET discharges in different regimes are analyzed at the radial position rho(t) = 0.6, one of them an L-mode and the other one an H-mode discharge. Results obtained from the computationally efficient fluid model EDWM and the gyro-fluid model TGLF are compared to linear and nonlinear gyrokinetic GENE simulations as well as the experimentally obtained density peaking. In these models, the fast ions are treated as a dynamic species with a Maxwellian background distribution. The dependence of the zero particle flux density gradient (peaking factor) on fast ion density, temperature and corresponding gradients, is investigated. The simulations show that the inclusion of a fast ion species has a stabilizing influence on the ITG mode and reduces the peaking of the main ion and electron density profiles in the absence of sources. The models mostly reproduce the experimentally obtained density peaking for the L-mode discharge whereas the H-mode density peaking is significantly underpredicted, indicating the importance of the NBI particle source for the H-mode density profile