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Flow regimes in wet conical spouted beds using glass bead mixtures

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Particuology 2008年第2期6卷 72-80页

作者： Marcelo S.Bacelos jos teixeira Freire Universidade Federal de Sāo Carlos Centro de Ciências Exatas e de TecnologiaPrograma de Pós-Graduacāo em Engenharia QuímicaCentro de Secagem de PastasSuspensōes e SementesRod.Washington LuizKm 23513565-905CP 676Sāo CarlosSPBrazil

Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures： a reference （monoparticles）, a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters （dp） ranging from 1.09 to 4.98 mm and particle diameter ratios （dpL/dps） ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.

关键词： Conical spouted bed Binary and ternary mixtures Processing of pastes Spouting regimes Spouting stability Pressure fluctuation

Mechanisms to explain soil liquefaction triggering,development,and persistence during an earthquake

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Earthquake Science 2024年第6期37卷 558-573页

作者： fernando teixeira MED-Mediterranean Institute for Agriculture Environment and DevelopmentInstitute for Advanced Studies and ResearchUniversidade deÉvoraPólo da MitraAp.947006-554ÉvoraPortugal

Mechanisms have been proposed to explain the triggering,development,and persistence of soil *** mechanism explaining the horizontal failure plane(triggering)and its depth below the phreatic surface is governed by the flux properties and effective stress at that *** the failure plane,the pore water pressure was higher than the effective stress,and the volume change was the *** pore water pressure is a function of the soil profile features(particularly the phreatic zone width)and bedrock motion(horizontal acceleration).The volume change at the failure plane is a function of the intrinsic permeability of the soil and bedrock *** failure plane was predicted to occur during the oscillation with the highest amplitude,disregarding further bedrock motion,which was consistent with low seismic energy *** mechanisms were proposed to explain the persistence of soil *** first is the existence of low-permeability layers in the depth range in which the failure planes are predicted to *** other allows for the persistence and development of soil liquefaction;it is consistent with homogeneous soils and requires water inflow from bedrock water *** latter explains many of the features of soil liquefaction observed during earthquakes,namely,surficial effects,“instant”liquefaction,and the occurrence of short-and long-term changes in the level of the phreatic *** model(hypothesis),the relationship between the flux characteristics and loss of soil shear strength,provides self-consistent constraints on the depth below the phreatic surfaces where the failure planes are observed(expected to occur).It requires further experimental and observational *** reasoning can be used to explain other saturated soil phenomena.

关键词： soil liquefaction triggering soil liquefaction persistence intrinsic soil permeability impervious soil layers bedrock water springs

Slope Processes, Mass Movement and Soil Erosion： A Review

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Pedosphere 2017年第1期27卷 27-41页

作者： Antonio jos teixeira GUERRA Michael Augustine FULLEN Maria do Carmo Oliveira JORGE joss fernando Rodrigues BEZERRA Mohamed S. SHOKR Department of Geography Federal University of Rio de Janeiro Rio de Janeiro 21941-972 (Brazil) Faculty of Science and Engineering University of Wolverhampton Wolverhampton WV1 1LY (UK) Department of Geography State University of Maranhao SSo Luis 65055-970 (Brazil) Soil and Water Department Faculty of Agriculture Tanta University Tanta 31527 (Egypt)

Soil erosion and land degradation are global problems and pose major issues in many countries. Both soil erosion and mass movement are two forms of land degradation and humans play important roles in these geomorphological processes. This paper reviews slope processes associated with mass movement and soil erosion and contributory factors, including physical and human agents. Acting together, these cause diverse geomorphological features. Slope processes are illustrated by reference to case studies from Brazil and UK. The causes and impacts of erosion are discussed, along with appropriate remedial bioengineering methods and the potential of the measures to prevent these types of environmental degradation. Although there are several agents of erosion, water is the most important one. Cultivation can promote soil erosion, due to ploughing and harvesting, which moves soil down slopes. Soil erosion and mass movement data would inform the viability of soil conservation practices. Integrated management of drainage basins offers a Dromising way forward for effective soil conservation and soil remedial bioengineering in Brazil and UK.

关键词： geomorphological feature land degradation hazards risks slope processes soil recuperation

Intraspecific competition in Zabrotes subfasciatus： Physiological and behavioral adaptations to different amounts of host

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Insect Science 2012年第1期19卷 102-111页

作者： Isabel R.V.teixeira fernando S.Zucoloto Insect Nutrition and Feeding Behavior Laboratory Department of BiologyFaculdade de Filosofia Ciencias e Letras de Ribeirao Preto Universidade de Sao PauloSao Paulo epartment of Biology Federal Institute of Sul de Minas-Campus MuzambinhoIFSULDEMINAS MuzambinhoMinas GeraisBrazil

The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples （6） and varying the amount of available host seeds： HC, high （limited availability of host： 1.35 g）; IC, intermediate （intermediate availability of host： 6 g）; and LC, low competition （abun- dance of host： 36 g）. It was found that the distribution of the eggs laid on grains was different among treatments： in LC, for example, although females showed high fecundity （35.4 ± 5.6 eggs/female） the number of eggs laid on each grain was small （1.2 ± 0.4 eggs on each seed）, thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity （27.04 ± 4.5 eggs/female） but laid many eggs on each grain （15.03 ± 4.3 eggs）. There were no changes in the ability to respond to different amounts of host via oviposition behavior （egg distribution） during 41 generations. How- ever, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.

关键词： bean weevil Coleoptera egg distribution oviposition Phaseolus vulgaris phenotypic plasticity

Leaf water potential and gas exchange of eucalypt clonal seedlings to leaf solar protectant

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Journal of Forestry Research 2019年第1期30卷 57-64页

作者： Talita Miranda teixeira Xavier josé Eduardo Macedo Pezzopane Ricardo Miguel Penchel josé Ricardo Macedo Pezzopane Departamento de Ciências Florestais e da Madeira Universidade Federal do Espírito Santo Fibria Celulose S.A Rodovia General Euryale Jesus Zerbini Embrapa Pecuária Sudeste

This experiment was carried out in acclimatized greenhouses with seedlings of two hybrid clones of Eucalyptus urophylla×Eucalyptus grandis. A sunscreen protector consisting of 62.5% calcium carbonate was sprayed on the seedlings at weekly intervals. Water stress was induced by suspending irrigation until the soil reached 30% available water and water was then replaced so that it returned to field capacity. Gas exchange and leaf water status were measured after 50 days. The experiment was set up in a 4×2 factorial randomized block design in four distinct environments:(1) temperatures less than 21.2℃ and vapor pressure deficit of 0.15 kPa;(2) intermediate temperatures of 24.2℃ and vapor pressure deficit of 0.69 kPa;(3) high temperatures of 27.0℃ and high vapor pressure deficit of 1.4 kPa; and,(4) high temperature of 27.0℃ and vapor pressure deficit below 1.10 kPa. Two leaf sun protector treatments were used, with five replications each. High atmospheric demand acted as a stress factor for the seedlings during the initial growth *** of leaf sunscreen protector provided beneficial effects in maintaining optimum water status and gas exchanges of the plants under water stress.

关键词： Eucalyptus urophylla×Eucalyptus grandis Calcium carbonate Water stress Atmospheric demand

Host preference of the bean weevil Zabrotes subfasciatus

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Insect Science 2008年第4期15卷 335-341页

作者： Isabel Ribeiro do Valle teixeira Angel Roberto Barchuk fernando Sergio Zucoloto Department of Biology Centro Universitario da Fundacao Educacional de Guaxupe Minas Gerais Department of Biology Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto Universidade de Sao Paulo Sao Paulo Department of Biological Sciences Universidade Federal de Alfenas UnifaI-MG Alfenas Minas Gerais Brazil

It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus. However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largely unknown. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of：（i） oviposition preference of a wild population of Z. subfasciatus on the usual host （bean） and unusual hosts （lentil, chickpea and soy）, and the performance of the offspring; （ii） artificial selection for increasing preference for hosts initially less frequently chosen; （iii） comparison of oviposition behavior between two different populations （reared for -30 generations in beans or chickpeas, respectively）; （iv） oviposition timing on usual and unusual hosts; and （v） identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host （chickpea） for 26 generations showed similar good fitness on both usual and unusual hosts, indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.

关键词： artificial selection evolution Phaseolus Cicer plant-insect interaction

Stochastic seismic inversion and Bayesian facies classification applied to porosity modeling and igneous rock identification

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Petroleum Science 2024年第2期21卷 918-935页

作者： Fábio Júnior Damasceno Fernandes Leonardo teixeira Antonio fernando Menezes Freire Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsFederal Fluminense UniversityNiter oiRJ24210-346Brazil Petrobras Rio de JaneiroRJ20231-030Brazil National Institute of Science and Technology of Petroleum Geophysics(INCT-GP/CNPQ) Niter oiRJ24210-346Brazil

We apply stochastic seismic inversion and Bayesian facies classification for porosity modeling and igneous rock identification in the presalt interval of the Santos Basin. This integration of seismic and well-derived information enhances reservoir characterization. Stochastic inversion and Bayesian classification are powerful tools because they permit addressing the uncertainties in the model. We used the ES-MDA algorithm to achieve the realizations equivalent to the percentiles P10, P50, and P90 of acoustic impedance, a novel method for acoustic inversion in presalt. The facies were divided into five: reservoir 1,reservoir 2, tight carbonates, clayey rocks, and igneous rocks. To deal with the overlaps in acoustic impedance values of facies, we included geological information using a priori probability, indicating that structural highs are reservoir-dominated. To illustrate our approach, we conducted porosity modeling using facies-related rock-physics models for rock-physics inversion in an area with a well drilled in a coquina bank and evaluated the thickness and extension of an igneous intrusion near the carbonate-salt interface. The modeled porosity and the classified seismic facies are in good agreement with the ones observed in the wells. Notably, the coquinas bank presents an improvement in the porosity towards the top. The a priori probability model was crucial for limiting the clayey rocks to the structural lows. In Well B, the hit rate of the igneous rock in the three scenarios is higher than 60%, showing an excellent thickness-prediction capability.

关键词： Stochastic inversion Bayesian classification Porosity modeling Carbonate reservoirs Igneous rocks

Mathematical simulation of radial heat transfer in packed beds by pseudohomogeneous modeling

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Particuology 2011年第2期9卷 107-113页

作者： Rodrigo Béttega Marcos Flávio Pinto Moreira Ronaldo Guimaraes Corrêa josé teixeira Freire Federal University of Uberlandia/School of Chemical Engineering-Av.Jo o Naves ávila 2121 Uberlandia-MGCEP 38400-902Brazil Western Paraná State University-Rua da Faculdade 645 Jardim La SalleToledo-PRCEP 85903-000Brazil Federal University of S o Carlos/Department of Chemical Engineering-Rod.Washington Luiz km 235 S o Carlos-SPCEP 13565-905P.O.Box 676Brazil

Uniform flow regime and constant effective thermal conductivity inside packed beds are commonly accepted in the evaluation of the fluid dynamics and heat transfer in such systems. However, several authors have confirmed the presence of an oscillatory velocity profile caused by the effective contribu~ tion of porosity profile in the fluid dynamic behavior of packed beds, which directly influences the heat transfer inside the beds. This paper describes the application of a pseudo-homogeneous mathematical model for describing heat transfer in packed beds with oscillatory profiles of velocity and porosity, using a radius-dependent model for effective thermal conductivity kr. Several temperature profiles were obtained in a packed bed system with thermal source located on the wall. The simulated temperature and effective thermal conductivity obtained from simulations were compared with experimental data and calculation from a model based on uniform kr fitting. The results indicate that the proposed mathematical modeling was capable of better reDresenting the heat transfer in the packed bed.

关键词： Packed bedHeat transferPseudohomogeneous modeling

Application of data science in the prediction of solar energy for the Amazon basin:a study case

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Clean Energy 2023年第6期7卷 1344-1355页

作者： AndréLuis Ferreira Marques Márcio joséteixeira Felipe Valencia de Almeida Pedro Luiz Pizzigatti Corrêa Polytechnic School of the University of Sao Paulo Av.Prof.Luciano Gualberto380-ButantaSao Paulo-SP05508-010Brazil Institute of Physics of the University of Sao Paulo Brazil

The need for renewable energy sources has challenged most countries to comply with environmental protection actions and to handle climate *** energy figures as a natural option,despite its *** has a green energy matrix with significant expansion of solar form in recent *** preserve the Amazon basin,the use of solar energy can help communities and cities improve their living standards without new hydroelectric units or even to burn biomass,avoiding harsh environmental *** novelty of this work is using data science with machine-learning tools to predict the solar incidence(W.h/m^(2))in four cities in Amazonas state(north-west Brazil),using data from NASA satellites within the period of ***-tree-based models and vector autoregressive(time-series)models were used with three time aggregations:day,week and *** predictor model can aid in the economic assessment of solar energy in the Amazon basin and the use of satellite data was encouraged by the lack of data from ground *** mean absolute error was selected as the output indicator,with the lowest values obtained close to 0.20,from the adaptive boosting and light gradient boosting algorithms,in the same order of magnitude of similar references.

关键词： solar energy renewable energy Amazon basin machine learning time series data science decision-trees ensemble vector autoregression