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A Parameter-Space Analysis of the Rikitake System

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Chinese Physics Letters 2013年第12期 17-20页

作者： rodrigo a.da silva Paulo C.Rech Departamento de Fisica Universidade do Estado de Santa Catarina

We investigate analytically and numerically the dynamics of the Rikitake *** Routh-Hurwitz criterion is used to study the stability of the equilibrium points of the differential equation system model,as functions of two *** dynamics of the model are numerically studied using diagrams that associate colors to the largest Lyapunov exponent value,in two-dimensional parameter ***,phase-space plots and bifurcation diagrams are used to distinguish periodic and chaotic attractors.

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A remote sensing approach to estimate the load bearing capacity of soil

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Information Processing in Agriculture 2024年第1期11卷 109-116页

作者： Italo Rômulo Mendes de Souza Edson Eyji Sano Renato Paiva de Lima Anderson rodrigo da silva Statistics and Geoprocessing Laboratory Instituto Federal GoianoGeraldo Silva Nascimento RoadKm 2.575790-000 UrutaíGoiásBrazil Embrapa Cerrados BR-020 RoadKm 18Mailbox 0822373310-970 PlanaltinaDFBrazil Department of Soil Science ‘Luiz de Queiroz’College of AgricultureUniversity of São PauloAv.Pádua Dias235-AgronomiaPiracicabaSP 13418-900Brazil

Preconsolidation pressure(σp)of soil can be considered as an indicator of the Load Bearing Capacity(LBC),which is the tolerated surface pressure before compaction,often caused by the traffic of agricultural *** this pioneering study,a remote sensing approach was introduced to estimate LBC throughσp from soils of the“Rio Preto”Hydrographic Basin,Bahia State,Brazil,in a monthly time lapse from 2016 to ***,σp is measured by a laborious and time demanding laboratory analysis,making it unfeasible to map large *** innovative methodology of this work consists of combining active–passive satellite data on soil moisture and pedotransfer functions of clay content and water matric potential to obtain geo-located estimates ofσ*** were analysed under different classes of soil use,land cover and slope;95%confidence intervals were built for the time series of mean values of LBC for each *** overall seasonal variation in LBC estimates is similar in areas with annual crops,grasslands and natural vegetation,and flat areas are less affected by soil moisture variations over the year(between seasons).LBC decreased,in general,at about 0.5%a year in flat ***,these areas demand attention,since they occupy 86%of the Basin and are mostly subjected to agricultural soil management and surface pressure by heavy machinery.

关键词： Soil compaction SMAP Preconsolidation stress Brazilian Cerrado

Efficiency of soil-applied ^(67)Zn-enriched fertiliser across three consecutive crops

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Pedosphere 2021年第4期31卷 531-537页

作者： Edson M.MATTIELLO Eduardo L.CANCELLIER rodrigo C.da silva Fien DEGRYSE Roslyn BAIRD Mike J.MCLAUGHLIN Department of Soil Science Universidade Federal de ViçosaViçosaMinas Gerais(Brazil) Department of Soil Science Universidade Federal de LavrasMinas Gerais(Brazil) The University of Adelaide School of AgricultureFood and WineFertiliser Technology Research CentrePMB 1Waite CampusGlen Osmond SA 5064(Australia)

A very small amount of applied zinc(Zn) is taken up by crops, resulting in low recovery by plants. Adding elemental sulphur to zinc oxide(ZnO) fertiliser could improve Zn solubilisation and exert a higher residual effect on crops than soluble Zn sources. We produced an isotopically labelled Zn-elemental sulphur fertiliser and evaluated its performance in comparison to traditional Zn sources during sequential crop cultivation. Three ^(67)Zn-labelled fertilisers,ZnO, zinc sulphate(ZnSO_(4)), and ZnO co-granulated with elemental sulphur(ZnOS^(0)), were soil applied, and their contributions to the uptake of Zn by three consecutive crops, wheat, ryegrass, and corn, were assessed in a 294-d pot experiment. The contributions of Zn fertilisers followed the order: ZnSO_(4) > ZnO= ZnOS^(0). The relative contributions of Zn fertilisers were lower in the first crop than in the subsequent crops. The overall recovery of applied Zn by the three crops was higher for ZnSO_(4) than for ZnO and ZnOS^(0), reaching 1.56%, 0.45%, and 0.33% of the applied Zn, respectively. Zinc recovery by plants was very low, regardless of the source of Zn. Adding elemental sulphur to ZnO did not increase its effectiveness up to 294 d after application. Fertiliser contribution was higher for the subsequent crops than for the initial crop, indicating the importance of assessing the residual effects of Zn fertilisers.

关键词： agronomic biofortification elemental sulphur fertilizer residual effect plant uptake Zn bioavailability Zn fertilization Zn source

Dendritic Growth, Eutectic Features and Their Effects on Hardness of a Ternary Sn–Zn–Cu Solder Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第6期30卷 528-540页

作者： Bismarck Luiz silva rodrigo Valenzuela Reyes Amauri Garcia JoséEduardo Spinelli Department of Materials Engineering Federal University of Rio Grande do Norte-UFRNNatalRN 59078-970Brazil Department of Materials Engineering Federal University of Sao Carlos-UFSCarSao CarlosSP 13565-905Brazil Department of Manufacturing and Materials Engineering University of CampinasUNICAMPCampinasSP 13083-860Brazil

The present investigation is based on the results of a directionally solidified （DS） Sn-9 wt%Zn-2 wt%Cu alloy, including primary/secondary/tertiary dendrite arm spacings of the Sn-rich matrix, the morphologies of the eutectic mixture and the corresponding interphase spacing, the nature and proportion of the Cu-Zn intermetallic compound （IMC）. The main purpose is to establish interrelations of these microstructure features with experimental solidification thermal parameters, such as cooling rates and growth rates （v）, macrosegregation and hardness. Such interrelations are interesting for both industry and academy since they represent a tool permitting the preprogramming of final properties based on the design of the microstructure. In the case of Sn-Zn-Cu alloys, hardly anything is known about the combined effects of the length scale of the microstructure and fraction and distribution of the primary IMC on hardness. The alloy microstructure is composed of a β-Sn dendritic region, surrounded by a eutectic mixture of α-Zn and β-Sn phases and the γ-Cu5Zn8 IMC. The eutectic interphase spacing varies in the range 1.2-3.6 μm, with the α-Zn phase having a globular morphology for ν 〉 0.5 mm/s and a needle-like morphology for ν 〈 0.3 mm/s. A modified Hall-Petch-type experimental expression relating hardness to the interphase spacing is proposed.

关键词： Sn-Zn-Cu solder alloy Solidification Microstructure Eutectic morphology Hardness

Catalytic combustion of soot over ceria-zinc mixed oxides catalysts supported onto cordierite

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Journal of Environmental Sciences 2014年第3期26卷 694-701页

作者： Leandro Fontanetti Nascimento Renata Figueredo Martins rodrigo Ferreira silva Osvaldo Antonio Serra Department of Chemistry FFCLRP University of Sao Paulo

Modified substrates as outer heterogeneous catalysts was employed to reduce the soot generated from incomplete combustion of diesel or diesel/biodiesel blends, a process that harms the environment and public health. The unique storage properties of ceria （CeO2） makes it one of the most efficient catalysts available to date. Here, we proposed that ceria-based catalysts can lower the temperature at which soot combustion occurs; more specifically, from 610℃ to values included in the diesel exhausts operation range （300-450℃）. The sol-gel method was used to synthesize mixed oxide-based catalysts （CeO2：ZnO）; the resulting catalysts were deposited onto cordierite substrates. In addition, the morphological and structural properties of the material were evaluated by XRD, BET, TPR-H2, and SEM. Thermogravimetric （TG/DTA） analysis revealed that the presence of the catalyst decreased the soot combustion temperature by 200℃ on average, indicating that the oxygen species arise at low temperatures in this situation, promoting highly reactive oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy （DRS） showed that catalyst-impregnated cordierite samples efficiently oxidized soot in a diesel/biodiesel stationary motor： soot emission decreased by more than 70%.

关键词： soot oxidation mixed oxides ceria

Chemical speciation of copper and manganese in solution of a copper-contaminated soil and young grapevine growth with amendment application

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Pedosphere 2023年第3期33卷 496-507页

作者： daniela Basso FACCO Edicarla TRENTIN Gerson Laerson DRESCHER rodrigo Knevitz HAMMERSCHMITT Carlos Alberto CERETTA Leandro Souza.da silva Gustavo BRUNETTO Paulo Ademar Avelar FERREIRA Department of Soil Science Federal University of Santa MariaSanta Maria 97105-900(Brazil) University of Arkansas System Division of Agriculture Arkansas 72704(USA) Federal University of Santa Maria Campus Cachoeira do SulCachoeira do Sul 96506-310(Brazil)

Copper(Cu)-based fungicide application to control foliar diseases in grapevine(Vitis vinifera L.)can increase soil Cu *** soils have high natural Cu and manganese(Mn)concentrations,increasing the potential for toxicity to grapevine *** of amendment substances can reduce the concentrations of toxic chemical species of Cu and Mn in soil solution,especially for the soils grown with young *** evaluated the chemical speciation of Cu and Mn in soil solution and young grapevine growth using a contaminated soil with amendment *** seedlings of Paulsen 1103rootstock were grown for 12 months on an old vineyard(>30 years of cultivation)soil without(control)and with vermicompost or limestone *** dry matter,root morphological characteristics,and plant tissue Cu and Mn concentrations were *** cation and anion concentrations,dissolved organic carbon,p H,and chemical speciation of Cu and Mn in soil solution from different soil layers were *** application did not reduce Cu and Mn phytotoxicity,and grapevine plants died after winter *** soluble Mn concentration in soil(5.56 mg L-1in 0–45 cm soil layer)and Mn concentration in plant tissue at pruning(380.8 mg kg-1)might be the primary cause of plant *** application reduced Cu2+and Mn2+chemical species in soil solution,thereby increasing plant *** Cu2+and Mn2+species were negatively correlated(P<0.05)with grapevine shoot production at pruning(r=-0.92 and-0.97,respectively)and at the end of the trial(r=-0.73 and-0.51,respectively).Limestone application increased grapevine shoot and root dry matter production by 36%and 41%,respectively,while also presenting the highest root length and volume in the 5–10 cm soil *** application is a viable and profitable alternative for reducing soil Cu and Mn availability and their phytotoxic effects.

关键词： bioavailability heavy metal limestone phytoxicity vermicompost vineyard Visual MINTEQ

Lameness prediction in broiler chicken using a machine learning technique

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Information Processing in Agriculture 2021年第3期8卷 409-418页

作者： Irenilza de Alencar Naas Nilsa Duarte da silva Lima rodrigo Franco Gonc¸alves Luiz Antonio de Lima Henry Ungaro Jair Minoro Abe Paulista University-Graduate Program in Production Engineering Sao PauloBrazil

Broiler flock welfare is usually assessed through mortality,physiology,behavior,and walk-ing *** possibility of assessing broiler chicken lameness using the bird walking abil-ity was investigated using the machine learning approach for the first *** on broiler walking speed and acceleration,genetic strain,and sex were recorded and input in a *** were classified according to the 6-point gait score(GS0 is a sound bird,and GS5 is a severely lame bird).Decision trees were built initially using all *** confusion matrix of each developed model was *** pruning technique was used,removing from the dataset the variables that did not infer in the classification *** reorganized the dataset and re-arranged the data by grouping the intermediate target class of gait score using the Borda Count ***-processing data,we obtained a new set of decision *** the 3-point gait score(GS0 is a sound bird,and GS2 is a lame bird),we obtained a new model with better accuracy(78%);however,the model had a lower accuracy for classifying lame broilers(GS2,5%).The final decision tree was selected for classifying broilers,either sound or lame,according to their walking *** developed model presented good accuracy(91%),and it ordered properly sound(86%)and lame birds(92%).The novel model might be used to assess broiler lameness on-farm by registering the bird displacement *** developments using the model might allow flock lameness detection automatically.

关键词： Broiler welfare Broiler walking speed Decision tree Confusion matrix Gait score

Alkaline hydrolyzable nitrogen and properties that dictate its distribution in paddy soil profiles

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Pedosphere 2020年第3期30卷 326-335页

作者： Gerson Laerson DRESCHER Leandro Souza.da silva Qamar SARFARAZ Gustavo daL MOLIN Laura Brondani MARZARI Augusto Ferreira LOPES Cesar CELLa.daniela Basso FACCO rodrigo Knevitz HAMMERSCHMITT Department of Soil Science Federal University of Santa MariaSanta Maria 97105-900Brazil Federal University of Santa Maria Campus Cachoeira do SulCachoeira do Sul 96506-310Brazil

Nitrogen(N) is a key nutrient for rice production, and its bioavailability in paddy soils is strongly coupled to soil organic matter(SOM) cycling. A better understanding of potentially available N forms in soil, such as alkaline hydrolyzable N(AH-N), and their depth distribution will support the development of best management practices to improve the N use efficiency of rice while minimizing adverse environmental effects. Fifteen rice(Oryza sativa L.) fields from Southern Brazil were selected, and stratified soil samples were taken to a depth of 60 cm before crop establishment. Selected soil physical and chemical properties were analyzed to evaluate their relationships with AH-N contents in the soil profile. The AH-N contents below 20 cm varied extensively(increased,reduced, or constant) compared with that above 20 cm. Although clay and clay + silt contents were highly correlated to AH-N for some soils, the major property dictating AH-N distribution by depth was total N(TN), as the correlation between TN and AH-N was mainly by direct effect. The proportion of TN recovered as AH-N across sites and depths presented high amplitude, and thus AH-N was not a constant N pool across depths, indicating that AH-N can be affected by soil management practices even when TN showed no major changes. The distinct distribution of AH-N across soil sampling sites and depths indicates that depths greater than 20 cm should be considered when calibrating the AH-N index for N fertilizer recommendations for flooded rice in Southern Brazil.

关键词： fertilizer recommendation nitrogen availability nutrient management practices organo-mineral interaction Oryza sativa L. soil analysis soil organic matter

Model of Three-Phase Transmission Line with the Theory of Modal Decomposition Implied

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Energy and Power Engineering 2013年第4期5卷 1139-1146页

作者： rodrigo Cleber da silva Sérgio Kurokawa Department of Electrical Engineering Unesp Ilha Solteira Brasil

This paper shows the development of transmission line model, based on lumped element circuit that provides answers directly in the time and phase domain. This model is valid to represent the ideally transposed line, the phases of each of the small line segments are separated in their modes of propagation and the voltage and current are calculated at the modal domain. However, the conversion phase-mode-phase is inserted in the state equations which describe the currents and voltages along the line of which there is no need to know the user of the model representation of the theory in the line modal domain.

关键词： π-circuits Electromagnetic Transients Transmission Lines Transmission Line Models