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A Parameter-Space Analysis of the Rikitake System

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Chinese Physics Letters 2013年第12期30卷 13-16页

作者： Rodrigo A.da Silva paulo C.Rech Departamento de Física Universidade do Estado de Santa Catarina89219-710 JoinvilleBrazil

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.

关键词： bifurcation exponent chaotic

Laparoscopic resection for hepatocellular carcinoma: eastern and western experiences

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Chinese Journal of Cancer Research 2014年第3期26卷 234-236页

作者： paulo Herman Fabricio Ferreira Coelho Liver Surgery Unit Department of GastroenterologyUniversity of Sao Paulo Medical School

Hepatocellular carcinoma （HCC） is the most common primary liver cancer （1）. The incidence is rising in the last decades due to many factors, especially hepatitis C, alcoholic liver disease and non-alcoholic steatohepatitis. Moreover, the introduction of screening programs in patients with chronic liver disease has led to an increase in HCC diagnosis （1,2）. In the western world, 80% to 90% of HCC eases occur in patients with liver cirrhosis （3） while this proportion is lower in some regions in Asia and sub-Saharian Africa, where hepatitis B remains as an important etiologic factor for chronic liver disease （2,4）. In 1990, the annual world frequency of HCC was 437,000 cases/year （1）, and in 2012 the number reached 782,200 cases/year being responsible for 746,000 deaths （5）. Nowadays, HCC represents the 6th most frequent neoplastic disease in the world and the 3rd in mortality （5）.

关键词： HCC eastern and western experiences Laparoscopic resection for hepatocellular carcinoma

Reviewing perovskite oxide sites influence on electrocatalytic reactions for high energy density devices

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Journal of Energy Chemistry 2023年第6期81卷 1-19,I0002页

作者： Lorrane C.C.B.Oliveira Raissa Venâncio paulo V.F.de Azevedo Chayene G.Anchieta Thayane C.M.Nepel Cristiane B.Rodella Hudson Zanin Gustavo Doubek Advanced Energy Storage Division Laboratory of Advanced Batteries(LAB)Center for Innovation on New Energies(CINE)School of Chemical EngineeringUniversity of Campinas(Unicamp)CampinasSao Paulo 13083-852Brazil Advanced Energy Storage Division Center for Innovation on New Energies(CINE)Brazilian Renewable Energies(BREnergies)groupManufacturing GroupSchool of Electrical and Computer EngineeringUniversity of Campinas(UNICAMP)CampinasSão Paulo 13083-852Brazil Paul Scherrer Institut(PSI) Swiss Light Source(SLS)Forschungsstrasse 1115232 Villigen PSIAargauSwitzerland Brazilian Center for Research in Energy and Materials(CNPEM)/Brazilian Synchrotron Light Laboratory(LNLS) CampinasSão Paulo 13083-100Brazil

Batteries,fuel cells,and supercapacitors are electrochemical devices already on the market and still need a boost in kinetics to match the high energy density demand of *** have attracted the scientific community's attention in the last decade due to their electrocatalytic activity,chemical and structural properties,tunability,low cost,and *** have been made to understand the active sites and the operational mechanisms in perovskite oxides to shape them as an electrocatalyst in advanced energy *** the role of perovskites is the key to engineering more controlled and efficient electrocatalysts via chemical synthesis,and there is still much to *** review highlights the use of perovskites in different energy storage and conversion *** A,B,and A&B doping-site effects are analyzed to understand the opportunities and challenges related to this class of *** addition,the synthesis methods and the properties related to the doping site are described and summarized.

关键词： Perovskites Energy storage systems Electrocatalysts Battery Oxide fuel cells Capacitors

Impact of tacrolimus intra-patient variability in adverse outcomes after organ transplantation

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World Journal of Transplantation 2023年第5期13卷 254-263页

作者： Maria Clara Morais Maria Eduarda Soares Gabriela Costa Laura Guerra Nayana Vaz Liana Codes paulo Lisboa Bittencourt School of Medicine Bahiana School of Medicine and Public HealthSalvador 40290-000BahiaBrazil School of Medicine Federal University of BahiaSalvador 40110-100BahiaBrazil Unit of Gastroenterology and Hepatology Portuguese HospitalSalvador 40130-030BahiaBrazil

Tacrolimus(Tac)is currently the most common calcineurin-inhibitor employed in solid organ *** intra-patient variability(IPV)of Tac(Tac IPV)has been associated with an increased risk of immune-mediated rejection and poor outcomes after kidney *** data are available concerning the impact of high Tac IPV in non-kidney ***,even in kidney transplantation,there is still a controversy whether high Tac IPV is indeed detrimental in respect to graft and/or patient *** may be due to different methods employed to evaluate IPV and distinct time frames adopted to assess graft and patient survival in those reports published up to now in the *** is also known about the influence of high Tac IPV in the development of other untoward adverse events,update of the current knowledge regarding the impact of Tac IPV in different outcomes following kidney,liver,heart,lung,and pancreas tran-splantation to better evaluate its use in clinical practice.

关键词： Tacrolimus Intra-patient variability Rejection Organ transplantation Graft survival Outcomes

Rice Drying,Storage and Processing:Effects of Post-Harvest Operations on Grain Quality

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Rice science 2022年第1期29卷 16-30页

作者： Amanda MÜLLER Marcela Trojahn NUNES Vanessa MALDANER paulo Carteri CORADI Rosana Santos de MORAES Samuel MARTENS Andressa Fernandes LEAL Vladison Fogliato PEREIRA Cristielle König MARIN Post-Graduation Program in Agricultural Engineering Rural Sciences CenterFederal University of Santa MariaCamobi 97105-900Santa MariaRio Grande do SulBrazil Department of Agricultural Engineering Campus Cachoeira do SulFederal University of Santa MariaHighway Taufik Germano3013-Passo D’Areia 96503-205Cachoeira do SulRio Grande do SulBrazil

Various post-harvest processes of rice are commonly employed,especially during the off-season,to ensure its consumption feasibility,which often affect the grain *** forms of drying,storage and processing of rice are evaluated to identify their effects on grain *** drying has emerged as an alternative to the widely-used intermittent-drying and fixed-bed-dryer methods of drying paddy *** of drying-air temperatures(between 40℃ and 60℃)according to the rice variety can improve quality,especially for exotic *** stored grain in hygroscopic balance,with water content between 11%to 15%,at temperatures between 16℃ and 20℃ and with intergranular relative humidity near 60%,allows 12 months of storage in a controlled environment without significant *** innovations,notably the application of artificial refrigeration to grain stored in bulk in vertical cylindrical silos and the use of impermeable packaging for storage,ensure the conservation of grain *** different stages and equipments used to obtain polished,brown and parboiled rice result in significant changes in the nutritional value of rice because of the removal of the outermost layers of the *** reduces the nutritional value and physical homogeneity of *** rice retains more bioactive compounds and nutrients because it does not lose the outer layer of the grains in the polishing *** rice,although less nutritious than brown rice,has better grain integrity and milling yield and less loss of nutrients than white rice.

关键词： agricultural engineering post-harvest rice engineering quality in rice pre-processing rice process industry

A Study of Fluid Flow in Sediments and the Effect of Tidal Pumping

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Journal of Earth Science 2017年第5期28卷 842-847页

作者： paulo Waltrich John Whitehead Richard Hughes Karsten Thompson Department of Petroleum Engineering Louisiana State University

Offshore drilling and production operations can result in spills or leaks of hydrocarbons into seabed sediments, which can potentially contaminate these sediments with oil. If this oil later mi- grates to the water surface it has the potential for negative environmental impacts. For proper contin- gency planning and to avoid larger consequences in the environment, it is essential to understand me- chanisms and rates for hydrocarbon migration from oil containing sediments to the water surface as well as how much will remain trapped in the sediments. It is believed that the amount of oil transported out of the sediment can be affected by tidal pumping, a common form of subterranean groundwater dis- charge （SGD）. However, we could find no study experimentally investigating the phenomenon of fluid flow in subsea sediments containing oil and the effects of tidal pumping. This study presents an experi- mental investigation of tidal pumping to determine if it is a possible mechanism that may contribute to the appearance of an oil sheen on the ocean surface above a sediment bed containing oil. An experimen- tal apparatus was constructed of clear PVC pipe allowing for oil migration to be monitored as it flowed out of a sand pack containing oil, while tidal pressure oscillations were applied in three different man- ners. The effect of tidal pumping was simulated via compression of air above the water （which simulated the increasing static head from tidal exchange）. Experimental results show that sustained oil release oc- curred from all tests, and tests with oscillating pressure produced for longer periods of time. Further- more, the experimental results showed that the oil migration rate was affected by grain size, oil satura- tion, and oscillation wave type. In all oscillating experiments the rate and ultimate recovery was less than the comparable static experiments. For the conditions studied, the experimental results indicate that with an oscillating pressure on top of a

关键词： tidal pumping oil migration sediments oil release rate.

Atlas of precipitation extremes for South America and Africa based on depth-duration-frequency relationships in a stochastic weather generator dataset

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International Soil and Water Conservation Research 2023年第4期11卷 726-742页

作者： Andrew Fullhart David C.Goodrich Menberu B.Meles paulo Tarso S.Oliveira Cristiano das Neves Almeida JoséC.de Araújo Shea Burns Southwest Watershed Research Center USDA-ARS 2000 E.Allen Rd.TucsonAZ85719United States Sustainable Agricultural Water Systems Unit USDA-ARS 239 Hopkins RoadDavisCA95616United States Faculty of Engineering Architecture and Urbanism and GeographyUniversidade Federal de Mato Grosso do SulCampo GrandeMS79070-900Brazil Water Resources and Environmental Engineering Laboratory Universidade Federal da ParaíbaJoao PessoaPB58051-900Brazil Department of Agricultural Engineering Campus do Pici Fortaleza Universidade Federal do CearáFortaleza60020-181Brazil

Information about extreme rainfall is lacking in regions of South America and *** study attempts to fill this scientific gap by use of a gridded parameterization for the stochastic weather generator,CLIGEN,to map depth-duration-frequency(DDF)*** of 500-year point-scale precipitation time series generated at each grid point allowed maps of return period precipitation to be produced for a se-lection of sixteen durations ranging from 10-min to 1-year and for nine return periods from 2 to 500 *** generalized extreme value(GEV)probability distribution was fitted for all durations,and given GEV quantiles,an interpolation method was applied to produce maps at 0.1° resolution that better resolve small-scale spatial climate *** addition to uncertainties related to GEV fitting,this study quantifies prediction intervals based on ground *** validation was important for identifying biases in CLIGEN,although uncertainties were not always satisfactorily defined due to sampling design and other *** daily/multi-day durations,100 stations with daily observations and ≥50-year records were selected for validation against the 0.1° CLIGEN map series,resulting in a median and average absolute error of 13%and 16%,*** sub-daily durations,prediction errors were larger *** analogy using available *** established the degree of bias in CUGEN for sub-daily durations,and three records in Brazil with high temporal resolutions were used to confirm that applied bias adjustments resulted in error ranges similar to the daily/multi-day *** atlas is freely available for study of extreme precipitation.

关键词： Africa Depth-duration-frequency Extreme precipitation South America

Proportionally Modular Diophantine Inequalities and Their Multiplicity

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Acta Mathematica Sinica,English Series 2010年第11期26卷 2059-2070页

作者： José Carlos ROSALES Manuel Batista BRANCO paulo VASCO Departamento de lgebra Universidad de Granada Departamento de Matemática Departamento de Matemática Universidade de Trás-os-Montes e Alto Douro

Let I be an interval of positive rational numbers. Then the set S （I） = T ∩ N, where T is the submonoid of （Q0＋, ＋） generated by T, is a numerical semigroup. These numerical semigroups are called proportionally modular and can be characterized as the set of integer solutions of a Diophantine inequality of the form ax rood b 〈 cx. In this paper we are interested in the study of the maximal intervals I subject to the condition that S （I） has a given multiplicity. We also characterize the numerical semigroups associated with these maximal intervals.

关键词： Numerical semigroup Diophantine inequality multiplicity Frobenius number

Analysis of Surface Integrity in Drilling Metal Matrix and Hybrid Metal Matrix Composites

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Journal of Materials Science & Technology 2012年第8期28卷 761-768页

作者： T.Rajmohan K.Palanikumar J.paulo Davim Department of Mechanical Engineering Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya University Department of Mechanical Engineering Sri Sai Ram Institute of Technology Department of Mechanical Engineering University of AveiroCampus Santiago3810-193 AveiroPortugal

Hybrid metal matrix composites consist of at least three constituents-a metal or an alloy matrix and two reinforcements in various forms, bonded together at the atomic level in the composite. Despite their higher specific properties of strength and stiffness, the non homogeneous and anisotropic nature combined with the abrasive reinforcements render their machining difficult. In this paper, the surface integrity of machining in drilling hybrid composites has been discussed. Drilling tests are carried out at different spindle speed, feed rates, and different drill tool materials to investigate the effect of the various cutting parameters on the surface quality and the extent of the deformation of drilled surface due to drilling. Materials used for the present investigation are A1356/IOSIC （wt%） metal matrix and A1356/10SiC-3mica （wt%） hybrid composites. The composites are fabricated using stir casting route. The drilling tests are conducted on vertical computer numeric control （CNC） machining center using carbide, coated carbide and polycrystalline diamond （PCD） drills. The surface roughness decreases with increasing spindle speed and increases with increasing feed rate. The machined surface is analyzed by scanning electron microscopy （SEM）. SEM images of the machined surfaces indicate the presence of grooves and pits. Microhardness depth profiles indicate that the subsurface damage is limited to the top of 100-250 μm.

关键词： Hybrid composites Scanning electron microscopy (SEM) Subsurface Drilling