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Acoustic streaming and Sun's meridional circulation

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Research in Astronomy and Astrophysics 2016年第9期16卷 101-106页

作者： jose Manuel Valverde Faculty of Physics University of Seville

A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjacent to the interface. Some examples are refracted sound waves, a fluid inside a spherical cavity undergoing torsional oscillations or a pulsating liquid droplet. Steady streaming around circular interfaces consists of a hemispherically symmetric recirculation of fluid from the equatorial plane to the polar axes closely resembling the meridional circulation pattern observed in the Sun＇s convection zone that determines the solar cycle. In this paper, it is argued that the acoustic pulsations exhibited by the Sun would lead to acoustic streaming in the boundary of the convection zone. A simple estimation using a typical dominant frequency of 3 mHz and the observed surface oscillation amplitude yields a steady streaming velocity Us - 10 m s^-1, which is on the order of the meridional circulation velocity observed in the Sun＇s convection zone.

关键词： Sun general -- Sun helioseismology -- Sun granulation -- Sun oscillations -- Sun fun-damental parameters -- Sun activity

Magnetic field assisted fluidization:A modified Richardson-Zaki equation

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China Particuology 2007年第1期5卷 61-70页

作者： jose Manuel Valverde Antonio Castellanos Faculty of Physics Universidad de Sevilla Avenida Reina Mercedes s/n 41012 Sevilla Spain

Magnetic particles can be uniformly fluidized by coupling the gas flow with an externally imposed magnetic field. Interparticle forces generated by the magnetic field cause aggregation of the particles in chain-like structures preferentially oriented along the magnetic field lines. In the present paper, we study the implications of the formation of these special types of aggregates on the empirical Richardson-Zaki （RZ） equation, originally proposed to describe the expansion of fluidized beds of non-aggregated particles. We have addressed two important issues, namely the flow regime, which is a function of the size of the aggregates, and the effect of shape and orientation of the chain-like aggregates with respect to gas flow on fluid drag. We propose a modified RZ equation （MRZE） in which the velocity scale, given by the terminal settling velocity of the individual aggregates, and the RZ exponent are predetermined as a function of the chain length. The chain length depends on the ratio of the magnetic energy to gravitational energy, and is estimated from the magnetic field intensity, and particle magnetization, size and density. Predictions of the MRZE are successfully compared with published results in the literature on the expansion of magnetic particles in the presence of externally applied magnetic fields.

关键词： Fluidization Geldart B Magnetic particles Aggregation Richardson-Zaki equation

Extending dynamic models of mining subsidence

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中国有色金属学会会刊：英文版 2011年第S3期21卷 536-542页

作者： Andrew JAROSZ jose SAAVEDRA-ROSAS Western Australian School of Mines Curtin University

The movement and deformation processes of the overburden strata and ground surface, induced by underground mining, are affected by mining method, spatial relationships, geotechnical conditions of the rock strata and time. The authors reviewed and extended an existing classical prediction model of the dynamic subsidence, and proposed potential new research avenues offered by Cellular Automata (CA) models. The Knothe's influence function model and the significance of subcritical mining geometry were analyzed. The prediction results were verified against the subsidence field survey data to assess their quality and acceptability.

关键词： dynamic subsidence subsidence prediction cellular automata

Changes in Olsen P in Relation to P Balance in Contrasting Agricultural Soils

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Pedosphere 2016年第5期26卷 636-642页

作者： Isabel DIAZ jose TORRENT Departamento de Ingeniería Aeroespacial y Mecánica de Fluidos Escuela Tdcnica Superior de Ingeniería Agronómica(ETSIA)Universidad de SevillaCtra de Utrera km 141013 Sevilla(Spain) Departamento de Agronomia Universidad de CordobaEdificio C4Campus de Rabanales14071 Cordoba(Spain)

Maintaining soil phosphorus （P） at adequate levels for plant growth requires assessing how the long-term P balance （viz., the difference between P inputs and outputs） results in changes in soil test P. The hypothesis that routinely measured soil properties can help predict the conversion factor of P balance into Olsen P was tested at 39 sites in agricultural areas of the Mediterranean region in Spair~. A set of soil samples from each site was analyzed for Olsen P, inorganic P （P extracted using 0.5 mol L-1 H2SO4）, pseudototal P （P extracted using 0.5 mol L-1 H2SO4 following ignition at 550 ~C）, and organic P （the difference between pseudototal P and inorganic P）. Organic and Olsen P were uncorrelated in most of the 39 soil sets, which suggests that organic P content changed little with P inputs and outputs. The slopes of the regression lines of Olsen P against pseudototal and inorganic P, which were used as two different measures of the conversion factor, ranged widely （from 0.03 to 0.25 approximately）, with their average values （about 0.10） being similar to those found in long-term experiments conducted in temperate areas. Neither conversion factor was significantly correlated with any routinely measured soil property; however, the conversion factor for inorganic P was significantly lower for calcareous soils than for noncalcareous soils. Our negative results suggest the need to isolate the influence of soil properties from that of management systems and environmental factors relating to P dynamics in future studies.

关键词： calcareous soils conversion factor inorganic P noncalcareous soils organic P pseudototal P soil property soil test P

A neural network to predict reactor core behaviors

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Nuclear Science and Techniques 2014年第1期25卷 75-80页

作者： Juan jose Ortiz-Servin David A.Pelta jose Alejro Castillo Instituto Nacional de Investigaciones Nucleares Carretera Mexico Toluca S/NLa Marquesa OcoyoacacEstado de Mexico ETS Ingenieria Informatica y Telecomunicaciones Universidad de GranadaC/Daniel Saucedo Aranda

The global fuel management problem in BWRs(Boiling Water Reactors) can be understood as a very complex optimization problem,where the variables represent design decisions and the quality assessment of each solution is done through a complex and computational expensive *** last aspect is the major impediment to perform an extensive exploration of the design space,mainly due to the time lost evaluating non promising *** this work,we show how we can train a Multi-Layer Perceptron(MLP) to predict the reactor behavior for a given *** trained MLP is able to evaluate the configurations immediately,thus allowing performing an exhaustive evaluation of the possible configurations derived from a stock of fuel lattices,fuel reload patterns and control rods *** our particular problem,the number of configurations is approximately 7.7×10^(10);the evaluation with the core simulator would need above 200 years,while only 100hours were required with our approach to discern between bad and good *** later were then evaluated by the simulator and we confirm the MLP *** good core configurations reached the energy requirements,satisfied the safety parameter constrains and they could reduce uranium enrichment costs.

关键词：神经网络预测行为质量评估堆芯沸水反应堆多层感知器 MLP 优化问题

Critical evaluation of transit policies in Lima,Peru;resilience of rail rapid transit(Metro)in a developing country

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Green Energy and Intelligent Transportation 2024年第5期3卷 23-33页

作者： Manuel jose Martinez Representante Legal Instituto de Avance del Transporte Peruano EIRLCalle Schrader 179dpto.202Lima 41San BorjaLimaPeru

This paper evaluates rail transit within the context of the transit policies implemented in Lima,*** it reviews the implementation of rapid transit,and bus ***,it evaluates the outcomes of such policies by using Total Factor Productivity for policy effectiveness,Data Envelopment Analysis for rapid transit performance,and Generalized Cost of Travel for *** paper finds that implementation failed in enforcing key requirements for rail transit regarding penetration of CBD and short transfers to bus transit;and that the basic assumptions of bus reform did not hold regarding bus oversupply,bus congestion or bus *** paper also finds that outcomes of policies failed dramatically in achieving the planning goals;however,rail transit(Metro)shows high level of resilience in serving large ridership at high *** the other hand,bus reform was associated with a disproportionate increase of motorization,well over the effect of income growth or car attractiveness,and more related to the excessive reduction of bus transit capacity ill-advised from unproved bus reform *** paper recommends expanding rail rapid transit due to its intensive use of green renewable energy and its potential of demand growth if combined with modern Intelligent Transportation services,but this opportunity can be wasted without the proposed policy constraint to achieve lower Generalized Cost of Travel at any governmental intervention for bus reform,instead of just reducing bus transit capacity as ***,this paper recommends government to government contracts to build rail transit and to enforce proper planning.

关键词： Public transportation Bus rapid transit Rail transportation Bus transit Developing countries Resilient

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Imprinting in plants

Chinese Science Bulletin 2009年第14期54卷 2383-2389页

作者： GUTIERREZ-MARCOS jose Warwick HRI University of WarwickWellesbourneCV35 9EF UK

Genomic imprinting leads to the differential expression of parental alleles after fertilization. Imprinting appears to have evolved independently in mammals and flowering plants to regulate the development of nutrient-transfer placental tissues. In addition, the regulation of imprinting in both mammals and flowering plants involves changes in DNA methylation and histone methylation, thus suggesting that the epigenetic signals that regulate imprinting have been co-opted in these distantly related species.

关键词：开花植物 DNA甲基化基因组印记哺乳类动物差异表达基因胎盘组织养分转移信号调节

Analyzing the multilevel structure of the European airport network

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Chinese Journal of Aeronautics 2017年第2期30卷 554-560页

作者： Oriol Lordan jose M.Sallan Department of Management Universitat Politecnica de Catalunya-BarcelonaTech Terrassa 08222 Spain

The multilayered structure of the European airport network（EAN）,composed of connections and flights between European cities,is analyzed through the k-core decomposition of the connections *** decomposition allows to identify the core,bridge and periphery layers of the *** core layer includes the best-connected cities,which include important business air traffic *** periphery layer includes cities with lesser connections,which serve low populated areas where air travel is an economic *** remaining cities form the bridge of the EAN,including important leisure travel origins and *** multilayered structure of the EAN affects network robustness,as the EAN is more robust to isolation of nodes of the core,than to the isolation of a combination of core and bridge nodes.

关键词： Air transport networks Complex networks k-core decomposition Network multilevel structure Robustness

CFD modelling:The most useful tool for developing mesoscale urban canopy parameterizations

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Building Simulation 2021年第3期14卷 407-419页

作者： Riccardo Buccolieri jose Luis Santiago Alberto Martilli Dipartimento di Scienze e Tecnologie Biologiche edAmbientali University ofSalentoS.P.6 Lecce-MonteroniLecce 73700Italy Environment Department Research Center for EnergyEnvironment and Technology(CIEMAT)Madrid 28040Spain

1 Introduction The fact that most of the world’s population lives in cities(UN-Habitat 2016)has increased interest in urban *** models,such as the Weather Research and Forecasting(WRF)model(***/weather-research-and-forecasting-model),are used to reproduce the meteorology and climatology over cities and around them,where the complex interactions between the atmosphere and urban surfaces(buildings,vegetation,urban obstacles,etc.)induce strong heterogeneity in the flow properties within the urban canopy layer(UCL)(Di Sabatino et al.2013;Lateb et al.2016;Tominaga and Stathopoulos 2016).

关键词： meteorology urban forecasting