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Viscous and Ohmic heating effects in doubly stratified free convective flow over vertical plate with radiation and chemical reaction

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Applied Mathematics and Mechanics(English Edition) 2013年第2期34卷 139-152页

作者： p.GANESAN R.K.SUGANTHI p.LOGANATHAN Department of Mathematics Anna University Chennai

An analysis is carried out to study the combined effects of viscous and Ohmic heating in the transient, free convective flow of a viscous, incompressible, and doubly stratified fluid past an isothermal vertical plate with radiation and chemical reactions. The governing boundary layer equations are solved numerically by an implicit finite difference scheme of the Crank-Nicolson type. The influence of different parameters on the velocity, the temperature, the concentration, the skin friction, the Nusselt number, and the Sherwood number is discussed with graphical illustrations. It is observed that an increase in either the thermal stratification or the mass stratification parameter decreases the velocity. An increase in the thermal stratification increases the concentration and decreases the temperature while an opposite effect is observed for an increase in the mass stratification. An augmentation in viscous and Ohmic heating increases the velocity and temperature while decreases the concentration. The results are found to be in good agreement with the existing solutions in literature.

关键词： thermal stratification mass stratification Ohmic dissipation viscousdissipation chemical reaction radiation

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Applied Mathematics and Mechanics(English Edition) 2010年第12期31卷 1517-1526页

作者： p.LOGANATHAN p.pUVI-ARASU R.KANDASAMY Department of Mathematics Anna University Erode Sengunthar Engineering College Computational Fluid Dynamics FSSWUniversiti Tun Hussein Onn Malaysia

Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by the Runge-Kutta-Gill scheme with the shooting method as well as the local non-similarity method up to the third level of truncation, which are used to reduce the governing partial differential equations into nine ordinary differential equations. The governing boundary layer equations are converted to a dimensionless form by Falkner-Skan transformations. Because of the effect of suction/injection on the wall of the wedge with buoyancy force and variable wall temperature, the flow field is locally non-similar. Numerical calculations up to the third order level of truncation are carried out as a special case for different values of dimensionless parameters. Effects of the magnetic field strength in the presence of chemical reaction with variable wall temperature and concentration on the dimensionless velocity, temperature and concentration profiles are shown graphically.

关键词： local non-similarity suction/injection buoyancy force magnetic field wallof wedge

Genetic and morphological variation in natural teak(Tectona grandis) populations of the Western Ghats in Southern India

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Journal of Forestry Research 2014年第4期25卷 805-812页

作者： p.M.Sreekanth M.Balasundaran p.A.Nazeem Biotechnology and Applied Genetics Bangalore City College New Campus Kalyan Nagar Banaswadi Outer Ring Road Bangalore 560043 India Environmental Biotechnology Tropical Institute of Ecological Sciences Velloor P.O Kottayam – 686501 Kerala India Centre for plant Biotechnology and Molecular Biology Kerala Agricultural University KAU Campus P.O Thrissur 680656 Kerala India

Teak （Tectona grandis L.f.） is a popular hardwood species native to South and South-East Asia. The possible association of ampli- fied fragment length polymorphism （AFLp） marker with morphological variables of eleven important characters viz. girth at breast height （GBH）, height of tree, bole height, branch knots, presence of fluting, spiral stem, leaf hair, leaf length/breadth ratio, branching pattern, bark colour and petiole shape for nine natural populations comprising 180 genotypes of teak （9 populations x 20 trees）. The phenogram constructed using Euclidean distances for the eleven morphological characters showed that the populations were not grouped according to their geographical origin. The Mantel＇s test for pairwise correlation between Euclidean distances of different morphological variables and genetic distances from AFLp data revealed that only petiole character （r =0.269; p =0.046） and height of tree （r =0,200; p =0.001） were significantly correlated with that of AFLp data matrix. The nine populations in this study covered a geographic area of about 1000 km stretch along the Western Ghat of South India. A test of correlation between genetic and geographic distance matrices revealed a significant positive correlation （r =0.475; p =0.009）. The lack of perfect congruence between morphological and molecular data except for geo-graphic distance, tree height and petiole character suggested that the morphological system might be useful for the morphotypes management but not appropriate to study the genetic structure of the teak populations.

关键词： AFLp genetic teak morphology Tectona grandis

preliminary attempt to distinguish the domesticated pigs from wild boars by the methods of carbon and nitrogen stable isotope analysis

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Science China Earth Sciences 2009年第1期52卷 85-92页

作者： Michael p.RICHARDS Department of Human Evolution Max-Planck Institute for Evolutionary AnthropologyDeutscher Platz 6D-04103LeipzigGermany

Despite great achievements in the origins of domestic pigs made by the methods of zooarchaeology and molecular biology,how to scientifically distinguish the domesticated pigs from wild boars during the early stage of pig domestication is still poorly *** to wild boar's diets which come from the natural environment,the diets of domestic pigs are more easily influenced by human feeding ***,in principle,exploration of the dietary differences among pigs and understanding the impact on pig diets fed by humans can have great potential to differentiate between wild boars and domesticated *** reveal dietary differences among pigs and distinguish the domesticated pigs from wild boars based on comparison with the diets of humans and other animals,we analyzed the carbon and nitrogen stable isotopes of human bones from Xiaojingshan Site and animal bones from Yuezhuang Site,both of which belong to Houli Culture in Shandong province and date to about 8500―7500 years *** mean δ 13C value((-17.8 ± 0.3)‰) and δ 15N value((9.0±0.6)‰) in human collagen indicate that although millet agriculture began it was not the main subsistence strategy as millets are typical of C4 plants and that humans made a living mainly by gathering,hunting or raising some domesticated *** δ 13C value(-16.1‰) and δ 15N value(6.9‰) in the bovine suggest that C3 plants were dominant in its diet with some C4 plants *** fish has lower δ 13C value(-24.9‰) and higher δ 15N value(8.8‰) than the bovine,which is the characteristic of the isotopic values from Eurasian freshwater *** on the differences in carbon and nitrogen isotope values,the pigs can be divided into three groups.A group,composed of two pigs,has low δ 13C values(-18.1‰,-20.0‰) and low δ 15N values(4.7‰,6.0‰).B group,only one pig,has the highest δ 13C value(-10.6‰) and mediate δ 15N value(6.4‰).As for the C group,also only one pig,low δ 13C value(-19.0‰) and the highest δ 15N value(9.1‰

关键词： origins of domestic pigs early stage of domestication differentiation of domesticated pigs from wild boars carbon and nitrogen stable isotope analysis millet agriculture

Recent results of zebra patterns in solar radio bursts

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Research in Astronomy and Astrophysics 2010年第9期10卷 821-866页

作者： Gennady p.Chernov Key Laboratory of Solar Activity National Astronomical ObservatoryChinese Academy of Science pushkov Institute of Terrestrial Magnetism Ionosphere and Radio Wave PropagationRussian Academy of Sciences (IZMIRAN)

This review covers the most recent experimental results and theoretical research on zebra patterns （Zps） in solar radio bursts. The basic attention is given to events with new peculiar elements of zebra patterns received over the last few years. All new properties are considered in light of both what was known earlier and new theoretical models. Large-scale Zps consisting of small-scale fiber bursts could be explained by simultaneous inclusion of two mechanisms when whistler waves ＂high- light＂ the levels of double plasma resonance （DpR）. A unique fine structure was observed in the event on 2006 December 13： spikes in absorption formed dark Zp stripes against the absorptive type Ⅲ-like bursts. The spikes in absorption can appear in accordance with well known mechanisms of absorptive bursts. The additional injection of fast particles filled the loss-cone （breaking the loss-cone distribution）, and the generation of the continuum was quenched at these moments. The maximum absorptive effect occurs at the DpR levels. The parameters of millisecond spikes are determined by small dimensions of the particle beams and local scale heights in the radio source. Thus, the DpR model helps to understand severai aspects of unusual elements of Zps. However, the simultaneous existence of several tens of the DpR levels in the corona is impossible for any realistic profile of the plasma density and magnetic field. Three new theories of Zps are examined. The formation of eigenmodes of transparency and opac- ity during the propagation of radio waves through regular coronal inhomogeneities is the most natural and promising mechanism. Two other models （nonlinear periodic space - charge waves and scattering of fast protons on ion-sound harmonics） could happen in large radio bursts.

关键词： Sun general -- Sun flare -- Sun radio radiation

proteins as nanomagnets and magnetoreceptors

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Zoological Research 2024年第4期45卷 831-832页

作者： p.J.Hore Department of Chemistry University of OxfordUK

It is an appealing notion that a protein molecule could act as a nanomagnet.A genetically encodable biomolecule with a permanent magnetic moment at room temperature could have a range of applications:a magnetogenetic actuator,a magnetic tag for purifying and immobilizing enzymes,a contrast agent for magnetic resonance imaging,and a basis for a biomimetic magnetic sensing device,to name just a few.A magnetic protein could perhaps also function as the sensor in the magnetic compass that enables small songbirds to navigate the huge distances between their breeding and wintering *** though such possibilities may be,how realistic are they?

关键词： magnetic magnets enable

Can lithium enhance the extent of axon regeneration and neurological recovery following peripheral nerve trauma?

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Neural Regeneration Research 2022年第5期17卷 948-952页

作者： Damien p.Kuffler Institute of Neurobiology Medical Sciences CampusUniversity of Puerto RicoSan JuanPRUSA

The clinical"gold standard"technique for attempting to restore function to nerves with a gap is to bridge the gap with sensory ***,autografts induce good to excellent recovery only across short nerve gaps,in young patients,and when repairs are performed a short time post nerve *** under the best of conditions,patients recover good *** many alternative techniques have been tested,none is as effective as ***,alternative techniques are required that increase the percentage of patients who recover function and the extent of their *** paper examines the actions of lithium,and how it appears to trigger all the cellular and molecular events required to promote axon regeneration,and how both in animal models and clinically,lithium administration enhances both the extent of axon regeneration and neurological *** paper proposes more extensive clinical testing of lithium for its ability and reliability to increase the extent of axon regeneration and functional recovery.

关键词： anastomosis axon regeneration lithium nerve crush nerve gaps nerve repair nerve trauma neurological recovery Schwann cells

Evolution of the paleogene succession of the western Himalayan foreland basin

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Geoscience Frontiers 2013年第2期4卷 199-212页

作者： B.p.Singh CAS in Geology.Banaras Hindu University

The paleogene succession of the Himalayan foreland basin is immensely important as it preserves evidence of India-Asia collision and related records of the Himalayan *** this paper,the depositional regime of the paleogene succession of the Himalayan foreland basin and variations in composition of the hinterland at different stages of the basin developments are *** paleogene succession of the western Himalayan foreland basin developed in two stages,*** stage and post-collisional *** the onset,chert breccia containing fragments derived from the hanging walls of faults and reworked bauxite developed as a result of erosion of the forebulge. The overlying early Eocene succession possibly deposited in a coastal system,where carbonates represent barriers and shales represent ***-section,the middle Eocene marl beds likely deposited on a tidal *** late Eocene/Oligocene basal Murree beds,containing tidal bundles,indicate that a mixed or semi-diurnal tidal system deposited the sediments and the sedimentation took place in a tidedominated *** the higher-up,the succession likely deposited in a river-dominated estuary or in meandering *** the beginning of the basin evolution,the sediments were derived from the precambrian basement or from the metasediments/volcanic rocks possessing terrains of the *** early and middle Eocene（54.7-41.3 Ma） succession of the embryonic foreland possibly developed from the sediments derived from the Trans-Himalayan schists and phyllites and Indus ophiolite of the north during syn-collisional *** detrital minerals especially the lithic fragments and the heavy minerals suggest the provenance for the late Eocene/Oligocene sequences to be from the recycled orogenic belt of the Higher Himalaya,Tethyan Himalaya and the Indus-suture zone from the north during post-collisional *** is also supported by the paleocurrent measurements those suggest main flows directed towards sou

关键词： Facies architecture provenance Basin evolution paleogene Himalayan foreland Tectonics

The structure of superabundant semigroups

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Science China Mathematics 2004年第5期47卷 756-771页

作者： K.p.Shum 2.Faculty of Science The Chinese University of Hong KongHong KongChina structure theorem for superabundant semigroups in terms of semilattices of normalized Rees matrix semigroups over some cancellative monoids is obtained. This result not only provides a construction method for superabundant semigroups but also generalizes the well-known result of Petrich on completely regular semigroups. Some results obtained by Fountain on abundant semigroups are also extended and strengthened.

A structure theorem for superabundant semigroups in terms of semilattices of normalized Rees matrix semigroups over some cancellative monoids is obtained. This result not only provides a construction method for superabundant semigroups but also generalizes the well-known result of petrich on completely regular semigroups. Some results obtained by Fountain on abundant semigroups are also extended and strengthened.

关键词： superabundant semigroups completely regular semigroups normalized Rees matrix semigroups