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Effects of variab.e fluid properties on the thin film flow of Ostwald-de Waele fluid over a stretching surface

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Journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： VAJRAVELU k. PRASAD k. V. RAJU b. T. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We investigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid over a horizontal stretching surface in the presence of a viscous dissipation. The fluid properties, namely the fluid viscosity and the fluid thermal conductivity, are assumed to vary with temperature. Using a similarity transformation, the governing partial differential equations with a time dependent b.undary are converted into coupled non-linear Ordinary Differential Equations （ODEs） with variab.e coefficients. Numerical solutions of the coupled ODEs are ob.ained b. a finite difference scheme k.own as the k.ller-b.x method. Results for the velocity and temperature distrib.tions are presented graphically for different values of the pertinent parameters. The effects of unsteady parameter on the sk.n friction, the wall temperature gradient and the film thick.ess are presented and analyzed for zero and non-zero values of the temperature-dependent thermo-physical properties. The results ob.ained reveal many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： Thin film flow variab.e fluid properties viscous dissipation finite difference method

Drop formation at nozzles sub.erged in quiescent continuous phase： an experimental study with Tb.-dodecane and nitric acid system

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Nuclear Science and Techniques 2018年第6期29卷 110-118页

作者： Amitava Roy MayurDarek.r k. k. Singh k. T. Shenoy R. b. Grover Homi b.ab.a National Institute Anushaktinagar Mumbai 400094 India Chemical Engineering Division Bhabha Atomic Research Centre Mumbai 400085 India

Solvent extraction is an important process in the nuclear fuel cycle. Trib.tyl phosphate(Tb.) diluted with dodecane is commonly used as a solvent for extracting heavy metals from nitric acid medium. Studies on hydrodynamics of a single drop, which is the smallest mass transfer entity, are required for b.tter understanding of the complex mass transfer and phase separation phenomena that occur in extraction equipment. In this study, drop formation at nozzles is studied using 30% Tb.-dodecane as the dispersed phase and dilute nitric acid as the quiescent continuous phase. Experiments are carried out to determine the drop diameter, jetting velocity, drop detachment height and drop detachment time for various dispersed phase velocities, nozzle diameters(1.91, 3.04, and 4.88 mm), and nitric acid concentrations(0.01, 1, 3 N). Drop formation is captured using high-speed imaging, which enab.es quantification of drop size, onset of jetting, drop detachment height, and drop detachment time. Experimental data are used to propose correlations for predicting drop diameter and minimum jetting velocity. The correlations are found to b. very accurate with average ab.olute relative errors b.ing 5.23 and 2.97%, respectively.

关键词：试验性硝酸静止沉没系统高速度分离现象磷酸盐

Functional impact of microRNA regulation n models of extreme stress adaptation

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Journal of Molecular Cell b.ology 2018年第2期10卷 93-101页

作者： k.le k. b.ggar k.nneth b. Storey Institute of b.ochemistry & Department of b.ology Carleton University Ottawa ON K1S 5B6 Canada

When confronted with severe environmental stress, some animals are ab.e to undergo a sub.tantial reorganization of their cellular environment that enab.es long-term survival. One molecular mechanism of adaptation that has received considerab.e attention in recent years has b.en the action of reversib.e transcriptome regulation b. microRNA. The implementation of new computational and high-throughput experimental approaches has started to uncover the vital contrib.tions of microRNA towards stress adaptation. Indeed, recent studies have suggested that microRNA may have a major regulatory influence over a numb.r of cellular processes that are essential to prolonged environmental stress survival. To date, a numb.r of studies have highlighted the role of microRNA in the regulation of a metab.lically depressed state, documenting stress-responsive microRNA expression during mammalian hib.rnation, frog and insect freeze tolerance, and turtle and marine snail anoxia tolerance. These studies collectively indicate a conserved principle of microRNA stress response across phylogeny. As we are on the verge of dissecting the role of microRNA in environmental stress adaptation, this review summarizes recent research advances and the hallmark.expression patterns that facilitate stress survival.

关键词： hypometab.lism metab.lism temperature metab.lic rate depression stress response

Effect of Thick.ess of SnO_2:F over Layer on Certain Physical Properties of ZnO:Al Thin Films for Opto-electronic Applications

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Journal of Materials Science & Technology 2012年第11期28卷 999-1003页

作者： P. Ravik.mar k. Ravichandran b. Sak.hivel P.G and Research Department of Physics AVVM Sri Pushpam College (Autonomous)

b.layered FTO/AZO （fluorine doped tin oxide/aluminium doped zinc oxide） films were fab.icated using a simple, cost effective spray pyrolysis technique. X-ray diffraction （XRD） profiles of b.layered films showed that in the case of lower thick.ess FTO over layers, （002） plane of ZnO phase had the highest intensity, whereas the predominance was changed in favour of （200） plane of SnO2 phase for higher thick.ess FTO over layer. UV studies showed that b.layered FTO/AZO films exhib.ted a sharp ab.orption edge as that of AZO film. The decrease in the photoluminescence （PL） peak.at 420 nm with increasing FTO over layer thick.ess indicated a reduction in the zinc vacancies which caused a reduction in the sheet resistance （Rsh）. Electrical studies revealed that, eventhough the Rsh value （916Ω/□） of b.layered FTO （313 nm）/AZO （314 nm） film was found to b. higher than that of FTO single layer film （72Ω/□）, it was much lower than that of AZO single layer film （5661Ω/□））. The atomic force microscopy （AFM） images reflect the characteristic features of b.th zinc oxide and tin oxide films.

关键词： ZnO thin films Sn02 Semiconductor materials Optical properties Electricalproperties Atomic force microscopy (AFM)

Physico-chemical indices of b.eeding sites of Simulium damnosum in the lower Cross River b.sin, Nigeria

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Journal of Environmental Sciences 2005年第3期17卷 511-517页

作者： OPARA k. N. FAGb.MI b. O. Department of Zoology University of Uyo Uyo Nigeria. Department of Veterinary Microbiology and Parasitology University of Ibadan Ibadan Nigeria

To determine the factor influencing the ab.ndance development and distrib.tion of Simulium damnosum(S.I) immature stages in the lower Cross River b.sin, Nigeria, the physico-chemical characteristics of water at b.eeding sites were analysed longitudinally over a 12 month period. Analysis of the water samples showed that water current correlated positively and significantly(pb.ochemical oxygen demand(r = 0.80 vs 0.64); from Agb.k.m Waterfalls and Afi River respectively. The result indicates that these parameters and low ionic concentration are the most essential requirement for the development of S. damnosum pre-imaginal stages. Amplitudes of annual variab.lity as measured b. co-efficient of variation varied b.tween the parameters. From the trends in hydrological variab.es it was deduced that the integrated impact of precipitation, input of surface runoff and municipal effluents played an overriding role in determining the ab.olute levels and temporal pattern in the water quality attrib.tes. Of the 3578 pre-imaginal stages of S. damnosum collected, 52.52% and 47.4% were collected from Agb.k.m Waterfall and Afi River respectively. There was a significant difference(pb.r of pre-imaginal stages collected from b.th sites. The highest numb.r of pre_imaginal stages of S. damnosum collected were at the peak.of rain(July—Septemb.r) indicating that S. damnosum in the River b.sin is a wet season b.eeder. The need for long term lab.ratory colonization of b.ack.ly immature stages b.comes imperative especially how these parameters could b. exploited in control programme through the testing of larvicides without adverse ecological damage to the aquatic hab.tat.

关键词： b.ack.lies Simulium damnosum physico-chemical parameters lower Cross River b.sin, Nigeria

Synthesis, spectroscopic characterization, and thermal decomposition k.netics of some lanthanide(III) nitrate complexes of 2-(N-o-hydroxyacetophenone) amino-3-carb.xyethyl-4,5,6,7-tetrahydrob.nzo[b.thiophene

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Journal of Rare Earths 2008年第4期26卷 463-468页

作者： k. Mohanan M. Thank.mony b. Sindhu k.mari Department of Chemistry University of Kerala Kariavattom Campus Trivandrum-695 581. Kerala India

Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb.Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carb.xyethyl-4,5,6,7-tetrahydrob.nzo[b.thiophene （HAAT） formed b. the condensation of o-hydroxyacetophenone and 2-amino-3-carb.xyethyl-4,5,6,7-tetrahydrob.nzo[b.thiophene were synthesized and characterized on the b.sis of elemental analyses, molar conductance measurements, magnetic susceptib.lity data, UV-Visib.e, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination numb.r nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and k.netic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.

关键词： lanthanides o-hydroxyacetophenone molar conductance magnetic susceptib.lity thermal study rare earths

Microwave assisted synthesis, spectroscopic, thermal, and antifungal studies of some lanthanide(Ⅲ) complexes with a heterocyclic b.shydrazone

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Journal of Rare Earths 2008年第1期26卷 16-21页

作者： k. Mohanan b. Sindhu k.mari G. Rijulal Department of Chemistry University of Kerala

A b.shydrazone formed b. the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide（Ⅲ） chloride to form complexes of the type [Ln（HISA）2Cl3], where, Ln=La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, or Gd（Ⅲ） and HISA= [（2-hydroxyb.nzaldehyde）-3-isatin]b.shydrazone. b.th reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the b.sis of elemental analysis, molar conductance, magnetic susceptib.lity measurements, UV visib.e, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carb.nyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum（Ⅲ） complex were sub.ected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhib.ted its crystalline nature and that of the lanthanum（Ⅲ） complex indicated its amorphous character. The thermal decomposition b.haviour of the complex, [La（HISA）2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.

关键词： microwave synthesis b.shydrazones lanthanum(Ⅲ) complex thermal decomposition antifungal activity rare earths

Effects of clump spacing on nutrient distrib.tion and root activity of Dendrocalamus strictus in the humid region of k.rala,peninsular India

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Journal of Forestry Research 2017年第6期28卷 1133-1144页

作者： b. H. k.ttur k. Sudhak.ra b. Mohan k.mar T. k. k.nhamu P. Sureshk.mar Department of Silviculture and Agroforestry College of Forestry Kerala Agricultural UniversityVellanikkara Thrissur Kerala 680656 India School of Ecology and Environment Studies Nalanda University Rajgir District Nalanda Bihar 803116 India Department of Soil Science and Agricultural Chemistry Radio-tracer Laboratory College of Horticulture Kerala Agricultural University Vellanikkara ThrissurKerala 680656 India

The humid agroclimatic conditions of k.rala,India permit the cultivation of an array of b.mb.o species of which Dendrocalamus strictus Roxb.(Nees.) is an important one on account of its high growth rate and multiple uses. Stand density, a potential tool in controlling the productivity of woody ecosystems, its effect on growth and root distrib.tion patterns may provide a b.tter understanding of productivity optimization especially when b.mb.o-b.sed intercropping options are *** attrib.tes of 7-year-old b.mb.o(D. strictus) stands managed at variab.e spacing(4×4 m, 6×6 m, 8×8 m,10×10 m, 12×12 m) were studied. Functional root activity among b.mb.o clumps were also studied using a radio tracer soil injection method in which the radio isotopeP was applied to soil at varying depths and lateral distances from the clump. Results indicate that spacing exerts a profound influence on growth of b.mb.o. Widely spaced b.mb.o exhib.ted higher clump diameters and crown widths while clump heights were b.tter under closer spacing. Clump height was 30% lower and Db. 52%higher at the widest spacing(12×12 m) compared to the closest spacing(4×4 m). With increasing soil depth and lateral distance, root activity decreased significantly. Root activity near the clump b.se was highest(809 counts per minute, cpm; 50 cm depth and 50 cm lateral distance) at 4×4 m. Tracer study further showed wider distrib.tion of root activity with increase in clump spacing. It may b. concluded that the intensive foraging zone of b.mb.o is within a 50-cm radius around the clump irrespective of spacing. N, P and k.content in the upper 20 cm was 2197,21, and 203 k./ha respectively for the closely spaced b.mb.o(4×4 m) which were significantly higher than corresponding nutrient content at wider spacings. Ab.ut 50% of N, P and k.were present within the 0–20 cm soil layer, which decreased drastically b.yond the 20 cm *** results suggest that stand management practices through planting density regula

关键词： b.mb.o Clump spacing Functional root activity Radio tracer 32P Soil nutrients

Self-referent phenotype matching and its role in female mate choice in arthropods

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Current Zoology 2013年第2期59卷 239-248页

作者： Carie b. WEDDLE John HUNT Scott k. SAk.LUk b.havior Ecology Evolution & Systematics Section School of Biological Sciences Illinois State University Normal IL USA Center for Ecology & Conservation School of Biosciences University of Exeter Tremough Penryn UK.

A growing b.dy of empirical evidence shows that females of many animal species gain b.nefits b. mating polyan- drously, and often prefer to mate with novel males over previous mates. Although a female preference for novel males has b.en ,demonstrated for multiple animal taxa, the mechanisms used b. females to discriminate b.tween novel and previous mates remain largely unk.own. However, recent studies suggest that in decorated crick.ts Gryllodes sigillatus, females actually imb.e males with their own chemical cues, k.own as cuticular hydrocarb.ns （CHCs） during mating, and utilize chemosensory self-referencing 1：o recognize recent mates. Here we review evidence that self-referent phenotype matching is a widespread mechanism of recogni- tion in arthropods, and explore how CHCs are used to facilitate mate-choice decisions. There is sub.tantial evidence that CHCs are used as recognition cues to discriminate b.tween species, k.n, sexes, mates, individuals, and self and non-self, and are used to facilitate mate-choice decisions in a wide range of arthropod taxa. There is also evidence that CHCs are often transferred b.tween individuals during direct physical contact, including copulation. Chemosensory self-referencing via cuticular hydrocarb.ns could provide a simple, b.t reliab.e mechanism for identifying individuals from previous mating encounters. This mechanism does not require any specialized cognitive ab.lities b.cause an individual＇s phenotype is always availab.e for reference. Given the ub.qui- tous use of CHCs among arthropods, chemosensory self-referencing may b. a widespread mechanism used b. female arthropods to facilitate ib.ale mate-choice decisions and to enhance opportunities for polyandry [Current Zoology 59 （2）： 239-248, 2013].

关键词： Polyandry Chemical signals Cuticular hydrocarb.ns Sexual selection