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Distribution of heavy metals in soils of Port Harcourt and its environs, Niger Delta, Nigeria

Chinese Journal of Geochemistry 2011年第4期30卷 415-421页

作者： Minapuye i odigi Lucky o. Ukren Hycienth o. Nwankwoala Department of Geology University of Port Harcourt

Geochemical evaluation of the distribution of heavy metals in soils of Port Harcourt and its environs in the Niger Delta region is presented in respect of anthropogenic factor and index of geoaccumulation. sixteen (16) soil samples were collected from two horizons (0-10 cm and 100 cm) from the various grids and analyzed. The geo-chemical analyses showed the vertical and horizontal distributions of heavy metals. The results showed the ranges of the metals determined as follows: Pb (6.86-2.49)×10-6, with an average of 4.63×10-6; Cd (0.05-0.00)×10-6, with an average of 0.02×10-6, As (0.01-0.00)×10-6, with an average of 0.00×10-6. Cu (15.36-10.80) ×10-6, with an average of 13.36×10-6, and V (1.36-0.20)×10-6, with an average of 0.94×10-6. Quantification of the degree of pollution was carried out using anthropogenic factor (AF) and index of geoaccumulation (igeo). The igeo values of 0.06, 0.02 and 0.00 for Pb, Cd and As, respectively indicate low-level contamination while Zn (1.14) and V (1.40) show me-dium-level contamination. The sources of contamination are attributed to urbanized anthropogenic activities. The majority of the samples analyzed show that the AF values are less than 1 with the exception of vanadium (V) whose AF values range from 2.73 to 13.60×10-6. Vanadium is more enriched than As, Cd, Pb, and Cu. The order of degrees of anthropogenic contamination and index of geoaccumulation in the soil is V >Zn >Pb >Cu >Cd >As. Metals were retained near the top soil and their concentrations in the deepest horizons were lower and normal for uncontaminated soils. Metal concentrations in the top soil horizons were significantly related to distance from the industrial and hu-man activities.

关键词：三角洲地区重金属尼日尔土壤周围地区尼日利亚地积累指数污染程度

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Biomimetic amelioration of zirconium nanoparticles on a rigid substrate over viscous slime--a physiological approach

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Applied Mathematics and Mechanics(English Edition) 2023年第9期44卷 1563-1576页

作者： s.i.ABDELsALAM A.Z.ZAHER instituto de Ciencias MatemHu DiNGticas iCMAT Madrid 28049Spain Basic science Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt Basic science Department Faculty of EngineeringShubra-Benha UniversityCairo 11884Egypt

in this article,an investigation is conducted to study the precise role of zirconium nanoparticles that exist in a slime-like fluid subject to specific *** gliding is a technique of mobility used by bacteria that lack motility components,bacteria travel on their own strength in gliding locomotion by secreting a layer of slime on the substrate.A model of an undulating sheet over a layer of slime of a Rabinowitsch fluid is investigated as a potential model of bacteria’s gliding *** the aid of long wavelength approximation,the equations governing the circulation of slime underneath the cells are established and analytically *** effects of pseudoplasticity,dilatation and non-Newtonian parameter on the behavior of zirconium concentration,speed of microorganism(bacteria),streamline patterns,and pressure rise for non-Newtonian and Newtonian fluids are *** power required for propulsion is also *** interpretation for the pertinent variables has been graphically discussed against the parameters under *** is found that with the increase in the concentration of zirconium nanoparticles,the bacterial flow is accelerated and attains its maximum near the rigid substrate wall while an opposite behavior is noticed in the rest region.

关键词： zirconium nanoparticle gliding bacterium Grashof heat transfer glider's speed Rabinowitsch fluid

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Weibull approach to brake pad wear analysis in the Nigerian market

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Friction 2015年第3期3卷 228-233页

作者： R.s.FoNo-TAMo o.o.osUNBoR o.A.KoYA Department of Mechanical and Biomedical Engineering Bells University of TechnologyOtaNigeria Department of Mechanical Engineering Obafemi Awolowo UniversityIle-IfeNigeria

in this study,we evaluated the wear properties of four brands of brake pad available in the Nigerian *** particular,we assessed the tribo performance and service life of the brake *** purchased four commercial brands of brake pads used in light duty cars and coded them as AU,sN,TY and sM,respectively.A small piece of the brake pad lining materials was carefully chiseled from the back plates to obtain samples for the *** conducted Brinell hardness tests using a tensometer and a pin-on-disc test rig to determine the coefficient of friction and the wear characteristics of the *** then correlated the wear on each set of brake pads with the running time and used Weibull’s equation to determine average service *** TY exhibited the highest hardness value(29.09)and sample sN the lowest(10.05).The determined coefficients of friction ranged between 0.3-0.36,with sample AU exhibiting the lowest value and sample sM the *** sN showed the lowest wear rate of 3.53×10^(9) g/min,while the wear rates of samples TY,AU,and sM were 5.64×10^(8),8.19×10^(9),and 2.10×10^(8) g/min,*** relative service life of samples sN,TY,and AU were similar,with average values of 2778.09,2725.41,and 2717.34 min,respectively,and sM had a relatively low service life(2017.82 min).We conclude that the overall performances of Nigerian brake pads do not meet all the specifications for friction materials used in road vehicle brake linings and pads.

关键词： Weibull wear rate service life brake pads friction composite

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Quantization of the o（N） Nonlinear sigma Model

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Communications in Theoretical Physics 2002年第5期37卷 567-570页

作者： s.i.Muslih DepartmentofPhysics Al－AzharUniversityGazaPalestine

The Hamilton-Jacobi method of quantizing singular systems is discussed. The equations of motion areobtained as total differential equations in many variables. it is shown that if the system is integrable, one can obtain thecanonical phase space coordinates and set of canonical Hamilton-Jacobi partial differential equations without any needto introduce unphysical auxiliary fields. As an example we quantize the o(2) nonlinear sigma model using two differentapproaches: the functional schrodinger method to obtain the wave functionals for the ground and the exited state andthen we quantize the same model using the canonical path integral quantization as an integration over the canonicalphase-space coordinates.

关键词：量子力学 o(N)非线性sigma模型量子化

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Methane oxidative carbonylation catalyzed by rhodium chalcogen halides over carbon supports

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Journal of Natural Gas Chemistry 2008年第1期17卷 1-7页

作者： G.R.Kosmambetoval P.E.strizhak V.i.Gritsenko s.V.Volkov L.B.Kharkova o.G.Yanko o.M.Korduban L.V Pisarzhevsky institute of Physical Chemistry of National Academy of sciences of Ukraine pr.Nauki 31Kiev03039Ukraine V.i.Vernadsky institute of General and inorganic Chemistry of National Academy of sciences of Ukraine pr.PaUadina 32/34Kiev03680Ukraine V.i.Vernadsky institute of General and inorganic Chemistry of National Academy of sciences of Ukraine pr.Palladina 32/34Kiev03680Ukraine G.V.Kurdyumov institute of Metal Physics of National Academy of sciences of Ukraine 36Vernadskij avKyiv03680Ukraine

Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carbon supports. XPs and iR-spectroscopy data show the formation of rhodium chalcogen halides in solids prepared by different methods. We have found that the productivity of acetic acid by carbon supported rhodium chalcogen halides depends strongly on the carbon carrier and the method of the catalyst preparation. Namely, the catalyst with highest productivity for the acetic acid is prepared by synthesizing the rhodium chalcogen halide over the carbon support followed by thermal destruction. We have also found that rhodium chalcogen halides over activated carbons are more active compared with fullerene supported catalysts.

关键词： catalysts methane oxidative carbonylation rhodium chalcogen halides carbon supports

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The transition from backarc extension to Andean growth:insights from geochronologic,sedimentologic,and structural studies of Mesozoic and Cenozoic sedimentary and volcanic rocks in south-central Chile(36°s)

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Geoscience Frontiers 2024年第5期15卷 93-117页

作者： Alfonso Encinas Nicolás Henríquez Daniel Castro Darío orts Diego Kietzmann Franco iovino Paulo Vásquez Andrés Folguera Victor Valencia Facundo Fuentes Departamento de Ciencias de la Tierra Facultad de Ciencias QuímicasUniversidad de ConcepciónVíctor Lamas 1290Concepción 4030000Chile Universidad Nacional de Río Negro.instituto de investigación en Paleobiología y Geología.General Roca Río NegroArgentina instituto de investigación en Paleobiología y Geología(iiPG).CoNiCET.Av.J.A.Roca 1242 8332 General RocaRío NegroArgentina Universidad de Buenos Aires Facultad de Ciencias Exactas y NaturalesDepartamento de Ciencias GeológicasCiudad UniversitariaPabellón ⅡIntendente Güiraldes 2160C1428EHA Ciudad Autónoma de Buenos AiresArgentina CoNiCET-Universidad de Buenos Aires Instituto de Geociencias BásicasAmbientales y Aplicadas de Buenos Aires(IGeBA)Ciudad UniversitariaPabellón ⅡIntendente Güiraldes 2160C1428EHA Ciudad Autónoma de Buenos AiresArgentina instituto de Estudios Andinos“Don Pablo Groeber”(iDEAN) CONICET-Universidad de Buenos AiresBuenos AiresArgentina Facultad de Ciencias Exactas y Naturales Universidad de Buenos AiresBuenos AiresArgentina Washington state University School of the EnvironmentPullmanUSA Yacimientos Petrolíferos Fiscales(YPF)s.A. Buenos AiresArgentina

Many studies propose a significant shift in the tectonic and paleogeographic evolution of the Andes in south-central Chile and Argentina during the Late *** has been proposed that the preceding Jurassic-Early Cretaceous extensional regime that resulted in a low-relief volcanic arc and the backarc Neuquén basin came to an end,giving way to shortening and Andean growth from the Late Cretaceous ***,there are disagreements regarding the timing and nature of this transition to Andean *** address these issues,we conducted geochronologic(U-Pb and^(40)Ar/&(39)Ar),sedimentologic,and structural studies on Mesozoic-Cenozoic sedimentary and volcanic rocks in the Río Maule area(Principal Cordillera,Chile,36°s).From our findings and prior analyses,we propose the following tectono-stratigraphic evolution of the region.(1)Marine deposition of the Tithonian-Hauterivian Baños del Flaco Formation took place in an extensional backarc basin.(2)After a~40 Myr hiatus,fluvial deposits of the Colimapu Formation and volcanic rocks of the Plan de los Yeuques Formation accumulated during the *** the Colimapu Formation displays evidence of syndepositional shortening,the Plan de los Yeuques Formation exhibits synextensional growth *** to other studies,our results suggest that the Chilean part of the Principal Cordillera was largely a zone of active deposition rather than an elevated fold-thrust belt during the Late *** propose that sedimentation occurred within a series of relatively stable intermontane subbasins generated by shortening,followed by extension.(3)After a~20 Myr hiatus,middle Eocene to early Miocene(Lutetian-Aquitanian)accumulation of a thick succession of andesitic lavas and minor clastic sediments of the Abanico Formation occurred in an intraarc extensional basin.(4)Finally,major shortening and uplift of previously deposited Mesozoic-Cenozoic rocks took place throughout the *** phase constitu

关键词： Andes south-central Chile Backarc basin Foreland basin Fold-thrust belt

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NEW PARAMETER FoR DEsCRiBiNG AND ANALYZiNG THE oPTiCAL-ANisoTRoPiC PRoPERTiEs oF BioLoGiCAL TissUEs

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Journal of innovative optical Health sciences 2011年第4期4卷 463-475页

作者： Yu.A.UsHENKo o.i.TELENGA A.P.PEREsUNKo o.K.NUMAN Correlation optics Department Chernivtsi National University 2 Kotsyubinsky StreetChernivtsi 58012Ukraine optics and spectroscopy Department Chernivtsi National University 2 Kotsyubinsky Street Chernivtsi 58012Ukraine Chernivtsi Medical University 2 Theatral sq Chernivtsi 58002Ukraine

To characterize the degree of similarity inherent to parameters of the optically uniaxial birefringent protein-fibril networks of biological tissues,a new parameter-complex degree of mutual anisotropy-has been *** technique of polarization measuring the coordinate distributions of the complex degree of mutual anisotropy of biological tissues has been *** has been shown that statistical approach to the analysis of complex degree of mutual anisotropy distributions for biological tissues in various morphological and physiological states and for different optical thicknesses appears to be more sensitive and efficient in differentiation of physiological state,as compared to investigations of complex degree of mutual polarization in the corresponding laser images.

关键词： Polarization birefringence correlation statistics biological tissue skin derma

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Approximate analytical solutions and mean energies of stationary schrodinger equation for general molecular potential

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Chinese Physics B 2021年第7期30卷 116-131页

作者： Eyube E s Rawen B o ibrahim N Department of Physics School of Physical SciencesModibbo Adama University of TechnologyP M B 2076 YolaAdamawa StateNigeria Directorate of Basic and Remedial studies Abubakar Tafawa Balewa University(ATBU)P M B 750001BauchiBauchi StateNigeria Department of Physics Faculty of ScienceP M B 1069MaiduguriBorno StateNigeria

The schrodinger equation is solved with general molecular potential via the improved quantization *** for bound state energy eigenvalues,radial eigenfunctions,mean kinetic energy,and potential energy are obtained in compact *** modeling the centrifugal term of the effective potential,a Pekeris-like approximation scheme is ***,we use the Hellmann–Feynman theorem to derive the relation for expectation *** state energy eigenvalues,wave functions and meanenergies of Woods–saxon potential,Morse potential,Mobius squared and Tietz–Hua oscillators are deduced from the general molecular *** addition,we use our equations to compute the bound state energy eigenvalues and expectation values for four diatomic molecules viz.H_(2),Co,HF,and o_(2).Results obtained are in perfect agreement with the data available from the literature for the potentials and *** also show that as the vibrational quantum number increases,the mean kinetic energy for the system in a Tietz–Hua potential increases slowly to a threshold value and then *** in a Morse potential,the mean kinetic energy increases linearly with vibrational quantum number increasing.

关键词： general molecular potential schrodinger equation improved quantization rule

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Focal depth,magnitude,and frequency distribution of earthquakes along oceanic trenches

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Earthquake science 2013年第2期26卷 75-82页

作者： o.s.Hammed o.i.Popoola A.A.Adetoyinbo M.o.Awoyemi G.o.Badmus o.B.ohwo Bells University of Technology University of ibadan obafemi Awolowo University Afe Babalola University

The occurrence of earthquakes in oceanic tren- ches can pose a tsunami threat to lives and properties in active seismic zones. Therefore, the knowledge of focal depth, magnitude, and time distribution of earthquakes along the trenches is needed to investigate the future occurrence of earthquakes in the zones. The oceanic trenches studied, were located from the seismicity map on： latitude ＋51 ° to＋53° and longitude -160° to 176° （Aleutian Trench）, latitude ＋40° to ＋53° and longitude ＋148° to＋165° （Japan Trench）, and latitude -75° to -64° and longitude -15° to ＋30° （Peru-Chile Trench）. The following features of seis- mic events were considered： magnitude distribution, focal depth distribution, and time distribution of earthquake. The results obtained in each trench revealed that the earthquakes increased with time in all the regions. This implies that the lithospheric layer is becoming more unstable. Thus, tectonic stress accumulation is increasing with time. The rate of increase in earthquakes at the Peru-Chile Trench is higher than that of the Japan Trench and the Aleutian Trench. This implies that the convergence of lithospheric plates is higher in the Peru-Chile Trench. Deep earthquakes were observed across all the trenches. The shallow earthquakes were more prominent than intermediate and deep earthquakes in all thetrenches. The seismic events in the trenches are mostly of magnitude range 3.0-4.9. This magnitude range may indi- cate the genesis of mild to moderate tsunamis in the trench zone in near future once sufficient slip would occur with displacement of water column.

关键词： Focal depth Magnitude Earthquakeoceanic trenche

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A Quasilinear system Related with the Asymptotic Equation of the Nematic Liquid Crystal’s Director Field

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Chinese Annals of Mathematics,series B 2021年第2期42卷 163-172页

作者： João-Paulo DiAs Departamento de Matemática and CMAFcio Faculdade de Ciências da Universidade de LisboaCampo GrandeEdificio C61749-016 LisboaPortugal

in this paper, the author studies the local existence of strong solutions and their possible blow-up in time for a quasilinear system describing the interaction of a short wave induced by an electron field with a long wave representing an extension of the motion of the director field in a nematic liquid crystal’s asymptotic model introduced in[saxton, R. A., Dynamic instability of the liquid crystal director. in: Current Progress in Hyperbolic systems(Lindquist, W. B., ed.), Contemp. Math., Vol.100, Amer. ***., Providence, Ri, 1989, pp.325–330] and [Hunter, J. K. and saxton, R. A., Dynamics of director fields, siAM J. Appl. Math., 51, 1991, 1498–1521] and studied in [Hunter, J. *** Zheng, Y., on a nonlinear hyperbolic variational equation i, Arch. Rat. Mech. Anal.,129, 1995, 305–353], [Hunter, J. K. and Zheng, Y., on a nonlinear hyperbolic variational equation ii, Arch. Rat. Mech. Anal., 129, 1995, 355–383] and in [Zhang, P. and Zheng,Y., on oscillation of an asymptotic equation of a nonlinear variational wave equation,Asymptotic Anal., 18, 1998, 307–327] and, more recently, in [Bressan, A., Zhang, P. and Zheng, Y., Asymptotic variational wave equations, Arch. Rat. Mech. Anal., 183, 2007,163–185].

关键词： Benney system Conservation law schrödinger equation Nematic liquid crystal Director field

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