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Distribution and geochemical significance of dibenzofurans,phenyldibenzofurans and benzo[b]naphthofurans in source rock extracts from Niger Delta basin,Nigeria

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Acta Geochimica 2020年第6期39卷 973-987页

作者： Abiodun b.Ogbesejana Oluwasesan M.bello Department of Applied Chemistry Federal University Dutsin-MaP.M.B.5001Dutsin-MaKatsina StateNigeria

The distribution and geochemical significance of dibenzofurans,phenyldibenzofurans and benzo[b]naptho-furans in source rocks from Niger Delta basin,Nigeria,were investigated by Rock-Eval pyrolysis and gas chro-matography--mass spectrometry(GC--MS).The data obtained from the source rocks evaluation showed that the rock samples contained type 1/III kerogen capable of generating oil and gas and were within immature to early mature *** relative abundance of the Cor,C1-and C2-dibenzofurans range from 1.75%to 29.82%,27.60%to 40.52%and 29.66%to 6889%,*** diben-zofurans were dominated by *** the C1-dibenzofurans,2-+3-methyldibenzofuran was the most abundant in the rock samples while 1-methy ldibenzofuran appeared to be the *** relative abundance of benzo[b]naphtho[1,2-d]furan(1,2]bNF),benzo[b]naph-tha[2,1-d]furan(2.1]bNF)and benzo[b]naphtha[2,3-d]fu-ran([2.3]bNF)in the rock extracts range from 12.01%to 52.58%,32.61%to 75.219%and 10.27%to 52.43%.The wide range of values recorded for the three isomers of benzo[b lnapthofurans in the samples suggest source rocks formed from mixed organic *** the pheny ldibenzofuran isomers,4-pheny ldibenzofuran was the most abundant while 1-phenyldibenzofuran was the *** ratio-1(PhFR-1)and pheny ldibenzofuran ratio-2(PhFR-2)values range from 0.13 to 1.20 and 0.11 to 2.11,*** resuls showed that the relative abundance of PhFR-1 and PhFR-2 increase gradually with increasing burial depth and maturity(VRo≤0.77%,MPI-1≤*** s 443℃),and have a good correlations with calculated vitrinite ***-I and maximum Temperature(Tmax)-This range of values suggested immature to early mature source *** source rocks were found to have shale and coul lithologics and deposited in a lacustrine/fuvial deltaic settings within immature to early mature stages based on the distribution of dibenzofurans,pheny ldiben-zofurans and benzo[b]naphthofurans in the source rock

关键词： Dibenzofurans benzo[b]napthofurans Source rocks Niger delta Gas chromatography-mass spectrometry

Nonlinear three-dimensional stretched flow of an Oldroyd-b fluid with convective condition, thermal radiation, and mixed convection

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Applied Mathematics and Mechanics(English Edition) 2017年第7期38卷 969-980页

作者： b. MAHANTHESH b. J. GIREESHA S.A. SHEHZAD F.M. AbbASI R. S. R. GORLA Department of Mathematics Christ University Bangalore 560029 Karnataka India Department of Studies and Research in Mathematics Kuvempu University Shankarghatta 577451 Karnataka India Department of Mathematics COMSATS Institute of Information Technology Sahiwal 57000 Pakistan Department of Mathematics COMSATS Institute of Information Technology Islamabad 44000 Pakistan Department of Mechanical and Civil Engineering Purdue University Northwest Indiana 46391 U. S. A

The effect of non-linear convection in a laminar three-dimensional Oldroyd-b fluid flow is addressed. The heat transfer phenomenon is explored by considering the non-linear thermal radiation and heat generation/absorption. The boundary layer as- sumptions are taken into account to govern the mathematical model of the flow analy- sis. Some suitable similarity variables are introduced to transform the partial differen- tial equations into ordinary differential systems. fifth-order techniques with the shooting method The Runge-Kutta-Fehlberg fourth- and are used to obtain the solutions of the dimensionless velocities and temperature. The effects of various physical parameters on the fluid velocities and temperature are plotted and examined. A comparison with the exact and homotopy perturbation solutions is made for the viscous fluid case, and an excellent match is noted. The numerical values of the wall shear stresses and the heat transfer rate at the wall are tabulated and investigated. The enhancement in the values of the Deborah number shows a reverse behavior on the liquid velocities. The results show that the temperature and the thermal boundary layer are reduced when the non- linear convection parameter increases. The values of the Nusselt number are higher in the non-linear radiation situation than those in the linear radiation situation.

关键词： nonlinear thermal convection nonlinear thermal radiation Oldroyd-b fluid,convective boundary condition heat source/sink

Synthesis and characterization of bulk composite Fe-Si-b alloys with small concentration of Nb and Mo

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Acta Metallurgica Sinica(English Letters) 2010年第6期23卷 401-408页

作者： S.bez I.betancourt I.A.Figueroa Institute for Materials Research National Autonomous University of Mexico (UNAM)

The preparation and some mechanical, thermal and magnetic properties of the as cast bulk composite ***4 （M=Nb, Mo） alloys obtained by suction casting are presented and discussed. The microstructrural results showed the existence of a crystalline a-Fe（Si） phase embedded in a glassy matrix. The values of microhardness （/Iv） and yield strength （ay） for the Nb-containing alloy are exceptionally high, i.e. （12.65~0.3） GPa and （4.22~0.10） GPa, respectively. The saturation polarization values are found to be as high as 1.24 T for both composite ~11oys. It is thought that the interplay between the secondary crystalline phases and amorphous matrix could be responsible for the mechanical and magnetic behaviour of these alloys.

关键词： bulk composite alloys Magnetic properties Mechanical proper- ties Thermal stability and suction casting

Synthesis, spectroscopic characterization, and thermal decomposition kinetics of some lanthanide(III) nitrate complexes of 2-(N-o-hydroxyacetophenone) amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[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. Thankamony b. Sindhu Kumari 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-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, 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 number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic 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 susceptibility thermal study rare earths

Corrosion by a Heavy Metal Oxide Glass

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Journal of Materials Science & Technology 2005年第2期21卷 243-245页

作者： b.b.Rana Department of Engineering Materials University of Sheffield Sheffield S1 4DU UK PCSIR Laboratories Complex LahorePakistan

Melts of lead bismuth gallate compositions are highly corrosive and attack on crucibles of different materials. In the present study, corrosion by a base glass (50PbO-30bi2O3-20Ga2O3 in mole fraction) melted using different crucibles and the effect on UV-VIS and IR edges were studied. by melting the base glass in platinum/2% rhodium, gold zirconia and alumina crucibles showed less effect on the IR edge and therefore shifted the infrared edge to longer wavelength, whereas silica crucible contaminated the glass, causing a severe deterioration in the infrared and hence shifted infrared edge to much shorter wavelength. In the UV-VIS region, base glass melted in platinum/2% rhodium crucible shifted the edge to the longest wavelength whereas silica crucible shifted the edge to shorter wavelength. The contaminants from gold, zirconia and alumina crucibles caused the UV-VIS edge of the base glass to lie between the two extremes of Pt/2% Rh and SiO2 crucibles. The glasses melted in above mentioned crucibles were also characterized with inductively coupled plasma spectroscopy (ICP) analysis to measure the level of contamination from the crucibles. Depending upon crucible used, the colors of glasses obtained ranged from red to yellow.

关键词： Oxide glass Corrosion Crucible

DNA-guided hepatitis b treatment,viral load is essential,but not sufficient

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World Journal of Gastroenterology 2009年第4期15卷 423-430页

作者： Rafael bárcena Marugán Silvia García Garzón Services of Liver-Gastroenterology Hospital Ramón y CajalUniversity of Alcalá Department of Gastroenterology Hospital Universitario de GuadalajaraUniversity of Alcalá

Hepatitis b virus （HbV） infection is a global public health problem that concerns 350 million people worldwide. Individuals with chronic hepatitis b （Crib） are at increased risk of developing liver cirrhosis, hepatic de-compensation and hepatocellular carcinoma. To maintain undetectable viral load reduces chronic infection complications. There is no treatment that eradicates HbV infection. Current drugs are expensive, are associated with adverse events, and are of limited efficacy. Current guidelines try to standardize the clinical practice. Nevertheless, controversy remains about management of asymptomatic patients with Crib who are hepatitis b e antigen （HbeAg）-positive with normal alanine aminotransferase, and what is the cut-off value of viral load to distinguish HbeAg- negative Crib patients and inactive carriers. We discuss in detail why DNA level alone is not sufficient to begin treatment of Crib.

关键词： Hepatitis b virus Viral DNA Alaninetransaminase Antiviral drug Hepatitis b e antigen Antiviral drug resistance

Nonsmooth Semi-Infinite Minmax Programming Involving Generalized(Φ, ρ)-Invexity

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Journal of Systems Science & Complexity 2015年第4期28卷 857-875页

作者： UPADHYAY b b MISHRA S K Department of basic Sciences & Humanities National Institute of Technology

This paper introduces some new generalizations of the concept of （~, p）-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature.

关键词： Duality, generalized invexity locally Lipschitz functions, minmax programming, semi-infinite programming.

Investigation of nanocrystalline structure in selected carbonaceous materials

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International Journal of Minerals,Metallurgy and Materials 2014年第9期21卷 940-946页

作者： Manoj b Department of Physics Christ University

The structural parameters of nine Indian coals were determined by X-ray diffraction （XRD） and Kaman spectroscopy. The study revealed that the coals contain crystalline carbon of turbostratic structure with amorphous carbon. The stacking height （Lc） and interlayer spacing （rico2） of the crystallite structure of the coals ranged from 1.986 to 2.373 nm and from 0.334 to 0.340 nm, respectively. The degree of graphitization was calculated to range from 42% to 99%, thereby confirming the ordering of the carbon layers with the increase in coal rank. An exponential correlation was observed among the aromaticity （fa）, the lateral size （La）, and the rank （I20/I26）, suggesting that the coal crystallites are nanocrystalline in nature. A very strong correlation was observed between the structural parameters （fa, d002, Lc, the H/C ratio, and I20/I26）, the volatile matter content, and the elemental carbon content, indicating the structures of coals are controlled by the degree of contact metamorphism. The Raman spectra exhibited two prominent bands： the graphitic band （G） and the fn＇st-order characteristic defect band （D）. The deconvolufion resulted in five peaks： G, D1, D2, D3, and D4. The intense D1 band, which appeared at -1350 cm^-1, corresponds to a lattice vibration mode with Alg symmetry. The D2 mode, which appeared at -1610 cm^-1, arises from the structural disorder as a shoulder on the G band.

关键词： nanocrystals graphitization aromaticity carbonaceous materials

Rethinking the solar flare paradigm

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Plasma Science and Technology 2018年第7期20卷 15-21页

作者： d b melrose SIfA School of PhysicsThe University of SydneyNSW 2006Australi

It is widely accepted that solar flares involve release of magnetic energy stored in the solar corona above an active region, but existing models do not include the explicitly time-dependent electrodynamics needed to describe such energy release. A flare paradigm is discussed that includes the electromotive force （EMF） as the driver of the flare, and the flare-associated current that links different regions where magnetic reconnection, electron acceleration, the acceleration of mass motions and current closure occur. The EMF becomes localized across regions where energy conversion occurs, and is involved in energy propagation between these regions.

关键词： solar flares electrodynamics time-dependence