16 research outputs found

    Effects of thermophoresis and Brownian motion for thermal and chemically reacting Casson nanofluid flow over a linearly stretching sheet

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    The current research explores the problem of steady laminar flow of nanofluid on a two dimensional boundary layer using heat transfer of Cassona cross the linearly stretching sheet. The governing equations are partial differential equations which are transformed into non-linear ordinary differential equations by using some similarity transformation. The converted form of the combined non-linear higher-order ODEswith a set of boundary conditions are solved by means of Runge-Kutta 4th-order approach along with the shooting method. The nanoparticle concentration profiles, velocity, and temperature are examined by taking account of their influence of Prandtl number, "Brownian motion parameter ", Lewis number, thermophoresis, and Casson fluid parameter. It is reported that the temperature increase as Nt and Nb increases which causes thickening of the thermal boundary layer. Also it is observed that, there is increment in temperature profile for increasing values of Brownian motion parameter and the energy distribution grows with increment in the values of Thermophoresis parameter. The comparison for the local Nusselt & local Sherwood number has been tabulated with respect to variation of the Brownian Motion Parameter and Thermophoresis parameter. All the findings of the results are graphically represented and discussed.Funding The work of U.F.-G. was supported by the government of the Basque Country for the ELKARTEK21/10 KK-2021/00014 and ELKARTEK22/85 research programs, respectively

    Structural refinement and electrochemical properties of one dimensional (ZnO NRs)1-x(CNs )x functional hybrids for serotonin sensing studies

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    Herein, the efficient serotonin (5-HT) sensing studies have been conducted using the (ZnO NRs) 1−x(CNs) x nanocomposites (NCs) having appropriate structural and electrochemical properties. Initially, the different compositions of ZnO nanorods (NRs), with varying content of carbon nanostructures (CNs=MWCNTs and RGO), are prepared using simple in-situ wet chemical method and thereafter these NCs have been characterized for physico-chemical properties in correlation to the 5-HT sensing activity. XRD Rietveld refinement studies reveal the hexagonal Wurtzite ZnO NRs oriented in (101) direction with space group ‘P6 3mc’ and both orientation as well as phase of ZnO NRs are also retained in the NCs due to the small content of CNs. The interconnectivity between the ZnO NRs with CNs through different functional moieties is also studied using FTIR analysis; while phases of the constituents are confirmed through Raman analysis. FESEM images of the bare/NCs show hexagonal shaped rods with higher aspect ratio (4.87) to that of others. BET analysis and EIS measurements reveal the higher surface area (97.895 m 2/g), lower charge transfer resistance (16.2 kΩ) for the ZCNT 0.1 NCs to that of other NCs or bare material. Thereafter, the prepared NCs are deposited on the screen printed carbon electrode (SPCE) using chitosan as cross-linked agent for 5-HT sensing studies; conducted through cyclic voltammetry (CV) and square wave voltammetry (SWV) measurements. Among the various composites, ZCNT0.1 NCs based electrodes exhibit higher sensing activity towards 5-HT in accordance to its higher surface area, lower particle size and lower charge transfer resistance. SWV measurements provide a wide linear response range (7.5–300 μM); lower limit of detection (0.66 μM), excellent limit of quantification (2.19 μM) and good reproducibility to ZCNT 0.1 NCs as compared to others for 5-HT sensing studies

    The Effects of MHD Flow and Heat Transfer for the UCM Fluid over a Stretching Surface in Presence of Thermal Radiation

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    An analysis is performed to investigate the effect of MHD and thermal radiation on the two-dimensional steady flow of an incompressible, upper-convected Maxwells (UCM) fluid in presence of external magnetic field. The governing system of partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations and is solved numerically by efficient shooting technique. Velocity and temperature fields have been computed and shown graphically for various values of physical parameters. For a Maxwell fluid, a thinning of the boundary layer and a drop in wall skin friction coefficient is predicted to occur for the higher elastic number which agrees with the results of Hayat et al. 2007 and Sadeghy et al. 2006. The objective of the present work is to investigate the effect of elastic parameter β, magnetic parameter Mn, Eckert number Ec, Radiation parameter N, and Prandtl number Pr on flow and heat transfer charecteristics

    Determination of (n,2n) reaction cross-section for

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    The (n,2n) reaction cross-sections of 154Sm, 150Nd and 82Se isotopes at 14.6 MeV neutron energy have been measured by neutron activation followed by off-line gamma-ray spectrometry with improved experimental methodology. The neutron flux was determined using the 197Au(n, 2n)196Aug monitor reaction which has not been used earlier for cross-section measurement for the above mentioned nuclei. The measured reaction cross-sections are found to have good agreement with calculated cross-section data, obtained independently, using Talys and ENDF codes. A detailed comparison of the present cross-section data with the existing literature has been presented in this paper

    Docking, synthesis, and characterization of novel heterocyclic ring system and their evaluation for mGlu8 receptor agonist as anticonvulsant agents

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    544-550This research work involves the synthesis of a series of substituted 1-(4-methoxy-1-phenyl/methyl-2-thioxo-1,2- dihydroquinolin-3-yl)ethanone [IVa/b(1-5)] derivatives by dimerization at third position and evaluation of their anticonvulsant activity. The starting material 3-acetyl-4-hydroxy-1-phenyl/methylquinolin-2(1H)-one Ia/b has been treated with P4S10:Al2O3 to yield compound 1-(4-hydroxy-1-phenyl/methyl-2-thioxo-1,2-dihydroquinolin-3-yl)ethanone (IIa/b). Compound IIa/b has been methylated to yield compound 1-(4-methoxy-1-phenyl/methyl-2-thioxo-1,2-dihydroquinolin-3-yl)ethanone (IIIa/b) which, on condensation with ketones forms dimers giving the title compounds IVa-b (1-5). All the synthesized compounds are satisfactorily characterized by spectral data. The in silico pharmacophore modeling of the title compounds has been performed using Molegro Virtual Docker (MVD-2007 software and mGlu8 is the target and in vivo anticonvulsant activity by phenylenetetrazole (PTZ) induced convulsion method. The results of docking have revealed that the synthesized compounds exhibit well-conserved hydrogen bonds with one or more amino acid residues in the active pocket of metabotropic glutamate receptor mGluR8 complexed with (S)-3,4-dicarboxyphenylglycine (DCPG) (PDB ID:6E5V)LY341495 antagonist (PDB ID: 3MQ4). The MolDock Score of compound 2,6-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl)hepato-2,5-dien- 4-one (IVa-1) has been found to be −141.617. The in vivo anticonvulsant activity results show that compound 2,6-bis(4- methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl)hepato-2,5-dien-4-one (IVa-1), 2,7-bis(4-methoxy-1-phenyl-2-thioxo- 1,2-dihydroquinolin-3-yl)octa-2,6-dien-4,5-dione (IVa-2), 2,6-bis(4-methoxy-1-methyl-2-thioxo-1,2-dihydroquinolin-3- yl)hepato-2,5-dien-4-one (IVb-2) and (2E,6E)-2,6-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl) cyclohexanone (IVb-4) have been found to be most potent against pentylenetetrazole induced convulsion

    Docking, synthesis, and characterization of novel heterocyclic ring system and their evaluation for mGlu8 receptor agonist as anticonvulsant agents

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    This research work involves the synthesis of a series of substituted 1-(4-methoxy-1-phenyl/methyl-2-thioxo-1,2-dihydroquinolin-3-yl)ethanone [IVa/b(1-5)] derivatives by dimerization at third position and evaluation of their anticonvulsant activity. The starting material 3-acetyl-4-hydroxy-1-phenyl/methylquinolin-2(1H)-one Ia/b has been treated with P4S10:Al2O3 to yield compound 1-(4-hydroxy-1-phenyl/methyl-2-thioxo-1,2-dihydroquinolin-3-yl)ethanone (IIa/b). Compound IIa/b has been methylated to yield compound 1-(4-methoxy-1-phenyl/methyl-2-thioxo-1,2-dihydroquinolin-3-yl)ethanone (IIIa/b) which, on condensation with ketones forms dimers giving the title compounds IVa-b (1-5). All the synthesized compounds are satisfactorily characterized by spectral data. The in silico pharmacophore modeling of the title compounds has been performed using Molegro Virtual Docker (MVD-2007 software and mGlu8 is the target and in vivo anticonvulsant activity by phenylenetetrazole (PTZ) induced convulsion method. The results of docking have revealed that the synthesized compounds exhibit well-conserved hydrogen bonds with one or more amino acid residues in the active pocket of metabotropic glutamate receptor mGluR8 complexed with (S)-3,4-dicarboxyphenylglycine (DCPG) (PDB ID:6E5V)LY341495 antagonist (PDB ID: 3MQ4). The MolDock Score of compound 2,6-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl)hepato-2,5-dien-4-one (IVa-1) has been found to be −141.617. The in vivo anticonvulsant activity results show that compound 2,6-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl)hepato-2,5-dien-4-one (IVa-1), 2,7-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl)octa-2,6-dien-4,5-dione (IVa-2), 2,6-bis(4-methoxy-1-methyl-2-thioxo-1,2-dihydroquinolin-3-yl)hepato-2,5-dien-4-one (IVb-2) and (2E,6E)-2,6-bis(4-methoxy-1-phenyl-2-thioxo-1,2-dihydroquinolin-3-yl) cyclohexanone (IVb-4) have been found to be most potent against pentylenetetrazole induced convulsion

    Magnetohydrodynamics and viscosity variation in couple stress squeeze film lubrication between rough flat and curved circular plates

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    Abstract A simplified mathematical model has been developed for understanding combined effects of surface roughness, viscosity variation and couple stresses on the squeeze film behaviour of a flat and a curved circular plate in the presence of transverse magnetic field. The Stokes (1966) couple stress fluid model is included to account for the couple stresses arising due to the presence of microstructure additives in the lubricant. In the context of Christensen’s (1969) stochastic theory for the lubrication of rough surfaces, two types of one-dimensional roughness patterns (radial and azimuthal) are considered. The governing modified stochastic Reynolds type equations are derived for these roughness patterns. Expressions for the mean squeeze film characteristics are obtained. Numerical computations of the results show that the azimuthal roughness pattern on the curved circular and flat plate results in more pressure buildup whereas performance of the squeeze film suffers due to the radial roughness pattern. Further the Lorentz force characterized by the Hartmann number, couple stress parameter and viscosity variation parameter improve the performance of the squeeze film lubrication as compared to the classical case (Non-magnetic, Newtonian case and non-viscous case)
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