The (5d10 + 5d96s) – 5d96p transitions in Tl IV, Pb V, and Bi VI

1990 ◽  
Vol 68 (3) ◽  
pp. 284-292 ◽  
Author(s):  
Y. N. Joshi ◽  
A. J. J. Raassen ◽  
A. A. Van der Valk
Keyword(s):  
Least Squares ◽  
Hyperfine Structure ◽  
Interaction Parameter ◽  
Magnetic Interaction ◽  
Spin Orbit ◽  
Magnetic Effects ◽  
Magnetic Interaction Parameter

The spectra of thallium, lead, and bismuth were photographed in the region 600–2000 Å using sliding spark and triggered spark sources. The (5d10 + 5d96s)–5d96p transitions in Tl IV, Pb V, and Bi VI were investigated. Earlier level values were revised and new lines were classified. Hyperfine structure splittings were observed for many lines in Tl IV and Bi VI. Least squares fitted calculations were done for each spectra. The deviations between the calculated and observed level values showed that parametric descriptions using only the spin-orbit magnetic interaction parameter to describe magnetic effects is not sufficient in the 5d-shell spectra.

Direct numerical simulation of forced MHD turbulence at low magnetic Reynolds number

1998 ◽  
Vol 358 ◽  
pp. 299-333 ◽  
Author(s):  
OLEG ZIKANOV ◽  
ANDRE THESS
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Boundary Conditions ◽  
Interaction Parameter ◽  
Three Dimensional ◽  
Magnetic Interaction ◽  
Two Dimensional ◽  
Mhd Turbulence ◽  
Magnetic Interaction Parameter

The transformation of initially isotropic turbulent flow of electrically conducting incompressible viscous fluid under the influence of an imposed homogeneous magnetic field is investigated using direct numerical simulation. Under the assumption of large kinetic and small magnetic Reynolds numbers (magnetic Prandtl number Pm[Lt ]1) the quasi-static approximation is applied for the computation of the magnetic field fluctuations. The flow is assumed to be homogeneous and contained in a three-dimensional cubic box with periodic boundary conditions. Large-scale forcing is applied to maintain a statistically steady level of the flow energy. It is found that the pathway traversed by the flow transformation depends decisively on the magnetic interaction parameter (Stuart number). If the magnetic interaction number is small the flow remains three-dimensional and turbulent and no detectable deviation from isotropy is observed. In the case of a strong magnetic field (large magnetic interaction parameter) a rapid transformation to a purely two-dimensional steady state is obtained in agreement with earlier analytical and numerical results for decaying MHD turbulence. At intermediate values of the magnetic interaction parameter the system exhibits intermittent behaviour, characterized by organized quasi-two-dimensional evolution lasting several eddy-turnover times, which is interrupted by strong three-dimensional turbulent bursts. This result implies that the conventional picture of steady angular energy transfer in MHD turbulence must be refined. The spatial structure of the steady two-dimensional final flow obtained in the case of large magnetic interaction parameter is examined. It is found that due to the type of forcing and boundary conditions applied, this state always occurs in the form of a square periodic lattice of alternating vortices occupying the largest possible scale. The stability of this flow to three-dimensional perturbations is analysed using the energy stability method.

Numerical Investigation of Slip Effects on Hydromagnetic Flow Due to a Rotating Porous Disk in a Nanofluid with Internal Heat Absorption

2017 ◽  
Vol 33 (3) ◽  
pp. 375-386
Author(s):  
S. P. Anjali Devi ◽  
T. Elakkiya Priya
Keyword(s):  
Differential Equations ◽  
Interaction Parameter ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Internal Heat ◽  
Magnetic Interaction ◽  
Heat Absorption ◽  
Slip Parameter ◽  
Suction Parameter ◽  
Magnetic Interaction Parameter

AbstractIn recent days, nanofluids have derived the attention of researchers, scientists and engineers due to their abundant applications in Engineering and technology and specific applications such as Electronics cooling, vehicle cooling, medical applications including cancer therapy and so on. Motivated by these applications of nanofluids, this work is mainly concerned with the convective heat transfer of nanofluids. MHD slip flow of nanofluids with heat absorption over a rotating disk subjected to suction has been analyzed. Two types of nanofluids such as copper-water nanofluid and silver-water nanofluid are considered for the present study. The system of axisymmetric nonlinear partial differential equations governing the hydromagnetic steady flow and heat transfer are reduced to nonlinear ordinary differential equations by introducing suitable similarity transformations. The resulting non-linear ordinary differential equations are solved numerically by most efficient Nachtsheim-Swigert shooting iteration technique for satisfaction of asymptotic boundary conditions along with Runge – Kutta Fehlberg Method. The flow field is affected by the presence of physical parameters, such as magnetic interaction parameter, suction parameter, slip parameter and solid volume fraction, whereas the temperature field is addionally affected by magnetic interaction parameter, suction parameter, internal heat absorption parameter and solid volume fraction. With the amplifying effect in magnetic interaction parameter, suction parameter, slip parameter and solid volume fraction, the radial and tangential velocities decline. Axial velocity gets decelerated for increasing magnetic interaction parameter and slip parameter whereas it gets accelerated for growing effect of suction parameter and solid volume fraction. The temperature of the fluid within the boundary layer enhances with the increasing effect of magnetic interaction parameter and solid volume fraction while it reduces for increasing values of the suction parameter and internal heat absorption parameter. Also the values of radial and tangential skin friction coefficients and Nusselt number are obtained numerically and are tabulated.

End effects in inviscid flow in a magnetohydrodynamic channel

1961 ◽  
Vol 11 (1) ◽  
pp. 121-132 ◽  
Author(s):  
G. W. Sutton ◽  
A. W. Carlson
Keyword(s):  
Magnetic Field ◽  
Interaction Parameter ◽  
Rectangular Cross Section ◽  
Fluid Velocity ◽  
Magnetic Interaction ◽  
Inviscid Flow ◽  
Magnetic Reynolds Number ◽  
Conducting Fluid ◽  
End Effects ◽  
Magnetic Interaction Parameter

The flow of an inviscid, incompressible electrical conducting fluid in a channel of constant rectangular cross-section is considered, when the flow enters a region which contains a magnetic field transverse to the flow and electrodes on opposite sides of the channel. This geometry is typical of a d.c. induction pump or magnetohydrodynamic generator. The conducting fluid external to the magnetic field acts as a shunt and produces a non-uniform electric potential field and hence a non-uniform Lorenz force on the fluid, and causes the fluid velocity profile to be distorted. These effects are calculated theoretically for small magnetic Reynolds number and small magnetic interaction parameter. It is found that the velocity at the centre-line of the channel is retarded and at the walls the velocity is accelerated. The fractional change of velocity at the wall is equal to approximately 0·44 times a modified magnetic interaction parameter.

First rotational analysis of the A2Π-X2Π system of the P35Cl+ cation

1987 ◽  
Vol 65 (5) ◽  
pp. 980-983 ◽  
Author(s):  
John A. Coxon ◽  
Stavros Naxakis ◽  
Utpal K. Roychowdhury
Keyword(s):  
Least Squares ◽  
Band System ◽  
Coupling Constants ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rotational Analysis ◽  
Entire Data

The visible A2Π → X2Π band system of PCl+ has been recorded photoelectrically with a resolution of 0.006 nm. Fourteen 2Π1/2–2Π1/2 and six 2Π3/2–2Π3/2 sub-bands of P35Cl+ in the ν′ = 0 and 1 progressions with 10 ≤ ν″ ≤ 20 have been rotationally analysed. The measured positions of 1214 lines have been fitted directly by least squares to obtain a set of reliable constants for the two states that reproduce the entire data. These constants include the first estimated spin–orbit coupling constants for both states. The reliability of these estimates is discussed. The equilibrium internuclear separations are re(X) = 0.1900 and re(A) = 0.2334 nm.

Spin–orbit distortion of the hyperfine structure in heavier molecules: Breakdown of the case (aβ) formalism in the B 3Φ–X 3Δ system of gaseous NbN

1989 ◽  
Vol 91 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Y. Azuma ◽  
J. A. Barry ◽  
M. P. J. Lyne ◽  
A. J. Merer ◽  
J. O. Schröder ◽  
...  
Keyword(s):  
Hyperfine Structure ◽  
Spin Orbit

HYPERFINE STRUCTURE OF THE LEVEL OF LITHIUM-6 AND LITHIUM-7

1965 ◽  
Vol 43 (5) ◽  
pp. 770-781 ◽  
Author(s):  
George J. Ritter
Keyword(s):  
Radio Frequency ◽  
Hyperfine Structure ◽  
Double Resonance ◽  
Resonance Method ◽  
Magnetic Interaction ◽  
Level 2

The hyperfine structure of the level 2 2P1/2 of both 6Li and 7Li has been investigated by means of the optical–radio–frequency double-resonance method. The following values were obtained for the magnetic interaction constants of the two isotopes:[Formula: see text]The gJ value for the 2P1/2 level was found to be −0.6668 ± 0.0020.

Theoretical Studies of the EPR g Factors and the Hyperfine Structure Constants of Cr3+ in MgS and SrS

2003 ◽  
Vol 58 (9-10) ◽  
pp. 503-506
Author(s):  
Shao-Yi Wu ◽  
Xiu-Ying Gao ◽  
Wei-Zi Yan
Keyword(s):  
Hyperfine Structure ◽  
Coupling Coefficient ◽  
Structure Constant ◽  
Theoretical Studies ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Hyperfine Structure Constant ◽  
Structure Constants ◽  
G Factors

The EPR g factors and the hyperfine structure constant A factors for Cr3+ in MgS and SrS are theoretically studied by using the two-spin-orbit (S.O.)-coupling-coefficient formulas for a 3d3 ion in octahedra based on the cluster approach. In these formulas, both the contributions due to the S.O. coupling coefficient of the central 3d3 ion and that of ligands are taken into account. Based on these studies, the g and A factors of Cr3+ in both MgS and SrS are satisfactorily explained. The results are discussed.

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