Hall effects on steady hydromagnetic flow in a rotating channel in the presence of an inclined magnetic field

Effects of Hall current on a steady hydromagnetic (MHD) fully developed flow in a rotating environment within a parallel plate channel in the presence of an inclined magnetic field is studied. From an extension of literature [13] subject to a forced oscillation it is observed that the present paper is methodically more correct to work first in the steady state where forced oscillation becomes insignificant and then new results are expected for an unsteady MHD flow under the influence of a pulse-oscillator. Exact solutions of the governing equations are obtained in a closed form. The graphical representation for the velocity and the induced magnetic field are depicted graphically and the heat transfer at both the plates are presented in tables.     

Charge-response of magnetization in nanoporous Pd-Ni alloys

This work reports isothermal reversible variation of magnetization in nanoporous Pd-Ni alloys subjected to continuous charging and discharging of the sample in aprotic electrolyte medium. Polarizing metal surface with excess charge also finds strain in the nanoporous structure using the sample as working electrode. Therefore, it is proposed that pressure induced by strain is the key parameter for the observed reversible magnetization in the transition metal alloys.     

Depth-resolved fluorescence measurement in a layered turbid medium by polarized fluorescence spectroscopy

We show that, when a turbid medium with a layered fluorophore distribution is excited by linearly polarized light, measurement of angle-resolved polarized fluorescence can provide depth-resolved fluorescence measurements.     

Operator method and eigenvalues of the triple-well anharmonic oscillator

Using an algebraic technique based on the Lie algebra of the group SO(2, 1) the eigenvalues of the triple-well anharmonic oscillator are calculated for all ranges of the coupling constant. Approximate analytic formulas for the eigenvalues up to second order are given. The results obtained are compared with those of other authors.     

Exact expressions for row correlation functions in the isotropicd=2 ising model

We present exact explicit expressions for the row spin-spin correlation functions _{00 n}0 in the isotropicd= 2 Ising model, in terms of elliptic integrals, forn 5. We also give a general structural formula for _{00 n}0.     

Dynamic critical behavior in para-azoxyanisole from nuclear relaxation studies

Contributions to the spin-lattice relaxation time (T ₁) and the spin-spin relaxation time (T ₂) due to critical fluctuations (CF) have been determined in para-azoxyanisole (PAA) from the corresponding proton relaxation times measured at 60 MHz over a temperature range of about 35 °K above the nematic-isotropic transition temperatureT _C .In determining the CF contributions, the procedure followed here is the same as the present authors used earlier for a similar study in p-methoxybenzylidene p-n butylaniline (MBBA). Like that in MBBA at 14 MHz, a maximum in the CF contribution toT ₁, has been observed. Following a recent theory we identify this contribution toT ₁ arising from the nonlocal part of CF, and we call thisT ₁)_CFN. The correlation time associated with this nonlocal part of CF, _CFN, has been determined at different temperatures fromT ₁)_CFN. The temperature dependence of _CFN is in good agreement with the Landau-de Gennes theory and is consistent with that observed earlier in MBBA. The temperature dependence ofT ₂)_CF is also in reasonable agreement with the above behavior of _CFN. However, ourT ₂)_CF data can also be fitted to a temperature dependence expected from a contribution toT ₂)_CF arising from the local part of CF, such a fitting is comparatively poorer than the former. Since ourT ₂)_CF data are neither sufficiently accurate nor elaborate, no attempt has been made here to separate these two contributions, nonlocal and local parts of CF, which have been predicted from theoretical considerations. A behavior similar to that of ourT ₂)_CF is also shown by the earlier data of Cabane and Clark obtained from¹⁴N resonance when their data are processed properly.Work done with the financial support of the Consiglio Nazionale delle Ricerche granted through the Gruppo Nazionale di Struttura della Materia to the Istituto di Fisica, Università dell' AquilaA preliminary report of this work was presented at the Fifth International Symposium on Magnetic Resonance held at Bombay, India, January 14–18, 1974     

New studies of X-ray diffraction line profiles from aggregates of distorted crystallites I

The fourth central moment of an X-ray diffraction profile from an aggregate of distorted crystallites has been expressed by Mitra (1964a) as a function of the crystallite size, strain and strain gradients in the specimen. While the usual methods of line profile analysis yield information regarding either the apparent strain or the rms strain, the present study provides additional information regarding strain distribution in the form of strain derivatives and rms displacements of atoms over a given distancet in the direction of study. The strain parameters like 〈ee′〉, 〈ee″〉 have been obtained from fourth moment of the strain profile against range plots. The strain parameters thus obtained have subsequently been used to determine the rms displacements of the atoms. Alloys of copper and zinc at different stages of cold working and annealing have been studied by this method. The results have been discussed in the light of dislocation distribution, polygonisation and grain growth as well as distortion waves in the distorted crystals.     

A new valence 2Π state of PO

Rotational structure of a series of new absorption bands of PO in the region 1850 to 1600 Å has been analyzed from a spectrum taken at high resolution. The bands are attributed to an electronic transition P²Π-X²Π, where P²Π is a new valence state of PO. Some of these bands have been found to be perturbed. A qualitative account of these perturbations is presented. A probable electron-configuration $\text{π}{}^3\text{π}{}^{12}$ has been suggested for the new state. From the predissociation observed in the higher vibrational levels of P an upper limit of 48 885 cm^?1 (X²Π, T₀ = 0) for the ground state dissociation energy has been obtained.     

Flows in a rotating elastico-viscous fluid induced by torsional oscillations of a plate acting for a finite time

Unsteady flows in an electrically conducting rotating elastico-viscous liquid in the presence of a uniform magnetic field and induced by small amplitude torsional oscillations, acting for a finite time, of an infinite, rigid, non-conducting plate, are discussed. This analysis indicates the general features of the steady and unsteady velocity field, and the structure of the associated boundary layers on the plate including the effect of rotation, hydromagnetic and elastic parameters involved in the problem. The velocity field related to small elastic parameter is calculated with physical significance. It is further shown that the Ekman suction velocity, which is responsible for the generation of an axial inflow toward the bounadry layer, does not appear unless the plate is subject to oscillations for an indefinite period. Several limiting results are found to follow as special cases of this analysis.