CHARACTERIZATION OF BACKBENDING IN EVEN–EVEN ISOTOPES OF 164–174Hf AND 154–164Dy NUCLEI BY A MODIFIED PHENOMENOLOGICAL MODEL

2013 ◽  
Vol 22 (07) ◽  
pp. 1350055
Author(s):  
L. A. NAJIM ◽  
MALEK. H. KHEDER
Keyword(s):  
Angular Momentum ◽  
Coriolis Force ◽  
Phenomenological Model ◽  
Energy Levels ◽  
Rotational Energy ◽  
Moment Of Inertia ◽  
Modified Model ◽  
The Moment ◽  
Variable Moment

A modified phenomenological model is used to calculate nuclear energy levels and describe successfully the backbending of the moment of inertia for the ground state bands in even–even isotopes of Hf and Dy nuclei. The model is a combination of the Myers and Swiatecki model with variable moment inertia (VMI) model. Since the Myers and Swiatecki model has a deviation from experimental energies in which it takes into account pairing effect with constant moment of inertia, in the rotation of nuclei, the Coriolis force acts to de-pair the nucleons pair and align their angular momentum with nuclei total angular momentum, thus Coriolis force increasing and decrease the rotational energy. So, the moment of inertia varies with the angular momentum. Therefore, we modified this model by adding a term to make the moment of inertia vary with angular momentum in the same manner of the VMI model which has a term added to the rotational energy equation. The modified model fits remarkably with the experimental observation and other models in many cases with the use of few parameters especially in rotational nuclei regions similar to Hf and Dy nuclei.

APPLICATION OF THE VARIABLE MOMENT OF INERTIA MODEL TO BANDS IN ODD-ODD NUCLEI

1990 ◽  
Vol 05 (29) ◽  
pp. 2403-2406 ◽  
Author(s):  
ALPANA GOEL ◽  
A. K. JAIN
Keyword(s):  
Angular Momentum ◽  
Significant Variation ◽  
Moment Of Inertia ◽  
Rotational Bands ◽  
Mixing Effects ◽  
Inertia Parameter ◽  
Rare Earth Nuclei ◽  
Inertia Model ◽  
The Moment ◽  
Variable Moment

The variable moment of inertia model is extended to rotational bands in odd-odd rare-earth nuclei. Results are presented for the K> = (Ωp + Ωn) bands which remain reasonably free from Coriolis mixing effects. The moment of inertia parameter exhibits significant variation with angular momentum which is strikingly similar to one of the odd-A rotational bands based on either the neutron or the proton configuration also involved in the odd-odd rotational band.

scholarly journals The Near-Synchronous Polar Candidate V4633 Sgr (Nova Sagittarii 1998)

2004 ◽  
Vol 190 ◽  
pp. 176-177
Author(s):  
Y. Lipkin ◽  
E. M. Leibowitz
Keyword(s):  
Angular Momentum ◽  
Momentum Transfer ◽  
White Dwarf ◽  
Moment Of Inertia ◽  
The Other ◽  
Angular Momentum Transfer ◽  
Classical Nova ◽  
Order Of Magnitude ◽  
Photometric Monitoring ◽  
The Moment

AbstractThe classical nova V4633 Sgr (1998) exhibits two photometric periodicities. The shorter period (P1=3.01 hr) is stable, while the other one, longer by ~2.5%, has decreased monotonically since shortly after the nova eruption, with Ṗ2 ≈ –10−6 (Lipkin et al. 2001).Here we report on results of photometric monitoring of the star in 2001 and 2002. During our observations, the longer period decreased more, and in 2002 it was only 1.8% longer than P1 The decrease rate (Ṗ2) in 2001-2002 was an order of magnitude smaller than in 1998-2000.These new results support the Near-Synchronous Polar classification which was suggested for V4633 Sgr (Lipkin et al. 2001). In this model, the longer period of V4633 Sgr is the spin of the white dwarf, and its variation since 1998 reflects changes in the moment of inertia of the white dwarf, and angular momentum transfer in the system following the nova eruption.

scholarly journals Magnetic Field Amplification and Polar Jet Formation in Protostars

1987 ◽  
Vol 115 ◽  
pp. 384-384
Author(s):  
S. Hinata
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Kinetic Energy ◽  
Accretion Disk ◽  
Outer Edge ◽  
Moment Of Inertia ◽  
Simple Relationship ◽  
Field Amplification ◽  
Background Magnetic Field ◽  
The Moment

There is a simple relationship among moment of inertia I, rotational kinetic energy K, and momentum L given by (David Layzer, private communication), 2IK ≧ L. During the Hayashi phase a rotating protostar will amplify the trapped magnetic field by a dynamo-like process. Since the rotation is expected to be fast, many unstable modes will be excited and will grow exponentially in time until some nonlinear processes saturate the amplitude. However, it may happen that the reduction in rotational kinetic energy becomes so large that without increasing the moment of inertia the inequality given above may not be satisfied. The only way to increase the moment of inertia is to move the mass outward. This can be done by transferring the angular momentum outward through the magnetic field. So we will have a fast rotating mass shell at the outer edge of the star. Further transfer of angular momentum will push the shell against the accretion disk; the moving masses of the disk will divert the mass flow along the background magnetic field which extends perpendicular to the accretion disk. This results in the hollow cone jets from both poles because the outward motion is primarily on the equatorial plane.

ERRATA: THE VMI-MODEL REVISITED IN THE ODD-ODD RARE-EARTH NUCLEI

1993 ◽  
Vol 02 (04) ◽  
pp. 923-941
Author(s):  
A. K. JAIN ◽  
ALPANA GOEL
Keyword(s):  
Rare Earth ◽  
Moment Of Inertia ◽  
Rotational Bands ◽  
Complete Formulation ◽  
Rare Earth Nuclei ◽  
Energy Ratios ◽  
Interesting Correlation ◽  
Inertia Model ◽  
The Moment ◽  
Variable Moment

A rather complete formulation of the variable moment of inertia model is presented for odd-odd nuclei and relationship obtained between the energy ratios and the parameters of the model. Range of validity of the model is defined and Mallmann-like curves are obtained for the odd-odd nuclei. An application is made to the rare-earth region and results are presented for the K+=(Ωp+Ωn) bands and those K−=|Ωp−Ωn| bands which remain reasonably free from Coriolis mixing. The parameters obtained from the fitting show excellent agreement with the predictions of the model. An interesting correlation between the variation of the moment of inertia of the odd-odd rotational bands with those of the neighboring odd-A nuclei involving either the same neutron or same proton configuration is also presented.

scholarly journals QUANTUM ALGEBRAIC SYMMETRIES IN NUCLEAR AND MOLECULAR PHYSICS

2020 ◽  
Vol 2 ◽  
pp. 168
Author(s):  
Dennis Bonatsos ◽  
E. N. Argyres ◽  
S. B. Drenska ◽  
P. P. Raychev ◽  
R. P. Roussev ◽  
...  
Keyword(s):  
Diatomic Molecules ◽  
Quantum Algebra ◽  
Moment Of Inertia ◽  
Molecular Spectra ◽  
Molecular Physics ◽  
Rotational Spectra ◽  
Inertia Parameter ◽  
Energy Formula ◽  
The Moment ◽  
Variable Moment

The first realizations of quanttun algebraic symmetries in nuclear and molecular spectra are presented. Rotational spectra of even-even nuclei are described by the quantum algebra SUq(2). The two parameter formula given by the algebra is equivalent to an expan- sion in terms of powers of j(j + 1), similar to the expansion given by the Variable Moment of Inertia (VMI) model. The moment of inertia parameter in the two models, as well as the small parameter of the expansion, are found to have very similar numerical values. The same formalism is found to give very good results for superdeformed nuclear bands, which are closer to the classical SU(2) limit, as well as for rotational bands of diatomic molecules, in which a partial summation of the Dunham expansion for rotation-vibration spectra is achieved. Vibrational spectra of diatomic molecules can be described by the q-deformed anhannonic oscillator, having the symmetry Uq(2)>Oq(2). An alternative de- scription is obtained in terms of the quantum algebra SUq(1,1). In both cases the energy  formula obtained is equivalent to an expansion in terms of powers of (v+½) , where ν is the vibrational quantum number, while in the classical ST(1,1) case only the first two powers appear. In all cases the improved description of the empirical data is obtained with q being a phase (and not a real number). Further applications of quantum algebraic symmetries in nuclei and molecules are discussed.

THE EVOLUTION PROPERTIES OF EVEN–EVEN 100-110Pd NUCLEI

2012 ◽  
Vol 21 (12) ◽  
pp. 1250101 ◽  
Author(s):  
I. M. AHMED ◽  
HEWA Y. ABDULLAH ◽  
S. T. AHMAD ◽  
I. HOSSAIN ◽  
M. K. KASMIN ◽  
...  
Keyword(s):  
Rotational Energy ◽  
Moment Of Inertia ◽  
Experimental Results ◽  
Interacting Boson Model ◽  
Gamma Energy ◽  
Boson Model ◽  
The Moment

The properties of the yrast states for 100-110 Pd even–even (e–e) nuclei have been established. The relation between the moment of inertia 2ϑ/ℏ2 and the square of the rotational energy (ℏω)2 has been drawn to identify the back-bending that may occur at a certain state for each isotope. The relation between gamma-energy over spin Eγ/I as a function of spin I has been drawn to determine the evolution in each isotope ranging from vibration to rotational properties. The suitable limit in the interacting boson model IBM-1 has been used to calculate the yrast states for each isotope, which are then compared with the experimental results.

Band head spin assignment of Tl isotopes of superdeformed rotational bands

Open Physics ◽  
2014 ◽  
Vol 12 (9) ◽  
Author(s):  
Alpana Goel ◽  
Uma Nair ◽  
Archana Yadav
Keyword(s):  
Spin Assignment ◽  
Band Head ◽  
Moment Of Inertia ◽  
Stiffness Parameter ◽  
Transition Energies ◽  
Rotational Bands ◽  
The Moment ◽  
Variable Moment ◽  
Theoretical Results ◽  
Good Agreement

AbstractThe Variable Moment of Inertia (VMI) model is proposed for the assignment of band head spin of super deformed (SD) rotational bands, which in turn is helpful in the spin prediction of SD bands. The moment of inertia and stiffness parameter (C), were calculated by fitting the proposed transition energies. The calculated transition energies are highly dependent on the prescribed spins. The calculated and observed transition energies agree well when an accurate band head spin (I 0) is assigned. The results are in good agreement with other theoretical results reported in literature. In this paper, we have reported the band head spin value 16 rotational band of super deformed Tl isotopes.

Ion–polar molecule encounters

1982 ◽  
Vol 384 (1787) ◽  
pp. 289-300 ◽  
Keyword(s):  
Rate Coefficient ◽  
Orbital Plane ◽  
Potential Energy Function ◽  
Rotational Energy ◽  
Moment Of Inertia ◽  
Rate Coefficients ◽  
Angular Momentum Vector ◽  
Dipole Orientation ◽  
Collision Problem ◽  
The Moment

It is permissible to assume that the rate coefficient for collisions between ions and polar molecules does not depend on the moment of inertia of the latter because the rotation time is brief compared with the collision time. On taking the moment of inertia to be vanishingly small the classical collision problem can be solved exactly when the angular momentum vector is normal to the orbital plane. Use is made of the adiabatic invariance of ∮ p d q /2π in which p is an appropriate momentum and q is the conjugate coordinate. This adiabatic invariant fixes the change in the rotational energy in moving from an infinite separation to any chosen position. The average dipole orientation is thereby determined, which fixes the force acting. The potential energy function (including due allowance for the rotational energy stored) is now written down and an integral expression for the primitive rate coefficient is thence obtained. The ratio of the primitive rate coefficient to the Langevin rate coefficient depends only on the initial rotational energy and on the dimensionless parameter β = 2 αkT/D 2 , where α is the polarizability, D is the dipole moment and T is the temperature. Extensive computations have been performed. Tables are presented giving the primitive rate coefficient and also approximations to the thermally averaged rate coefficients for linear and for spherical top molecules.

scholarly journals Un análisis biomecánico de la patada descendente de taekwondo modificada

2012 ◽  
Vol 2 (1) ◽  
pp. 28
Author(s):  
Luigi T. Bercades ◽  
Willy Pieter
Keyword(s):  
Angular Momentum ◽  
Theoretical Analysis ◽  
Rigid Body ◽  
Moment Of Inertia ◽  
Font Size ◽  
Alternate Version ◽  
The Moment

<p class="MsoNormal" style="text-align: justify; margin: 0cm 0cm 6pt;"><span style="mso-ansi-language: EN-US;" lang="EN-US"><span style="font-size: small;"><span style="font-family: Calibri;">This study is a theoretical analysis of the kinematic and kinetic aspects of the modified taekwondo axe kick. The traditional or classical axe kick has the whole kicking leg (the thigh and the shank) considered as a rigid body on both the upswing and downswing phases of the kick, which is speculated to have sufficient angular momentum to increase the risk of some forms of injuries in competition. The present study seeks to present an alternate version that will decrease the moment of inertia on the downswing, reduce the subsequent angular momentum<em style="mso-bidi-font-style: normal;">, </em>and finally decrease the resultant impulse to the target. Theoretically, this will reduce the chances of certain types of injury caused by the kick.</span></span></span></p>

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