Collective bands in 80,82Kr

2007 ◽  
Vol 85 (3) ◽  
pp. 269-278 ◽  
Author(s):  
S Mishra ◽  
K C Tripathy ◽  
R Sahu
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Configuration Space ◽  
Negative Parity ◽  
Model Calculations ◽  
Ground Band ◽  
Particle Orbits ◽  
Inert Core ◽  
21.60 Jz ◽  
Different Levels

Deformed shell-model calculations are performed to study the structure of the collective bands in 80,82Kr. In our microscopic model, the single particle orbits 1p3/2, 0f5/2, 1p1/2, and 0g9/2 constitute the configuration space with 56Ni as the inert core. A modified Kuo interaction for this basis space is used in our calculation. The different levels are classified into collective bands on the basis of the B(E2) values among them. The calculated ground bands and quasi-gamma bands for both the nuclei agree reasonably well with experiment. The negative parity bands are also well-reproduced in our calculation. The calculated B(E2) values are compared with available experimental data. The nature of angular momentum alignment in the ground band is also discussed. PACS Nos.: 21.10.–k, 21.60.Jz, 27.50.+e

COLLECTIVE BANDS IN 68Se

2002 ◽  
Vol 11 (06) ◽  
pp. 531-538 ◽  
Author(s):  
K. C. TRIPATHY ◽  
R. SAHU
Keyword(s):  
Configuration Space ◽  
Single Particle ◽  
Fock States ◽  
Hartree Fock ◽  
Ground Band ◽  
Prolate Shape ◽  
Particle Orbits ◽  
Excited Band ◽  
Inert Core ◽  
Configuration Mixing

The collective bands of the N = Z nucleus 68 Se are studied within our deformed configuration mixing shell model based on Hartree–Fock states. The configuration space consists of the spherical single particle orbits 1p3/2, 0f5/2, 1p1/2 and 0g9/2 with 56 Ni as the inert core. A modified Kuo interaction for this basis space has been used in our calculation. The calculated ground band, K = 2+ excited band and the K = 5- excited band agree reasonably well with the experiment. Our calculation shows that the ground band is essentially of oblate shape and the excited K = 2+ band is of prolate shape. This is in agreement with the conclusions drawn from the recent experimental analysis.

Testing the core-cluster model calculations for some heavy deformed nuclei

2019 ◽  
Vol 28 (07) ◽  
pp. 1950049
Author(s):  
L. I. Abou-Salem ◽  
K. E. Abdelmageed ◽  
I. A. Elmashad ◽  
R. Al Allam
Keyword(s):  
Experimental Data ◽  
Cluster Model ◽  
Theoretical Calculations ◽  
Transition Probability ◽  
Parent Nucleus ◽  
Negative Parity ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Core ◽  
Core Cluster

In this work, the spectra of some even–even isotopes are studied by selecting core-cluster decomposition of the parent nucleus. The considered nuclei lie in the rare-earth and the transition metal regions. The Schrödinger equation can be solved using Bohr–Sommerfeld relation and the modified Woods–Saxon beside Coulomb potentials to reproduce the spectra of these isotopes with mass number [Formula: see text]. The theoretical calculations of the excitation energies of the ground state rotational band are compared to the experimental data. The cluster model calculations show a good agreement with the experimental data for the transitional and rotational nuclei more than the vibrational nuclei. Some negative parity bands of the chosen nuclei are studied. The core-cluster charge products are correlated with the transition probability [Formula: see text].

scholarly journals ROTATIONAL BANDS AND ELECTROMAGNETIC TRANSITIONS OF SOME EVEN–EVEN NEODYMIUM NUCLEI IN PROJECTED HARTREE–FOCK MODEL

2012 ◽  
Vol 21 (07) ◽  
pp. 1250070 ◽  
Author(s):  
S. K. GHORUI ◽  
P. K. RAINA ◽  
P. K. RATH ◽  
A. K. SINGH ◽  
Z. NAIK ◽  
...  
Keyword(s):  
Negative Parity ◽  
Electromagnetic Properties ◽  
Matrix Elements ◽  
Substantial Agreement ◽  
Projection Model ◽  
Model Calculations ◽  
Rotational Bands ◽  
Hartree Fock ◽  
Ground Band ◽  
Self Consistent

Rotational structures of even–even 150 – 160 Nd nuclei are studied with the self-consistent deformed Hartree–Fock (HF) and angular momentum (J) projection model. Spectra of ground band, recently observed K = 4-, K = 5- and a few more excited, positive and negative parity bands have been studied up to high spin values. Apart from these, detailed electromagnetic properties (like E2, M1 matrix elements) of all the bands have been obtained. There is substantial agreement between our model calculations and available experimental data. Predictions are made about the band structures and electromagnetic properties of these nuclei. Some 4-qasiparticle K-isomeric bands and their electromagnetic properties are predicted.

scholarly journals Study of the Electric Quadrupole Transitions in 50-51Mn Isotopes by Using F742pn and F7cdpn Interactions

2021 ◽  
Vol 22 (2) ◽  
pp. 1-5
Author(s):  
Ali Hasan ◽  
Fatema Obeed ◽  
Azahr Rahim
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Nuclear Shell Model ◽  
Radial Wave ◽  
Model Calculations ◽  
Ground Band ◽  
Nuclear Shell

The nuclear shell-model has been used to compute excitation levels of ground band and electric quadrupole transitions for 50-51Mn isotopes in f-shell. In the present study, f742pn and f7cdpn effective interactions have been carried out in full f-shell by using Oxbash Code. The radial wave functions of the single-particle matrix elements have been calculated in terms of the harmonic oscillator (Ho) and Skyrme20 potentials. The predicted theoretical results have been compared with the available experimental data; it has been seen that the predicted results are in agreement with the experimental data. From the current results of the calculations, many predictions of angular momentum and parities of experimental states have been made, and the energy spectra predictions of the ground band and B(E2; ↓) electric quadrupole transitions in 50-51Mn isotopes of the experimental data are not known yet. In the nuclear shell-model calculations framework, energy levels have been determined for 50-51Mn isotopes; new values of electric quadrupole transitions have been predicted in the studied results. This investigation increases the theoretical knowledge of all isotopes with respect to the energy levels and reduced transition probabilities.

A Method for Estimating Mass Transfer Coefficients in a Packed Column Using Reactive Absorption Data

2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Optimization Technique ◽  
Packed Column ◽  
Effective Area ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Model Calculations ◽  
Unit Model ◽  
Reactive Absorption

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.

Low-lying Negative-parity Levels of 17N and 18N

1984 ◽  
Vol 37 (1) ◽  
pp. 17 ◽  
Author(s):  
FC Barker
Keyword(s):  
Shell Model ◽  
Weak Coupling ◽  
Coupling Model ◽  
Negative Parity ◽  
Positive Parity ◽  
Model Calculations

On the basis of a weak-coupling model, adjustments are made to the interactions used in the full shell model calculations of Millener in order to fit the experimental energies of the low-lying negativeparity levels of 16N and of the low-lying positive-parity levels of 180 and 190 . The predicted energies of the low-lying negative-parity levels of 17N then agree better with experiment, while those for 18N lead to suggested spin assignments for the observed levels.

Torsional characterization of ropes used offshore

2008 ◽  
Vol 43 (2) ◽  
pp. 121-139 ◽  
Author(s):  
I M L Ridge
Keyword(s):  
Experimental Data ◽  
Torsional Response ◽  
In Series ◽  
Different Levels

The first part of this paper presents a general discussion of the various problems which must be addressed when combining different ropes in series or, in some cases, in using a rope in conditions where it is rotationally unrestrained. The paper will pay particular attention to the various classes of rope used in the offshore environment and their main torsional characteristics. In the second part, equipment is shown which is suitable for the measurement of the torsional response of various rope constructions at different levels of twist. Experimental data are presented for a variety of rope constructions at sizes comparable with those used in offshore applications. Comparison is made with data obtained in similar previous studies but with smaller‐diameter ropes.

Evolution of hindlimb posture in nonmammalian therapsids: biomechanical tests of paleontological hypotheses

Paleobiology ◽  
2001 ◽  
Vol 27 (1) ◽  
pp. 14-38 ◽  
Author(s):  
Richard W. Blob
Keyword(s):  
Experimental Data ◽  
Biomechanical Model ◽  
Axial Rotation ◽  
Morphological Data ◽  
Upright Posture ◽  
Cross Sectional ◽  
Model Calculations ◽  
Limb Bones ◽  
Plausible Model ◽  
Bending Stresses

Analyses of limb joint morphology in nonmammalian therapsid “mammal-like reptiles” have suggested that among many lineages, individual animals were capable of shifting between sprawling and upright hindlimb postures, much like modern crocodilians. The ability to use multiple limb postures thus might have been ancestral to the generally more upright posture that evolved during the transition from “mammal-like reptiles” to mammals. Here I derive a biomechanical model to test this hypothesis through calculations of expected posture-related changes in femoral stress for therapsid taxa using different limb postures. The model incorporates morphological data from fossil specimens and experimental data from force platform experiments on iguanas and alligators.Experimental data suggest that the evolutionary transition from sprawling to nonsprawling posture was accompanied by a change in the predominant loading regime of the limb bones, from torsion to bending. Changes in the cross-sectional morphology of the hindlimb bones between sphenacodontid “pelycosaurs” and gorgonopsid therapsids are consistent with the hypothesis that bending loads increased in importance early in therapsid evolution; thus, bending stresses are an appropriate model for the maximal loads experienced by the limb bones of theriodont therapsids. Results from the model used to estimate stresses in these taxa do not refute the use of both sprawling and more upright stance among basal theriodont therapsids. Thus, the hypothesis that the use of multiple postures was ancestral to the more upright posture typical of most mammals is biomechanically plausible. Model calculations also indicate that the axial rotation of the femur typical in sprawling locomotion can reduce peak bending stresses. Therefore, as experimental data from alligators and iguanas suggest, the evolution of nonsprawling limb posture and kinematics in therapsids might have been accompanied by increased limb bone bending stress.

scholarly journals Large Scale Shell Model Calculations of the Negative-Parity States Structure in 24Mg Nucleus

2021 ◽  
Vol 66 (4) ◽  
pp. 293
Author(s):  
A.A. Al-Sammarraie ◽  
F.A. Ahmed ◽  
A.A. Okhunov
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Form Factors ◽  
Model Space ◽  
Negative Parity ◽  
Matrix Elements ◽  
Model Calculations

The negative-parity states of 24Mg nucleus are investigated within the shell model. We are based on the calculations of energy levels, total squared form factors, and transition probability using the p-sd-pf (PSDPF) Hamiltonian in a large model space (0 + 1) hW. The comparison between the experimental and theoretical states showed a good agreement within a truncated model space. The PSDPF-based calculations successfully reproduced the data on the total squared form factors and transition probabilities of the negative-parity states in 24Mg nucleus. These quantities depend on the one-body density matrix elements that are obtained from the PSDPF Hamiltonian. The wave functions of radial one-particle matrix elements calculated with the harmonic-oscillator potential are suitable to predict experimental data by changing the center-of-mass corrections.

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