Reply to Comment on Extension of the Bethe-Weizsacker mass formula to light nuclei and some new shell closures

Some properties of the modified Bethe-Weizsacker mass formula (BWM) are discussed. As BWM has no shell effect included, the extra-stability or, magicity in nuclei clearly stands out when experimental mass data are compared with BWM predictions. If the shell effect quenches, the BWM predictions come closer to the experimental data.Comment: 2 pages, no figur

Analysis of a Nonautonomous Delayed Predator-Prey System with a Stage Structure for the Predator in a Polluted Environment

A two-species nonautonomous Lotka-Volterra type model with diffusional migration among the immature predator population, constant delay among the matured predators, and toxicant effect on the immature predators in a nonprotective patch is proposed. The scale of the protective zone among the immature predator population can be regulated through diffusive coefficients Di(t), i=1,2. It is proved that this system is uniformly persistent (permanence) under appropriate conditions. Sufficient conditions are derived to confirm that if this system admits a positive periodic solution, then it is globally asymptotically stable

Analysis of a delay nonautonomous predator-prey system with disease in the prey

In this paper we have considered a nonautonomous predator-prey model with time delay due to gestation, in which a disease that can be transmitted by contact spreads among the prey only. Here, we have established some sufficient conditions on the permanence of the system by using inequality analytical technique. By Lyapunov functional method, we have also obtained some sufficient conditions for global asymptotic stability of this model. We have observed that the time delay has no effect on the permanence of the system but it has an effect on the global asymptotic stability of this model. The aim of the analysis of this model is to identify the parameters of interest for further study, with a view to informing and assisting policy-makers in targeting prevention and treatment resources for maximum effectiveness

Folding model analysis of proton radioactivity of spherical proton emitters

Half lives of the decays of spherical nuclei away from proton drip line by proton emissions are estimated theoretically. The quantum mechanical tunneling probability is calculated within the WKB approximation. Microscopic proton-nucleus interaction potentials are obtained by single folding the densities of the daughter nuclei with M3Y effective interaction supplemented by a zero-range pseudo-potential for exchange along with the density dependence. Strengths of the M3Y interaction are extracted by fitting its matrix elements in an oscillator basis to those elements of the G-matrix obtained with the Reid-Elliott soft-core nucleon-nucleon interaction. Parameters of the density dependence are obtained from the nuclear matter calculations. Spherical charge distributions are used for calculating the Coulomb interaction potentials. These calculations provide reasonable estimates for the observed proton radioactivity lifetimes of proton rich nuclei for proton emissions from 26 ground and isomeric states of spherical proton emitters.Comment: 6 page

Petdimenzijski LRS Bianchijev model svemira tipa 1 sa strunama u općoj relativnosti

Field equations in the presence of cosmic string source are obtained in general theory of relativity in Kaluza-Klein type space-time. An exact inflationary string cosmological model is obtained in which the sum of tension density and rest energy density of strings vanishes. Some physical and geometrical properties of the model are discussed.Izveli smo jednadžbe polja opće teorije relativnosti u Kaluza-Kleinovom prostoruvremenu uz prisustvo svemirskih struna. Dobili smo egzaktan naduvni svemirski model sa strunama u kojemu je zbroj gustoće naprezanja i energije mirovanja struna jednak nuli. Raspravljamo neka fizička i geometrijska svojstva modela

Petdimenzijski LRS Bianchijev model svemira tipa 1 sa strunama u općoj relativnosti

Field equations in the presence of cosmic string source are obtained in general theory of relativity in Kaluza-Klein type space-time. An exact inflationary string cosmological model is obtained in which the sum of tension density and rest energy density of strings vanishes. Some physical and geometrical properties of the model are discussed.Izveli smo jednadžbe polja opće teorije relativnosti u Kaluza-Kleinovom prostoruvremenu uz prisustvo svemirskih struna. Dobili smo egzaktan naduvni svemirski model sa strunama u kojemu je zbroj gustoće naprezanja i energije mirovanja struna jednak nuli. Raspravljamo neka fizička i geometrijska svojstva modela

Remarks on the Noncommutative Gravitational Quantum Well

A planar phase space having both position and momentum noncommutativity is defined in a more inclusive setting than that considered elsewhere. The dynamics of a particle in a gravitational quantum well in this space is studied. The use of the WKB approximation and the virial theorem enable analytic discussions on the effect of noncommutativity. Consistent results are obtained following either commutative space or noncommutative space descriptions. Comparison with recent experimental data with cold neutrons at Grenoble imposes an upper bound on the noncommutative parameter. Also, our results are compared with a recent numerical analysis of a similar problem.Comment: Latex, 17 pages, Title changed, minor modifications, 3 new references added, To appear in Phys. Rev.