Shell closure effects studied via cluster decay in heavy nuclei

The effects of shell closure in nuclei via the cluster decay is studied. In this context, we have made use of the Preformed Cluster Model ($PCM$) of Gupta and collaborators based on the Quantum Mechanical Fragmentation Theory. The key point in the cluster radioactivity is that it involves the interplay of close shell effects of parent and daughter. Small half life for a parent indicates shell stabilized daughter and long half life indicates the stability of the parent against the decay. In the cluster decay of trans lead nuclei observed so far, the end product is doubly magic lead or its neighbors. With this in our mind we have extended the idea of cluster radioactivity. We investigated decay of different nuclei where Zirconium is always taken as a daughter nucleus, which is very well known deformed nucleus. The branching ratio of cluster decay and $\alpha$-decay is also studied for various nuclei, leading to magic or almost doubly magic daughter nuclei. The calculated cluster decay half-life are in well agreement with the observed data. First time a possibility of cluster decay in $^{218}U$ nucleus is predicted

Hidden Degeneracy in the Brick Wall Model of Black Holes

Quantum field theory in the near-horizon region of a black hole predicts the existence of an infinite number of degenerate modes. Such a degeneracy is regulated in the brick wall model by the introduction of a short distance cutoff. In this Letter we show that states of the brick wall model with non zero energy admit a further degeneracy for any given finite value of the cutoff. The black hole entropy is calculated within the brick wall model taking this degeneracy into account. Modes with complex frequencies however do not exhibit such a degeneracy.Comment: 8 pages, Latex fil

Operational Behaviour of a Complex System Under Priority Repair Echelons

A mathematical model is set up to evaluate the reliability of a complex system comprising two subsystems (with stand by redundancy in one subsystem). The failure and repair of units for both the subsystems follow exponential and general time distributions respectively. The switching over device for standby subsystem is not perfect and its repair is opportunistic. The repair for both subsystems is carried out under priority. The concept of waiting time for the repair of failed units in staidly subsystem has also been introduced. Supplementary variable and Laplace Transform techniques have been applied to obtain the transient state probabilities for such a system. From these pointwise availability has been evaluated. In the end, a particular case when repair follows exponential time distribution has been derived and asymptotic behaviour of such a system has also been examined

Analysis and Process for Uninteresting Time Compensators with Smith Predictor and Virtual Sensor

Dead time is often present in control systems as computational or informational delay but in most cases it is very small and is neglected. Dead time is widely found in the process industries when transporting materials or energy. Generally stable processes are represented by first-order-plus-dead-time or second order- plus-dead-time models for analysis. In this paper analysis of secure processes with dead time is done. Here PI controller and Smith Predictor & virtual sensor are used as dead time compensators but virtual sensor eliminates the technology-related dead-time and makes the control of dead-time processes possible without high development costs and at the end of paper we will be compare the effectiveness of both

CP violating anomalous top-quark couplings at the LHC

We study the T odd correlations induced by CP violating anomalous top-quark couplings at both production and decay level in the process gg --> t t_bar --> (b mu+ nu_mu) (b_bar mu- nu_mu_bar). We consider several counting asymmetries at the parton level and find the ones with the most sensitivity to each of these anomalous couplings at the LHC.Comment: 14 LaTeX Pages, 1 EPS Figure, minor typos correcte

Comparative efficacy of agomelatine versus sertraline in major depressive disorder in Himalayan region of India

Background: Depression, a major common affective disorder which carries excess mortality through suicide. Among various drug classes available SSRI’s are usually a choice, but many patients show inadequate response, residual symptoms or discontinue medication due to intolerable side effects. Disturbances of circadian rhythm function are an etiopathogenic hallmark of depression. The degree of circadian misalignment correlates with the severity of depression and circadian abnormalities may partially be a consequence of alterations in behavior and sleep patterns that accompany depression. Agomelatine an agonist acts on MT1 and MT2 receptors and antagonist of 5HT2c receptors contributes to its resynchronization of circadian rhythms, enhancement of dopaminergic and adrenergic input to the frontal cortex, induction of hippocampal neurogenesis, and ultimately, to its antidepressant effect.Methods: The study was randomized, prospective, comparative and interventional regarding the efficacy of therapy. Hundred consenting patients of MDD attending psychiatry OPD were screened for possible enrollment into group A(Agomelatine) and group B(Sertraline). Patients were assessed by semi-structured case recording form, DSM-IV- TR Criteria for major depressive episode, Hamilton Rating Scale for Depression (HAM-D) and Clinical Global Impressions for severity (CGI-S) at baseline and CGI for improvement (CGI-I), every two weeks interval and final assessment at 8 weeks.Results: Socio-demographic parameters like age and sex distribution, marital status, locality, family type, educational status, occupation and socio-economic class were comparable between two groups. Similarly baseline HAM-D and CGI-S values between the two groups were statistically non-significant. HAM-D, CGI-S and CGI-I values at eight weeks among the two groups were also statistically non-significant but in all three sertraline had decreased the values to a greater extent and showed a trend towards improvement.Conclusions: Both groups had shown significant decrease in scores of all scales i.e. HAM-D, CGI-S, and CGI-I at the end of 8th week as compared to baseline scores, indicating that the uses of agomelatine and sertraline have resulted in significant improvement in symptoms of patients of MDD and reinforcing there efficacy in treatment of MDD. No statistical difference was observed between two groups.