Effects of the Nearest-Neighbour Coulomb Interactions on the Ground State of the Periodic Anderson Model

The magnetic and non-magnetic ground states of the periodic Anderson model with Coulomb interaction between $f$-electrons on the nearest-neighbour(NN) sites are investigated using a variational method, which gives exact calculation of the expectation values in the limit of infinite dimensions. It is shown that for a critical value of NN Coulomb interactions the magnetic ground state of the periodic Anderson model in the Kondo regime is unstable. Factors in terms of the physical processes responsible for instability of the magnetic ground state are also discussed. Our study indicates the importance of the NN Coulomb interactions for correlated two band models.Comment: RevTeX, 6 pages, 5 figures, to appear in Phys. Rev.

Maternal mortality: a tertiary centre panic

Background: Maternal death has a serious implication on the family, society and nation. The preventable and avoidable factors have been noted in most of the maternal deaths and these can be reduced by effective and affordable actions. The objective of present study was to evaluate the causes of maternal mortality in a tertiary care hospital, assess its epidemiological aspects and suggest remedial measures to reduce the same.Methods: A retrospective study of all hospital records and death summaries of all maternal deaths over a period of 16 months from April 2015 to July 2016 was carried out and epidemiological factors and causes affecting maternal mortality were assessed.Results: A total of 100 maternal deaths occurred over a period of 15 months out of which unbooked and late referrals constituted 75.55 % of maternal deaths. Most maternal deaths occurred in the age group of 20–30 years, multiparous women (73%) and women from rural areas (71.%). Direct obstetric causes were responsible for 91 maternal deaths whereas 50 maternal deaths were due to indirect causes. Most common cause of death (41) was hemorrhage, followed by pregnancy-induced hypertension including eclampsia (15) and sepsis (21).Conclusions: Hemorrhage, sepsis and hypertension including eclampsia were seen as the direct major causes of death. There is a wide scope of improvement because a large proportion of the observed deaths are preventable

Thermal stress analysis in a functionally graded hollow elliptic-cylinder subjected to uniform temperature distribution

In this paper, an analytical method of a thermoelastic problem for a medium with functionally graded material properties is developed in a theoretical manner for the elliptic-cylindrical coordinate system under the assumption that the material properties except for Poisson’s ratio and density are assumed to vary arbitrarily with the exponential law in the radial direction. An attempt has been made to reconsider the fundamental system of equations for functionally graded solids in a two-dimensional state under thermal and mechanical loads. The general solution of displacement formulation is obtained by the introduction of appropriate transformation and carried out the analysis by taking into account the variation of inhomogeneity parameters. Furthermore, the aforementioned problem degenerated into the problem of the circular region by applying limiting conditions, and the results are validated. Numerical computations are carried out for ceramic-metal-based functionally graded material, in which zirconia is selected as ceramic and aluminium as metal and are represented graphically

Thermoelastic analysis of a nonhomogeneous hollow cylinder with internal heat generation

In the present paper, we have determined the heat conduction and thermal stresses of a hollow cylinder with inhomogeneous material properties and internal heat generation. All the material properties except Poisson’s ratio and density are assumed to be given by a simple power law in axial direction. We have obtained the solution of the two dimensional heat conduction equation in the transient state in terms of Bessel’s and trigonometric functions. The influence of inhomogeneity on the thermal and mechanical behavior is examined. Numerical computations are carried out for both homogeneous and nonhomogeneous cylinders and are represented graphically

Isolated Post-Traumatic Radial Head Dislocation, A Rare and Easily Missed Injury-A Case Report

Dislocation of the head of the radius may be either congenital, an isolated injury or more commonly part of a complex injury to the elbow such as the Monteggia fracturedislocation. Isolated traumatic radial head dislocation without associated injuries in children is a rare and easily missed condition. We report such a case in a 7-year-old boy without any associated injuries or co-morbid conditions. Initially the diagnosis was missed, and 6 weeks later open reduction was performed with annular ligament reconstruction surgery. At the one-year follow up, the patient had returned to most normal activities, showing only slight terminal restriction of pronation. We discuss the injury mechanism and management for the Monteggia fracturedislocation and review the available literature

Almost sure stability of the Euler-Maruyama method with random variable stepsize for stochastic differential equations

In this paper, the Euler–Maruyama (EM) method with random variable stepsize is studied to reproduce the almost sure stability of the true solutions of stochastic differential equations. Since the choice of the time step is based on the current state of the solution, the time variable is proved to be a stopping time. Then the semimartingale convergence theory is employed to obtain the almost sure stability of the random variable stepsize EM solution. To our best knowledge, this is the first paper to apply the random variable stepsize (with clear proof of the stopping time) to the analysis of the almost sure stability of the EM method

On wealth and the diversity of friendships: high social class people around the world have fewer international friends

Having international social ties carries many potential advantages, including access to novel ideas and greater commercial opportunities. Yet little is known about who forms more international friendships. Here, we propose social class plays a key role in determining people's internationalism. We conducted two studies to test whether social class is related positively to internationalism (the building social class hypothesis) or negatively to internationalism (the restricting social class hypothesis). In Study 1, we found that among individuals in the United States, social class was negatively related to percentage of friends on Facebook that are outside the United States. In Study 2, we extended these findings to the global level by analyzing country-level data on Facebook friends formed in 2011 (nearly 50 billion friendships) across 187 countries. We found that people from higher social class countries (as indexed by GDP per capita) had lower levels of internationalism—that is, they made more friendships domestically than abroad