VIBRATION ANALYSIS OF A ROTATING TAPERED COMPOSITE BEAM WITH TIP MASS

In this study, free vibration responses of a rotating tapered composite beam with tip mass are investigated. The energy expressions for the kinetic and potential energies of a rotating composite beam with tip mass have been formulated. The energy expressions are then applied in Lagrange’s equations to develop the equation of motion of a composite beam with tip mass. The stiffness and mass matrices for a standard composite beam element with two end nodes with two degrees of freedom at each node are derived. Various parametric studies are performed to investigate the effect of tip mass and the rotational speed on the variation of natural frequencies of the composite beam. The investigations are also done to study the effect of hub radius on the natural frequencies. It is shown that the addition of tip mass increases the stiffness of the structure and consequently increases the natural frequencies

Separability in Cohomogeneity-2 Kerr-NUT-AdS Metrics

The remarkable and unexpected separability of the Hamilton-Jacobi and Klein-Gordon equations in the background of a rotating four-dimensional black hole played an important role in the construction of generalisations of the Kerr metric, and in the uncovering of hidden symmetries associated with the existence of Killing tensors. In this paper, we show that the Hamilton-Jacobi and Klein-Gordon equations are separable in Kerr-AdS backgrounds in all dimensions, if one specialises the rotation parameters so that the metrics have cohomogeneity 2. Furthermore, we show that this property of separability extends to the NUT generalisations of these cohomogeneity-2 black holes that we obtained in a recent paper. In all these cases, we also construct the associated irreducible rank-2 Killing tensor whose existence reflects the hidden symmetry that leads to the separability. We also consider some cohomogeneity-1 specialisations of the new Kerr-NUT-AdS metrics, showing how they relate to previous results in the literature.Comment: Latex, 15 pages, minor typos correcte

Particle Motion and Scalar Field Propagation in Myers-Perry Black Hole Spacetimes in All Dimensions

We study separability of the Hamilton-Jacobi and massive Klein-Gordon equations in the general Myers-Perry black hole background in all dimensions. Complete separation of both equations is carried out in cases when there are two sets of equal black hole rotation parameters, which significantly enlarges the rotational symmetry group. We explicitly construct a nontrivial irreducible Killing tensor associated with the enlarged symmetry group which permits separation. We also derive first-order equations of motion for particles in these backgrounds and examine some of their properties.Comment: 16 pages, LaTeX2

Separability of Hamilton-Jacobi and Klein-Gordon Equations in General Kerr-NUT-AdS Spacetimes

We demonstrate the separability of the Hamilton-Jacobi and scalar field equations in general higher dimensional Kerr-NUT-AdS spacetimes. No restriction on the parameters characterizing these metrics is imposed.Comment: 4 pages, no figure

Wigner distribution transformations in high-order systems

By combining the definition of the Wigner distribution function (WDF) and the matrix method of optical system modeling, we can evaluate the transformation of the former in centered systems with great complexity. The effect of stops and lens diameter are also considered and are shown to be responsible for non-linear clipping of the resulting WDF in the case of coherent illumination and non-linear modulation of the WDF when the illumination is incoherent. As an example, the study of a single lens imaging systems illustrates the applicability of the method.Comment: 16 pages, 7 figures. To appear in J. of Comp. and Appl. Mat

A Killing tensor for higher dimensional Kerr-AdS black holes with NUT charge

In this paper, we study the recently discovered family of higher dimensional Kerr-AdS black holes with an extra NUT-like parameter. We show that the inverse metric is additively separable after multiplication by a simple function. This allows us to separate the Hamilton-Jacobi equation, showing that geodesic motion is integrable on this background. The separation of the Hamilton-Jacobi equation is intimately linked to the existence of an irreducible Killing tensor, which provides an extra constant of motion. We also demonstrate that the Klein-Gordon equation for this background is separable.Comment: LaTeX, 14 pages. v2: Typo corrected and equation added. v3: Reference added, introduction expanded, published versio

Studies on influence of modified atmospheric storage conditions on biochemical parameters in pigeonpea seeds

An experiment was conducted to study the influence of modified atmospheric storage conditions on biochemical parameters of pigeonpea seeds. The experiment was conducted at the Department of Seed Science and Technology, College of Agriculture, Raichur, Karnataka. The seeds are exposed to various gaseous combinationsand stored in 700 gauge polyethylene bag for ten months during July-2012 to April- 2013. The results revealed that, the seeds exposed to gaseous combination of 40% N2+00% O2+ 60% CO2 showed less reduction in dehydrogenase enzyme activity and protein content (0.276 OD (optical density) value, 19.33 % respectively) as compared to the control (0.211 OD value and 18.13 % respectively) after ten months of storage. In addition less seed leachate (2.029 dSm-1) was recorded in gaseous combination of 40% N2+00% O2+ 60% CO2 as compared to control (2.207dSm-1). It indicates the potential use of modified atmospheric storage technology for maintenance of seed viability and vigour during storage in pulses

Survival of \u3ci\u3eEnterococcus faecium\u3c/i\u3ein Turkey Litter Under Different Temperature and Moisture Combinations

Untreated poultry litter introduces a substantial load of fecal pathogens to the environment, impacting agriculture, public health and ecosystem function. There is substantial evidence that temperature and moisture are the primary drivers of fecal bacteria survival across ecosystems. However, both temperature and moisture effects have been shown to be modulated by the matrix in which the fecal bacteria are living. This context dependence highlights the importance of understanding fecal bacteria survival in a variety of matrices in order to implement effective waste management plans. In this study, we determined the survival patterns of Enterococcus faecium in post-use turkey litter under two levels of temperature (5°C, 30°C) and moisture (E. faecium abundance did not change over the course of 14 days. However, at 30°C, the low moisture treatment resulted in 23% decrease in E. faecium concentration over 14 days, while the high moisture treatment resulted in 16% growth over the course of the experiment. Since high temperature is usually sufficient to result in fecal bacteria decay in other matrices, this study highlights the context dependence of fecal bacteria survival. Furthermore, poultry litter waste-management plans should consider both temperature and moisture of litter storage conditions in order to mitigate litter impacts on public health