FEM analysis of LTA-7 horizontal tail

A finite element structural analysis of the stabilizer portion of the horizontal tail has been performed using the MSC/NASTRAN package. The critical loading case is identified by subjecting the structure to loading corresponding to several different load cases. From NASTRAN stress output for these cases, the Va maneuvering 5700 kg ., n = 1.0, 0.2412c, elevator up deflection is seen to be critical. Stresses from this case are used to compute the margins in buckling for skin panels and shear webs. It is seen that stresses are within allowable limits but from the buckling point of view, while the skin panels are over-designed, the midspar web is under-designed and must be stiffened. Comparisons with the stress analysis results from the simple bending theory/shear flow analysis carried out by the ASDE/CAU design group show that there is scope for improvement in the design

Shadows of rotating five-dimensional charged EMCS black holes

Higher dimensional theories admit astrophysical objects like supermassive black holes, which are rather different from standard ones, and their gravitational lensing features deviate from general relativity. It is well known that a black hole shadow is a dark region due to the falling geodesics of photons into the black hole and, if detected, a black hole shadow could be used to determine which theory of gravity is consistent with observations. Measurements of the shadow sizes around the black holes can help to evaluate various parameters of the black hole metric. We study the shapes of the shadow cast by the rotating five-dimensional charged Einstein-Maxwell-Chern-Simons (EMCS) black holes, which is characterized by the four parameters, i.e., mass, two spins, and charge, in which the spin parameters are set equal. We integrate the null geodesic equations and derive an analytical formula for the shadow of the five-dimensional EMCS black hole, in turn, to show that size of black hole shadow is affected due to charge as well as spin. The shadow is a dark zone covered by a deformed circle, and the size of the shadow decreases with an increase in the charge $q$ when compared with the five-dimensional Myers-Perry black hole. Interestingly, the distortion increases with charge $q$. The effect of these parameters on the shape and size of the naked singularity shadow of five-dimensional EMCS black hole is also discussed.Comment: 27 pages, 9 figures, matches with published versio

Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques

This paper describes the application of lumped parameter modeling techniques to designing high temperature superconducting bearings for outer-rotor flywheel energy storage systems. The lumped parameter models decrease computational time by 99% compared to Finite Element Analysis (FEM) without compromising fidelity needed to capture the non-linear and hysteretic force-displacement behavior between a levitated permanent magnet and bulk superconductor. The techniques formulated can be used to quickly evaluate lifting capacity and translational stiffness for a superconducting bearing design. The validity of the modeling approach has been verified by comparing results from FEM studies and experimental tests.Center for Electromechanic

The Improved MPPT Controller For Photovoltaic System Under Partial Shading Condition

The performance of a photovoltaic (PV) array is affected by temperature, solar insolation, shading and array configuration. The PV system exhibits a non-linear I-V characteristic and its unique maximum power point on the P-V curve varies with insolation and temperature. Often the PV array gets shadowed, completely or partially, by passing clouds, neighbouring buildings and trees. This situation is of particular interest in case of large PV installations such as those used in a distributed power generation scheme and residential PV systems. Under partially shaded conditions, the P-V characteristic becomes more complex with multiple peaks. Conventional Maximum Power Point Tracking (MPPT) techniques fail to reach global peak power point and tend to stay in local peak power point which significantly reduces the efficiency of the PV system. This paper mainly focuses on extracting the maximum power from PV array under partially shaded conditions by executing improved hill climbing algorithm to identify the global maximum power point (GMPP)

MICROSCOPICAL OBSERVATIONS ON CISSUS VITIGINEA L.

The present study discloses detailed investigation on Macro and Microscopical characters of the leaves and roots of Cissus vitiginea L. Yanadhi tribes of Nellore district, have been using the root powder and leaf paste of C. vitiginea as a single drugs remedy to heal the wounds and to get immediate relief from swellings and sprains respectively. The plant belongs to Vitaceae family. In dried form identification of leaves and roots is hard and at present authentic pharmacognostical data is not available. With this view, leaves and roots of C. vitiginea were subjected to various pharmacognostical studies like, powder microscopy, sectioning, maceration and florasense studies to identify authentically. In the microscopical studies, different cell structures like trichomes, elongated fibers, raphide sacs, acicular crystals and different arrangements like, raphide sacs in the parenchymatous region reddish tannin content in the phloem region were noticed