Deterministic Global Attitude Estimation

A deterministic attitude estimation problem for a rigid body in an attitude dependent potential field with bounded measurement errors is studied. An attitude estimation scheme that does not use generalized coordinate representations of the attitude is presented here. Assuming that the initial attitude, angular velocity and measurement noise lie within given ellipsoidal bounds, an uncertainty ellipsoid that bounds the attitude and the angular velocity of the rigid body is obtained. The center of the uncertainty ellipsoid provides point estimates, and its size gives the accuracy of the estimates. The point estimates and the uncertainty ellipsoids are propagated using a Lie group variational integrator and its linearization, respectively. The estimation scheme is optimal in the sense that the attitude estimation error and the size of the uncertainty ellipsoid is minimized at each measurement instant, and it is global since the attitude is represented by a rotation matrix.Comment: IEEE Conference on Decision and Control, 2006. 6 pages, 6 figure

STRESS CONCENTRATION IN ISOTROPIC & ORTHOTROPIC COMPOSITE PLATES WITH CENTER CIRCULAR HOLE SUBJECTED TO TRANSVERSE STATIC LOADING

The present study brings out the thorough analysis of isotropic and orthotropic fixed rectangular plate with center circular hole under transverse static loading condition. In this paper influence of stress concentration and deflection due to singularity for isotropic and orthotropic composite materials under different parametric conditions is obtained. The effect of thickness -to- width of plate (T/A) and diameter-to-width (D/A) ratio upon stress concentration factor (SCF) for different stresses were studied. An isotropic and one composite material were considered for analysis to determine the variation of SCF with elastic constants. Deflection in transverse direction were calculated and analyzed. Results are presented in graphical form and discussed. Three-dimensional finite element models were created using ANSYS software. Results showed that maximum stress appear near the vicinity of the hole at the upper and lower portions of the plate. The effect of material properties, (E1/E2) on SCF for stresses along x, y and z axis is established thorough this analysis

Grind Optimisation Studies at Rakha Concentrator by Laboratory Tests

This paper briefly describes the studies conducted in Rakha concentrator for improvements in economy of operation. Studies have been conducted on flotation of ore, ground to a coarser size than the present milling practice. The objective of grinding to coarser sizes is to optimise the grind size and mix so that overgrinding may be reduced, which in turn, will help to improve the overall economy

Enterotoxigenicity of chicken isolates of Campylobacter jejuni in ligated ileal loops of rats

Ligated ileal loops in rats of the Charles-Foster strain, weighing 200-250 g and aged 7-8 months, provided a sensitive and reproducible means of testing the enterotoxigenicity of Campylobacter jejuni. All of 16 chicken isolates caused fluid accumulation comparable to that produced by toxigenic Vibrio cholerae O1, strain 569B. However, 11 of the isolates required one to three consecutive passages through the rat gut before doing so. The amount of fluid produced increased after each passage. Of three culture media tested, brucella broth of pH 6.7 supported the highest degree of enterotoxigenesis. Filtrates of cultures of all 16 chicken isolates in this medium were as effective as viable C. jejuni in producing fluid in ileal loops. The enterotoxin was neutralised completely by cholera antitoxin diluted 1 in 160, indicating its close immunobiological relationship to cholera toxin

Correlations among some Physical Properties of Coke - a Statistical Study

VARIOUS tests are employed in different countries for assessing the physical properties of coke. While the Shatter and the B.S. Abrasion tests are in general use in the United Kingdom, European practice is to employ the Alicuni test.In the U.S.A., the Haven test is employed in addition to a Shatter test similar to that of the U.K. The Indian steel plants carry out the Shatter.Micum and Haven tests. One of these plants uses a modified form of the original Breslau test in place of the standard Micum test1