Implementation of a model based fault detection and diagnosis for actuation faults of the Space Shuttle main engine

In a previous study, Guo, Merrill and Duyar, 1990, reported a conceptual development of a fault detection and diagnosis system for actuation faults of the space shuttle main engine. This study, which is a continuation of the previous work, implements the developed fault detection and diagnosis scheme for the real time actuation fault diagnosis of the space shuttle main engine. The scheme will be used as an integral part of an intelligent control system demonstration experiment at NASA Lewis. The diagnosis system utilizes a model based method with real time identification and hypothesis testing for actuation, sensor, and performance degradation faults

Spiritual and Psychological Aspects of Illness: Dealing with Sickness, Loss, Dying, and Death (Mahway, NJ: Paulist Press, 2010)

Reviewed by John Gillman

Elastic moduli approximation of higher symmetry for the acoustical properties of an anisotropic material

The issue of how to define and determine an optimal acoustical fit to a set of anisotropic elastic constants is addressed. The optimal moduli are defined as those which minimize the mean squared difference in the acoustical tensors between the given moduli and all possible moduli of a chosen higher material symmetry. The solution is shown to be identical to minimizing a Euclidean distance function, or equivalently, projecting the tensor of elastic stiffness onto the appropriate symmetry. This has implications for how to best select anisotropic constants to acoustically model complex materials.Comment: 20 page

The behaviour of boron compounds in treated rattan when dehydrated at high temperatures

The behaviour of boron compounds per se and boron compounds in treated stem of rotan manau (Calamus manan A1iq.) dried at elevated temperatures was studied. When borax and boric acid are mixed, sodium 1:5 borate is formed. After drying at 100±30, 50±10, or <O°C, the measured and the calculated (in parentheses) percentage weight losses from the mixtures were 40.34 (40.10), 39.31 (36.39) and 29.43% (30.11 %), respectively. The experimentally measured values were used to estimate the amount of solute retained in the rattan samples which had been treated with such a boric acid-borax mixture and then dried. The further weight losses of the mixture in treated rattan dried at higher temperatures are presumably attributable to: 1. the volatilization of low molecular weight rattan components; 2. the volatilization of boric acid in water vapour during drying and 3. the mechanical loss of permeating liquid during the early stage of drying. Treatments of rattan or other cellulosic material which involve boric acid in aqueous solution should avoid high temperature drying in order to ensure optimum retention of boric acid equivalent (BAE)

Tidally Driven Processes Leading to Near-Field Turbulence in a Channel at the Crest of the Mendocino Escarpment*

In situ observations of tidally driven turbulence were obtained in a small channel that transects the crest of the Mendocino Ridge, a site of mixed (diurnal and semidiurnal) tides. Diurnal tides are subinertial at this latitude, and once per day a trapped tide leads to large flows through the channel giving rise to tidal excursion lengths comparable to the width of the ridge crest. During these times, energetic turbulence is observed in the channel, with overturns spanning almost half of the full water depth. A high-resolution, nonhydrostatic, 2.5-dimensional simulation is used to interpret the observations in terms of the advection of a breaking tidal lee wave that extends from the ridge crest to the surface and the subsequent development of a hydraulic jump on the flanks of the ridge. Modeled dissipation rates show that turbulence is strongest on the flanks of the ridge and that local dissipation accounts for 28% of the energy converted from the barotropic tide into baroclinic motion.United States. Office of Naval Research (Grant ONR N00014- 12-1-0943)National Science Foundation (U.S.). (Grant NSF OCE 1129763

Thermo-elasticity for anisotropic media in higher dimensions

In this note we develop tools to study the Cauchy problem for the system of thermo-elasticity in higher dimensions. The theory is developed for general homogeneous anisotropic media under non-degeneracy conditions. For degenerate cases a method of treatment is sketched and for the cases of cubic media and hexagonal media detailed studies are provided.Comment: 33 pages, 5 figure

Field Evaluations of Insecticide Modes of Action Classes for Control of Horn Flies in Nebraska

Insecticides of different Mode of Action (MoA) classes were tested for their ability to reduce horn fly populations on cattle in Nebraska pastures between 2009 and 2016. Macrocyclic lactone products were the most efficacious, reducing horn fly numbers by an average of 93% over ten location years of testing. Organophosphate and pyrethroid MoA products, tested in 7 and 12 location years, reduced fly numbers by 75% and 73%. Classes tested only once were METI (88% reduction) and a combination of organophosphate + pyrethroid (64%)