Direct inversion of rigid-body rotational dynamics

The global linearization (inversion) of rigid-body rotational dynamics is reviewed and representations in terms of quaternions and direction cosines are compared. Certain properties common to quaternions and direction cosines that make their use preferable to Euler angles and that simplify the inversion procedure are described. Applications of the inversion procedure for state estimation and attitude control are discussed. To avoid complexities caused by aerodynamics, an example of direct inversion for linear feedback control of spacecraft attitude is given

Flow field and heat transfer for developing flow of molten glass in a duct

The molten glass flow (temperature range 1300 to 1500°C) in the entrance region of a duct was investigated with numerical methods. The mathematical model was restricted by assuming: (1) two dimensional, steady state, (2) Newtonian fluid, variable viscosity, and (3) Rosseland approximation. In addition, appropriate use was made of the fact that the Reynolds number is small and the Eckert number is very small. The inclusion of temperature dependent viscosity and a Rosseland approximation for radiation produced from the mass, momentum, and energy equations a system of coupled, nonlinear, partial differential equations which were solved by an iterative finite difference approximation employing unequal step sizes. The computations involved calculating the velocity profiles assuming constant viscosity, calculating the temperature profiles using the velocities found in the constant viscosity flow, and iterating once by putting the nonisothermal temperature field into the momentum equation and recalculating the velocity profiles as evolved from variable viscosity. In addition to velocity and temperature results, conclusions were drawn from pressure gradients, heat transfer, and wall shear stress. Results indicated that the finite difference method involving unequal step sizes improved efficiency as compared to equal grid spacing for a given accuracy. In addition, one iteration of the energy-momentum equation coupling gave a good indication of actual results. Results showed that the velocity profile had only a minor influence on the temperature distribution, but the existence of convective terms was important. For the temperature distribution conduction played only a minor role. As a result of the coupling the variable viscosity almost doubled the relative magnitude of the velocity kinks found on both sides of the center axis near the entrance. The center line velocity for the variable viscosity case was found to increase and then decrease unlike the isothermal flow velocity, thereby making the variable viscosity development length greater than the isothermal development length --Abstract, pages iii-iv

God Keep Me From Ever Completing Anything: Problems of Writing and Identity in Four American Narratives.

This study examines the relationship between writing and American identity in four works--William Bradford\u27s Of Plymouth Plantation, Benjamin Franklin\u27s Autobiography, Herman Melville\u27s Typee: A Peep at Polynesian Life, and Nathaniel Hawthorne\u27s The Marble Faun: Or The Romance of Monte Beni--by illuminating the difficulty that the narrator of each work has in constructing and maintaining his vision of American identity. For Bradford and Franklin, the analysis centers on their attempts to confront the historical complexities of American society--Bradford confronting the economic realities of colonialism, Franklin confronting the difficulty of organizing governance after the American Revolution. For Melville and Hawthorne, the analysis centers on their ironic but historically-based presentation of American identity through a self-interested or naive narrator, and on their texts\u27 subsequent comments on the problems of American expansionism and slavery. Though not strictly a Bakhtinian analysis, this study employs Mikhail Bakhtin\u27s categories of monological and dialogical discourse as a reference for showing how language and history help destabilize written constructions of American identity. In each work, a narrator creates American identity by suppressing or ignoring elements of American experience that subsequent events, or even events contemporary to the narrators, have proved to be of essential importance. When read retrospectively from our own point in time, these elements show their hidden presence in the narratives by disrupting their schemes for American identity. The appearance of these elements proves instructive about the works themselves, their times, their authors, and their relationships with each other. Each chapter addresses the problem of writing and American identity by describing a literary and historical basis for each construction of American identity, by identifying the suppressed elements of American experience in each construction, and by showing how knowledge of these elements affects both the narrator\u27s construction of American identity and the way in which we read the narratives. Each chapter ends with a conclusion that attempts to resituate the works in relation to the increasing emphasis on social and political consciousness that affects American literary studies

Gas filter correlation radiometry: Report of panel

To measure the concentration of a gas in the troposphere, the gas filter radiometer correlates the pattern of the spectral lines of a sample of gas contained within the instrument with the pattern of the spectral lines in the upwelling radiation. A schematic diagram of a generalized gas filter radiometer is shown. Three instruments (the Gas Filter Radiometer, GFR; the Halogen Occultation Experiment, HALOE; and the Gas Filter Correlation Spectrometer, GASCOFIL) that have application to remotely measuring tropospheric constituents are described. A set of preliminary calculations to determine the feasibility of performing a multiple-layer, tropospheric carbon monoxide measurement experiment was performed. It can be seen that a three-layer measurement in the troposphere is possible

TSAFE Interface Control Document v 2.0

This document specifies the data interface for TSAFE, the Tactical Separation-Assured Flight Environment. TSAFE is a research prototype of a software application program for alerting air traffic controllers to imminent conflicts in enroute airspace. It is intended for Air Route Traffic Control Centers ("Centers") in the U.S. National Airspace System. It predicts trajectories for approximately 3 minutes into the future, searches for conflicts, and sends data about predicted conflicts to the client, which uses the data to alert an air traffic controller of conflicts. TSAFE itself does not provide a graphical user interface

Recreational Rights and Titles to Bed on Western Lakes and Streams

What rights do riparians, their licensees, and the public have to use the small lakes and streams of the West when the beds are privately owned? This is the question which this Article attempts to answer. However, to do this, an analysis had to be made of which lake and stream beds were privately owned. Thus, the Article covers both the questions of title to beds and rights of surface use. This Article represents the first time that an effort has been made to systematically and comprehensively survey the lake and stream surface use cases of the Western part of the Nation, or of any large section of the Nation, and to critically compare and evaluate these cases

Recreational Rights and Titles to Beds on Western Lakes and Streams

What rights do riparians, their licensees, and the public have to use the small lakes and streams of the West when the beds are privately owned? This is the question which this Article attempts to answer. However, to do this, an analysis had to be made of which lake and stream beds were privately owned. Thus, the Article covers both the questions of title to beds and rights of surface use. This Article represents the first time that an effort has been made to systematically and comprehensively survey the lake and stream surface use cases of the Western part of the Nation, or of any large section of the Nation, and to critically compare and evaluate these cases

A User Guide for Smoothing Air Traffic Radar Data

Matlab software was written to provide smoothing of radar tracking data to simulate ADS-B (Automatic Dependent Surveillance-Broadcast) data in order to test a tactical conflict probe. The probe, called TSAFE (Tactical Separation-Assured Flight Environment), is designed to handle air-traffic conflicts left undetected or unresolved when loss-of-separation is predicted to occur within approximately two minutes. The data stream that is down-linked from an aircraft equipped with an ADS-B system would include accurate GPS-derived position and velocity information at sample rates of 1 Hz. Nation-wide ADS-B equipage (mandated by 2020) should improve surveillance accuracy and TSAFE performance. Currently, position data are provided by Center radar (nominal 12-sec samples) and Terminal radar (nominal 4.8-sec samples). Aircraft ground speed and ground track are estimated using real-time filtering, causing lags up to 60 sec, compromising performance of a tactical resolution tool. Offline smoothing of radar data reduces wild-point errors, provides a sample rate as high as 1 Hz, and yields more accurate and lag-free estimates of ground speed, ground track, and climb rate. Until full ADS-B implementation is available, smoothed radar data should provide reasonable track estimates for testing TSAFE in an ADS-B-like environment. An example illustrates the smoothing of radar data and shows a comparison of smoothed-radar and ADS-B tracking. This document is intended to serve as a guide for using the smoothing software

An Experimental Investigation of the Pressure Distribution on A 1/15-Scale Model of the Lockheed WS-117L Vehicle Plus Booster "B" at Mach Numbers from 0.70 to 1.45

Results obtained with two nose shapes tested at a Reynolds number per foot of 5 x 10(exp 6) at angles of attack from -4 deg to +10 deg at 0 deg angle of sideslip are presented in tabulated pressure coefficient form without analysis

Review of Lives of Victorian Literary Figures I, George Eliot, Charles Dickens, Alfred, Lord Tennyson

Like Pickering and Chatto\u27s Lives of the Great Romantics, these volumes, each one devoted to a major Victorian writer, offer a collection of facsimile reproductions of 19th or early 20th century essays, reviews and extracts from memoirs and biographies with the emphasis, according to Ralph Pite\u27s \u27General Introduction\u27, on material hard to find outside copyright libraries. Each volume contains a thoughtful and illuminating introduction; pithy but highly informative headnotes to each item, outlining the personal relationship (if any) and general attitude of its author towards Eliot, Dickens or Tennyson and in the process attuning our ears to the sound of the grinding of various axes; and helpful annotation of the selected texts, especially in the Tennyson volume (69 pages of notes as opposed to 15 for Eliot and 13 for Dickens). An admirably detailed analytical index appears at the end of Vol. 3 and the books are handsomely produced, apart from some unfortunate instances of clumsy photocopying resulting in distortions of the text adjacent to the right-hand margin