An engine trade study for a supersonic STOVL fighter-attack aircraft, volume 1

The best main engine for an advanced STOVL aircraft flight demonstrator was studied. The STOVL aircraft uses ejectors powered by engine bypass flow together with vectored core exhaust to achieve vertical thrust capability. Bypass flow and core flow are exhausted through separate nozzles during wingborne flight. Six near term turbofan engines were examined for suitability for this aircraft concept. Fan pressure ratio, thrust split between bypass and core flow, and total thrust level were used to compare engines. One of the six candidate engines was selected for the flight demonstrator configuration. Propulsion related to this aircraft concept was studied. A preliminary candidate for the aircraft reaction control system for hover attitude control was selected. A mathematical model of transfer of bypass thrust from ejectors to aft directed nozzle during the transition to wingborne flight was developed. An equation to predict ejector secondary air flow rate and ram drag is derived. Additional topics discussed include: nozzle area control, ejector to engine inlet reingestion, bypass/core thrust split variation, and gyroscopic behavior during hover

Interplanetary magnetic fields as a cause of comet tails

Interplanetary magnetic fields as cause of comet tail

Work Sampling as a Method of Evaluating a School Food Service Training Program

Feasible use of work sampling as a method of evaluating school food service employees\u27 performance before and after training sessions on work simplification was studied. Random observations of employees\u27 activities throughout two nine day periods resulted in 1,163 observations the first period and 1,110 the second period. Comparisons of the two periods on the basis of percent of time spent in three work functions and in each of 18 activities showed greatest changes in processing activities, with 2.2 percent more time during the second period; transportation activities, with 2.0 percent less time; cleaning activities, with 1.3 percent more time; and personal delays, with 1.4 percent more time. The general decrease in time spent in transportation and redistribution of the processing activities might be an indication of positive results of the training on work simplification. Comparison of activities by individual workers indicated that those with fewer years experience in school food service who attended training sessions spent less time in transportation activities after training. Employees with many years experience, regardless of their attendance of the training sessions, did not show these changes. Work sampling might be used to indicate the effects of training by comparison of employees\u27 use of time before and after training. Although this work sampling was not specific enough to indicate the actual time of the individual\u27s activity, it could be used to indicate problem areas for further study

A House of Conceits: A Study of the Drama of Jean-Paul Sartre, Albert Camus, Eugene Ionesco, and Samuel Beckett

This study is an effort to define and demonstrate the convention of the conceit as it is employed in the drama of Jean-Paul Sartre, Albert Camus, Eugene Ionesco, and Samuel Beckett. Critics such as Martin Esslin and Jacques Guicharnaud have complained, somewhat bitterly at times, that one or the other of the schools to which these playwrights are assigned belongs to a relatively new convention, which has not been widely understood or even adequately defined. Each of these experts, of course, has attempted to lessen this lack, Esslin with The Theatre of the Absurd, and Guicharnaud, Modern French Theatre: from Giraudoux to Genet. I intend A House of Conceits to be another framework of reference showing the works of Sartre, Camus, Ionesco, and Beckett within their own convention

Applying Monte Carlo Simulation to Launch Vehicle Design and Requirements Analysis

This Technical Publication (TP) is meant to address a number of topics related to the application of Monte Carlo simulation to launch vehicle design and requirements analysis. Although the focus is on a launch vehicle application, the methods may be applied to other complex systems as well. The TP is organized so that all the important topics are covered in the main text, and detailed derivations are in the appendices. The TP first introduces Monte Carlo simulation and the major topics to be discussed, including discussion of the input distributions for Monte Carlo runs, testing the simulation, how many runs are necessary for verification of requirements, what to do if results are desired for events that happen only rarely, and postprocessing, including analyzing any failed runs, examples of useful output products, and statistical information for generating desired results from the output data. Topics in the appendices include some tables for requirements verification, derivation of the number of runs required and generation of output probabilistic data with consumer risk included, derivation of launch vehicle models to include possible variations of assembled vehicles, minimization of a consumable to achieve a two-dimensional statistical result, recontact probability during staging, ensuring duplicated Monte Carlo random variations, and importance sampling

QCD as a Quantum Link Model

QCD is constructed as a lattice gauge theory in which the elements of the link matrices are represented by non-commuting operators acting in a Hilbert space. The resulting quantum link model for QCD is formulated with a fifth Euclidean dimension, whose extent resembles the inverse gauge coupling of the resulting four-dimensional theory after dimensional reduction. The inclusion of quarks is natural in Shamir's variant of Kaplan's fermion method, which does not require fine-tuning to approach the chiral limit. A rishon representation in terms of fermionic constituents of the gluons is derived and the quantum link Hamiltonian for QCD with a U(N) gauge symmetry is expressed in terms of glueball, meson and constituent quark operators. The new formulation of QCD is promising both from an analytic and from a computational point of view.Comment: 27 pages, including three figures. ordinary LaTeX; Submitted to Nucl. Phys.

Quantum Monte Carlo Study on Magnetization Processes

A quantum Monte Carlo method combining update of the loop algorithm with the global flip of the world line is proposed as an efficient method to study the magnetization process in an external field, which has been difficult because of inefficiency of the update of the total magnetization. The method is demonstrated in the one dimensional antiferromagnetic Heisenberg model and the trimer model. We attempted various other Monte Carlo algorithms to study systems in the external field and compared their efficiency.Comment: 5 pages, 9 figures; added references for section 1, corrected typo