ALTERNATIVE APPROACHES TO POST-HIGH SCHOOL EDUCATION

Teaching/Communication/Extension/Profession,

Modeling of hydrogen-air diffusion flame

Work performed during the first six months of the project duration for NASA Grant (NAG-1-861) is reported. An analytical and computational study of opposed jet diffusion flame for the purpose of understanding the effects of contaminants in the reactants and thermal diffusion of light species on extinction and reignition of diffusion flames is in progress. The methodologies attempted so far are described

Friends at Mid-Century

The Isaac T. and Lida K. Johnson Lectureship, made possible by their gift, was created by the Executive Committee of the Five Years Meeting in its sessions of April, 1940. The creative minute of the Executive Committee is in part as follows: It is the duty of the Executive Committee to determine the use of this money and the Central Committee submits this recommendation: (1) that the gift be made a continuing memorial to these dear friends and (2) that the memorial be in the form of a lectureship for the Five Years Meeting, and, as it may direct, to be known as the Isaac T. and Lida K. Johnson Lectureship. It is further recommended that these lectures shall within the jurisdiction of the Executive Committee, be restricted to the field of Christian scholarship and the Christian message and its application to life. It is the confident expectation of the Executive Committee that not only the constituency of the Five Years Meeting, but all of Quakerism will be enriched by the successive messages made possible by this gift.https://digitalcommons.georgefox.edu/quakerbooks/1072/thumbnail.jp

Representations of the quantum doubles of finite group algebras and solutions of the Yang--Baxter equation

Quantum doubles of finite group algebras form a class of quasi-triangular Hopf algebras which algebraically solve the Yang--Baxter equation. Each representation of the quantum double then gives a matrix solution of the Yang--Baxter equation. Such solutions do not depend on a spectral parameter, and to date there has been little investigation into extending these solutions such that they do depend on a spectral parameter. Here we first explicitly construct the matrix elements of the generators for all irreducible representations of quantum doubles of the dihedral groups $D_n$. These results may be used to determine constant solutions of the Yang--Baxter equation. We then discuss Baxterisation ans\"atze to obtain solutions of the Yang--Baxter equation with spectral parameter and give several examples, including a new 21-vertex model. We also describe this approach in terms of minimal-dimensional representations of the quantum doubles of the alternating group $A_4$ and the symmetric group $S_4$.Comment: 19 pages, no figures, changed introduction, added reference

Analysis of opposed jet hydrogen-air counter flow diffusion flame

A computational simulation of the opposed-jet diffusion flame is performed to study its structure and extinction limits. The present analysis concentrates on the nitrogen-diluted hydrogen-air diffusion flame, which provides the basic information for many vehicle designs such as the aerospace plane for which hydrogen is a candidate as the fuel. The computer program uses the time-marching technique to solve the energy and species equations coupled with the momentum equation solved by the collocation method. The procedure is implemented in two stages. In the first stage, a one-step forward overal chemical reaction is chosen with the gas phase chemical reaction rate determined by comparison with experimental data. In the second stage, a complete chemical reaction mechanism is introduced with detailed thermodynamic and transport property calculations. Comparison between experimental extinction data and theoretical predictions is discussed. The effects of thermal diffusion as well as Lewis number and Prandtl number variations on the diffusion flame are also presented