Comparative morphology of configurations with reduced part count derived from the octahedral-tetrahedral truss

Morphology (the study of structure and form) of the octahedral-tetrahedral (octet) truss is described. Both the geometry and symmetry of the octet truss are considered. Morphological techniques based on symmetry operations are presented which enable the derivation of reduced-part-count truss configurations from the octet truss by removing struts and nodes. These techniques are unique because their Morphological origination and they allow for the systematic generation and analysis of a large variety of structures. Methods for easily determining the part count and redundancy of infinite truss configurations are presented. Nine examples of truss configurations obtained by applying the derivation techniques are considered. These configurations are structurally stable while at the same time exhibiting significant reductions in part count. Some practical and analytical considerations, such as structural performance, regarding the example reduced-part-count truss geometries are briefly discussed

Art Ecology and Planning: Strategic Concepts and Creativity within the Post Industrial Public Realm

This is a digitised version of a thesis that was deposited in the University Library. If you are the author and you have a query about this item please contact PEARL Admin ([email protected])Metadata merged with duplicate record (http://hdl.handle.net/10026.1/775 - now deleted) on 20.12.2016 by CS (TIS).The intent of this thesis and its attendant body of practical work was to examine and test ideas and practices that can inform and expand the artists' role in the post-industrial public realm and its environmental context. The general focus was on transformative approaches to contemporary public art. The specific interest (and area of practice) is defined by artwork that takes an interdisciplinary approach to new forms of social creativity in the context of post-industrial environmental change. This dissertation begins with a broad literature review to understand public art and its relationship to: the public realm, ecology, nature and the environment. The intent was to understand the theory and process that inform answers to questions regarding the artists' ability to affect public policy; the ability to expand the creative act beyond singular authorship and finally the question of can we verify the impact of art? The thesis closes with two chapters describing practical work on 'Nine Mile Run' a project that developed an ecological restoration approach to post-industrial public space; also '3 Rivers 2nd Nature' which focused upon the emancipation of, and a means to advocate for post industrial nature. These projects were developed with the intention to test theory through application and value through outcome. The goal was to provide a better understand of ideas that define and enable collaborative or inter-relational approaches to transformative art practice. The intention was to make a small contribution to the theoretical framework that informs the conceptualization, experience and valuation of transformative public art practices that intend to affect the material and conceptual forms of the post-industrial public realm. It is through intellectual study and ongoing practice that the three original questions are addressed with a cautionary affirmative. Other specific findings include the following. • The ongoing tension between individual freedom and social interaction is best addressed through a moral commitment to creativity in relationship to the emancipation of people, places and things. • Visual evidence can not be the sole focal point of critical engagement with transformative practice. • Transformative practices that undertake an inter-relational methodology demand ethical, responsible and distributed outcomes

Electromagnetic field distribution and power absorption of 3D spherical objects.

Microwave and radiofrequency heating has great promise in many engineering and biomedical applications because of its non-contact, volumetric heat generation and selective heating. However, the heating patterns and temperature distributions are non-uniform and difficult to control. Electromagnetic power absorption guides the heating pattern which is a complex function of dielectric properties, electromagnetic frequencies, size, and shape of the target object. A closed form expression of power absorption with functional relationship with various parameters is obtained for a spherical shaped dielectric object using Maxwell's equations in spherical coordinate. Maxwell's equations are solved using vector potentials and separation of variables. Mathematical tools such as Bessel functions, Legendre Polynomials, infinite series, and complex number expressions are employed in finding the solution. The electromagnetic power absorption is calculated from the knowledge of electromagnetic field within the object using Poynting theorem. The analytical expression of the electric field, magnetic field, and power generation within the sphere are coded in MATLAB and FORTRAN to get numerical results for spherical shaped meat balls of 1.0, 2.0, 3.0 and 5.0 cm radii with varying properties and electromagnetic frequencies of 2800 MHz, 2450 MHz, 915 MHz, and 300 MHz. Origin Labs is utilized to produce 1-D plots and also 2-D polar plots by reading the data text files generated in the FORTRAN program. Results show that the presence of local maxima of electric and magnetic field strength due to the constructive interference of the electromagnetic wave in the target object. The spatial distribution of microwave power absorption follows the trend of electromagnetic field distribution. The locations of local maxima and minima of power absorption and electromagnetic field distributions vary with the radius of the sphere and applied frequencies. The results also show that the strength of the absorbed electromagnetic wave at the 2450 MHz is most non-uniform at the radius of 3 cm nugget. The smallest (1 cm radius) and largest (5 cm radius) dielectric radii show a lower electromagnetic and power generation peak values but a more even distribution of energy overall. Analysis reveals the correlations of propagating wavelength, penetration depth of electromagnetic waves and size of the beef nuggets. Results indicate that the uniform and effective electromagnetic power absorption can be facilitated by proper design of the object of interest and selection of appropriate frequencies. This rigorous analytic investigation will provide significant insight in understanding the power absorption and temperature distribution mechanism for spherical shaped objects under electromagnetic wave (microwave and radiofrequency) treatment