Technical University of Nova Scotia

No Abstract

As part of the Radiance in a Dynamic Ocean (RaDyO) program, we have developed a numerical model for efficiently simulating the polarized light field under highly dynamic ocean surfaces. Combining the advantages of the three‐dimensional Monte Carlo and matrix operator methods, this hybrid model has proven to be computationally effective for simulations involving a dynamic air‐sea interface. Given water optical properties and ocean surface wave slopes obtained from RaDyO field measurements, model‐simulated radiance and polarization fields under a dynamic surface are found to be qualitatively comparable to their counterparts from field measurements and should be quantitatively comparable if the light field measurement and the wave slope/water optical property measurements are appropriately collocated and synchronized. This model serves as a bridge to connect field measurements of water optical properties, wave slopes and polarized light fields. It can also be used as a powerful yet convenient tool to predict the temporal underwater polarized radiance in a real‐world situation. When appropriate surface measurements are available, model simulation is shown to reveal more dynamic features in the underwater light field than direct measurements.

There is an emerging need for all sectors of society to find ways to optimize the opportunities which information and communications technologies present. Research and development work in Information Systems and information technology has accepted a model of computing where the individual interacts directly with the computer and, through the computer and communication systems, with other individuals. Thus the objective of IT research and development has been to continuously enhance and extend the capabilities of individuals within the context of the corporations, organizations, and governments for which they work. However, ICT also can be used to support communities in their efforts for social and economic development. Community informatics is a technology strategy or discipline which links economic and social development efforts at the community level with emerging opportunities in such areas as electronic commerce, community and civic networks and telecentres, electronic democracy and on-line participation, self-help and virtual health communities, advocacy, cultural enhancement, and others.Request access from your librarian to read this chapter's full text.

Physical scale modeling (PSM) is an experimental technology that has been used to evaluate and design shipboard impressed current cathodic protection (ICCP) systems by various researchers and designers. PSM is also a preferred tool for validating ICCP numerical modeling results, owing to the well-controlled conditions in PSM experiments. However, one issue in using PSM for the validation of numerical modeling results is the lack of information on the actual polarization behavior of the cathodes on a model hull during PSM experiments. Consequently, the polarization curve data used as boundary conditions in numerical modeling trials is usually different from the polarization behavior of the cathodes in PSM experiments. This difference can result in a discrepancy between the numerical modeling and the PSM results, which is difficult to separate from other numerical errors. A discrete area current control (DACC) technique was developed in a previous ICCP PSM study to simulate the polarization behavior of a propeller material under various conditions. The present study extended the DACC technique to simulate the polarization curve behavior of four discrete cathodes representing one nickel aluminum bronze (NAB) propeller and three discrete steel patches. This study also demonstrated that use of the DACC technique can ensure that both PSM and numerical modeling studies use identical polarization curve relationships as boundary conditions. The technique facilitates the use of the PSM results for comparison with numerical modeling results. The comparison study showed good agreement between the PSM results and numerical modeling results, in both simulated static and dynamic flow conditions.

<P>This chapter contains sections titled: <UL> <LI> <P>Introduction</P> </LI> <LI> <P>The Synchronous Machine: Preliminaries</P> </LI> <LI> <P>Fields in a Synchronous Machine</P> </LI> <LI> <P>A Simple Equivalent Circuit</P> </LI> <LI> <P>Open-Circuit and Short-Circuit Characteristics</P> </LI> <LI> <P>Principal Steady-State Characteristics</P> </LI> <LI> <P>Power-Angle Characteristics and the Infinite Bus Concept</P> </LI> <LI> <P>Static Stability Limit Curves</P> </LI> <LI> <P>Accounting for Saliency</P> </LI> <LI> <P>Salient-Pole Machine Power Angle Characteristics</P> </LI> </UL> </P> <P>This chapter contains sections titled: <UL> <LI> <P>Some Solved Problems</P> </LI> <LI> <P>Problems</P> </LI> </UL> </P>

A wollastonite-mullite composite system has been investigated in order to assess the viability of using a natural mineral as a reinforcing dispersed phase. The wollastonite particles were mixed with high purity commercial mullite in aqueous suspension in the basic pH range. Prior to mixing, hard agglomerates were eliminated from the mullite powder by sedimentation. In order to increase solid content, the homogenized slurry was centrifuged and redispersed using a deflocculant; the final suspension contained approximately 50 vol% solids, and was pseudoplastic at low, and dilatant at higher shear rates.