Softcover reprint of the hardcover 1st edition 1998 All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission.
The unique properties of phosphate ester surfactants make them highly functional components in a multitude of formulations throughout the agricultural industry. Synthetic routes leading to the formation of phosphate esters are relatively well understood. The formation of mono-, di-, tri- and pyrophosphate ester species, however, varies considerably with reaction conditions and stoichiometry. Historically, the analysis of these mixtures has centered around the potentiometric titration of acidic species to determine the concentration of the various phosphate ester species present. The information obtained using this approach can be misleading and fails to provide the comprehensive characterization possible using through the application of state-of-the-art analytical methodology; including 31P nuclear magnetic resonance spectroscopy, high performance liquid chromatography and capillary electrophoresis. These techniques will be compared relative to the examination of phosphate ester surfactants. Specifically prepared phosphate esters were studied for hydrolytic stability at ambient and elevated temperature. Little evidence for hydrolysis was observed past seven days exposure, with minor effects noted due to temperature and water concentration.
The diversity of mobile devices and their limitations have raised many challenges for the actual deployment of mobile learning across institutions. The main objective of this work is to present a solution that encourages institutions to adopt mobile learning as a tool to support the learning process. We present a generic framework for interoperability with existing VLEs that provides a compact and an easy to use implementation of their learning activities on Java enabled mobile devices. In this paper, we discuss the design and the prototype of the proposed interoperability framework. The results and the feedback of the prototype evaluation with tutors are reported. The reported results and comments cover the system's usability and its value for both tutors and students.
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