Flow analysis based on a pulsed flow of solution: theory, instrumentation and applications

The increased demands placed on solution propulsion by programmed flow systems, such as sequential injection analysis, lab-on-value technology, bead injection and multi-commutation, has highlighted the inability of many conventional pumps to generate a smooth, consistent flow. A number of researchers have examined ways to overcome the inadvertent, uncontrolled pulsation caused by the mechanical action of peristaltic pumps. In contrast, we have developed instruments that exploit the characteristics of a reproducible pulsed flow of solution. In this paper, we discuss our instrumental approaches and some applications that have benefited from the use of a reproducible pulsed flow rather than the traditional linear flow approach. To place our approach in the context of the continuously developing field of flow analysis, an overview of other programmed flow systems is also presented.

Prominent messages in education and applied linguistic abstracts : how do authors appeal to their prospective readers?

This study investigates the rhetorical structure of abstracts of papers published in Applied Linguistics and Education. It examines how abstract authors in these two fields emphasise the significance of their research, and how they appeal to their prospective readership. Although abstracts in both disciplinary groups are found to display a coordinate textual development they exhibit a utilization of different relational schemata to indicate the functional prominence of textual propositions. In particular, different relational patterns are seen to be employed to fulfil the two primary objectives of an abstract: to provide a synopsis of the accompanying article, and to promote it to relevant research and professional communities. The way authors demonstrate the value of their research and their professional credibility appears to be conditioned by disciplinary writing conventions. It is proposed that relational choices, which result in differences in the accentuation of communicative messages in Applied Linguistics and Education abstracts, depend on the perceived relationship between the author and the discourse community in terms of expectations of prior knowledge.

Influence of N2O flow rate on reliability of SiOx films deposited by SiH4-N2O gas mixture plasma

SiO_x films have several advantages as an interlayer dielectric in electronic devices owing to the strong adhesion between SiO_x and the substrate. In this study, the coating performance as a function of the N₂O flow rate was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests in an undisturbed environment. In addition, the coatings were examined by atomic force microscopy and Fourier transform infrared reflection spectroscopy. The SiO_x films on a stainless-steel substrate showed the highest coating performance at a N₂O flow rate of 120 sccm. This was attributed to the films having the lowest porosity value among those examined as a result of the fragmentation of SiO and SiO₂ bonds and the improved surface roughness.