Photo-doping of plasma-deposited polyaniline (PAni)

Although polyaniline (PAni) has been studied extensively in the past, little work has been done on producing films of this material via plasma deposition. We have synthesized and analysed the photoresponse behavior of plasma-deposited polyaniline films and proceeded to dope the films using light and with various metal ions. Upon illumination, the photocurrent responses of the thin plasma films increased over time, and the response was dependent on the film thickness. On doping the film with metal ions, the photocurrent densities were enhanced from nano- to micro-amperes per square centimeters. Doping seemed, however, to cause the films to become unstable. Despite this setback, which requires further research, the drastic increase in current shows great promise for the development of plasma-deposited polyaniline films for application in the area of organic electronics and photovoltaics

Usability challenges of upgrading a word processor user interface

Published ArticleThis study evaluated the difficulty, in terms of usability, of upgrading from one version of a word processor user interface (Microsoft Word 2003) to another (2007). Laboratory-based usability testing involving 23 participants, who had never used Microsoft Word 2007 before, was conducted. All participants used the two versions in a repeated-measures experimental design. A Tobii 1750 Eye Tracker was used for screen recordings during testing. Participants were also required to fill in user satisfaction questionnaires. Results from the usability test showed that, in terms of usability, migrating from an original interface to a completely changed user interface is not easy

Comprehensive two-dimensional liquid chromatographic analysis of rooibos (Aspalathus linearis) phenolics

ArticleRooibos tea is an unique beverage prepared from unfermented and fermented plant material of the endemic Cape fynbos plant, Aspalathus linearis. The well-known health-promoting benefits of rooibos are partly attributed to its phenolic composition. Detailed investigation of the minor phenolic constituents of rooibos is, however, hampered by the limitations associated with conventional HPLC methods used for its analysis. In this study, the applicability of comprehensive two-dimensional liquid chromatographic methods for the in-depth analysis of rooibos phenolics was investigated. Phenolic compounds were separated according to polarity by hydrophilic interaction chromatography (HILIC) in the first dimension, whilst reversed-phase liquid chromatography (RP-LC) provided separation according to hydrophobicity in the second dimension. Ultraviolet photodiode array and electrospray ionisation mass spectrometry were used to identify phenolic compounds. Comprehensive HILIC × RP-LC demonstrated its applicability for the analysis of a diverse range of phenolic compounds in unfermented and fermented rooibos samples, in which large qualitative differences in the phenolic composition were established. The combination of these orthogonal separations provided a significant improvement in resolution, as exemplified by practical peak capacities in excess of 2000 and 500 for off-line and on-line methods, respectively. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Erratum to " Kinetic optimisation of the reversed phase liquid chromatographic separation of rooibos tea (Aspalathus linearis) phenolics on conventional high performance liquid chromatographic instrumentation" [J. Chromatogr. A 1219 (2012) 128-139]

[No abstract available

Kinetic optimisation of the reversed phase liquid chromatographic separation of rooibos tea (<I>Aspalathus linearis</I>) phenolics on conventional high performance liquid chromatographic instrumentation

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Variation in phenolic content and antioxidation activity of fermented rooibos herbal tea infusions: Role of production season and quality grade

NatuurwetenskappeChemie & PolimeerwetenskapPlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

A new concept for variance analysis of hyphenated chromatographic data avoiding signal warping

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)NatuurwetenskappeChemie & Polimeerwetenska

High-dimensional nested analysis of variance to assess the effect of production season, quality grade and steam pasteurization on the phenolic composition of fermented rooibos herbal tea

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)NatuurwetenskappeChemie & Polimeerwetenska