Search

Presents an on-line, server-based examination system for analytical chemistry or any other subject suitable for administration over large geographical areas for students in distance education to do self-assessment. Discusses the advantages of the system which combines course material with the examination system so that the examination system may be used by students to measure their preparedness. (Author/YDS)

An efficient new electrophilic reagent combination of N-Halosuccinimides (NXS)/BF3-H2O is developed as BF3-H2O is more economic, easy to prepare, nonoxidizing and offers high acidity. The structural aspects of the BF3-H2O complex are investigated.

The use of home kits for teaching undergraduate analytical chemistry laboratory exercises successfully is discussed. The materials provided in the kit are mentioned.

Engineering programs in Sri Lanka, like others that were long ago modelled on the British system, are analysis-intensive and weak on liberal studies components such as ethics, although Britain herself has now adopted broader educational goals for engineering education. This paper describes our attempts to include professional ethics in the engineering curriculum in Sri Lanka. We make the case that 'Asian values' in the narrow technical sense in which the term is defined in the literature for Southeast Asia is equally applicable to South Asia. In particular, two of these common Asian values militate against the ethical norms frequently encountered in a Western class. First, there is really little support in Sri Lankan or South Asian culture for keeping religion out of public life. The religious ethos where multiculturalism is understood to be polytheistic favors a Hindu/Buddhist celebration of religion involving all gods at public functions which is then passed off as multiculturalism. Second, there is strong loyalty to the family and clan and obedience to elders that works against administrative impartiality. We therefore use in our teaching a legislatively and democratically evolved and socially accepted system of international human rights law as the proper basis for justifying ethics. Though human rights exhibits some cultural conflicts with Asian values, it is neutral with respect to the parties to the civil war in Sri Lanka. [ABSTRACT FROM AUTHOR]

N-Halosuccinimides (NXS, 1) are efficiently activated in trifluoromethanesulfonic acid and BF3- H2O, allowing the halogenations of deactivated aromatics. Because BF3-H2O is more economic, easy to prepare, nonoxidizing, and offers sufficiently high acidity (-H0 ≈ 12, only slightly lower than that of trifluoromethanesulfonic acid), an efficient new electrophilic reagent combination of NXS/BF3-H2O has been developed. DFT calculations at the B3LYP/6-311++G**//B3LYP/6-31G* level suggest that protenated N-halosuccinimides undergo further protosolvation at higher acidities to reactive superelectrophilic species capable either in the transfer of X+ from the protonated forms of NXS to the aromatic substrate or in forming a highly reactive and solvated X+ which would readily react with the aromatic substrates. Structural aspects of the BF3-H2O complex have also been investigated. [ABSTRACT FROM AUTHOR]