Mobile learning technologies are spreading rapidly in educational institutions throughout the world. Although research findings concerning the efficacy of mobile technologies for improving student outcomes are generally promising, there are still significant gaps in the research literature, particularly data from direct observational studies. This empirical investigation focused on how students made use of tablet devices and digital pens for learning Chemistry in an undergraduate university course. Observational data in the form of videos and static images, as well as, interview responses, were the main sources of data collected for the study. Activity theory was employed as the guiding theoretical framework to analyse and interpret the data. Several themes emerged from the data analyses, including the affordances of digital pen technology for facilitating reflective thinking, flexibility, peer collaboration, emerging learning and focused learning. It was also found that the use of these mobile technologies was contextualized, dependent on individual differences, and had challenges, for example, there was limited synchronicity between the operational design of the mobile devices and natural human movement. One of the main implications of the research is that when higher education institutions consider the potential benefits and challenges associated with mobile technologies they should take account of the interactions that occur between components within a system including, students, technological devices, and emerging learning processes.

In the Bayer process of preparing alumina from bauxite small molecular weight compounds such as C 2 -C 6 , mono-, di-, and trialiphatic carboxylic acids which have hydroxy substituents are formed from a humic material. While involatile as anions under refinery conditions, upon acidification they become volatile and can be lost either in processing or in workup of process liquors in the laboratory. The origin of these organics is unknown; however, this paper shows that they are directly derived from the water-soluble (mainly carbohydrate) fraction in the vegetation that is dissolved with the bauxite in preparing process liquors. Glucitol is shown to be a particularly stable carbohydrate to digestion and may, therefore, play an important role in Bayer poisoning processes.

The effect of annealing at 1400 1C in argon on the bond structure of graphite ball milled for 100 h at 400 rpm in polar (water) and in non-polar (n-dodecane) liquids was investigated primarily by near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and transmission electron microscopy (TEM). Carbon K-edge NEXAFS allows the distortion of bonds in the hexagonal lattice to be investigated. It is shown that in-plane sp 2 bonds are strained and distorted after ball milling because sp 3 bonds are introduced. Not surprisingly, annealing of the milled product restores sp 2 bonds but at the same time, coiling and formation of tube-like structures takes place. It is well established that graphite is not formed on annealing, and hence the results shown here demonstrate that the loss of sp 3 carbons on annealing must proceed via a different mechanism by which they are formed by milling. r