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This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capability of preparing Primary Standard gas Mixtures (PSMs), performing the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this subsequent key comparison is classified as a track B key comparison, which means that the results of this key comparison can be used to underpin calibration and measurement capabilities for propane under the default scheme. The artefact was a binary mixture of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The result of the participating laboratory is consistent with the key comparison reference value within the respective expanded uncertainties and deviates less than 0.1 %. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The purpose of this paper is to explore components that influence the Mobile User Experience (MEX) in a mlearning interaction through a review of relevant literature. The application of mobile cellular technology in education has been the focus of the emerging domain of mlearning, and has, through numerous pilots and initiatives, been shown as having the potential to overcome several barriers experienced in education. This potential is, however counterbalanced by studies that show the relative high dropout rate and non-use for learners using a diverse array of electronic learning systems when compared to the traditional face-to-face classroom interactions. The learners as end-users often indicate a frustration with the technology as a major obstacle for the use and participation in technology enhanced learning systems. Moreover, organizations are increasingly requiring evidence that technology enhanced learning systems and programs will be widely accepted and utilized before implementing them. This paper explores and documents the components that would impact on the phenomena within a discourse between the technology affordances and domain requirements as revealed by the literature in the domains of mlearning and Mobile Human Computer Interaction (MHCI).

The South African Reference Materials (SARMs) have traditionally been certified through interlaboratory studies involving reputable national and international laboratories. The ISO definition of a Certified Reference Material (CRM) has changed recently. In view of these changes re-certification of the SARMs with the use of primary methods to provide measurement traceability and complete evaluation of the uncertainties associated with the methods are urgently needed. The CSIR-National Metrology Laboratory of South Africa (CSIR-NML) has embarked on a project to re-certify some of the rock type South African Reference Materials (SARM 3 and 4) for selected trace elements using the primary method of isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS). Analysis data published in the literature for these SARMs since their production and certification in 1978 was also collected and critically evaluated (data due to be published). Based on this work, new recommended values with associated expanded uncertainties are proposed for some trace elements of SARM 3 and SARM 4.

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The rapid development of computer-supported collaborative environments has highlighted the need for collaborative knowledge construction devices. Because most available mindtools do not promote collaboration, there is a need for social mindtools that can be used in collaborative learning situations. We have used activity theory as a conceptual framework to define the requirements of social mindtools as awareness of other participants, communication and the ability to edit common objects together. We present the concept of Woven Stories and use it as an example of an effective social mindtool. We also describe a case study in which Woven Stories software was used as an online debating forum. This case study reveals the potential inherent in the concept, compared with other text-oriented Web 2.0 tools, such as wikis. IntroductionBecause of the continuous flow of powerful new technologies, research in the field of educational technology tends to concentrate on the use of mobile technologies, virtual worlds, and other relatively complex tools and technologies. Given the popularity of technology-driven developments of this kind in research, it is easy to overlook the fact that learning is inextricably bound up with thinking and that simple solutions can often be crucial in the evolution of educational research. Jonassen (1992) notes: 'Rather than developing more powerful teaching software, we should be teaching learners how to think more efficiently'. If we are to accomplish what Jonassen recommends, we need to develop a range of simple and generic thinking tools that can be taught to learners. The development of simple tools of this kind is predicated on the realisation that the primary purpose of learning is not how to use the tool but how to think efficiently.

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