Corrosion induced cracking modelled by a coupled transport-structural approach

Transport of corrosion products into pores and cracks in concrete must be considered when predicting corrosion induced cracking in reinforced concrete structures, since this transport significantly delays the onset of cracking and spalling by reducing the amount of radial displacement imposed on the concrete at the steel/concrete interface. We aim to model this process by means of a coupled transport-structural approach, whereby the transport of corrosion products is determined by a pressure gradient generated by the confined volumetric expansion due to the transformation of steel into corrosion products. This pressure driven transport was studied by using both an axisymmetric thick-walled cylinder model and a network approach. The network approach was then applied to corrosion induced cracking experiments reported in the literature

Use of Linguistic Qualifiers and Intensifiers in a Computer Conference

Previous research in text-based computer conferencing has reported that analysis of transcripts of online discussions can reveal how participants network socially, exchange information, and attempt to construct knowledge. Some have detected gender differences in online discussions, which may affect the interpersonal dynamics within the group. This study investigated a possible gender-related communications difference (the use of linguistic qualifiers and intensifiers) in a computer conference transcript. The study differed from some previous work in using the sentence as the unit of analysis and in employing a newly developed tool for coding, the Transcript Analysis Tool. Results suggested a tendency for women to use more of the forms thought likely to sustain dialogue (qualifiers, conditional and parenthetic statements, and personal pronouns), whereas men’s postings generally contained fewer qualifiers and more intensifiers. The differences were seen as generally supporting previous findings and also as demonstrating that in a moderated conference the range of interactive behavior is less extreme than in “open” or unstructured environments

Evaluating Vendor Supplied Information

Distance educators are not normally equipped by their training or experience for the complex task of evaluating technologies. One of the areas of potential disadvantage is in interpreting information provided by vendors themselves, and in relating effectively with sales, marketing and technical representatives. An objective and thorough product evaluation requires that information be selected, and sometimes generated, to aid the process. Vendors may agree to provide additional information, including direct experience with their products, if evaluators know what to ask for and what to expect from vendors

The occurrence and character of stories and story-telling in a computer conference.

Abstract: Constructivist views of online interaction often refer to the power of stories and the role of story-telling in the sharing and construction of knowledge, and the creation of learning communities. No empirical evidence of the presence or character of stories in online conferences has been systematically reported, however. This study described the occurrence of stories in a CMC (computer-mediated communication) transcript generated by experienced online communicators (graduate students), in relation to some of the expectations of a constructivist view of narrative in online interaction, and in contrast with a historical model for describing face-to-face interaction (Bales, 1950). Findings included the observation that, while stories occurred in about 1 posting in 5, students used stories markedly more often than the instructor-moderator; stories tended to be descriptive, rather than analytic, advisory, or hortatory; gender was not an issue in story use; and both story and non-story postings were highly group-supportive, providing information and answers to questions, and avoiding negative social interactions (a finding noted previously in moderated, academic conferences)

Indicators of Support in Online Interaction

Peer-to-peer interaction using computer-mediated communication (CMC) would appear to be a promising source of timely and cost-effective student support, but little empirical evidence regarding actual participant support behaviour has been presented (Lee, 2000). This paper reports a study of the occurrence of 13 online strategies defined as “supportive,” according to the categorizations found in an instrument called the Transcript Analysis Tool (TAT). The corpus used in the study consisted of three transcripts produced by students (graduate degree and professional development diploma candidates) engaged in course-related CMC conferencing. Analysis of the transcripts generated by the three groups showed the following: • The support strategies most frequently used by the three groups were referential statements (statements which made reference to others’ previous comments; TAT type 2B), signatures, greetings, and horizontal questions (open-ended questions which invited negotiation of a plausible answer; TAT type 1B). • There was some variability among the groups in the frequency of use of referential statements, horizontal questions, emoticons, and invitations to others. • High- and low-support groups differed from each other in their use of referential statements, signatures, greetings, horizontal questions, rhetorical questions, and humour. As an examination of the social element of three communities of inquiry, the study described how members of these groups attempted to connect with one another interpersonally, using asynchronous conferencing, on topics related to the conceptual content of the courses. The paper concludes that while in this case the above behaviours were the means most often used to support and encourage interaction, further examination of online support behaviours and strategies is needed, especially in relation to valued outcomes such as persistence, greater motivation, less stress, and, ultimately, enhanced learning