Finite element simulation of the ski–snow interaction of an alpine ski in a carved turn

Skiing manufacturers depend on the development of new skis on trial and error cycles and extensive product testing. Simulation tools, such as the finite element method, might be able to reduce the number of required testing cycles. However, computer programs simulating a ski in the situation of a turn so far lack realistic ski–snow interaction models. The aim of this study was to (a) implement a finite element simulation of a ski in a carved turn with an experimentally validated ski–snow interaction model, and (b) comparison of the simulation results with instantaneous turn radii determined for an actual carved turn. A quasi-static approach was chosen in which the ski–snow interaction was implemented as a boundary condition on the running surface of the ski. A stepwise linear function was used to characterise the snow pressure resisting the penetration of the ski. In a carved turn the rear section of the ski interacts with the groove that forms in the snow. Two effects were incorporated in the simulation to model this situation: (a) the plasticity of the snow deformation, (b) the influence of the ski’s side-cut on the formation and shape of this groove. The simulation results agreed well with experiments characterising snow penetration. Implementation of the groove in the ski–snow interaction model allowed calculation of the instantaneous turn radii measured in actual turns, but also caused significant numerical instability. The simulation contributes to the understanding of the mechanical aspects of the ski–snow interaction in carved turns and can be used to evaluate new ski designs.     

WhatsApp use among African international distance education (IDE) students: transferring,translating and transforming educational experiences

ABSTRACT

Much of the research on how social media is embedded into the educational practices of higher education students has a Western orientation. In concentrating on a case study of the varied ways in which African International Distance Education (IDE) students actively use social media to shape their learning experiences, we discuss an under-researched group. The paper draws on analysis of 1295 online questionnaires and 165 in-depth interviews with IDE students at UNISA, South Africa, one of the largest providers of IDE globally. WhatsApp emerges as ‘the’ key social media tool that opens up opportunities for IDE students to transfer, translate and transform their educational journey when studying ‘at a distance’. Although WhatsApp does provide a ‘space of opportunity’ for some students, this is framed through socio-technical marginalisation, itself a reflection of demographic legacies of inequality. Exploring social media practices though the case of African IDE students places these students centre stage and adds to the awareness of the multiple centres from which international education is practiced.     

Promoting basic arithmetic competence in early school years–using a response to intervention model

This study investigated whether mathematics education based on a multi-tiered response to intervention (RTI) model can support students' arithmetic competence in primary schools in Sweden. The intent was to identify and support students at risk of failure. In this study, 113 students participated in the intervention, and 30 students participated in the control group. Both groups were followed from Grade 1 to the end of Grade 2 and compared. During the first semester in Grade 1, all students were taught basic addition and subtraction with explicit instructions in Tier 1. Those who did not respond to Tier 1 after one semester were provided support within Tier 2 during the second semester. The same was repeated in grade 2 and the students that did not respond to Tier 2 were supported within Tier 3. At the end of Grade 2, students in the intervention group performed significantly higher on the basic arithmetic competence in the number range 1–9 than the control group. No significant difference was found in a test measuring basic arithmetic competence in the number range 10–19. This study shows that using multi-tiered RTI might be sufficient to identify and support students at risk in early arithmetic competence.     

Health science libraries in Sweden: new directions,expanding roles

Librarians in Sweden are facing huge challenges in meeting the demands of their organisations and users. This article looks at four key areas: coping with open science/open access initiatives; increasing demands from researchers for support doing systematic reviews; understanding user experiences in Swedish health science libraries; and the consequences of expanding roles for recruitment and continuing professional development. With regard to changing roles, there is an increasing shift from the generalist towards the expert role. The authors raise the issue as to how to prepare those new to the profession to the changing environment of health science libraries.     

What is implied when researchers claim to use a theory?

The focus of this article is on the use of theories and on what we imply when we in research claim to use a theory. In this article, diverse uses of one theory will be illustrated with reference to 10 different studies. The aim is not to evaluate or judge how the theory is used in these studies, but to discuss how the diverse uses of one and the same theory may infer very different things in research. Questions are raised about what happens with the hierarchy and the coherence of an argument and what conclusions can be drawn when only some parts of a theory are used.     

Individual,co‐operative and collaborative data use: A conceptual and empirical exploration

In recent decades, the belief has originated that data use contributes to more thought‐out decisions in schools. The literature has suggested that fruitful data use is often the result of interactions among team members. However, up until now, most of the available research on data use has used ‘collaboration’ as an umbrella concept to describe very different types of interaction, without specifying the nature of collaboration or the degree of interdependency that takes place in interactions. Therefore, the current study investigates and describes Flemish teachers’ individual, co‐operative and collaborative data use. In doing so, the level of interdependency of teachers’ interactive activities (storytelling, helping, sharing, joint work) is taken into account. The results of a qualitative study with semi‐structured interviews show that teachers’ data use is predominantly of an individual nature and that felt interdependencies among teachers are few. The study enhances knowledge and opens the conceptual debate about teachers’ interactions in the context of data use.     

Fellows' Perceptions of a Mandatory Reflective Electronic Portfolio in a Geriatric Medicine Fellowship Program

Electronic portfolios (ePortfolios) can be useful for evaluating and documenting mastery of competencies. We investigated geriatric medicine fellows' perceptions of an ePortfolio. We conducted surveys and focus groups followed by quantitative and qualitative data analysis. Our study revealed that fellows considered the ePortfolio acceptable and accessible. Fellows reflected on aspects relevant to postgraduate training and future practice and documented adherence to competencies. However, fellows expressed resentment about the self-reflection component, which interfered with the overall acceptance of the ePortfolio. Although ePortfolios can be powerful and reflective tools for competency assessment, care must be taken in their implementation.