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.     

Analyzing interdisciplinarity: Typology and indicators

Both funding agencies and scholars in science studies have become increasingly concerned with how to define and identify interdisciplinarity in research. The task is tricky, since the complexity of interdisciplinary research defies a single definition. Our study tackles this challenge by demonstrating a new typology and qualitative indicators for analyzing interdisciplinarity in research documents. The proposed conceptual framework attempts to fulfill the need for a robust and nuanced approach that is grounded in deeper knowledge of interdisciplinarity. As an example of using the framework, we discuss our empirical investigation of research proposals funded by a national funding agency in Finland.     

Organisational capacity to absorb external R&D: industrial differences in assessing intellectual capital drivers

Knowledge Management Research & Practice - Being competitive entails continuously performing product and process innovations. The acquisition of externally generated R&D is therefore...     

Das hepatozelluläre Karzinom

Ohne Zusammenfassung     

Relations Between Parenting Quality and Cognitive Performance of Children Experiencing Varying Amounts of Childcare

Associations between parenting quality and 3-year-olds' school readiness, receptive, and expressive language were examined in relation to the amount of time they spent in childcare, based on data from the NICHD Study of Early Child Care and Youth Development ( N = 1,364). Associations for school readiness and receptive language were stronger among children who experienced medium amounts of childcare than among children who experienced high amounts of childcare, and they were not weaker than among children who experienced primarily maternal care. Contrary to expectations, the association between parenting quality and school readiness among children who experienced medium amounts of childcare was significantly stronger than among children who experienced predominantly maternal care.     

Second and fourth graders' copying ability: from graphical to linguistic processing

Particularly in primary school, good performance on copy tasks is an important working technique. With respect to writing skills, copying is a very basic process on which more complex writing abilities are based. We studied the copying ability of second and fourth graders across four types of symbols which vary with respect to their semantic and phonological characteristics: arbitrary graphical objects, unpronounceable consonant strings, numerals and meaningful text. Results show, in terms of average copying speed, significant effects of both factors: fourth graders performed generally faster than second graders, and for both class levels, the number of copied characters per time decreased from meaningful text to graphical objects, all pair-wise contrasts between symbol types being statistically significant. Moreover, a significant interaction shows that fourth graders improved more when copying symbols that form pronounceable chunks, namely meaningful text and numerical strings. This indicates an increasing role of phonological (and probably also semantic) processes involved in copying across primary school.     

Muscle and tendon tissue properties of competitive soccer goalkeepers and midfielders

The purpose of this pilot study was to investigate the effect of playing-position-dependent training routines in soccer on the various muscle–tendon parameters. We hypothesized that there would be differences in such parameters between competitive goalkeepers and midfielders. According to their playing position, 21 healthy volunteers were assigned to goalkeeper (n?=?7), midfielder (n?=?7), and control (n?=?7) groups. To investigate the muscle–tendon parameters, we determined the maximum dorsiflexion range of motion and the corresponding muscle thickness, fascicle length, and pennation angle of the gastrocnemius medialis. Passive resistive torque and maximum voluntary contraction were measured with a dynamometer. Observation of muscle–tendon junction displacement with ultrasound allowed us to determine length changes in the tendon and muscle, respectively, and hence to calculate stiffness. There was no significant difference in range of motion, passive resistive torque, muscle–tendon stiffness, and the examined structural parameters (e.g., tendon stiffness) between the three groups. However, we found a significant difference in maximum voluntary contraction torque between the goalkeepers and midfielders vs. the controls, but not between the athlete groups. Habitual training leads to higher muscle strength in soccer players compared to less active persons. However, soccer training does not lead to specific muscle and tendon architecture adaptations according to playing position or when compared to less active persons.     

Injuries in formal and informal non-professional soccer – an overview of injury context,causes, and characteristics

The objective of this study is to analyse context, causes, and characteristics of injuries in non-professional soccer. Therefore, a retrospective telephone survey was carried out with persons who were injured while playing soccer and who reported this accident to the Swiss National Accident Insurance Fund (Suva). Based on these data, an analysis of 708 soccer injuries was performed. The findings show that 30.1% of the injuries occurred during informal soccer play, and 75.4% of the injured persons were soccer club members. 53.0% of all injuries were caused by contact and 29.5% by foul play. Foul play was not associated with injury severity. With respect to injury severity, twisting/turning and being tackled by an opponent were identified as the most influental injury causes. Moreover, the risk of being severely injured was particularly high players of the 30+/40+ amateur leagues. In conclusion, the findings highlight that 30+/40+ league players are a major target group for the prevention of severe soccer injuries. Soccer clubs may constitute an appropriate multiplier for implementing prevention strategies such as fair play education, healthy play behaviours, and prevention programmes. Finally, a better understanding of injury situations leading to severe injuries is needed to improve injury prevention.