Application of Computational MBD for Simulation of Wrap Packaging Performance

This paper concerns evaluation of the performance of plastic wrap films applied for packaging engineering by numerical simulation. In particular, the feasibility of computational techniques as supporting tool for packaging testing is investigated. A wrap film model constituted by a web of point masses connected by springs and dampers is applied to a number of stacked box-shaped objects. These will be modeled as perfectly rigid using simulation techniques from 3D multibody dynamics. Contact mechanics are simulated by penalization methods. A simple example demonstrates the potential of the developed framework

On numerical simulation of the dynamics of bottles in conveyor systems

The present paper concerns the dynamic behavior of bottles transported by conveyor systems. Such systems are widely applied in numerous industries. However, if systems are not properly designed or controlled, multiple undesired phenomena, like clogging or severe bottle scuffing, may occur in the bottle bulk. These effects are eventually strongly linked to the dynamic behavior of- and interaction between bottles. In order to propose a simulation model to support the design process needed for bottle conveyors, the plane mechanical behavior of bottles in a parametrically defined plant is considered. Generation of geometry, contact simulations by penalization and Coulomb friction is included in the model, which is solved by numerical integration of the Newton-Euler equations. The model is developed applying basic concepts from mechanics and numerical analysis and is therefore well-suited for implementation in any software for scientific programming. Results obtained with the model represent the expected physical effects for soft bottles well. A strategy for improvement of the computational efficiency of the method for modeling of high stiffness bottles is outlined

Treatment of HIV-Infected Individuals with the Histone Deacetylase Inhibitor Panobinostat Results in Increased Numbers of Regulatory T Cells and Limits &ITEx Vivo&IT Lipopolysaccharide-Induced Inflammatory Responses

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Estimating measurement error in child language assessments administered by daycare educators in large scale intervention studies

Measurement error is a ubiquitous element of social science studies. In large-scale effectiveness intervention studies on child language, administration of the assessment of language and preliteracy outcomes by speech and language pathologists is costly in money and human resources. Alternatively, daycare educators can administer the assessment, which preserves considerable resources but may increase the measurement error. Using data from two nationwide child language intervention studies in Denmark, this article evaluates daycare educators’ measurement error when administering a test of language and preliteracy skills of 3 to 5 year old children that in part is used in a national screening program. Since children were randomly assigned to educators, hierarchical linear models can estimate the amount of additional measurement error caused by educators’ language assessments. The result shows that the amount of additional measurement error varied between different language subscales, ranging from 4% to 19%, which can be compensated for by increasing the sample size by the latter percentage. The benefits and risks of having daycare educators administer language assessments are discussed