The influence of media violence on youth

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83429/1/2003.Anderson_etal.InfluenceofMediaViolenceonYouth.PsychologicalScienceinthePublicInterest.pd

Determining VCE damage zones using the GAME correlations and explosion regions

Predicting potential consequences of Vapor Cloud Explosions (VCEs) has always been an important issue in safety assessments, because of the devastating damage that this phenomenon can create on (petro chemical) production sites. Although the TNO Multi-Energy method has been recognized as one of the best methods to predict blast overpressures of vapor cloud explosions, its application has been complicated by the required expert knowledge to choose a blast strength category and the congested fraction of the flammable cloud. In the GAME project (Guidance on Application of Multi-Energy, a contract research project for HSE), TNO already developed a quantitative method to derive the blast strength of VCEs, based on well-defined congestion area properties. Recently, this method has been extended and combined with dispersion models to derive a practical cloud coverage fraction, which is used to find the other important influencing parameter: the explosive mass of the congested part of the flammable cloud. This so-called "explosion regions" method can be used to determine the potential damage zones on a realistic site, with various potential sources of releases and multiple congestion areas or "receptors". The paper will give a full description of the calculation procedure used and provide potential benefits and drawbacks of its application

Optimization of layered material configuration for shock attenuation

Multi-layered materials with alternating impedances as a mean to mitigate sympathetic detonation is considered in this investigation by studying the wave scattering and energy absorption phenomena. This is achieved using an analytical wave-tracking model that accounts for the different wave interactions within and at the interface of each layer. It is shown that there is a critical areal density of the overall multi-layered system beyond which the performance is increased significantly due to a larger amount of energy absorption. This trend is increasingly significant for increasing impedance mismatch between the different layers. It is also shown that increasing the number of interfaces increases slightly the system performance. The analytical results are supported by numerical simulations. Furthermore mitigation of sympathetic detonation using multi-layered materials is demonstrated experimentally

Large scale dust explosions in linked enclosed vessels

TNO participated in the DESC project (Dust Explosion Simulation Code) which was supported by the European Union. The aim of this project was to obtain a numerical model (CFD-code) to simulate dust explosions for complex geometries, like industrial facilities. To be able to validate this model, TNO performed large scale dust explosions in linked enclosed vessels. Two I m3 explosion vessels were connected with pipes of various lengths and with or without a bend. Dust explosions with Potato Starch, Coal and Silicon powder were performed to determine, beside the pipe configuration, the influence of the ignition location, the presence of obstacles, and pressure relief by venting one of the vessels. These determinations resulted in a very useful data-set for validating the CFD-code. Although these experiments were not meant to fully understand all the observed phenomena, some explanations for observations were given

A consequence analysis method for out of area field storage

AASTP-5, Part II establishes North Atlantic Treaty Organisation (NATO) guidelines for the storage, maintenance and transport of ammunition during deployed missions and operations. It assists in the planning, reconnaissance and establishment of an Ammunition Area and the management of the ammunition. The document is designed for use by the Operational Commander’s specialist. AASTP-5, Part II, defines - as a main part - the Field Distances (FDs) to be kept between PES (Potential Explosion Site) and PES (preventing prompt propagation of explosions) and between PES and ES (Exposed Site) (ensuring an appropriate safety level for exposed personnel and public). In cases where these FDs cannot be applied, e.g. due to lack of available area or tactical mission requirements, a consequence and/or risk analysis has to be conducted before making a decision to deviate from the FDs. NATO AC/326 (CNAD Ammunition Safety Group) has asked CHE and NLD to develop a consequence and risk analysis method to be incorporated in AASTP-5, Part II. For this purpose BK&P has developed the general outline of the method, while TNO Defence, Security and Safety calculated the explosion effects and consequence data. The consequences are expressed in terms of lethality, injury, and damage to assets. The method enables to take into account protective measures like barricades, and overhead protection, and distinguishes between different types of structures relevant to Out of Area (OoA) operations. This paper describes the results obtained so far

A universal throw model and its applications

A deterministic model has been developed that describes the throw of debris or fragments from a source with an arbitrary geometry and for arbitrary initial conditions. The initial conditions are defined by the distributions of mass, launch velocity and launch direction. The item density in an exposed area, i.e. the number of impacting debris or fragments per unit of area, has been expressed analytically in terms of these initial conditions. While existing models make use of the Monte Carlo technique, the present model uses the source function theorem, an underlying mathematical relation between the debris density and the initial distributions. This gives fundamental insight in the phenomenon of throw, and dramatically reduces the required number of trajectory calculations. The model has been formulated for four basic source geometries: a point source, a vertical cylinder, a horizontal cylinder, and a vertical plane. In combination with trajectory calculations the item density can be quantified. As an illustration of the model, analytical results are presented and compared for the vertical plane and the vertical cylinder geometry under simplified assumptions. If uncertainties exist in the initial conditions, the model can be used to investigate these initial conditions based on experimental data. This has been illustrated on the basis of a trial with 5 ton of ammunition stacked in an ISO container. In this case the model has been successfully applied to determine the debris launch angle and velocity distribution, by means of backward calculations. If, on the other hand, sufficient information on the initial conditions is available, the model can be used as an effect model in risk assessment methods, or for the requirements on protective measures. The model can be used to predict safety distances based on any desired criterion. © 2007 Elsevier Ltd. All rights reserved

Background television as an inhibitor of performance on easy and difficult homework assignments

Item does not contain fulltextTwo experiments were conducted to investigate the effects of two types of background television programs on students' performance on easy and difficult homework assignments. In both experiments, students in Grade 8 (Experiment 1: N = 90; Experiment 2: N = 144) were matched on reading proficiency. Subsequently, the participants were randomly assigned to one of three experimental conditions in which they did homework with (a) a Dutch-language soap opera, (b) English-language music videos, or (c) no television in the background. The execution of homework was hindered only when it was combined with watching a soap opera. The distraction effect of the soap opera was expressed either in a performance decrement (Experiment 1) or in an extension of performance time (Experiment 2)