Learning interaction patterns using diagrams varying in level and type of interactivity

An experiment was conducted to investigate the differences between learners when using computer based learning environments (CBLEs) that incorporated different levels of interactivity in diagrams. Four CBLEs were created with combinations of the following two interactivity properties: (a) the possibility to rotate the whole diagram (b) the possibility to move individual elements of the diagram in order to apprehend the relationships between them. We present and discuss the qualitative findings from the study in terms of the learners’ interaction patterns and their relevance for the understanding of performance scores. This supports our previous quantitative analysis showing an interaction between cognitive abilities and interactivity. Based on our findings we reflect on the possibilities to inform CBLEs with relevant information regarding learners’ cognitive abilities and representational preferences

Rejecting Religious Intolerance in South-East Asia

This article is going to discuss religious intolerance in Myanmar and Indonesia. Religious intolerance in these two countriesis driven by extreme ideologies which reject tolerance and diversity. These ideologies influence society and generate a culture of discrimination. In Myanmar, Muslims and Christians face a campaign of hatred led by a militant ultra-nationalist Buddhist movement which has resulted in several outbreaks of violence in the past five years. The predominantly Muslim Rohingya people have been the most severely victimized, enduring grave human rights violations which some international experts describe as ‘ethnic cleansing’, ‘crimes against humanity’ and potentially genocide.In Indonesia, a country with a tradition of religious tolerance, radical Islamism has become an increasing threat to non-Sunni Muslim minorities, particularly the Ahmadiyya and Shi’a communities, as well as Christians and other religions and to Sunni moderates who work to preserve Indonesia’s pluralism. To challenge the pervasive influence of intolerance, a variety of imaginative strategies are necessary.Recommendations will call state actors, media and civil society to work together to combat hate speech narratives through all available channels: education, the judiciary, campaigning platforms, the media, legislation and international diplomacy

INVESTIGATION OF FLOOD FORCES ON MASONRY ARCH BRIDGES USING SPH

Masonry arch bridges constitute a substantial proportion of the existing bridge stock in the UK and elsewhere. Although this durable bridge form often demonstrates good structural performance under normal service loading, bridges spanning watercourses are vulnerable to damage from flood-induced loads. Fluvial flooding generates both hydrostatic and hydrodynamic effects on the arch superstructure in addition to well known-scour effects on the substructure, all of these have the potential to cause structural failure. While research on scour is relatively well advanced, quantification of the hydrodynamics forces on the bridge superstructure is not yet comprehensively understood. Where fast flood flows come into contact with the bridge superstructure, highly transient behaviour is observed, this may develop into violent interactions, particularly where floating debris is involved. This paper explores the novel use of smoothed particle hydrodynamics (SPH) to capture detailed pressure time histories and associated spatial distribution on masonry arches subject to fluvial flooding. SPH uses moving particles to represent the flow and is therefore ideal to simulate highly transient and potentially violent free-surface flows encountered during fast events. A typical arch bridge and representative flood flows are simulated in order to demonstrate the capability of the method. Under typical real-life flood flows, significant hydrodynamic pressures are generated which need to be considered in the assessment of such structures

Modelling of tsunami-induced bore and structure interaction

A series of three-dimensional smoothed particle hydrodynamics (SPH) and finite-element (FE) models, with a domain in the form of a water tank, were undertaken to simulate tsunami-induced bore impact on a discrete onshore structure on a dry bed. The fluid motion was simulated using the SPH-based software DualSPHysics. The tsunami-like waves were represented by solitary waves with different characteristics generated by the numerical paddle wavemaker. Numerical probes were uniformly distributed on the structure's vertical surface providing detailed measures of the pressure distribution across the structure. The peak impact locations on the structure's surface were specifically determined and the associated peak pressures then compared with the prediction of existing commonly used design equations. Using the pressure–time histories from the SPH model, FE analysis was conducted with Abaqus to model the dynamic response of a representative timber structure. The results show that the equations used to estimate the associated pressure for design purposes can be highly non-conservative. By gaining a detailed insight into the impact pressures and structure response, engineers have the potential means to optimise the design of structures under tsunami impact loads and improve survivability. </jats:p

Composite modelling of subaerial landslide-tsunamis in different water body geometries and novel insight into slide and wave kinematics

This article addresses subaerial landslide-tsunamis with a composite (experimental-numerical) modelling approach. A shortcoming of generic empirical equations used for hazard assessment is that they are commonly based on the two idealised water body geometries of a wave channel (2D) or a wave basin (3D). A recent systematic comparison of 2D and 3D physical block model tests revealed wave amplitude differences of up to a factor of 17. The present article investigates two of these recently presented 2D-3D test pairs in detail, involving a solitary-like wave (scenario 1) and Stokes-like waves (scenario 2). Results discussed include slide and water particle kinematics and novel pressure measurements on the slide front. Instantaneous slide-water interaction power graphs are derived and potential and kinetic wave energies are analysed. Solitary wave theory is found most appropriate to describe the wave kinematics associated with scenario 1, whereas Stokes theory accurately describes the tsunami in scenario 2. The data of both scenarios are further used to calibrate the smoothed particle hydrodynamics (SPH) code DualSPHysics v3.1, which includes a discrete element method (DEM)-based model to simulate the slide-ramp interaction. Five intermediate geometries, lying between the ideal 2D and 3D cases, are then investigated purely numerically. For a “channel” geometry with a diverging side wall angle of 7.5°, the wave amplitudes along the slide axes were found to lie approximately halfway between the values observed in 2D and 3D. At 45°, the amplitudes are practically identical to those in 3D. The study finally discusses the implications of the findings for engineering applications and illustrates the potential and current limitations of DualSPHysics for landslide-tsunami hazard assessment

Modelling of seaweed ingress into a nuclear power station cooling water intake

Water Qualit