Evaluation of Energy Saving Operational Modes for Industrial Fracture Connected Processes on the Basis of Incubation Time Fracture Criterion

A problem for a central crack in a plate subjected to plane strain conditions is investigated.Mode Ⅰ crack loading is created by a dynamic pressure pulse applied at a large distance from the crack.It was found that for a certain combination of amplitude and duration of the pulse applied,the energy transmitted to the sample has a strongly marked minimum,meaning that with the pulse amplitude or duration moving away from the optimal values,minimum energy required for initiation of crack growth increases rapidly.The results obtained indicate a possibility to optimise energy consumption of different industrial processes connected with fracture.Much could be gained in,for example,drilling or rock pounding where energy input accounts for the largest part of the process cost.Presumably further investigation of the effect observed can make it possible to predict optimal energy saving parameters,i.e.frequency and amplitude of impacts,for industrial devices,e.g.bores,grinding machines,and hence significantly reduce the process cost.The prediction can be given based on the parameters of the media fractured (material parameters,prevalent crack length and orientation,etc.).     

Using scenarios to design complex technology-enhanced learning environments

Science Created by You (SCY) learning environments are computer-based environments in which students learn about science topics in the context of addressing a socio-scientific problem. Along their way to a solution for this problem students produce many types of intermediate products or learning objects. SCY learning environments center the entire learning process around creating, sharing, discussing, and re-using these learning objects. This instructional approach requires dedicated instructional designs, which are supplied in the form of what are called pedagogical scenarios. A SCY pedagogical scenario presents the learning process as an organized assembly of elementary learning processes, each associated with a specific learning object and a tool for creating this learning object. Designing a SCY learning environment is basically a two-step procedure: the first step is to select one of the available scenarios, and the second step is to define the domain content. The SCY technical infrastructure then handles the instantiation of the scenario as a SCY computer-based learning environment. In this article we describe the SCY pedagogical design scenarios and report on our experiences in designing four different SCY learning environments.