Universal features of grain boundary networks in FCC materials

Grain boundary character distributions and triple junction distributions have been determined for 70 experimental microstructures, comprising aluminum-, copper-, austenitic iron- and nickel-based alloys in a wide variety of processed states. In these FCC metals, the fraction of coincidence site lattice (CSL) boundaries ranges from about 12% (as for a random Mackenzie distribution) to values as high as 75%. Despite wide variations in composition, processing, and grain size, we find that the grain boundary character distribution and triple junction distributions of these materials have striking similarities, and can be described by just a few parameters. This universality arises due to the highly non-random laws that govern the assembly of the grain boundary network, and due to the kinematic limitation that CSL boundaries arise primarily through twinning.     

A theory of superconducting transition temperature for non-phonon interactions

For non-phonon interaction mechanisms which span a frequency range comparable to the Fermi energy, solution of the Eliashberg equation must cover both a range of frequencies and a range of momentum values. Kirzhnits, Maksimov, and Khomskii (KMK) have derived an intergral equation for the superconducting transition where frequency is eliminated in favor of the momentum. We have found a systematic correction to the KMK equation and investigated the effect onT _cfor model interactions.Supported by the National Science Foundation under grant DMR-80-18440.     

Computer game design: Opportunities for successful learning

Developing children as successful learners is a key aim of A Curriculum for Excellence in Scotland. This paper presents qualitative results from an eight week exploratory field study in which a class of ten year olds made their own computer games. The analysis focuses on the development of aspects of successful learning as identified in the curriculum: enthusiasm and motivation for learning, determination to reach high standards of achievement, independent and group learning, and linking and applying learning in new situations. As teachers have an important role in facilitating and supporting learners as they use technology, the paper concludes with a discussion of implications for classroom practice.     

The Product Piracy Conflict Matrix – Finding Solutions to Prevent Product Piracy

Product and brand piracy has developed into a worldwide mass phenomenon. Affected companies are not only burdened with commercial losses such as lost sales volume and lower sales prices, but also by decreasing brand value and company reputation, lower licence revenues and, finally, costs for counteracting product piracy. Companies are gradually facing up to the challenge and taking action. Besides legal measures, an increasing number of firms are also willing to implement strategic and technical measures in their organizations or products respectively. A number of non‐legal mechanisms have recently been identified, and efforts to structure these mechanisms are in progress. However, so far systematic, methodological guidance in matching mechanisms with specific products and corporate boundary conditions is basically non‐existent. Focusing on this issue, the paper introduces a new TRIZ‐based method to create solutions concerning product piracy. The so‐called Product Piracy Conflict matrix (PPC matrix) resembles the well‐established TRIZ contradiction table and has been designed to help companies create powerful protection concepts while avoiding undesired or harmful effects within their own value chains.     

A new generation of cooperative development paradigm in the tool and die making branch: strategy and technology

To keep up with the changed corporate strategy and sourcing strategy of customers, the tool and die industry is more than ever obliged to improve its development strategy and justify its role within the value chain. The main aims of this research are to (1) comprehend, formalize and explore the new cooperation relationship between product customers and tool and die suppliers based on the rational principles of early supplier involvement (ESI); and (2) develop a new generation of cooperative development strategy, which can provide a powerful tool for a stronger integration of tool maker into the process chain of product development. Making use of EDEN™ software, a supporting environment to implement the new cooperative development strategy in tool and die making branch has been established. The implementation environment comprises three components: enterprise design, product and tool development, as well as benchmarking, which can provide a comprehensive support to cooperative development in the tool and die making branch, not only initial implementation support but more importantly a means to sustain and continuously improve the proposed cooperative development strategy. Individual industrial cases already reveal the potential of this new generation of cooperative development paradigm, which has enlightened that the future tool maker is a highly and competent partner along the value chain of the entire product life cycle.     

Contributions to the interfacial adhesion in co-sintered bilayers

The adhesive strength of co-sintered bilayers is influenced by several factors, including the nature of bonding along the joined interface, residual stresses evolved during processing, and the sintered properties of the individual layers. Here these separate contributions are isolated through careful control of the co-sintering process for W/Al₂O₃ bilayers, and in particular through control of the W-layer properties by using the process of activated sintering. Four-point bending delamination tests are used to evaluate adhesion and strength of the bilayers, and the interfacial fracture mechanics of the system is numerically studied using finite element simulations. Improvements in sintered density are found to increase the adhesive strength of the system only up to a point, beyond which shrinkage mismatch compromises the intrinsic toughness of the interface.