Upcycling by grafting onto semi-crystalline polymers using supercritical CO2

The creation of graft copolymers by selectively grafting a second polymer to the amorphous fraction of a semi-crystalline polymer in supercritical CO₂ is demonstrated herein. The graft copolymer is synthesized by free radical polymerization of a vinyl monomer within the semi-crystalline polymer below its melt temperature. Such conditions afford selective grafting on the amorphous regions (block “B”) while leaving the crystalline domains (block “A”) unmodified. Accordingly, unique A-B, A-B-A, A-B-A-B-A, and so forth. block structures are formed. In this work, styrene is polymerized within polyamide 6, polyethylene terephthalate, and isotactic polypropylene. Purification of these material is performed to remove the un-grafted homopolymer, allowing for determination of the graft yield, the portion of polymer which covalently bonds to the semi-crystalline matrix. Grafting yields achieved in polyamide 6, polyethylene terephthalate, and isotactic polypropylene were 98%, 59%, and 15%, respectively. Property enhancements were observed upon further characterization of polystyrene-polyamide 6 copolymers, including high glass transition temperatures, the ability to be remelted, and tunable grafting molecular weight. Additionally, hydrophobicity is controlled by varying polystyrene composition. The remarkable range of accessed properties demonstrates this as a potential route to upcycling plastics.     

Exploring creative thinking in graphically mediated synchronous dialogues

This paper reports on an aspect of the EC funded Argunaut project which researched and developed awareness tools for moderators of online dialogues. In this study we report on an investigation into the nature of creative thinking in online dialogues and whether or not this creative thinking can be coded for and recognized automatically such that moderators can be alerted when creative thinking is occurring or when it has not occurred after a period of time. We outline a dialogic theory of creativity, as the emergence of new perspectives from the interplay of voices, and the testing of this theory using a range of methods including a coding scheme which combined coding for creative thinking with more established codes for critical thinking, artificial intelligence pattern-matching techniques to see if our codes could be read automatically from maps and ‘key event recall’ interviews to explore the experience of participants. Our findings are that: (1) the emergence of new perspectives in a graphical dialogue map can be recognized by our coding scheme supported by a machine pattern-matching algorithm in a way that can be used to provide awareness indicators for moderators; (2) that the trigger events leading to the emergence of new perspectives in the online dialogues studied were most commonly disagreements and (3) the spatial representation of messages in a graphically mediated synchronous dialogue environment such as Digalo may offer more affordance for creativity than the much more common scrolling text chat environments. All these findings support the usefulness of our new account of creativity in online dialogues based on dialogic theory and demonstrate that this account can be operationalised through machine coding in a way that can be turned into alerts for moderators.     

Herstellung und Eigenschaften von hochfesten, vergüteten Grobblechen

The basis for an efficient material development is provided by the knowledge of the quantitative effects of alloying elements and processing parameters on the mechanical properties of heavy plates. For this reason the influence of alloying elements on the mechanical properties of quenched and tempered heavy plates was investigated in an extensive laboratory program. In this article the approach and the results are presented.     

A dialogic understanding of the relationship between CSCL and teaching thinking skills

How to teach flexible thinking and learning skills, particularly creativity and the skill of “learning to learn,” is a key concern for CSCL in the context of the emerging Networked Society. The currently dominant paradigms for supporting pedagogical design within CSCL, including socio-cultural theory, are limited in the support that they can offer to the project of teaching general thinking skills. This paper uses critical literature review, conceptual analysis, and evidence from case studies to argue for the value of a dialogic interpretative framework that links the goal of teaching thinking with the method of CSCL. The evidence reviewed suggests that dialogue is itself the primary thinking skill from which all others are derived. It is argued from this that dialogic theory offers a possible solution to the problem of how to conceptualize general thinking skills for CSCL: this is that teaching dialogue as an end in itself promotes the learning of general thinking skills. Implications of the proposed framework for pedagogical design are brought out through case studies illustrating the use of CSCL to broaden and deepen dialogic spaces of reflection.     

Movement Awareness for Ubiquitous Game Control

This paper describes a sensing system for recognising and characterising human movements and its application to ubiquitous gaming. In particular this paper considers the control of computer games through players interacting with the physical environment around them in a natural and appropriate manner. This pushes the interface into the environment, and pulls ubiquitous computing into the game. This is achieved using a sentient computing system. Such a system senses the location, motions, actions and even physiological responses of users. This sensory data can be used to interface and control a game. A good example is 3D first-person games and we demonstrate a system in which actions in the game are mapped to similar actions in the real world. Correspondence to: R. Headon, Laboratory for Communications Engineering, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK. Email: rph25@cam.ac.uk     

Approaching a formal framework for graphics software standards

A graphics software standard has to specify precisely what the software is expected to do. For this purpose, the paper exhibits a formal framework for the specification of software modules which may be structured hierarchically and which may be based on abstract data types. An important aspect concerns the special mathematical semantics of the data types: The semantics of a type is its class of all finitely generated models. This semantics enables a uniform definition of a standard which, nevertheless, may cover a large variety of implementations on very different graphics hardware devices. The kernel of this approach is some axiomatic characterization of the notion of finitely generated images. Another important aspect is that, from such a formal software specification, an implementation may be derived. At least in principle, the careful documentation of such a program derivation could serve as a basis for a verification-oriented certification of graphics standard implementations.