Towards an approach for analysing external representations created during sensemaking using generative grammar

During sensemaking, users often create external representations to help them make sense of what they know, and what they need to know. In doing so, they necessarily adopt or construct some form of representational language using the tools at hand. By describing such languages implicit in representations we believe that we are better able to describe and differentiate what users do and better able to describe and differentiate interfaces that might support them. Drawing on approaches to the analysis of language, and in particular, Mann and Thompson’s Rhetorical Structure Theory, we analyse the representations that users create to expose their underlying ‘visual grammar’. We do this in the context of a user study involving evidential reasoning. Participants were asked to address an adapted version of IEEE VAST 2011 mini challenge 3 (interpret a potential terrorist plot implicit in a set of news reports). We show how our approach enables the unpacking of the heterogeneous and embedded nature of user-generated representations and allows us to show how visual grammars evolve and become more complex over time in response to evolving sensemaking needs

Thermo-mechanical properties of a highly filled polymeric composites for Fused Deposition Modeling

This paper presents an investigation on thermal and mechanical properties of new metal-particle filled Acrylonitrile Butadiene Styrene (ABS) composites for applications in Fused Deposition Modeling rapid prototyping process. Test samples of Iron/ABS and Copper/ABS composites involving metal content up to 40% by volume have been made by controlled centrifugal mixing, thermally compounded through a single-screw extruder and compression moulding. Dynamic Mechanical Analysis (DMA) techniques were used in order to characterize viscoelastic properties of these newly developed composites materials for use in Fused Deposition Modeling process. It has been shown that significant improvements of ABS thermal and mechanical properties due to incorporation of metallic fillers can potentially promote processing of high performance and functional prototypes on the existing FDM platform for a wide range of applications. Sample prototypes from the new composite materials have been successfully made and tested

Non-woven textiles from melt spun recycled PET

The influence of nucleating agents on the physical properties of melt drawn fibres produced from post-consumer recycled poly(ethylene terephthalate) (PETP) soft drink bottles was investigated. Various levels of titanium dioxide and carbon black were added using linear low density polyethylene and PETP as carriers. In the absence of nucleating agent, processability through the spinning plant was poor, but once the masterbatch additives were added the level of crystallinity and processability increased. It was concluded that post-consumer polymer of appropriate purity and intrinsic viscosity was suitable for the manufacture of non-woven textiles, and that textiles produced at 5-8% higher fabric weights had comparable physical properties to those of virgin materials

A comparative study of force fields for predicting shape memory properties of liquid crystalline elastomers using molecular dynamic simulations

Molecular dynamic (MD) simulation techniques are increasingly being adopted as efficient computational tools to design novel and exotic classes of materials for which traditional methods of synthesis and prototyping are either too costly, unsafe, and time-consuming in laboratory settings. Of such class of materials are liquid crystalline elastomers (LCEs) with favorable shape memory characteristics. These materials exhibit some distinct properties, including stimuli responsiveness to heat or UV and appropriate molecular structure for shape memory behaviors. In this work, the MD simulations were employed to compare and assess the leading force fields currently available for modeling the behavior of a typical LCE system. Three force fields, including Dreiding, PCFF, and SciPCFF, were separately assigned to model the LCE system, and their suitability was validated through experimental results. Among these selected force fields, the SciPCFF produced the best agreement with the experimentally measured thermal and viscoelastic properties compared to those of simulated steady-state density, transition temperature, and viscoelastic characteristics. Next, shape fixity (Rf) and shape recovery (Rr) of LCEs were estimated using this force field. A four-step simulated shape memory procedure proceeded under a tensile mode. The changes in molecular conformations were calculated for Rf and Rr after the unloading step and the reheating step. The results revealed that the model LCE system exhibits characteristic behaviors of Rf and Rr over the thermomechanical shape memory process, confirming the suitability of selected force field for use in the design and prediction of properties of typical LCE class of polymers

New Cooling Channel Design for Injection Moulding

Abstract — Injection moulding is one of the most versatile and important operation for mass production of plastic parts. In this process, cooling system design is very important as it largely determines the cycle time. A good cooling system design can reduce cycle time and achieve dimensional stability of the part. This paper describes a new square sectioned conformal cooling channel system for injection moulding dies. Both simulation and experimental verification have been done with these new cooling channels system. Comparative analysis has been done for an industrial part, a plastic bowel, with conventional cooling channels using the Moldflow simulation software. Experimental verification has been done for a test plastic part with mini injection moulding machine. Comparative results are presented based on temperature distribution on mould surface and cooling time or freezing time of the plastic part. The results provide a uniform temperature distribution with reduced freezing time and hence reduction in cycle time for the plastic part. Index Terms—Conformal cooling channel, Cycle time Moldflow, Square shape

Use of post consumer recycled polyethylene terephthalate (PET) in the manufacture of geotextiles and carpet fibre

Abstract not available

Thermo-mechanical properties of an iron-filled abs composite for fused deposition modelling

Astract not available

Thermal-structural analysis of bi-metallic conformal cooling for injection moulds

In injection moulding process, cooling time greatly affects the total cycle time. As thermal conductivity is one of the main factors for conductive heat transfer in cooling phase of IMP, a cooling channel made by higher thermal conductive material will allow faster extraction of heat from the molten plastic materials, thus resulting in shorter cycle time and higher productivity. The main objective of this paper is to investigate bi-metallic conformal cooling channel design with high thermal conductive copper tube insert for injection moulds. Thermal-structural finite element analysis has been carried out with ANSYS workbench simulation software for a mould with bi-metallic conformal cooling channels and the performance is compared with a mould with conventional straight cooling channels for an industrial plastic part. Experimental verification has been carried out for the two moulds using two different types of plastics, polypropylene (PP) and acrylonitrile butadiene styrene, in a mini injection moulding machine. Simulation and experimental results show that bi-metallic conformal cooling channel design gives better cycle time, which ultimately increases production rate as well as fatigue life of the mould

Improvement of plastic properties using square shape conformal cooling channels

Effective cooling channel design in the mould is important because it not only affects cycle time but also quality of the injection moulded plastic part. A good cooling system design can reduce cycle time and achieve dimensional stability of the part which will consequently produce better quality part. This paper describes a new square sectioned conformal cooling channel system for injection moulding. Both simulation and experimental verification have been done with these new cooling channels system. Comparative analysis has been done for an industrial part, a plastic bowl, with conventional cooling channels using the Moldflow simulation software. Experimental verification has been done for a test plastic part with mini injection moulding machine. Comparative results are presented based on temperature distribution on mould surface, cooling time or freezing time of the plastic part and hardness number of the plastic part. Results provide a uniform temperature distribution and hardness number with reduced freezing time of the plastic part

Cycle time optimization and part quality improvement using novel cooling channels in plastic injection moulding

Cooling channel design in injection moulding is very important as it greatly affects the cycle time as well as the shrinkage and warpage of the plastic part. Traditionally, cooling channels have been machined into mould components with gun-barrel drilling, with that only straight channels were possible to manufacture. An advanced method of cooling system that 'conforms' to the shape of the part in the mould can be made possible with free form fabrication technique such as DMD (direct metal deposition). This paper presents an investigation on the optimization of mould design of conformal cooling channels of different cross sections for plastic injection moulding. Comparative study has been done with the conventional straight cooling channels. ANSYS thermal simulation software has been used to get comparative temperature profile on the mould and Moldflow simulation software has been used to compare shrinkage, warpage and temperature profile of the part itself during moulding process . Comparative results are presented based on temperature distribution and cooling time for the mould and warpage deflection, volumetric shrinkage and temperature profile of the part. The results provide a uniform temperature distribution with reduced shrinkage and warpage and reduction in cycle time for the plastic part