Selective Infrared Sintering of Polymeric Powders using Radiant IR Heating & Ink Jet Printing

Established methods of rapid prototyping by sintering polymeric powders have predominantly focused on the use of lasers to selectively heat the polymeric particles together to form fused layers. Although effective, this route requires the laser to draw in the entire cross section of the slice and this limits the speed of the process, particularly for the production of thick walled parts. The use of IR radiant lamps to fuse an entire layer simultaneously has been explored by several groups and is now the basis of at least one commercially available process (Speed Part). An alternative route, developed by the Rapid Prototyping & Manufacturing Group (RPMG) at DeMonfort University, where areas of the powder bed are selectively treated to promote absorption by particular IR radiation will be described in this paper. The advantages of this approach and the limitations which must be overcome through further research will be fully discussed.Mechanical Engineerin

Laser Printing of Polymeric Materials

Electrophotography, the basis of photocopying and laser printing, is a reliable and well developed method of precisely depositing fine powders to form text or images. The process is highly adaptable to different types of materials; commercial toners are based on particular polymers but researchers have already shown the potential to deposit other materials including metals and ceramics. Once the powder layer has been deposited it can be heated to form a fused layer. This paper describes research conducted at DeMontfort University to develop a range of toners based on conventional engineering polymers and concludes by outlinning the challenges which will be tackled in the next phase of research.Mechanical Engineerin

Using Participatory Action Research to Support Knowledge Translation in Practice Settings

Health care practitioners must underpin their practice with sound scientific evidence. Yet realising this is not straightforward, especially in light of the amount and appropriateness of research evidence available and its relationship to practice, coupled with practitioners’ own ideology about the contribution of propositional knowledge (the use of propositions, ideas and theories). Knowledge translation is a collaborative means of making the best use of knowledge resulting from theory, policy and research evidence to ensure delivery of best practice to clients and carers to improve health outcomes. This paper presents participatory action research (PAR) as a methodology to meet the challenge of engaging professional staff in knowledge translation to support practice demands through a considered process of reflection, dialogue and action with others. Insights demonstrating PAR methods and results for knowledge translation will be drawn from the literature and from first-hand experience of a professional practice development research project involving occupational therapists working across a health and academic setting in the United Kingdom (UK).The principles and practice of PAR methodology, including a brief history of its purpose and development, are examined. Strategies for ‘getting going’, including consideration of research participant roles, examination of authentic participation and the process of analysis or meaning making are discussed. The overall aim of the paper is to illustrate how PAR might usefully be applied in practice settings to support knowledge translation

Chemical Weathering and Erosional Transport in an Ancient Shield Terrain

This project investigates how isotope systems respond to changes in continental weathering processes and the consequences for the chemical composition of the oceans. Both experimental and natural data indicate that Li and Mg stable isotope systems preserve information on the mineral reactions controlling water chemistry. Dissolution experiments indicate that primary mineral dissolution has little effect on Li, but does fractionate the isotopes of Mg, whereas secondary mineral formation involves preferential uptake of the lighter isotopes of both Li and Mg. Glacial regions have low chemical weathering rates so their rivers should, in principal, have Li isotope compositions (δ7Li) that are similar to those of the underlying rock. In practise, glacial rivers in Greenland have δ7Li values that differ significantly from the source rock. Subglacial uptake of 6Li by iron oxyhydroxides appears to influence the riverine Li isotope composition. In contrast, the principal control on Mg isotopes in glacial rivers appears to be primary mineral weathering. Carbonate dissolution dominates the chemistry of glacial rivers, and this phase possesses a light Mg isotope composition imparting this signature to the Greenland rivers. Both the Li and Mg isotope compositions of glacial rivers are similar to their respective global riverine averages, suggesting that the impact of glaciation on the Li and Mg composition of seawater may be small. The Re-Os radiogenic isotope system is also a useful tracer of continental weathering, its composition in the oceans being sensitive to changes in the flux and composition of continental weathering. Laterites are widespread in tropical regions and are shown to contain high concentrations of highly unradiogenic Os. Consequently, their subsequent weathering and erosion has potential to significantly affect the Os isotope composition delivered to the oceans

Cognitive Profiles and the Impact of Medication on Children with Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most frequently diagnosed disorders in children and adolescents. Individuals with ADHD often display behavioral symptoms, including inattention and/or impulsivity, which can also lead to struggles in the school setting. Current research has suggested that deficits in processing speed and working memory are common in individuals diagnosed with ADHD and are often seen on measures of cognitive ability. Positive outcomes have been associated with the use of psychostimulant medication to treat the symptoms of ADHD, although little research has supported this form of treatment to improve cognitive functioning in individuals diagnosed with ADHD. The current study replicated and expanded on Friedman (2006) and McLaughlin’s (2009) studies. The purpose of this study was to compare the cognitive profiles of children diagnosed with ADHD and a control sample. The cognitive profiles were analyzed at the Full Scale, Index, and Subtest levels. In addition, the current study sought to determine whether or not the medication status impacted performance on the cognitive measures. The results of this study indicated that individuals with ADHD did perform lower on measures of Full Scale IQ, Perceptual Reasoning, Working Memory and Processing Speed. It was also noted that the use of medication yielded higher performance, as compared with the nonmedicated ADHD group. At the subtest level analysis, ADHD individuals typically performed better on the following task pairs: they worked better on verbal reasoning than on working memory tasks; they were more successful with perceptual reasoning than with processing speed tasks. In addition, ADHD groups also performed roughly the same on the following task pairs: on nonverbal reasoning and working memory tasks, on verbal reasoning and processing speed, on verbal reasoning and perceptual reasoning, and on working memory and processing speed. Regarding medication status, positive trends were noted for medication use, but minimal statically significant results were found. Significant results were found in favor of medication use for the VCI \u3e PSI and PRI \u3e VCI comparisons