Effects of process parameters upon the shape memory and pseudo-elastic behaviors of laser-welded NiTi thin foil

This article discusses the effects of laser welding parameters such as power, welding speed, and focus position on the weld bead profile, microstructure, pseudo-elasticity (PE), and shape memory effect (SME) of NiTi foil with thickness of 250 um using 100W CW fiber laser. The parameter settings to produce the NiTi welds for analysis in this article were chosen from a fractional factorial design to ensure the welds produced were free of any apparent defect. The welds obtained were mainly of cellular dendrites with grain sizes ranging from 2.5 to 4.8 um at the weld centerline. A small amount of Ni3Ti was found in the welds. The onset of transformation temperatures (As and Ms) of the NiTi welds shifted to the negative side as compared to the as-received NiTi alloy. Ultimate tensile stress of the NiTi welds was comparable to the as received NiTi alloy, but a little reduction in the pseudo-elastic property was noted. Full penetration welds with desirable weld bead profiles and mechanical properties were successfully obtained in this study.

Exploring public awareness and perceptions of palliative care: a qualitative study

Background: Research suggests that the public appear to be confused about the meaning of palliative care. Given the ageing population and associated increase in the number of patients requiring palliative care, it is vital to explore the public's understanding of this concept. Health-promoting palliative care seeks to translate hospice and palliative care ideals into broader public health practice.

Aim: To explore public perceptions of palliative care and identify strategies to raise awareness.

Design: An exploratory qualitative approach. Participants: Semi-structured telephone interviews were undertaken (N = 50) with members of the public who volunteered to participate in the study. The interviews focused on knowledge and perceptions of palliative care, expectations of palliative care services and the identification of strategies to raise public awareness of palliative care. The interviews were audio recorded and content analysed.

Results: Most participants had a general knowledge of palliative care, largely influenced by their own personal experience. They identified that palliative care was about caring for people who were dying and maintaining comfort in the last days of life. Participants expectations of services included the following: holistic support, symptom management, good communication and practical support to enable choice and carer support. Key aspects identified for promoting palliative care were the development of understanding and use of the term itself and targeted educational strategies.

Conclusion: Experience of palliative care generates understanding in the general public who also have ideas for increasing knowledge and awareness. The findings can inform policymakers about strategies to raise public awareness of palliative care.

Hardware Acceleration of Background Modeling in the Compressed Domain

In intelligent video surveillance systems, scalability (of the number of simultaneous video streams) is important. Two key factors which hinder scalability are the time spent in decompressing the input video streams, and the limited computational power of the processor. This paper demonstrates how a combination of algorithmic and hardware techniques can overcome these limitations, and significantly increase the number of simultaneous streams. The techniques used are processing in the compressed domain, and exploitation of the multicore and vector processing capability of modern processors. The paper presents a system which performs background modeling, using a Mixture of Gaussians approach. This is an important first step in the segmentation of moving targets. The paper explores the effects of reducing the number of coefficients in the compressed domain, in terms of throughput speed and quality of the background modeling. The speedups achieved by exploiting compressed domain processing, multicore and vector processing are explored individually. Experiments show that a combination of all these techniques can give a speedup of 170 times on a single CPU compared to a purely serial, spatial domain implementation, with a slight gain in quality.

Stressor intensity determines antagonistic interactions between species invasion and multiple stressor effects on ecosystem functioning

Biological invasions, nutrient enrichment and ocean warming are known to threaten biodiversity and ecosystem functioning. The independent effects of these ecological stressors are well studied, however, we lack understanding of their cumulative effects, which may be additive, antagonistic or synergistic. For example, the impacts of biological invasions are often determined by environmental context, which suggests that the effects of invasive species may vary with other stressors such as pollution or climate change. This study examined the effects of an invasive seaweed (Sargassum muticum) on the structure and functioning of a benthic marine assemblage and tested explicitly whether these effects varied with nutrient enrichment and ocean warming. Overall, the presence of Sargassum muticum increased assemblage productivity rates and warming altered algal assemblage structure, which was characterised by a decrease in kelp and an increase in ephemeral green algae. The effects of Sargassum muticum on total algal biomass accumulation, however, varied with nutrient enrichment and warming producing antagonistic cumulative effects on total algal biomass accumulation. These findings show that the nature of stressor interactions may vary with stressor intensity and among response variables, which leads to less predictable consequences for the structure and functioning of communities.

Real time measurement and control of viscosity for extrusion processes using recycled materials

The aim of this paper is to develop a new generation of extruder control system for recycled materials which has ability to automatically maintain constant a polymer melt viscosity of mixed recycled polymers during extrusion, regardless of variations in the Melt Flow Index (MFI) of recycled mixed grade high density polyethylene (HDPE) feedstock. The variations in MFI are due to differences in the source of the recycled material used. The work describes how melt viscosity for specific extruder/die system is calculated in real time using the rheological properties of the materials, the pressure drop through the extruder die and the actual throughput measurements using a gravimetric loss-in-weight hopper feeder. A closed-loop controller is also developed to automatically regulate screw speed and barrel temperature profile to achieve constant viscosity and enable consistent processing of variable grade recycled HDPE materials. Such a system will improve processability of mixed MFI polymers may also reduce the risk of polymer melt degradation, reduce producing large volumes of scrap/waste and lead to improvement in product quality. The experimental results of real time viscosity measurement and control using a 38 mm single screw extruder with different recycled HDPEs with widely different MFIs are reported in this work.

Characterization of optical properties of PtSi at 3.392 mu m from 300 K to 85 K and relation of morphological effects

PtSi/Si Schottky junctions, fabricated using a conventional technique of Pt deposition with a subsequent thermal anneal, are examined using X-ray diffraction, atomic force microscopy and a novel prism/gap/sample optical coupling system. With the aid of X-ray diffraction and atomic farce microscopy it is shown that a post-anneal etch in aqua regia is essential for the removal of an unreacted, rough surface layer of Pt, to leave a much smoother PtSi film. The prism/gap/sample or Otto coupling rig is mounted in a small UHV chamber and has facilities for remote variation of the gap (by virtue of a piezoactuator system) and variation of the temperature in the range of similar to 300 K - 85 K. The system is used to excite surface plasmon polaritons on the outer surface of the PtSi and thus produce sensitive optical characterisation as a function of temperature. This is performed in order to yield an understanding of the temperature dependence of phonon and interface scattering of carriers in the PtSi.

Clozapine-induced liver injury and pleural effusion

Clozapine, whilst associated commonly with a transient and benign increase in liver enzymes, has also been associated with varying presentations of hepatitis in existing case reports. This report describes what we believe to be the first documented case of acute liver injury and pleural effusion associated with clozapine, resolving after cessation of the agent. The case supports existing literature in advocating a high index of suspicion, particularly in the 4-5 weeks following clozapine initiation, when considering nonspecific clinical symptoms and signs.

Psychosocial aspects in cardiac rehabilitation: From theory to practice. A position paper from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation of the European Society of Cardiology

A large body of empirical research shows that psychosocial risk factors (PSRFs) such as low socio-economic status, social isolation, stress, type-D personality, depression and anxiety increase the risk of incident coronary heart disease (CHD) and also contribute to poorer health-related quality of life (HRQoL) and prognosis in patients with established CHD. PSRFs may also act as barriers to lifestyle changes and treatment adherence and may moderate the effects of cardiac rehabilitation (CR). Furthermore, there appears to be a bidirectional interaction between PSRFs and the cardiovascular system. Stress, anxiety and depression affect the cardiovascular system through immune, neuroendocrine and behavioural pathways. In turn, CHD and its associated treatments may lead to distress in patients, including anxiety and depression. In clinical practice, PSRFs can be assessed with single-item screening questions, standardised questionnaires, or structured clinical interviews. Psychotherapy and medication can be considered to alleviate any PSRF-related symptoms and to enhance HRQoL, but the evidence for a definite beneficial effect on cardiac endpoints is inconclusive. A multimodal behavioural intervention, integrating counselling for PSRFs and coping with illness should be included within comprehensive CR. Patients with clinically significant symptoms of distress should be referred for psychological counselling or psychologically focused interventions and/or psychopharmacological treatment. To conclude, the success of CR may critically depend on the interdependence of the body and mind and this interaction needs to be reflected through the assessment and management of PSRFs in line with robust scientific evidence, by trained staff, integrated within the core CR team.

The Equiprobability Bias from a Mathematical and Psychological Perspective

The equiprobability bias (EB) is a tendency to believe that every process in which randomness is involved corresponds to a fair distribution, with equal probabilities for any possible outcome. The EB is known to affect both children and adults, and to increase with probability education. Because it results in probability errors resistant to pedagogical interventions, it has been described as a deep misconception about randomness: the erroneous belief that randomness implies uniformity. In the present paper, we show that the EB is actually not the result of a conceptual error about the definition of randomness. On the contrary, the mathematical theory of randomness does imply uniformity. However, the EB is still a bias, because people tend to assume uniformity even in the case of events that are not random. The pervasiveness of the EB reveals a paradox: The combination of random processes is not necessarily random. The link between the EB and this paradox is discussed, and suggestions are made regarding educational design to overcome difficulties encountered by students as a consequence of the EB.

Electron-acoustic solitons in an electron-beam plasma system with kappa-distributed electrons

We investigate the existence conditions and propagation properties of electron-acoustic solitary waves in a plasma consisting of an electron beam fluid, a cold electron fluid, and a hot suprathermal electron component modeled by a k-distribution function. The Sagdeev pseudopotential method was used to investigate the occurrence of stationary-profile solitary waves. We have determined how the soliton characteristics depend on the electron beam parameters. It is found that the existence domain for solitons becomes narrower with an increase in the suprathermality of hot electrons, increasing the beam speed, and decreasing the beam-to-cold electron population ratio.

Very high speed 17 Gbps SHACAL encryption architecture

Very high speed and low area hardware architectures of the SHACAL-1 encryption algorithm are presented in this paper. The SHACAL algorithm was a submission to the New European Schemes for Signatures, Integrity and Encryption (NESSIE) project and it is based on the SHA-1 hash algorithm. To date, there have been no performance metrics published on hardware implementations of this algorithm. A fully pipelined SHACAL-1 encryption architecture is described in this paper and when implemented on a Virtex-II X2V4000 FPGA device, it runs at a throughput of 17 Gbps. A fully pipelined decryption architecture achieves a speed of 13 Gbps when implemented on the same device. In addition, iterative architectures of the algorithm are presented. The SHACAL-1 decryption algorithm is derived and also presented in this paper, since it was not provided in the submission to NESSIE. © Springer-Verlag Berlin Heidelberg 2003.

Development and Application of Medication Appropriateness Indicators for Persons with Advanced Dementia: A Feasibility Study

Background: No studies have been conducted in the UK context to date that categorise medications in terms of appropriateness for patients with advanced dementia, or that examine medication use in these vulnerable patients.

Objectives: The objectives of this study were to categorise the appropriateness of a comprehensive list of medications and medication classes for use in patients with advanced dementia; examine the feasibility of conducting a longitudinal prospective cohort study to collect clinical and medication use data; and determine the appropriateness of prescribing for nursing home residents with advanced dementia in Northern Ireland (NI), using the categories developed.

Methods: A three-round Delphi consensus panel survey of expert clinicians was used to categorise the appropriateness of medications for patients with advanced dementia [defined as having Functional Assessment Staging (FAST) scores ranging from 6E to 7F]. This was followed by a longitudinal prospective cohort feasibility study that was conducted in three nursing homes in NI. Clinical and medication use for participating residents with advanced dementia (FAST scores ranging from 6E to 7F) were collected and a short test of dementia severity administered. These data were collected at baseline and every 3 months for up to 9 months or until death. For those residents who died during the study period, data were also collected within 14 days of death. The appropriateness ratings from the consensus panel survey were retrospectively applied to residents’ medication data at each data collection timepoint to determine the appropriateness of medications prescribed for these residents.

Results: Consensus was achieved for 87 (90 %) of the 97 medications and medication classes included in the survey. Fifteen residents were recruited to participate in the longitudinal prospective cohort feasibility study, four of whom died during the data collection period. Mean numbers of medications prescribed per resident were 16.2 at baseline, 19.6 at 3 months, 17.4 at 6 months and 16.1 at 9 months. Fourteen residents at baseline were taking at least one medication considered by the consensus panel to be never appropriate, and approximately 25 % of medications prescribed were considered to be never appropriate. Post-death data collection indicated a decrease in the proportion of never appropriate medications and an increase in the proportion of always appropriate medications for those residents who died.

Conclusions: This study is the first to develop and apply medication appropriateness indicators for patients with advanced dementia in the UK setting. The Delphi consensus panel survey of expert clinicians was a suitable method of developing such indicators. It is feasible to collect information on quality of life, functional performance, physical comfort, neuropsychiatric symptoms and cognitive function for this subpopulation of nursing home residents with advanced dementia.

Revisiting Iris Marion Young on Normalisation, Inclusion and Democracy

Vieten's edited collection brings together papers that were given at the I M Young Memorial Symposium 'Inclusion and Democracy Revisited', held in Amsterdam in 2012. The different chapters presented explore in-depth, Young's models of a 'politics of cultural difference', and a 'politics of positional difference' read in combination with her critique of normalisation. Young regards the latter as decisive to any change for the better when reaching out politically to a fairer and more just democratic society.
With the current political, economic and socio-cultural crisis in mind, the contemporary world of global speed and transformed societies in and beyond Europe needs a refinement of what we understand 'normalisation' and 'difference' to be. How can we connect to each other, and in what ways can Young's 'structural inequality model' be applied to develop alternative outlooks on how to enhance inclusion and democracy in different nation states?

Fibre laser joining of highly dissimilar materials: Commercially pure Ti and PET hybrid joint for medical device applications

Laser transmission joining (LTJ) is growing in importance, and has the potential to become a niche technique for the fabrication of hybrid plastic-metal joints for medical device applications. The possibility of directly joining plastics to metals by LTJ has been demonstrated by a number of recent studies. However, a reliable and quantitative method for defining the contact area between the plastic and metal, facilitating calculation of the mechanical shear stress of the hybrid joints, is still lacking. A new method, based on image analysis using ImageJ, is proposed here to quantify the contact area at the joint interface. The effect of discolouration on the mechanical performance of the hybrid joints is also reported for the first time. Biocompatible polyethylene terephthalate (PET) and commercially pure titanium (Ti) were selected as materials for laser joining using a 200 W CW fibre laser system. The effect of laser power, scanning speed and stand-off distance between the nozzle tip and top surface of the plastic were studied and analysed by Taguchi L9 orthogonal array and ANOVA respectively. The surface morphology, structure and elemental composition on the PET and Ti surfaces after shearing/peeling apart were characterized by SEM, EDX, XRD and XPS.

Design, production and characterisation of granular adsorbent material for arsenic removal from contaminated wastewater

The objective of this research was to design granulated iron oxide for the adsorption of heavy metals from wastewater. Polyvinyl acetate (PVAc) was chosen as a suitable binder; as it is water insoluble. Initial experiments on selection of suitable solvent of the polymer were carried out using three solvents namely; methanol, acetone and toluene. Based on the initial tests on product yield and mechanical strength, acetone was selected as the solvent for the polyvinyl acetate binder. Design of experiment was then used to investigate the influence of granulation process variables; impeller speed, binder concentration and liquid to solid ratio on the properties of the granular materials. The response variables in the study were granules mean size, stability in water and granule strength. The results showed that the combination of high impeller speed and high binder concentration favour the formation of strong and stable granules. Results also showed that leaching of the binder into the simulated was water was negligible. Trial adsorption experiments carried out using the strongest and most stable iron oxide granules produced in this work showed removal efficiency of around 70% of synthetic arsenic solutions with initial concentration of 1000 ppb.