Effect of multimodal plasmon resonances on the optical properties of five-pointed nanostars

© 2015 Author(s). The optical transmission and electric field distribution of plasmonic nanostructures dictate their performance in nano-optics and nano-biosensors. Here, we consider the use of hollow, five-pointed, star-shaped nanostructures made of Al, Ag, Au or Cu. We use simulations based on finite-difference time-domain and the discrete dipole approximation to identify the strongest plasmon resonances in these structures. In particular, we were seeking plasmon resonances within the visible part of the spectrum. The silver pentagrams exhibited the strongest such resonance, at a wavelength of about 530 nm. The visiblelight resonances of Au and Cu pentagrams were relatively weaker and red-shifted by about 50 nm. The main resonances of the Al pentagrams were in the ultra-violet. All the nanostars also showed a broad, dipolar-like resonance at about 1000 nm. Surprisingly, the maximum field intensities for the visible light modes were greatest along the flanks of the stars rather than at their tips, whereas those of the dipolar-like modes in the near-infrared were greatest at the tips of the star. These findings have practical implications for sensor design. The inclusion of a conformally hollow interior is beneficial because it provides additional 'hot spots'

Optimal piston crevice study in a rapid compression machine

Multi-dimensional effects such as vortex generation and heat losses from the gas to the wall of the reactor chamber have been an issue to obtaining a reliable RCM data. This vortex initiates a flow in the relatively cold boundary layer, which may penetrate the core gas. This resulting non-uniformity of the core region could cause serious discrepancies and give unreliable experimental data. To achieve a homogenous temperature field, an optimised piston crevice was designed using CFD modelling (Ansys fluent). A 2-Dimensional computational moving mesh is assuming an axisymmetric symmetry. The model adopted for this calculation is the laminar flow model and the fluid used was nitrogen. To get the appropriate crevice volume suitable for the present design, an optimisation of the five different crevice volume was modelled which resulted to about 2-10% of the entire chamber volume. The use of creviced piston has shown to reduce the final compressed gas temperature and pressure in the reactor chamber. All the crevice volumes between 2-10% of the chamber volume adequately contained the roll up vortexes, but the crevice volume of 282 mm 3 was chosen to be the best in addition to minimising the end gas pressure and temperature drop. The final pressure trace from experiment shows a reasonable agreement with the CFD model at compression and post compression stage

Energy consumption and capacity utilization of galvanizing furnaces

An explicit equation leading to a method for improving furnace efficiency is presented. This equation is dimensionless and can be applied to furnaces of any size and fuel type for the purposes of comparison. The implications for current furnace design are discussed. Currently the technique most commonly used to reduce energy consumption in galvanizing furnaces is to increase burner turndown. This is shown by the analysis presented here actually to worsen the thermal efficiency of the furnace, particularly at low levels of capacity utilization. Galvanizing furnaces are different to many furnaces used within industry, as a quantity of material (in this case zinc) is kept molten within the furnace at all times, even outside production periods. The dimensionless analysis can, however, be applied to furnaces with the same operational function as a galvanizing furnace, such as some furnaces utilized within the glass industry. © IMechE 2004

PRO: confronting resistance to rule-based medicine is essential to improving outcomes

The past 20 years have seen two great changes in the practice of medicine: the widespread adoption of evidence-based medicine, and the increasing challenge of managing complex multimorbid patients. Both these developments have resulted in clinical rules and protocols becoming ever more abundant and increasingly critical to delivering safe and effective patient care. These evidence-based clinical rules perform at least as well as expert opinion, and the increasing volume and quality of available clinical data suggests their performance could continue to improve. This article considers why clinicians deviate from effective rules, highlighting key issues such as the persisting culture of heroism, institutional inertia, deference to authority and personal heuristics. We argue that better rules can be created, and that clinical improvements will follow if there is a ‘common knowledge’ of these rules. Furthermore, we argue that there is a ceiling to the effectiveness of any rule, even one as simple as ensuring hand hygiene, unless individuals are held accountable for transgressions

The little book of thermofluids (3rd edition)

Reference book for Engineering students

Unfolding: A multisensorial dialogue in 'material time'

This essay investigates the multisensorial encounter between people, things and place, through the analysis of a shared experience in a museum store room. In the to-and-fro of dialogue, its co-authors discuss the visceral bodily response both experienced in the simple act of unfolding a piece of cloth in the attic room of a house. Theories of emplacement, flow, resonance and intimacy are explored across the co-authors’ home disciplines of craft and making, material culture, history, pedagogy and museology, but are also followed into less familiar territory including biology and neuroscience. The essay makes the case for a particular quality of time and space, found by both authors in the maker’s workshop and the museum store; a quality they describe as ‘material time’. In ‘material time’, being slows down, the body takes over and boundaries between self and other begin to dissolve. As a maker-educator and curator-historian, both located within the art school, the co-authors consider the implications of these findings for learning and creative practice

The Relative Contributions of Experiential Avoidance and Distress Tolerance to OC Symptoms

Background: Obsessive beliefs account for substantial (but not all) obsessive-compulsive (OC) symptoms. Intolerance of internal experiences (IIE), which encompasses the constructs of experiential avoidance (EA) and distress tolerance (DT), refers to difficulty managing unwanted thoughts, emotions, and other internal states, and might add to current explanatory models. Although IIE appears to be conceptually relevant to obsessive-compulsive (OC) symptoms, scant research has examined this relationship empirically. Aim: The present study examined the relative contributions of EA and DT as predictors of OC symptom dimensions. Method: A nonclinical sample ( n = 496) completed self-report questionnaires measuring general distress, EA, DT and OC symptom dimensions. Results: All variables of interest were significantly (all p s ≤ .001) correlated with one another, such that higher general distress, higher EA, and lower DT were associated with greater OC symptom severity for all symptom dimensions; however, only EA independently predicted obsessional symptoms, but not other OC symptom dimensions. Conclusions: One's willingness to endure (i.e. EA), rather than their ability to tolerate (i.e. DT) unpleasant internal experiences best predicts obsessional symptoms (i.e. obsessing) above and beyond general distress. Potential implications for understanding, assessing, and treating OC symptoms are discussed

Analysis: Voices from the movement: What can the Trade Union Act (2016) tell us about trade union organising?

yesIntroduction It is easy to think of the Trade Union Act (2016) as ‘Thatcher Round 2’: the economic strategy of austerity once again pits the haves against the have-nots, creating the potential for a re-invigorated trade union movement to return to its economically disruptive habits, which the government seeks to constrict. Thus, TUC General Secretary Frances O’Grady condemned the Conservatives for ‘refighting the battles of the 1980s’ instead of taking a more constructive approach (O’Grady, 2016). However, while the trade union legislation of the 1980s followed a decade marked by entrenched union disputes, the Trade Union Act (2016) has been introduced against a very different backdrop. The UK currently has historically low levels of industrial action, stagnating levels of union membership and limited areas of union density (DBIS, 2015; Godard, 2011; Dix et al, 2008). Could it be that the Trade Union Act (TUA) has more to tell us about trade union weakness than their strength? The Act comes at an important moment in the history of the labour move- ment. The Conservative austerity agenda not only attacks living standards, but reduces union membership through extensive job losses. The significance of this for the movement is exacerbated because the public sector is the most heavily unionised sector. This matters for many reasons, not least because the movement’s ability to resist the worst excesses of the austerity agenda rests on its membership and strength. This situation in turn shines a spotlight on what is perhaps the most pressing question facing the movement – the need for a model of unionism which can reach beyond the public sector, and in particular which meets the needs of the ever-growing body of precarious workers

Anxiety sensitivity as a predictor of outcome in the treatment of obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES: To address the fact that not all individuals who receive cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) exhibit complete symptom reduction, research has examined factors that predict outcome; however, no studies have examined anxiety sensitivity (AS) as a predictor of outcome of CBT for OCD. AS refers to the fear of anxious arousal that results from mistaken beliefs about the dangerousness of anxiety-related body sensations. It is important to understand whether AS influences OCD treatment outcome, considering that (a) some obsessions directly relate to AS, and (b) OCD patients with high AS may be reluctant to engage in anxiety-provoking components of CBT for OCD. METHODS: Patients (N = 187) with a primary diagnosis of OCD who received residential CBT for OCD participated in this study, which involved completing a self-report battery at pre- and post-treatment. RESULTS: Results supported study hypotheses, in that (a) baseline AS positively correlated with baseline OCD severity, and (b) greater baseline AS prospectively predicted higher posttreatment OCD symptom severity even after controlling for pretreatment OCD and depression severity. LIMITATIONS: The study was limited by its use of an older measure of AS, reliance on self-report measures, and nonstandardized treatment across participants. CONCLUSIONS: Findings highlight the importance of AS in the nature and treatment of OCD. Clinical implications and future directions are discussed

Genetic Algorithm optimised Chemical Reactors network: A novel technique for alternative fuels emission prediction

Sustainability of the conventional jet fuels and climate change has attracted the aviation sector to diversity to alternative fuels. However, fuel diversification requires an assessment of the long term impact to engine performance and engine emissions through the combustion process, as alternative fuels are not as well understood as conventional jet fuel. A detailed experimental study on alternative fuels emissions across the entire aircraft fleet is impractical. Therefore a plausible method of computer modelling combined Genetic Algorithm and Chemical Reactors network was developed to predict alternative fuels gaseous emissions, namely, Carbon Monoxide, Nitrogen Oxides and Unburned Hydrocarbons in aircraft engines. To evaluate the feasibility and accuracy of the technique, exhaust emission measurements were performed on a re-commissioned Artouste Mk113 Auxiliary Power Unit, located at the University of Sheffield's Low Carbon Combustion Centre. The simulation produced results with good agreements with the experimental data. The optimised model was used to extrapolate emissions data from different blends of alternative fuels that did not operate during the campaign. The proposed technique showed that it can develop a data base of alternative fuels emissions and also act as a guideline for alternative fuels development