Investigation into high-temperature corrosion in a large-scale municipal waste-to-energy plant

High-temperature corrosion in the superheater of a large-scale waste-to-energy plant was investigated. A comparison of nickel-/iron-based alloys and austenitic stainless steel probes placed in the furnace demonstrated that temperature and particle deposition greatly influence corrosion. Nickel-based alloys performed better than the other metal alloys, though an aluminide coating further increased their corrosion resistance. Sacrificial baffles provided additional room for deposit accumulation, resulting in vigorous deposit-induced corrosion. Computational modelling (FLUENT code) was used to simulate flow characteristics and heat transfer. This study has shown that the use of aluminide coatings is a promising technique for minimising superheater corrosion in such facilities. (C) 2010 Elsevier Ltd. All rights reserved

Kinematics and constraints associated with swashplate blade pitch control

An important class of techniques to reduce helicopter vibration is based on using a Higher Harmonic controller to optimally define the Higher Harmonic blade pitch. These techniques typically require solution of a general optimization problem requiring the determination of a control vector which minimizes a performance index where functions of the control vector are subject to inequality constraints. Six possible constraint functions associated with swashplate blade pitch control were identified and defined. These functions constrain: (1) blade pitch Fourier Coefficients expressed in the Rotating System, (2) blade pitch Fourier Coefficients expressed in the Nonrotating System, (3) stroke of the individual actuators expressed in the Nonrotating System, (4) blade pitch expressed as a function of blade azimuth and actuator stroke, (5) time rate-of-change of the aforementioned parameters, and (6) required actuator power. The aforementioned constraints and the associated kinematics of swashplate blade pitch control by means of the strokes of the individual actuators are documented

Comparison of three controllers applied to helicopter vibration

A comparison was made of the applicability and suitability of the deterministic controller, the cautious controller, and the dual controller for the reduction of helicopter vibration by using higher harmonic blade pitch control. A randomly generated linear plant model was assumed and the performance index was defined to be a quadratic output metric of this linear plant. A computer code, designed to check out and evaluate these controllers, was implemented and used to accomplish this comparison. The effects of random measurement noise, the initial estimate of the plant matrix, and the plant matrix propagation rate were determined for each of the controllers. With few exceptions, the deterministic controller yielded the greatest vibration reduction (as characterized by the quadratic output metric) and operated with the greatest reliability. Theoretical limitations of these controllers were defined and appropriate candidate alternative methods, including one method particularly suitable to the cockpit, were identified

The social patterning of deaths due to assault in Scotland, 1980–2005: population-based study

<p>OBJECTIVES: The objectives of this study were to explore the extent of the social gradient for deaths due to assault and its impact on overall inequalities in mortality and to investigate the contribution to assault mortality of knives and other sharp weapons. </p> <p>DESIGN: An analysis of death records and contemporaneous population estimates was conducted. </p> <p>SETTING: The authors investigated the social patterning of homicide in Scotland. </p> <p>PARTICIPANTS: This study included deaths between 1980 and 2005 due to assault. </p> <p>MAIN MEASUREMENTS: Death rates were standardised to the European standard population. Time trends were analysed and inequalities were assessed, using rate ratios and the slope index of inequality, along axes defined by individual occupational socioeconomic status and area deprivation. </p> <p>RESULTS: An increase in mortality due to assault was most pronounced at ages 15-44 and was steeper among assaults involving knives. The death rate among men in routine occupations aged 20-59 was nearly 12 times that of those in higher managerial and professional occupations. Men under 65 living in the most deprived quintile of areas had a death rate due to assault 31.9 times (95% CI 13.1 to 77.9) that of those living in the least deprived quintile; for women, this ratio was 35.0 (4.8 to 256.2). Despite comprising just 3.2% of all male deaths between 15 and 44 years, assault accounted for 6.4% of the inequalities in mortality. </p> <p>CONCLUSIONS: Inequalities in mortality due to assault in Scotland exceed those in other countries and are greater than for other causes of death in Scotland. Reducing mortality and inequalities depends on addressing the problems of deprivation as well as targeting known contributors, such as alcohol use, the carrying of knives and gang culture.</p&gt

Use of record-linkage to handle non-response and improve alcohol consumption estimates in health survey data: a study protocol

<p>Introduction: Reliable estimates of health-related behaviours, such as levels of alcohol consumption in the population, are required to formulate and evaluate policies. National surveys provide such data; validity depends on generalisability, but this is threatened by declining response levels. Attempts to address bias arising from non-response are typically limited to survey weights based on sociodemographic characteristics, which do not capture differential health and related behaviours within categories. This project aims to explore and address non-response bias in health surveys with a focus on alcohol consumption.</p> <p>Methods and analysis: The Scottish Health Surveys (SHeS) aim to provide estimates representative of the Scottish population living in private households. Survey data of consenting participants (92% of the achieved sample) have been record-linked to routine hospital admission (Scottish Morbidity Records (SMR)) and mortality (from National Records of Scotland (NRS)) data for surveys conducted in 1995, 1998, 2003, 2008, 2009 and 2010 (total adult sample size around 40 000), with maximum follow-up of 16 years. Also available are census information and SMR/NRS data for the general population. Comparisons of alcohol-related mortality and hospital admission rates in the linked SHeS-SMR/NRS with those in the general population will be made. Survey data will be augmented by quantification of differences to refine alcohol consumption estimates through the application of multiple imputation or inverse probability weighting. The resulting corrected estimates of population alcohol consumption will enable superior policy evaluation. An advanced weighting procedure will be developed for wider use.</p> <p>Ethics and dissemination: Ethics approval for SHeS has been given by the National Health Service (NHS) Multi-Centre Research Ethics Committee and use of linked data has been approved by the Privacy Advisory Committee to the Board of NHS National Services Scotland and Registrar General. Funding has been granted by the MRC. The outputs will include four or five public health and statistical methodological international journal and conference papers.</p&gt

How effective is the Forestry Commission Scotland's woodland improvement programme--'Woods In and Around Towns' (WIAT)--at improving psychological well-being in deprived urban communities? A quasi-experimental study

Introduction: There is a growing body of evidence that suggests that green spaces may positively influence psychological well-being. This project is designed to take advantage of a natural experiment where planned physical and social interventions to enhance access to natural environments in deprived communities provide an opportunity to prospectively assess impacts on perceived stress and mental well-being.<p></p> Study design and methods: A controlled, prospective study comprising a repeat cross-sectional survey of residents living within 1.5 km of intervention and comparison sites. Three waves of data will be collected: prephysical environment intervention (2013); postphysical environment intervention (2014) and postwoodland promotion social intervention (2015). The primary outcome will be a measure of perceived stress (Perceived Stress Scale) preintervention and postintervention. Secondary, self-report outcomes include: mental well-being (Short Warwick-Edinburgh Mental Well-being Scale), changes in physical activity (IPAQ-short form), health (EuroQoL EQ-5D), perception and use of the woodlands, connectedness to nature (Inclusion of Nature in Self Scale), social cohesion and social capital. An environmental audit will complement the study by evaluating the physical changes in the environment over time and recording any other contextual changes over time. A process evaluation will assess the implementation of the programme. A health economics analysis will assess the cost consequences of each stage of the intervention in relation to the primary and secondary outcomes of the study.<p></p> Ethics and dissemination: Ethical approval has been given by the University of Edinburgh, Edinburgh College of Art Research, Ethics and Knowledge Exchange Committee (ref. 19/06/2012). Findings will be disseminated through peer-reviewed publications, national and international conferences and, at the final stage of the project, through a workshop for those interested in implementing environmental interventions.<p></p&gt

Experimental effects of mindfulness inductions on self-regulation: Systematic review and meta-analysis.

Self-regulation is the control of aspects of the self to allow pursuit of long-term goals, and it is proposed as a central pathway through which mindfulness may exert benefits on well-being. However, the effects of a single mindfulness induction on self-regulation are not clear, as there has been no comprehensive review of this evidence. The current review synthesized existing findings relating to the effect of a mindfulness induction delivered in a laboratory setting on measures of self-regulation. Twenty-seven studies were included and grouped according to 3 outcomes: regulation of experimentally induced negative affect (k = 15; meta-analysis), emotion-regulation strategies (k = 7) and executive functions (k = 9; narrative synthesis). A mindfulness induction was superior to comparison groups in enhancing the regulation of negative affect (d = -.28). Executive-function performance was enhanced only when the experimental design included an affect induction or when the outcome was sustained attention. The effect on emotion-regulation strategies was inconclusive, but with emerging evidence for an effect on rumination. Overall, the findings indicate that, in the form of an induction, mindfulness may have the most immediate effect on attention mechanisms rather than exerting cognitive changes in other domains, as are often reported outcomes of longer mindfulness training. Through effecting change in attention, emotion regulation of negative affect can be enhanced, and subsequently, executive-function performance more quickly restored. The interpretations of the findings are caveated with consideration of the low quality of many of the included study designs determined by the quality appraisal tool

CrCuAgN PVD nanocomposite coatings: Effects of annealing on coating morphology and nanostructure

CrCuAgN PVD nanocomposite coatings were produced using pulsed DC unbalanced magnetron sputtering. This investigation focuses on the effects of post-coat annealing on the surface morphology, phase composition and nanostructure of such coatings. In coatings with nitrogen contents up to 16 at.%, chromium exists as metallic Cr with N in supersaturated solid solution, even after 300 °C and 500 °C post-coat annealing. Annealing at 300 °C did not obviously change the phase composition of both nitrogen-free and nitrogen-containing coatings; however, 500 °C annealing resulted in significant transformation of the nitrogen-containing coatings. The formation of Ag aggregates relates to the (Cu + Ag)/Cr atomic ratio (threshold around 0.2), whereas the formation of Cu aggregates relates to the (Cu + Ag + N)/Cr atomic ratio (threshold around 0.5). The primary annealing-induced changes were reduced solubility of Cu, Ag and N in Cr, and the composition altering from a mixed ultra-fine nanocrystalline and partly amorphous phase constitution to a coarser, but still largely nanocrystalline structure. It was also found that, with sufficient Cu content (>12 at.%), annealing at a moderately high temperature (e.g. 500 °C) leads to transportation of both Cu and Ag (even at relatively low concentrations of Ag, ≤3 at.%) from inside the coating to the coating surface, which resulted in significant reductions in friction coefficient, by over 50% compared to that of the substrate (from 0.31 to 0.14 with a hemispherical diamond indenter, and from 0.83 to 0.40 with an alumina ball counterface, respectively). Results indicate that the addition of both Cu and Ag (in appropriate concentrations) to nitrogen-containing chromium is a viable strategy for the development of ‘self-replenishing’ silver-containing thin film architectures for temperature-dependent solid lubrication requirements or antimicrobial coating applications

Small-scale rotor test rig capabilities for testing vibration alleviation algorithms

A test was conducted to assess the capabilities of a small scale rotor test rig for implementing higher harmonic control and stability augmentation algorithms. The test rig uses three high speed actuators to excite the swashplate over a range of frequencies. The actuator position signals were monitored to measure the response amplitudes at several frequencies. The ratio of response amplitude to excitation amplitude was plotted as a function of frequency. In addition to actuator performance, acceleration from six accelerometers placed on the test rig was monitored to determine whether a linear relationship exists between the harmonics of N/Rev control input and the least square error (LSE) identification technique was used to identify local and global transfer matrices for two rotor speeds at two batch sizes each. It was determined that the multicyclic control computer system interfaced very well with the rotor system and kept track of the input accelerometer signals and their phase angles. However, the current high speed actuators were found to be incapable of providing sufficient control authority at the higher excitation frequencies