Powder painting of aluminium

The mechanisms involved in the production of chromate-phosphate conversion coatings on aluminium have been investigated. A sequence of coating nucleation and growth has been outlined and the principle roles of the constituent ingredients of the chromate-phosphate solution have been shown. The effect of dissolved aluminium has been studied and its role in producing sound conversion coatings has been shown. Metallic contamination has been found to have a dramatic influence on chromate-phosphate coatings when particular levels have been exceeded. Coating formation was seen to be affected in proportion to the level of contaminaton; no evidence of sudden failure was noted. The influence of substrate and the effect of an acidic cleaner prior to conversion coating have been studied and explained. It was found that the cleaner ages rapidly and that this must .be allowed for when attempting to reproduce industrial conditions in the laboratory. A study was carried out on the flowing characteristics of polyester powders of various size distributions as they melt using the hot-stage microscopy techniques developed at Aston. It was found that the condition of the substrate (ie extent of pretreatment), had a significant effect on particle flow. This was explained by considering the topography of the substrate surface. A number of 'low-bake' polyester powders were developed and tested for mechanical, physical and chemical resistance. The best formulation had overall properties which were as good as the standard polyester in many respects. However chemical resistance was found to be slightly lower. The charging characteristics of powder paints during application by means of electrostatic spraying was studied by measuring the charge per unit mass and relating this to the surface area. A high degree of correlation was found between charge carried and surface area, and the charge retained was related to the powder's formulation

Decadal-to-centennial increases of volcanic aerosols from Iceland challenge the concept of a Medieval Quiet Period

Existing global volcanic radiative aerosol forcing estimates portray the period 700 to 1000 as volcanically quiescent, void of major volcanic eruptions. However, this disagrees with proximal Icelandic geological records and regional Greenland ice-core records of sulfate. Here, we use cryptotephra analyses, high-resolution sulfur isotope analyses, and glaciochemical volcanic tracers on an array of Greenland ice cores to characterise volcanic activity and climatically important sulfuric aerosols across the period 700 to 1000. We identify a prolonged episode of volcanic sulfur dioxide emissions (751–940) dominated by Icelandic volcanism, that we term the Icelandic Active Period. This period commences with the Hrafnkatla episode (751–763), which coincided with strong winter cooling anomalies across Europe. This study reveals an important contribution of prolonged volcanic sulfate emissions to the pre-industrial atmospheric aerosol burden, currently not considered in existing forcing estimates, and highlights the need for further research to disentangle their associated climate feedbacks

Management of COPD exacerbations:a European Respiratory Society/American Thoracic Society guideline

This document provides clinical recommendations for the prevention of chronic obstructive pulmonary disease (COPD) exacerbations. It represents a collaborative effort between the European Respiratory Society and the American Thoracic Society.Comprehensive evidence syntheses were performed to summarise all available evidence relevant to the Task Force's questions. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach and the results were summarised in evidence profiles. The evidence syntheses were discussed and recommendations formulated by a multidisciplinary Task Force of COPD experts.After considering the balance of desirable (benefits) and undesirable consequences (burden in the form of adverse effects and cost), quality of evidence, feasibility, and acceptability of various interventions, the Task Force made recommendations for mucolytic, long-acting muscarinic antagonist, phosphodiesterase-4 inhibitor (roflumilast) and macrolide therapy, as well as a conditional recommendation against fluoroquinolone therapy. All of the recommendations were conditional, except for a strong recommendation for the use of a long-acting antimuscarinic agent versus a long-acting β2-adrenergic, indicating that there was uncertainty about the balance of desirable and undesirable consequences of the intervention, and that well-informed patients may make different choices regarding whether to have or not have the specific intervention.The guideline summarises the evidence and provides recommendations for pharmacological therapy for the prevention of COPD exacerbations

Pulmonary rehabilitation for patients with COPD during and after an exacerbation-related hospitalisation: back to the future?

We thank M.A. Spruit and colleagues for their questions about our decisions regarding initiating pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD) exacerbations. Their main objection is the recommendation against initiating pulmonary rehabilitation during the patient's hospitalisation. We agree that the recommendation was based primarily on the finding of increased mortality (6-min walking test had statistically significant improvement and hospital readmission had non-statistically significant improvement) and that the trial led by Greening et al. [1] contributed 389 out of 415 patients. We further agree that there is uncertainty about whether or not inpatient-initiated pulmonary rehabilitation is associated with increased mortality, particularly since the mortality difference emerged more than 5 months after hospital discharge in the study by Greening et al. [1] and that the per protocol analysis in this study found no difference in mortality among those who actually received pulmonary rehabilitation versus the control group

Change Over Time: Conducting Longitudinal Studies of Children's Cognitive Development

Developmental scientists have argued that the implementation of longitudinal methods is necessary for obtaining an accurate picture of the nature and sources of developmental change (Magnusson & Cairns, 1996; Morrison & Ornstein, 1996; Magnusson & Stattin, 2006). Developmentalists studying cognition have been relatively slow to embrace longitudinal research, and thus few exemplar studies have tracked individual children’s cognitive performance over time and even fewer have examined contexts that are associated with this growth. In this article we first outline some of the benefits of implementing longitudinal designs. Using illustrations from existing studies of children’s basic cognitive development and of their school-based academic performance, we discuss when it may be appropriate to employ longitudinal (versus other) methods. We then outline methods for integrating longitudinal data into one’s research portfolio, contrasting the leveraging of existing longitudinal data sets with the launching of new longitudinal studies in order to address specific questions concerning cognitive development. Finally, for those who are interested in conducting longitudinal investigations of their own, we provide practical on-the-ground guidelines for designing and carrying out such studies of cognitive development

Exome Array Analysis Identifies a Common Variant in IL27 Associated with Chronic Obstructive Pulmonary Disease

Rationale: Chronic obstructive pulmonary disease (COPD) susceptibility is in part related to genetic variants. Most genetic studies have been focused on genome-wide common variants without a specific focus on coding variants, but common and rare coding variants may also affect COPD susceptibility. Objectives: To identify coding variants associated with COPD. Methods: We tested nonsynonymous, splice, and stop variants derived from the Illumina HumanExome array for association with COPD in five study populations enriched for COPD. We evaluated single variants with a minor allele frequency greater than 0.5% using logistic regression. Results were combined using a fixed effects meta-analysis. We replicated novel single-variant associations in three additional COPD cohorts. Measurements and Main Results: We included 6,004 control subjects and 6,161 COPD cases across five cohorts for analysis. Our top result was rs16969968 (P = 1.7 × 10(−14)) in CHRNA5, a locus previously associated with COPD susceptibility and nicotine dependence. Additional top results were found in AGER, MMP3, and SERPINA1. A nonsynonymous variant, rs181206, in IL27 (P = 4.7 × 10(−6)) was just below the level of exome-wide significance but attained exome-wide significance (P = 5.7 × 10(−8)) when combined with results from other cohorts. Gene expression datasets revealed an association of rs181206 and the surrounding locus with expression of multiple genes; several were differentially expressed in COPD lung tissue, including TUFM. Conclusions: In an exome array analysis of COPD, we identified nonsynonymous variants at previously described loci and a novel exome-wide significant variant in IL27. This variant is at a locus previously described in genome-wide associations with diabetes, inflammatory bowel disease, and obesity and appears to affect genes potentially related to COPD pathogenesis