Synchrotron X-ray studies on polyamide composites prepared by reactive injection molding

Semicrystalline polyamide 6 (PA6) and composites on its basis are among the most frequently used polymer materials for highly demanding applications. The performance of these composites depends on the crystalline structure of the PA6 matrix in which two crystalline forms most frequently coexist: α- and γ-polymorphs. This work reports on the crystalline structure of a variety of composite materials produced by in-mold reactive polymerization of caprolactam in specially designed semi-automatic equipment for reactive processing of nylons (NYRIM), carried out in the presence of particulate mineral reinforcements (natural or-ganically treated aluminum silicates and synthetic titanosilicates), PA6 oriented monofilaments and textile structures of glass fibers. The morphology and the crystalline structure of all composites were studied by syn-chrotron X-ray diffraction. Transcrystalline PA6 layer was observed in all fibrous PA6 laminates whose struc-ture fine crystalline structure was accessed.Fundação para a Ciência e Tecnologia; German Synchrotorn Radiation Source - DESY, Hambur

The prevalence of diabetes and stress hyperglycemia in the acute myocardial infarction patients

OBJETIVOS: Determinar a prevalência do diabetes melito (DM) e da hiperglicemia de estresse (HE) em pacientes com infarto agudo do miocárdio (IAM) admitidos em unidade de emergência cardiológica. MÉTODOS: Análise retrospectiva de 2.262 pacientes com IAM, avaliando, além da prevalência de diabetes referido, o diagnosticado e a hiperglicemia de estresse. RESULTADOS: Apesar de referido em 12,1% dos pacientes (H: 10,7%, M: 15,8%), o DM ocorria efetivamente em 24,8% (H: 22,9%, M: 29,7%) e a HE em 13,6% (H: 14,3%, M: 11,7%) dos indivíduos dessa população. Portanto, alterações glicêmicas ocorreram em 37,4% dos indivíduos com IAM (H: 37,2%, M: 41,4%). Nos pacientes com DM, observou-se maior precocidade etária do IAM, maior prevalência de óbitos (DM: 20,7%, ND:13,8%, HE: 13,4%) e de procedimentos cirúrgicos (ND: 33,8%, HE: 18,0%, DM: 21,7%). CONCLUSÃO: A elevada prevalência de DM e hiperglicemia de estresse observada em nosso estudo indica que as alterações glicêmicas constituem um dos mais importantes fatores de risco para o IAM.OBJECTIVES: To evaluate in our population the real prevalence of diabetes (DM) and stress hyperglycemia (HE) in patients with myocardial infarction (IAM) admitted in a cardiologic emergency unit. METHODS: A retrospective analysis of 2262 patients with AMI evaluating the prevalence of DM (referred and diagnosed) and stress hyperglycemia. RESULTS: Besides 12,1% of subjects were previously referred to be diabetic (men: 10.7% and women: 15.8%), diabetes was effectively diagnosed in 24,8% (M: 22,9%, W: 29,7%) and stress hyperglycemia in 13,6% HE of the patients (M: 14,3%, W: 11,7%) indicating that glycemic alterations were effectively observed in 37.2.% of the patients with IAM (M: 37,2%, W: 41,4%). In DM subjects IAM events occurred earlier, total intra-hospital mortality was higher (DM: 20.7%, ND: 13,8%, HE: 13,4%) and less surgical procedures were performed (ND 33.8%, DM: 21.7%, HE: 18.0%). CONCLUSION: The elevated DM and stress hyperglycemia prevalence observed in our study indicates that glycemic alterations is one of the most important risk factors for IAM

Particle size and potential toxic element speciation in municipal solid waste incineration (Mswi) bottom ash

The speciation of potentially toxic elements (PTE) in bottom ashes from municipal solid waste incineration (MSWI) and their relationship with grain size is investigated. The proposed enrichment of several potential toxic elements in lower sized grains is discussed, comparing the literature and new data on Parma’s waste incinerator. Results from X-ray fluorescence spectrometry (XRF), SEM-EDS, and XRD analyses on different grain size show (1) a positive Si-trend, correlated with grain size and few lithophile elements, such as Zr and Rb. In Parma, Al, K, Mg, and Fe also correlate with Si for the portion below 2 mm; (2) a Ca-trend, with a strong negative correlation with Si and a positive correlation with loss on ignition (LOI), S, Cl, Ti, Zn, Pb, and Sn. Mineralogical composition shows a little change in grain size, as in previous investigations, but with substantial differences in amorphous content. SEM-EDS analysis shows that the amorphous portion is highly heterogeneous, with portions coming from melting during incineration, residual glass, and unburnt loss on ignition (LOI). The above results show that PTE elements are either present as metals (such as Cu and Ni, or Zn, Pb and Sn) in carbonate, sulfate, and amorphous residual LOI portions

Mechanistic model for the compression strength prediction of masonry columns strengthened with fibre–polymer composites

A mechanistic model is presented for the strength prediction of squared columns made of masonry with a periodic arrangement and strengthened with a fibre–polymer composite jacketing. The formulation is based on an incremental plasticity theory that relies on equilibrium, compatibility, and kinematic equations. The strength domain of brick units and mortar joints is bounded by a multi-surface yield criterion: a Mohr–Coulomb strength domain with a linear cap in compression and a Rankine cut-off in tension. An elasto-plastic response with limited ductility is assumed for both masonry components. Differently, the FRP response is assumed elastic with a brittle failure governed by a limited tensile strain. Phenomenological-based assumptions are undertaken and justified. Details are also provided for the computational implementation of the procedure. The model accuracy is validated against experimental data on masonry squared columns and compared with existing standard-based formulas. Results demonstrate it provides real-time and accurate compressive strength solutions for squared masonry columns with or without a polymer-based wrapping and yet requiring few input parameters for the masonry constituents and reinforcement

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Integrated management of ash from industrial and domestic combustion : a new sustainable approach for reducing greenhouse gas emissions from energy conversion

This work supports, for the first time, the integrated management of waste materials arising from industrial processes (fly ash from municipal solid waste incineration and coal fly ash), agriculture (rice husk ash), and domestic activities (ash from wood biomass burning in domestic stoves). The main novelty of the paper is the reuse of wood pellet ash, an underestimated environmental problem, by the application of a new technology (COSMOS-RICE) that already involves the reuse of fly ashes from industrial and agricultural origins. The reaction mechanism involves carbonation: this occurs at room temperature and promotes permanent carbon dioxide sequestration. The obtained samples were characterized using XRD and TGA (coupled with mass spectroscopy). This allowed quantification of the mass loss attributed to different calcium carbonate phases. In particular, samples stabilized using wood pellet ash show a weight loss, attributed to the decomposition of carbonates greater than 20%. In view of these results, it is possible to conclude that there are several environmental benefits from wood pellet ash reuse in this way. In particular, using this technology, it is shown that for wood pellet biomass the carbon dioxide conversion can be considered negative

Urban mining of municipal solid waste incineration (MSWI) residues with emphasis on bioleaching technologies: a critical review

Metals are essential in our daily lives and have a finite supply, being simultaneously contaminants of concern. The current carbon emissions and environmental impact of mining are untenable. We need to reclaim metals sustainably from secondary resources, like waste. Biotechnology can be applied in metal recovery from waste streams like fly ashes and bottom ashes of municipal solid waste incineration (MSWI). They represent substantial substance flows, with roughly 46 million tons of MSWI ashes produced annually globally, equivalent in elemental richness to low-grade ores for metal recovery. Next-generation methods for resource recovery, as in particular bioleaching, give the opportunity to recover critical materials and metals, appropriately purified for noble applications, in waste treatment chains inspired by circular economy thinking. In this critical review, we can identify three main lines of discussion: (1) MSWI material characterization and related environmental issues; (2) currently available processes for recycling and metal recovery; and (3) microbially assisted processes for potential recycling and metal recovery. Research trends are chiefly oriented to the potential exploitation of bioprocesses in the industry. Biotechnology for resource recovery shows increasing effectiveness especially downstream the production chains, i.e., in the waste management sector. Therefore, this critical discussion will help assessing the industrial potential of biotechnology for urban mining of municipal, post-combustion waste