Finite Boundary Conditions Due to the Bar Presence in the Model of Chloride Penetration.

The chloride penetration is usually modelled through the application of a solution of Fick's second law of diffusion, based on the assumption of semi-infinite boundary conditions. However, the presence of the bars, on whose surface the chlorides accumulate, makes this assumption incorrect. As the time progresses, the chlorides in the steel/concrete interface increase in concentration more than the chlorides overpassing the bar position without obstacles. This circumstance, although previously studied, has not been introduced in common practice, in spite of it supposes early reaching of the chloride threshold. The study in this paper shows a deterministic analysis of the chloride diffusion process by the finite element method (FEM) which numerically solves Fick's second law, taking into account the accumulation of the chlorides on the bar surface. Several examples are calculated and factors between the finite/semi-infinite solutions are given. These factors depend on the cover depth and the diffusion coefficient, and with less importance, on the diameter of the bar, which make it unfeasible to propose a general trend.

Improvement of the Concrete Permeability by Using Hydrophilic Blended Additive.

Crystalline hydrophilic additives are increasingly used as efficient methods for reducing water permeability in concrete. Their effectiveness in hindering water penetration has been proven in different cementitious materials, although scarce information has been reported concerning their action mechanism. In the present work, the efficacy of a hydrophilic blended crystalline mix (Krystaline Add1) as a water-reducing additive has been confirmed. Furthermore, an extended study about how the presence of the additive influences both the fresh state and the hardened state properties is presented. Finally, characterization techniques such as Mercury Intrusion Porosimetry (MIP), X-ray Powder Diffraction (XRD) and Back-Scattered Scanning Electron Microscopy (BSEM) with Energy Dispersive X-ray analysis (EDAX) have been used for deducing the mechanism of the additive. No significant deleterious influence on the concrete properties due to the addition of the additive has been detected. In fact, the additive seems to have provided a positive influence on the concrete given that a slight reduction in the w/c ratio for similar consistency has been detected, with the subsequent improvement of the compressive strength values. Its effectiveness as a water permeability reducing additive has shown encouraging results having reduced the water permeability by approximately 50% during testing. The action mechanism of the studied additive seems to be related to hydration reactions in the presence of water, producing new solid amorphous phases in the concrete bulk.

Miopatias inflamatórias idiopáticas: relato de caso / The idiopathic inflammatory myopathies: case report

JUSTIFICATIVA E OBJETIVOS: As miopatias inflamatórias idiopáticas, também conhecidas como síndrome de miosite, são da família de doenças sistêmicas adquiridas do tecido conjuntivo, caracterizadas por efeitos clínicos e patológicos de inflamação muscular crônica de causa desconhecida. As formas mais comuns são a polimiosite e a dermatomiosite, que tem seu diagnóstico com base em uma combinação de achados clínicos, laboratoriais e histopatológicos. O objetivo deste estudo foi abordar a característica clínica da dermatopolimiosite e demonstrar a evolução e o tratamento da doença. RELATO DO CASO: Paciente do sexo feminino, 66 anos, apresentando quadro de dor no abdômen e nos membros superiores e inferiores, associada com diminuição da força muscular. Presença de dispnéia acompanhada de tosse produtiva. Foi submetida à avaliação reumatológica, levantando-se a hipótese de dermatopolimiosite, concluindo-se o diagnóstico após avaliação clinica e laboratorial. CONCLUSÃO: O tratamento da doença ocorreu de acordo com o padrão evolutivo que a paciente se encontrava.

BACKGROUND AND OBJECTIVES: The idiophatic inflammatory myopathies - or syndrome myositis - are a group of acquired systemic diseases of connective tissue with characteristic of clinical and pathological effect of chronic inflammatory of muscle whose your pathogenesis is strange. The types habitual are the polymyositis and the dermatomyositis. For diagnosis is necessary a arrangement of clinical, laboratory and histopathologic founds. In this article we approach the characteristics of idiopathic inflammatory myopathies, aiming to demonstrate the evolution and treatment of disease. CASE REPORT: Female patient, 66 years, presenting chart of pain in abdomen and lower and upper members, associated with diminution of the muscular force. Presence of dyspnea accompanied of productive cough. It was submitted to Rheumatologic clinical evaluation being raised the hypothesis of dermatopolymyositis, concluding the diagnosis after evaluation is in clinical practice and laboratory. CONCLUSION: The handling of the illness occurs according to the developing standard that the patient is found.