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The usefulness of photoacoustic techniques in characterizing the thermal properties of kaolinite clays, which are a very abundant mineral in some regions of Brazil, was investigated. Different behavioural patterns are observed below and above a heating temperature of 950 °C and can be attributed to the change from metakaolinite to an amorphous three-dimensional mineral which crystallises to mullite and crystobalite above 1200 °C. The implications of the results in the manufacture of clay bricks are briefly considered. This is important in tropical regions where a knowledge of the thermal properties of materials used in the building construction industry is highly desirable.

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The ever-growing consumption and improper disposal of non-biodegradable plastic wastes is bringing worrisome perspectives on the lack of suitable environmentally correct solutions. Consequently, an increasing interest in the circular economy and sustainable techniques is being raised regarding the management of these wastes. The present work proposes an eco-friendly solution for the huge amount of discarded polyethylene terephthalate (PET) wastes by addition into soil-cement bricks. Room temperature molded 300 × 150 × 70 mm bricks were fabricated with mixtures of clay soil and ordinary Portland cement added with up to 30 wt.% of PET waste particles. Granulometric analysis of soil indicated it as sandy and adequate for brick fabrication. As for the PET particles, they can be considered non-plastic and sandy. The Atterberg consistency limits indicated that addition of 20 wt.% PET waste gives the highest plasticity limit of 17.3%; moreover, with PET waste addition there was an increase in the optimum moisture content for the compaction and decrease in specific weight. Standard tests showed an increase in compressive strength from 0.83 MPa for the plain soil-cement to 1.80 MPa for the 20 wt.% PET-added bricks. As for water absorption, all bricks displayed values between 15% and 16% that attended the standards and might be considered an alternative for non-structural applications, such as wall closures in building construction.

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Takotsubo cardiomyopathy is a reversible cardiomyopathy frequently precipitated by a sudden emotional or physical stress. The exact physiopathology is still debated and may involve catecholamine-induced myocardial stunning. Alcohol withdrawal is associated with an hyperadrenergic state and may be a period at risk of cardiac events. We report a 56-year-old man with Takotsubo cardiomyopathy triggered by alcohol withdrawal.