Destruição da arte tumular por um preço vil / Destruction of tomb art for a vile price

A arte tumular ou funerária representa o respeito dado a um indivíduo dentro do contexto histórico; acompanhada de grande carga emotiva, deve ser preservada para que este legado afetivo seja reverenciado. O bronze é uma liga metálica composta basicamente de cobre e estanho, contendo ainda outros elementos químicos, fusão que aumenta a resistência do cobre sem alterar sua capacidade de deformação, permitindo a realização de obras de arte. Infelizmente, o cobre presente em artefatos de bronze, desperta a ganância de vândalos, que por alguns trocados destroem a memória de pessoas ilustres e queridas, um quadro revoltante pelo descaso dos responsáveis pela preservação do patrimônio cultural abrigado nos cemitérios. Tanto as placas de bronze, vasos e portas dos jazigos levadas de vários cemitérios estão sendo substituídas por desgraciosas peças de granito, sem valor comercial, porém padronizadas, acabando com as referências que individualizam cada jazigo, denegrindo a memória dos que ali repousam. ABSTRACT Tomb or funerary art stands for the respect given to an individual within the historical context; coupled with a great emotional burden, it must be preserved so that this affective legacy is revered. Bronze is a metallic alloy basically composed of copper and tin, also containing some other chemical elements, and producing a fusion that increases the resistance of copper without altering its deformation capacity which allows the creation of art work. Unfortunately, the copper present in bronze artifacts awakens the greed of vandals who, for a few pennies, destroy the memory of distinguished and beloved people. This is a revolting consequence caused by the negligence of those responsible for preserving the cultural heritage housed in cemeteries. Either the bronze plates or vases and tomb doors taken from various cemeteries are being replaced by clumsy pieces of granite, with no commercial value, but standardized, putting an end to the references that individualize each tomb and disparaging the memory of those who rest there.

Assessing the Potential Association Between Microbes and Corrosion of Intra-Oral Metallic Alloy-Based Dental Appliances Through a Systematic Review of the Literature

Objective: Systematic review assessing the association between oral microorganisms and corrosion of intra-oral metallic alloy-based dental appliances.Design: PubMed, Scopus, and Web of Science were searched using keyword combinations such as microbes and oral and corrosion; microbes and dental and corrosion; microorganisms and oral and corrosion; microorganisms and dental and corrosion.Results: Out of 141 articles, only 25 satisfied the selection criteria. Lactobacillus reuteri, Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Streptococcus sobrinus, Streptococcus salivarius, sulfate-reducing bacteria, sulfate oxidizing bacteria, Veilonella, Actinomyces, Candida albicans were found to have a potential association with corrosion of intraoral metallic alloys such as stainless steel, titanium, nickel, cobalt-chromium, neodymium-iron-boron magnets, zirconia, amalgam, copper aluminum, and precious metal alloys.Conclusion: The included studies inferred an association between oral microorganisms and intra-oral metallic alloys-based dental appliances, although, it is vital to acknowledge that most studies in the review employed an in-vitro simulation of the intra-oral condition.

Elastic Properties and Glass Forming Ability of the Zr50Cu40Ag10 Metallic Alloy

The elastic properties of the Zr50Cu40Ag10 metallic alloy, such as the bulk modulus B, the shear modulus G, the Young’s modulus E and the Poisson’s ratio σ, are investigated by molecular dynamics simulation in the temperature range T=250–2000 K and at an external pressure of p=1.0 bar. It is shown that the liquid–glass transition is accompanied by a considerable increase in the shear modulus G and the Young’s modulus E (by more than 50%). The temperature dependence of the Poisson’s ratio exhibits a sharp fall from typical values for metals of approximately 0.32–0.33 to low values (close to zero), which are characteristic for brittle bulk metallic glasses. Non-monotonic temperature dependence of the longitudinal and transverse sound velocity near the liquid-glass transition is also observed. The glass forming ability of the alloy is evaluated in terms of the fragility index m. Its value is m≈64 for the Zr50Cu40Ag10 metallic glass, which is in a good agreement with the experimental data for the Zr-based metallic glasses.