Nickel-titanium (NiTi) shape-memory alloys (SMAs) have been used in the manufacture of orthodontic wires due to their shape memory properties, super-elasticity, high ductility, and resistance to corrosion. SMAs have greater strength and lower modulus of elasticity when compared with stainless steel alloys. The pseudoelastic behavior of NiTi wires means that on unloading they return to their ori...

Methods Based on a computed tomography angiography of the aorta, we made a delrin ring, keeping the anatomical characteristics of the aortic annulus. A matrix one following we made from stainless steel with the shape of the three cusp aortic valve, followed by preparation of the injection of liquid polyurethane segmented (SPU), using a esterolitografia technique. In vitro tests: The materials u...

The operating environment in an engine can have negative effects on the performance of connecting rods, as it is well-known that the strength of most steels quickly deteriorates at higher temperatures. Although the mechanical properties of the materials used to manufacture connecting rods have been widely characterized at room temperature, their strength has not been investigated at higher temp...

Introduction The tangible products of our world are made from materials, some resulting from natural forces and others from manufacturing. Regardless of the source, the performance we expect from a product depends critically on the materials in that product. For manufactured products, the reliability of the prediction of performance is dependent on the reliability of the materials data used to ...

The zinc protoporphyrin/haemoglobin (ZPP/Hb) ratio was measured in the field with a haematofluorometer. A significant increase in ZPP/Hb ratio with advancing age was found in 1295 men who denied any excess exposure to lead. Ninety-seven per cent of the results were below 110 mumol ZPP/mol Hb(Fe) (4.4 microgram ZPP/g Hb). The ZPP/Hb ratio was determined in a lead-exposed population of 2275 men, ...