AIM To develop an accurate finite element (FE) model for studying rotary endodontic instruments and to demonstrate the usefulness of the FE method in improving the knowledge of the mechanical behaviour of these instruments during root canal preparation. METHODOLOGY An accurate geometrical model of a Ni-Ti ProTaper F1 instrument was created. The interaction between the rotating instrument and ...

This study analyzes the mechanical behavior of low density polyethylene foam core sandwich panels subjected to edgewise compression. In order to monitor panel response to buckling, strains generated in the facesheets and overall out-of-plane deformations are measured with strain gages and projection moiré, respectively. A finite element (FE) model simulating the experimental test is developed. ...

in the present study, the influence of annealing temperature on mechanical properties and the microstructure of a high manganese austenitic steel (fe-30mn-4al-4si-0.5c) was investigated. x-ray diffractometry, optical and scanning electron microscopy, hardness and tensile tests were used to analyze the relationship between mechanical properties and microstructure after annealing process. the res...

In this study, the effects of Fe2O3 (addition, 2, 5, 10, and 50 wt %) on the microstructure, mechanical properties, corrosion behaviors, and in vitro biocompatibility of Fe-Fe2O3 composites fabricated by spark plasma sintering were systematically investigated as a novel-structure biodegradable metallic material. The results of X-ray diffraction analysis and optical microscopy indicated that Fe-...

The development of predictive mathematical models can contribute to a deeper understanding of the specific stages of bone mechanobiology and the process by which bone adapts to mechanical forces. The objective of this work was to predict, with spatial accuracy, cortical bone adaptation to mechanical load, in order to better understand the mechanical cues that might be driving adaptation. The ax...

It has long been recognized that hydrogen bonds formed by protein backbone amides with cysteinyl S(γ) atoms play important roles in modulating the functional and structural properties of the iron-sulfur centers in proteins. Here we use single molecule atomic force microscopy, cyclic voltammetry, and protein engineering techniques to investigate directly how the strength of N-H···S(γ) hydrogen b...

In this work, iron-doped SnO2 powders were prepared by two methods: mechanical alloying and mechanochemical alloying with successive thermal treatment. The influence of different milling conditions such as ball to powder weight ratio, milling time, rotation velocity of supporting disc and the type of iron starting reactive and their Fe concentration on the structural and magnetic properties of ...

Understanding how structural and functional alterations of individual tissues impact on whole-joint function is challenging, particularly in humans where direct invasive experimentation is difficult. Finite element (FE) computational models produce quantitative predictions of the mechanical and physiological behaviour of multiple tissues simultaneously, thereby providing a means to study change...

Finite element (FE) models are advantageous in the study of intervertebral disc mechanics as the stress-strain distributions can be determined throughout the tissue and the applied loading and material properties can be controlled and modified. However, the complicated nature of the disc presents a challenge in developing an accurate and predictive disc model, which has led to limitations in FE...

Mg²⁺ shares a distinctive relationship with RNA, playing important and specific roles in the folding and function of essentially all large RNAs. Here we use theory and experiment to evaluate Fe²⁺ in the absence of free oxygen as a replacement for Mg²⁺ in RNA folding and catalysis. We describe both quantum mechanical calculations and experiments that suggest that the roles of Mg²⁺ in RNA folding...