Studies of bone have determined multiple toughening mechanisms slowing the propagation of a crack. These toughening mechanisms contribute to the fracture toughness of bone in life, making their activities of clinical interest. The primary standard methods for measuring bone fracture toughness use a single-notched compact type specimen (CT) or single-notched bending specimens in four-point (SN4P...

We show that, if NP 6= ZPP, for any ε > 0, the toughness of a graph with n vertices is not approximable in polynomial time within a factor of 1 2 (n 2 ). We give a 4-approximation for graphs with toughness bounded by 1 3 and we show that this result cannot be generalized to graphs with a bounded toughness. More exactly we prove that there is no constant approximation for graphs with bounded tou...

Recently, a method for evaluating the fracture toughness of ceramics has been proposed by Fett based on the computed crack-opening displacements of cracks emanating from Vickers hardness indentations. To verify this method, experiments have been conducted to determine the toughness of a commercial silicon carbide ceramic, Hexoloy SA, by measuring the crack-opening profiles of such Vickers inden...

A heterogeneous brittle material characterized by a random field of local toughness K c (x) can be represented by an equivalent homogeneous medium of toughness, K eff. Homogenization refers to a process of estimating K eff from the local field K c (x). An approach based on a perturbative expansion of the stress intensity factor along a rough crack front shows the occurrence of different regimes...

The concept of mental toughness is widely used, but empirical evidence is required to fully understand this construct and its related variables. The purpose of this paper was to explore the relationship between: (a) mental toughness and coping, (b) mental toughness and optimism, and (c) coping and optimism. Participants were 677 athletes (male 454; female 223) aged between 15 and 58 years (M ag...

The purpose of this study was to investigate and analyse the fracture toughness of yttria stabilized tetragonal zirconia polycrystal (Y-TZP) dental ceramics by means of the Vickers indentation technique. Fracture toughness was analysed under the following loads: 29.42 N, 49.03 N, 196.13 N, and 294.20 N. Cracks that had developed from the vertices of a Vickers indentation were measured and used ...

The measured toughness J(C) of adipose and dermal porcine tissues are 4.1 and 17 kJ m(-2), respectively, via a trouser tear test. An assessment is made of the contribution to overall toughness from the microstructural elements. The analysis suggests that the toughness of adipose tissue is determined by the collagen network that surrounds the adipocytes. The volume fraction of the interlobular s...

The present study investigated the contribution of positive and negative youth sport experiences (i.e., processes or experiences that occur in a particular activity or setting) to self-reported mental toughness among youth-aged cricketers. A sample of 308 male cricketers aged between 13 and 18 years self-reported mental toughness using the Cricket Mental Toughness Inventory (CMTI; Gucciardi & G...

Toughness is a complex material characteristic that is viewed from multiple aspects and is influenced by numerous factors. It is very important to have ability to assess toughness, i.e. to determine ductile or brittle material behaviour at any specific time. Beside total impact energy obtained at Charpy instrumented pendulum, the use of additional parameters such as lateral extension measuremen...