Relationships between crack initiation and crack growth toughness are reviewed by examining the crack tip fields and microscopic (local) and macroscopic (continuum) fracture criteria for the onset and continued quasi-static extension of cracks in ductile materials. By comparison of the micromechanisms of crack initiation via transgranular cleavage and crack initiation and subsequent growth via ...

Background: In the present study, we explored the associations between hypomania, symptoms of depression, sleep complaints, physical activity and mental toughness. The latter construct has gained interest for its association with a broad variety of favorable behavior in both clinical and non-clinical samples. Subjects and Methods: The non-clinical sample consisted of 206 young adults (M = 21.3 ...

The effects of silicon (Si) on the mechanical properties and fracture toughness of heavy-section ductile cast iron were investigated to develop material for spent-nuclear-fuel containers. Two castings with different Si contents of 1.78 wt.% and 2.74 wt.% were prepared. Four positions in the castings from the edge to the center, with different solidification cooling rates, were chosen for micros...

An experiment was carried out in order to locate and quantify osteon types within a sample of cortical bone taken from a human tibia. This was done using a microscope-camera assembly and the BioQuant computer software. The results of this were correlated with a previous experiment's results on fracture toughness so that an analysis could be run on the data in order to determine the factors that...

BACKGROUND This study compared two well-known computer-aided-design/computer-aided-manufactured (CAD/CAM) blocks (Paradigm MZ100 [3M ESPE] and Vitablocs Mark II [Vita] in terms of fracture toughness (Kic), index of brittleness (BI) and stress/strain distributions. MATERIAL AND METHODS Three-point bending test was used to calculate the fracture toughness, and the relationship between the Kic a...

Mechanical behaviour of unsaturated polyester resin used for the composite materials has been studied to determine various important parameters, such as tensile and compressive, single edge-notch tensile fracture toughness, flexural properties and fracture energy. Fracture toughness, KIC, and fracture energy, GIC, obtained for the polyester resin lie between the typical values for epoxy resins ...

Purpose: The mechanical strength of polymethyl methacrylate (PMMA) remains far from ideal for maintaining the longevity of denture. The purpose of this study was to evaluate the effect of Zirconium oxide (ZrO2) nanofillers powder with different concentration (1.5%, 3%, 5% and 7%) on the flexural strength, fracture toughness, and hardness of heat-polymerized acrylic resin. Materials and methods:...

The aim of the present work was to study the effect of various process parameters i.e. current, voltage, travel speed, electrode diameter, flux composition, pre heating of workpiece, electrode stick-out and edge including angle on changes in tensile strength and toughness of the weld bead geometry of HSLA Steel and to optimize the process so that minimal changes occur in the material properties...

In this paper, we introduce the novel parameters indicating Normalized Tenacity ($T_N$) and Normalized Toughness ($t_N$) by a modification on existing Tenacity and Toughness parameters.  Using these new parameters enables the graphs with different orders be comparable with each other regarding their vulnerabilities. These parameters are reviewed and discussed for some special graphs as well.

The toughness of a graph G is the minimum of |S|/k(G − S) over all sets S of vertices such that k(G − S) ≥ 2. In this paper upper bounds on the toughness of a cubic graph are derived in terms of the independence number and coloring parameters. These are applied to cycle permutation graphs. Running head: as per title.