A combination of subsurface borehole imaging data and drilling logs were used to characterize the fractures and lithology in 40 bedrock wells at the fractured-rock research site in the Mirror Lake area in Grafton County, New Hampshire. The purpose of the research was to determine whether subsurface lithology and fractures have an effect on the hydraulic conductivity of the crystalline-rock aqui...

The mechanical behavior of multicracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, experimental and numerical studies on the fracture property of three collinear cracks under compression were implemented. The specimens were a square concrete plate, and the cracks were made by a very thin film. The tests were conduct...

Single crystal specimens of Fe-17 at. % Ga were tested in tension at room temperature. Specimens with a tensile axis orientation of [110] displayed slip lines on the specimen faces corresponding to slip on the {110}with a critical resolved shear stress of 220 MPa. Yielding began at 0.3% elongation and 450 MPa. An ultimate tensile strength of 580 MPa was observed with no fracture occurring throu...

The aging-related deterioration of the fracture properties of bone, coupled with higher life expectancy, is responsible for increasing incidence of bone fracture in the elderly; consequently, an understanding of how these fracture properties degrade with age is essential. In this study, ex vivo fracture experiments have been performed to quantitatively assess the effect of age on human cortical...

A 0.4C-2Si-1Cr-1Mo steel with an ultrafine elongated grain (UFEG) structure and an ultrafine equiaxed grain (UFG) structure was fabricated by multipass caliber rolling at 773 K and subsequent annealing at 973 K. A static three-point bending test was conducted at ambient temperature and at 77 K. The strength-toughness balance of the developed steels was markedly better than that of conventionall...

In this paper, the fatigue and fracture properties of bovine dentin are evaluated using in vitro experimental analyses. Double cantilever beam (DCB) specimens were prepared from bovine maxillary molars and subjected to zeroto-tension cyclic loads. The fatigue crack growth rate was evaluated as a function of the dentin tubule orientation using the Paris law. Wedge-loaded DCB specimens were also ...

Fractures during clinical function have been reported as the major concern associated with all-ceramic dental restorations. The aim of this study was to analyze the fracture features of glass-ceramic and zirconia-based restorations fractured during clinical use. Twenty-seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in func...

The experiments on dynamic crack propagation in PMMA (polymethyl methacrylate) and in soda lime glass conducted by Fineberg and Sharon (see [1-2] and quoted references) during the last decade pointed out some characteristic features of the microbranching instability in brittle materials. They observed the existence of a critical velocity for the onset of the microbranching; described the relati...

The myelin sheath of the goldfish lateral line nerve has been studied by means of the freeze-etch technique. Fracture faces of the myelin lamellae reveal linear structural elements which in some respects resemble those of tight junctions. In unfixed myelin rows of particles on the ef face are matched by narrow grooves on the pf face. Fixation with glutaraldehyde produces a partitioning of junct...

TiAlN/Al2O3 multilayers with different Ar/N2 ratios were deposited on Si substrates in different N2 partial pressure by magnetron sputtering. The crystalline and multilayer structures of the multilayers were determined by a glancing angle X-ray diffractometer (XRD). A nanoindenter was used to evaluate the hardness, the elastic modulus and scratch scan of the multilayers. The chemical bonding wa...