Scale removing technic on metal fracture surface.

Removing the Cosmological Bound on the Axion Scale

The current cosmological bound on the invisible axion scale may be avoided in the class of theories in which the gauge coupling constant is determined through the expectation value of some scalar field (e.g. moduli in supergravity and string theories). This leads to the cosmological scenario different from that of the standard invisible axion, since the initial values of the fields are usually ...

Surface States, Surface Metal-Insulator, and Surface Insulator-Metal Transitions ∗

I present an informal discussion of various cases where two-dimensional surface metal-insulator structural and charge-density-wave instabilities driven by partly filled surface states have been advocated. These include reconstructions of clean semiconductor surfaces and of W(100) and Mo(100), as well as anomalies on the hydrogen-covered surfaces H/W(110) and H/Mo(110), and possibly alkali-cover...

Fracture of Metal Coated Elastomers

Polydimethyldisiloxane (PDMS) substrates were coated with thin layers of gold varying in thickness between 40 nm and 160 nm. Arrays of parallel cracks formed when a tensile strain was applied to the coated system, with the spacing between the cracks being approximately inversely proportional to the strain. When the crack profiles were examined, it was noted that the cracks extended deep into th...

Fracture Toughness of Metal Castings

Roentgen Technic