The role of stress waves reflected from the free surface in rock breaking by blasting

1978 ◽  
Vol 14 (2) ◽  
pp. 165-168 ◽  
Author(s):  
N. E. Trufakin ◽  
V. D. Belyakov
Keyword(s):  
Free Surface ◽  
Rock Breaking ◽  
Stress Waves

On the role of tin underlays for the prevention of thermal grooving in thin gold films

1986 ◽  
Vol 44 ◽  
pp. 732-733
Author(s):  
Jin Young Kim ◽  
R. E. Hummel ◽  
R. T. DeHoff
Keyword(s):  
Thin Film ◽  
Free Surface ◽  
Grain Boundary ◽  
Beneficial Effect ◽  
Failure Mechanism ◽  
Failure Mechanisms ◽  
Distinct Advantage ◽  
Gold Films ◽  
Gold Thin Film

Gold thin film metallizations in microelectronic circuits have a distinct advantage over those consisting of aluminum because they are less susceptible to electromigration. When electromigration is no longer the principal failure mechanism, other failure mechanisms caused by d.c. stressing might become important. In gold thin-film metallizations, grain boundary grooving is the principal failure mechanism.Previous studies have shown that grain boundary grooving in gold films can be prevented by an indium underlay between the substrate and gold. The beneficial effect of the In/Au composite film is mainly due to roughening of the surface of the gold films, redistribution of indium on the gold films and formation of In2O3 on the free surface and along the grain boundaries of the gold films during air annealing.

Free surface over a horizontal shear layer: vorticity generation and air entrainment mechanisms

2017 ◽  
Vol 813 ◽  
pp. 1007-1044 ◽  
Author(s):  
Matthieu A. André ◽  
Philippe M. Bardet
Keyword(s):  
Free Surface ◽  
Shear Layer ◽  
Air Entrainment ◽  
Horizontal Shear ◽  
Vortex Instability ◽  
Image Velocimetry ◽  
Planar Laser ◽  
Spatio Temporal ◽  
The Waves

Two air entrainment mechanisms driven by vortex instability are reported in the unstable relaxation of a horizontal shear layer below a free surface. This flow is experimentally investigated by means of planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) coupled with surface profilometry. PLIF identifies counter-rotating vortex pairs (CRVP) emanating from the surface following the growth of high steepness two-dimensional millimetre-size waves for Reynolds and Weber numbers based on the momentum thickness of 177 to 222 and 7.59 to 13.9, respectively. High spatio-temporal resolution PIV reveals the role of surface-generated vorticity and flow separation in the highly curved trough of the waves on the injection of a CRVP. Air bubbles are entrapped in the wake of these CRVPs at Reynolds number above 190. PIV data and spanwise PLIF images show two initiation mechanisms: primary vortex instability modulating the spanwise location where the flow separates, resulting in the pinch off of an air ligament, and secondary vortex instability turning a CRVP into$\unicode[STIX]{x1D6FA}$-shaped loops pulling the surface down. Instability wavelengths agree with linear stability analysis, and models for these new air entrainment mechanisms are proposed.

On the role of stress waves in dynamic rupture of cylindrical tubes

2017 ◽  
Vol 40 (12) ◽  
pp. 2008-2018 ◽  
Author(s):  
M. Mirzaei ◽  
S. Tavakoli ◽  
M. Najafi
Keyword(s):  
Stress Waves ◽  
Dynamic Rupture ◽  
Cylindrical Tubes

Role of algal biofilm in improving the performance of free surface, up-flow constructed wetland

2014 ◽  
Vol 169 ◽  
pp. 596-604 ◽  
Author(s):  
Neha Badhe ◽  
Shaswati Saha ◽  
Rima Biswas ◽  
Tapas Nandy
Keyword(s):  
Free Surface ◽  
Constructed Wetland ◽  
Algal Biofilm

Evidence for the Role of Propagating Stress Waves during Fracture

1998 ◽  
Vol 81 (20) ◽  
pp. 4428-4431 ◽  
Author(s):  
L. C. Krysac ◽  
J. D. Maynard
Keyword(s):  
Stress Waves
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