Fracture is the ultimate source of failure amorphous carbon (a-C) films, however it challenging to measure fracture properties a-C from nano-indentation tests and results reported experiments are not consistent. Here, we use atomic-scale simulations make quantitative mechanistic predictions on a-C. Systematic large-scale K-field controlled crack propagation performed for samples with densities ...

A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely ...

modelling of crack propagation by finite element method under mixed mode conditions is of prime importance in fracture mechanics. this paper describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. crack growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress criterion,...

OBJECTIVES HIV prevalence among people who inject drugs (PWID) in Ottawa is estimated at about 10%. The successful integration of peers into outreach efforts and wider access to HIV point-of-care testing (POCT) create opportunities to explore the role of peers in providing HIV testing. The PROUD study, in partnership with Ottawa Public Health (OPH), sought to develop a model for community-based...

OBJECTIVE To examine relationships between parenting behaviors, parent-child relationship, and moderating effects of age on youth substance use among a community sample of African-American mothers who use crack cocaine and their children (12-17 years). METHODS Maternal-child dyads (n = 208) were recruited through street outreach and snowball sampling and completed interviews about substance u...

In this work, a mechanistic model of drop coalescence based upon a stochastic film-drainage analysis is developed. The coalescence model accounts for previously considered factors, such as turbulence intensity, drop size, and drop deformability, while additionally describing the dual effects of drop surface potential and system electrolyte concentration. Model results indicate that electrostati...

Molecular dynamics simulations were performed to investigate the wetting and coalescence of liquid Al and Pb drops on four carbon-based substrates. We highlight the importance of the microstructure and surface topography of substrates in the coalescence process. Our results show that the effect of substrate on coalescence is achieved by changing the wettability of the Pb metal. Additionally, we...

We present data on the pinch-off and coalescence of thin liquid alkane lenses floating on water. Pinch-off in quasi-2D lenses is distinctly different from pinch-off in axisymmetric 3D drops and involves a cascade of satellite droplets which extends to micron length scales. In contrast, coalescence of lenses is qualitatively similar to coalescence of 3D drops. Coalescence is predicted to involve...

Mechanisms and dynamics of bubble coalescence in silicic magmas 1 Jonathan M. Castro (University of Mainz) 2 Alain Burgisser (ISTO-CNRS) 3 Ian Schipper (ISTO-CNRS) 4 Simona Mancini (ISTO-Université d’Orléans) 5 6 Abstract 7 Bubble coalescence is an important process that strongly affects magmatic degassing. 8 Without coalescence, bubbles remain isolated from one another in the melt, severely 9 ...