in suspension polymerization, particle size distribution of polymer is the outcome of dynamic equilibrium between the break up and coalescence phenomena. the rates of break up and coalescence and consequently polymerization stability depend on several parameters, the most important of which are type and concentration of stabilizer. in this study, the effects of type and concentration of stabili...

In this study, the underlying atomic-scale plastic deformation mechanisms responsible for crack propagation process in nanograined gold thin film with an average grain size of ~10 nm (ranging from ~2 to ~22 nm) is investigated by situ high-resolution transmission electron microscope observations (i.e., a homemade device atomic force inside microscope) and atomistic molecular dynamic simulations...

Abstract In this study, numerical simulations of uniaxial compression, biaxial and unloading were performed on granite specimens that contained different prefabricated defects. The microscopic parameters in models verified by the compression experiments intact standard cylindrical specimen square with influences from stress paths, shapes defects, numbers distribution defects strength, deformati...

Experimental and computational methods to assess the fracture toughness of 15Kh2NMFA-A reactor vessel steel are analyzed based on local models: Rice–Tracey developed in Pisarenko Institute Problems Strength National Academy Sciences Ukraine. The master curve was experimentally constructed, parameters used examined models were obtained. model modification, which takes into account averaging rela...

A novel method for preparing and testing bending specimens in-situ the TEM has been developed. This method provides high visibility of the crack front and its associated plastic zone. This is significant because energy release rates can now be calculated at many points throughout the test based on crack tip opening displacement (CTOD), crack opening angle (COA), and crack advance. Further refin...

In this work, the plastic deformation mechanisms responsible for mechanical properties and fracture toughness in nanotwinned (NT) magnesium is studied by molecular dynamics (MD) simulation. The influence of twin boundary (TBs) spacing and crack position on deformation behaviors are investigated. The microstructure evolution at the crack tip are not exactly the same for the left edge crack (LEC)...

In this work, the effect of rock bolt angle on the shear behavior of Rock Bridges is investigated using the particle flow code in two dimensions (PFC2D) for three different Rock Bridge lengths. Firstly, the calibration of PF2D is performed to reproduce the gypsum sample. Then the numerical models with the dimensions of 100 mm * 100 mm are prepared. The Rock Bridge is created in the middle of th...

The limit relations for the partial derivatives of the two-electron atomic wave functions at the two-particle coalescence lines have been obtained numerically using accurate correlation function hyperspherical harmonic method wave functions. The asymptotic solutions of the proper two-electron Schrödinger equation have been derived for both electron-nucleus and electron-electron coalescence. It ...

The growth and characterization of ( 10 1 ¯ ) semipolar GaN buffer, InGaN multiple quantum wells (MQWs), light-emitting diode (LED) structure on patterned silicon-on-insulator (SOI) substrates, implementing the aspect ratio technique (ART), are reported. early stages result in continuous uniform stripes with small height variations that cause formation chevrons. Three coalescence strategies tes...