Parallel software tool for decomposing and meshing of 3d structures

An algorithm for automatic parallel generation of three-dimensional unstructured computational meshes based on geometrical domain decomposition is proposed in this paper. Software package build upon proposed algorithm is described. Several practical examples of mesh generation on multiprocessor computational systems are given. It is shown that developed parallel algorithm enables us to reduce mesh generation time significantly (dozens of times). Moreover, it easily produces meshes with number of elements of order 5 · 107, construction of those on a single CPU is problematic. Questions of time consumption, efficiency of computations and quality of generated meshes are also considered

Liquid low-level radioactive wastes treatment by using hydrophobized track-etched membranes

In this paper, we present the results of liquid low-level radioactive wastes (LLLRW) treatment by direct contact membrane distillation (DCMD) using polyethylene terephthalate (PET) track-etched membranes (TeMs). PET TeMs were modified by styrene and triethoxyvinylsilane (TEVS) using UV-induced grafting. Modification led to increase in the contact angle to 99° of PET TeMs (pore size from 150 to 300 nm). Hydrophobic PET TeMs were investigated by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), goniometric analysis, gas permeability test, liquid entry presser (LEP) analysis and scanning electron microscope (SEM). Prepared membranes were tested in treatment of LLLRW by DCMD. The influence of pore size on water flux and rejection degree was studied. Rejection degree was evaluated by conductometry and atomic emission methods. Decontamination factors (evaluated by gamma-ray spectroscopy) for 60Co, 137Cs, and 241Am were found to be 85, 1900 and 5 respectively. In most cases degree of rejection of Cs, Mo, Sr, Sb, Al, Ca, Fe, K, Mg and Na ions were more than 90% and close to 100%. The use of TeMs with a narrow pores size distribution and without tortuous channels allowed us to achieve better purification from radioactive wastes in comparison with hollow-fiber membranes. © 2019 Elsevier LtdMinistry of Education and Science of the Republic of Kazakhstan: AP05132110This study was funded by the Ministry of Education and Science of the Republic of Kazakhstan (grant No AP05132110 “Preparation of track-etched membranes with specified properties for membrane distillation and forward osmosis”)

Parallel software tool for decomposing and meshing of 3d structures

An algorithm for automatic parallel generation of three-dimensional unstructured computational meshes based on geometrical domain decomposition is proposed in this paper. Software package build upon proposed algorithm is described. Several practical examples of mesh generation on multiprocessor computational systems are given. It is shown that developed parallel algorithm enables us to reduce mesh generation time significantly (dozens of times). Moreover, it easily produces meshes with number of elements of order 5 · 107, construction of those on a single CPU is problematic. Questions of time consumption, efficiency of computations and quality of generated meshes are also considered