UNLABELLED BACKGROUND Chalcones are ubiquitous natural compounds with a wide variety of reported biological activities, including antitumoral, antiviral and antimicrobial effects. Furthermore, chalcones are being studied for its potential use in organic electroluminescent devices; therefore the description of their spectroscopic properties is important to elucidate the structure of these mol...

Молекулу N,N-дифенилциклогекса-2,5-диен-1,4-диимина можно рассматривать как структурный фрагмент макромолекулы полианилина в окисленном состоянии. Сравнительный расчѐт структуры этой молекулы проведѐн методами молекулярной механики, полуэмпирической квантовой механики и ab initio (HF DFT). При расчѐте методом DFT использованы функционалы ωB97X-D3, ωB97M-V, ωPBE-D3, M11, M06HF-D3, BLYP-D3, M05-2...

Accurate description of hydrogen-bonding energies between water molecules and van der Waals interactions between guest molecules and host water cages is crucial for study of methane hydrates (MHs). Using high-level ab initio MP2 and CCSD(T) results as the reference, we carefully assessed the performance of a variety of exchange-correlation functionals and various basis sets in describing the no...

Current treatment planning systems (TPSs) for partial breast irradiation using the MammoSite brachytherapy applicator (Cytyc Corporation, Marlborough, MA) often neglect the effect of inhomogeneity, leading to potential inaccuracies in dose distributions. Previous publications either have studied only a planar dose perturbation along the bisector of the source or have paid little attention to th...

BACKGROUND The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in treatment TPSs. OBJECTIVES The purpose of this stu...

For a wide range of magnetic fields, 0 B 2000 a.u., we present a systematic comparative study of the performance of different types of density-functional approximations in light atoms (2 Z 6). Local, generalized-gradient approximation (GGA; semilocal), and meta-GGA ground-state exchange-correlation (xc) functionals are compared on an equal footing with exact-exchange, Hartree-Fock (HF), and cur...

Purpose. To determine and evaluate technogenic risks within the water purification systems of TSs TPSs during normal operation in terms electrocoagulation plant. Methodology. It is proposed to apply a fault tree method for analysis various failures facilities heat power industry. Additional method, applied at stages one two risk determination, suggested its use. The based upon construction matr...