On the Distributivity and Modularity Properties of the Lattice of Fitting Classes

Mathematical Notes - It is proved that the lattice of all Fitting classes of finite groups is not distributive, and conditions under which Fitting classes satisfy the distributive and modular laws...     

Inversions of Hölder’s Inequality

Mathematical Notes - In the present paper, new theorems on the inversion of the Hölder inequality that refine similar inversions known previously are proved.     

Polyfrequency Vibrations of Electromagnetic Shock and Vibration System

International Applied Mechanics - The polyfrequency mode of vibrations of the electromagnetic shock and vibration system for compaction of mortars is studied. Physical and mathematical models of...     

Admittance of Pentacene- Based Mis-Structures with Two-Layer Insulator SiO2–Al2O3

Russian Physics Journal - Experimental studies of the admittance of MIS structures based on pentacene with a two-layer insulator SiO2–Al2O3 and back contacts made of various materials (Au,...     

Dynamic Modeling of the Feed Drive System of a CNC Metal Cutting Machine

Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control (CNC) machines. The preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational conditions. Rotational acceleration of the screw also affects the performance of the CNC feed drive when machining small parts. This paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able to eliminate an observed resonance occurred at high rotational speeds of the screw, corresponding to high feed rates. Additionally, rational structural parameters of the feed drive system are selected in order to increase the rotational acceleration for improving the performance of the CNC machine. Experiments and analyses showed that by selecting specific parameters of feed drive system and simultaneously applying a certain value of preload, a 97% increase in rotational acceleration and 30% time reduction considering the vibration resistance at high rotational speeds can be achieved.     

Application of Electron Energy-Loss Spectroscopy for Analysis of the Microstructure of Reactor Materials

Crystallography Reports - It is shown by the example of hydrogen (in hydrides ZrH), helium (in pores after implantation), and nickel (in G-phase precipitates) that the application of electron...     

The X-ray Structures of (R)-2,2′-Dimethyl-1,1′-binaphthyl and (±)-2-Bromomethyl-2′-dibromomethyl-1,1′-binaphthyl

Journal of Chemical Crystallography - Molecular structures of (R)-2,2′-dimethyl-1,1′-binaphthyl [monoclinic, a?=?11.24420 (11), b?=?10.56190 (9),...     

Advances in the computational analysis of SARS-COV2 genome

Nonlinear Dynamics - Given a data-set of Ribonucleic acid (RNA) sequences we can infer the phylogenetics of the samples and tackle the information for scientific purposes. Based on current data and...     

On the Right-Symmetric Algebras with a Unital Matrix Subalgebra

Siberian Mathematical Journal - Under study are the right-symmetric algebras over a field  $ F $ which possess a “unital” matrix subalgebra  $...     

Solitons and Other Solutions for the Nonlinear Convection–Diffusion–Reaction Equation with Power-Law Nonlinearity by the Extended Simplest Equation Method

Computational Mathematics and Modeling - Based on the extended simplest equation method, we construct solitons and other solutions for the nonlinear convection-diffusion-reaction equation with...