Escape of a forced-damped particle from weakly nonlinear truncated potential well

Nonlinear Dynamics - Escape from a potential well is an extreme example of transient behavior. We consider the escape of the harmonically forced particle under viscous damping from the benchmark...     

Influence of Porosity on Fracture Toughness of Hydroxyapatite/Multi-Walled Carbon Nanotubes Biocomposite Materials

Russian Physics Journal - The paper analyzes the influence of porosity of hydroxyapatite (HA)/multi-wall carbon nanotubes (MWCNTs) composites on their fracture toughness. It is found that two...     

Quaternion Attitude Determination by Vector Measurement

International Applied Mechanics - Quaternion attitude determination algorithms based on vector measurements are proposed. The projections of the normalized vectors in the reference and the...     

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...     

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...     

Extreme Values of the Strength of Single Filaments and Threads of a Paraaramide Fiber After Its Treatment by a Water Suspension of Carbon Nanoparticles

Mechanics of Composite Materials - The paper presents results of changes in the extreme values (minimum and maximum possible) of the tensile strength of threads and single filaments of an aramid...