Electron Microscopy and Electron Diffraction Studies of Morphology and Crystal Structure of Natural Silicas

Crystallography Reports - The development of fundamental and applied geology requires an ever-increasing amount of data on the structures and properties of rocks at different scales. Of particular...     

$ P $ -Stability of Some Classes of $ S $ -Acts

Siberian Mathematical Journal - The notion of $ P $ -stability is a particular case of the generalized stability of complete theories. This paper discusses some problems that are related to the $ P...     

Effect of External Factors on the Ferromagnetic Resonance Line Width in Exchange-Biased Structures

Physics of the Solid State - The external factors which influence the ferromagnetic resonance (FMR) line width in bilayer (ferromagnet/antiferromagnet) exchange-biased systems are studied. The...     

Application of Synchrotron Radiation to Analyze the Friction-Induced Structural and Phase Transformations of Chrome-Nickel Austenitic Steel

Russian Physics Journal -     

Equation for Condensed Matter Phase Transitions

Russian Physics Journal - A unified equation for the pressure drop in the apparatus with the stationary and fluidized granular layers is derived. The resulting recurrent equation is used to...     

Analysis of Vibration Signals of Drivetrain Failures in Wind Turbines for Condition Monitoring

Experimental Techniques - In the last years, the wind industry has increased in a large scale. A wind turbine out of service leeds to high costs due to both maintenance and repair costs and the...     

Study of Beauty Baryons at the LHCb Experiment

Physics of Atomic Nuclei - The high statistics collected by the LHCb experiment in proton-proton collisions during Run 1 and 2 of the Large Hadron Collider provides a unique opportunity for study...     

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.     

1-Meixner Random Vectors

Journal of Theoretical Probability - A definition of d-dimensional n-Meixner random vectors is given first. This definition involves the commutators of their semi-quantum operators. After that we...     

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.