Structure–phase state of the surface layers in rails subjected to differential hardening

A layer-by-layer analysis of the structures, the phase compositions, and the defect substructures of differentially hardened rails has been carried by optical and transmission electron microscopy. It is found that the material volume of the rail head fillet is cooled faster than the volume located along the central axis.     

Relationship Between the Thermodynamic Parameters,Structure, and Anticorrosion Properties of Al-Zr-Ni-Fe-Y Alloys

Metallurgical and Materials Transactions A - The influence of the chemical composition on the crystallization process, amorphous phase formation, and the anticorrosion properties of Al-Zr-Ni-Fe-Y...     

Effect of Railcar Wheel Tire Profiles on the Contact Stress Level in Subway Rails

Strength of Materials - The statistical analysis performed on the defectiveness of rails in the Kiev subway railway shows that the main cause of the occurrence of most defects is the contact...     

Robust predictive extended state observer for a class of nonlinear systems with time-varying input delay

ABSTRACT

This paper deals with asymptotic stabilisation of a class of nonlinear input-delayed systems via dynamic output feedback in the presence of disturbances. The proposed strategy has the structure of an observer-based control law, in which the observer estimates and predicts both the plant state and the external disturbance. A nominal delay value is assumed to be known and stability conditions in terms of linear matrix inequalities are derived for fast-varying delay uncertainties. Asymptotic stability is achieved if the disturbance or the time delay is constant. The controller design problem is also addressed and a numerical example with an unstable system is provided to illustrate the usefulness of the proposed strategy.     

Effect of the Porous Skeletal Iron Structure on the Infiltration of Aluminum Melts

Powder Metallurgy and Metal Ceramics - The infiltration of aluminum melts into porous metal skeletons produced by powder metallurgy methods, including 3D printing, under a pressure gradient was...     

Fracture Resistance of Brittle Materials Under Local Loading by Scratching to Edge Chipping. Part. 1. Methodical Grounds of Research

Strength of Materials - Methodical aspects of experimental investigation of brittle materials under local edge loading by scratching the specimen surface with a Rockwell indenter to its edge...     

A Method of Transferring the Unit of Power of High-Intensity Laser Radiation

Measurement Techniques - A method is proposed for transferring the unit of mean power of laser radiation by means of measuring high-intensity power (kilowatts), with the possibility of constant...     

On Heating and Relaxation of the Electron—Hole-Gas Energy in the Track of a Primary Recoil Atom

Semiconductors - On the basis of the Monte Carlo algorithm, a method for calculating the energy spectrum of hot nonequilibrium electrons and holes in the track of a primary recoil atom after being...