Emission, propagation, and reflection of light as mechanical phenomena in inertial frames

The kinematics of balls with mass in the inertial frames is like that in the frame at absolute rest. Practical examples of balls with mass studied at the limit when their mass is zero indicate that the kinematics of massless balls is like that of balls with mass. Light as a wave or particle is a massless entity. Therefore, it is natural to apply the kinematics behavior of the massless balls to light in its interactions with matter during the phenomena of emission and reflection. Thus, the kinematics of light depends on its kinetics of electromagnetic nature and by its mechanical interactions of emission and reflection with the matter. Light behaves in the inertial frames like in the frame at absolute rest, and the speed of light is the constant <mml:math display="inline"> <mml:mi>c</mml:mi> </mml:math> in the inertial frames in which the source and mirror are at rest. The terrestrial experiments with light cannot prove the motion of Earth. This study explains the result of the experiment performed at CERN, Geneva, in 1964. Including the massless balls within Newtonian mechanics, the emission, propagation, and reflection of light can be considered mechanical phenomena.

Linear Viscoelasticity: Review of Theory and Applications in Atomic Force Microscopy

Recently, much research has been performed involving the mechanical analysis of biological and polymeric samples with the use of Atomic Force Microscopy (AFM). Such materials require careful treatments which consider the rate-dependence of their viscoelastic response. Here, we review the fundamental theories of linear viscoelasticity, as well as their application to the analysis of AFM spectroscopy data. An outline of general viscoelastic mechanical phenomena is initially given, followed by a brief outline of AFM techniques. Then, an extensive outline of linear viscoelastic material models, as well as contact mechanics descriptions of AFM systems, are presented.

Study on the temperature and strain fields in gas foil bearings – measurement method and numerical simulations

Gas foil bearings belong to the group of slide bearings and are used in devices in which operation at high rotational speeds of the shafts are of key importance, e.g., in gas turbines. The air film developed on the surface of the bearing’s top foil allows this structural component to be separated from the shaft. This ensures a non-contact operation of the bearing. In the case of the mentioned type of bearings, their resultant operational properties are influenced by both thermal and mechanical phenomena. The current work presents a model of a gas foil bearing developed making use of the Finite Element Method. The model takes into account thermomechanical couplings which are necessary for the correct simulation of the operation of physical components of the modeled system. The paper reports the results of numerical analyzes conducted for the elaborated model as well as the relevant conclusions concerning thermomechanical couplings present in gas foil bearings. The method for the experimental identification of the temperature and strain fields in the bearing’s top foil proposed to validate the numerical model is also presented.

ANALYTICAL STUDY OF THE UNLOADING PROCESS OF ELEVATOR BUCKETS

The purpose of the article is to analyze the main results of the works that are used in the calculations of elevators with moderate speed modes, to clarify the suitability of their individual positions for developing the parameters of centrifugal unloading of high-speed elevators. Works devoted to the study of the operation of high-speed elevators, the results of which have not received a decent interpretation and development, are of considerable interest. As the efficiency of high-speed elevators is determined by the quality of centrifugal unloading and by the operation of the belt-drum mechanism without slipping, there is a need to analyze the work aimed at solving this problem. The paper presents known solutions for determining the parameters of centrifugal unloading, which are based on various hypotheses of the movement of material particles inside the bucket. The physical and mechanical phenomena that affect the movement of material particles in the elevator bucket are studied. The advantages and disadvantages of each hypothesis are revealed. The theoretical study of the process of centrifugal unloading is complicated by the fact that during the movement and exit of the material from the bucket, there is an unstable movement of the bulk material under the influence of a changing system of forces: the forces of attraction, centrifugal and coriolis forces, and the friction force. Meanwhile, even the simplest cases of material motion under a gravitational or mixed discharge regime are difficult to analyze theoretically. In this regard, the dependencies and methods of constructing the trajectories of the material movement are established, as well as the relevance of using a particular equation.

On Boolean posets of numerical events

With many physical processes in which quantum mechanical phenomena can occur, it is essential to take into account a decision mechanism based on measurement data. This can be achieved by means of so-called numerical events, which are specified as follows: Let S be a set of states of a physical system and p(s) the probability of the occurrence of an event when the system is in state $$s\in S$$ s ∈ S . A function $$p:S\rightarrow [0,1]$$ p : S → [ 0 , 1 ] is called a numerical event or alternatively, an S-probability. If a set P of S-probabilities is ordered by the order of real functions, it becomes a poset which can be considered as a quantum logic. In case the logic P is a Boolean algebra, this will indicate that the underlying physical system is a classical one. The goal of this paper is to study sets of S-probabilities which are not far from being Boolean algebras by means of the addition and comparison of functions that occur in these sets. In particular, certain classes of so-called Boolean posets of S-probabilities are characterized and related to each other and descriptions based on sets of states are derived.

A review on chemical and mechanical phenomena at the wafer interface during chemical mechanical planarization

As the minimum feature size of integrated circuit elements has shrunk below 7 nm, chemical mechanical planarization (CMP) technology has grown by leaps and bounds over the past several decades. There has been a growing interest in understanding the fundamental science and technology of CMP, which has continued to lag behind advances in technology. This review paper provides a comprehensive overview of various chemical and mechanical phenomena such as contact mechanics, lubrication models, chemical reaction that occur between slurry components and films being polished, electrochemical reactions, adsorption behavior and mechanism, temperature effects, and the complex interactions occurring at the wafer interface during polishing. It also provides important insights into new strategies and novel concepts for next‐generation CMP slurries. Finally, the challenges and future research directions related to the chemical and mechanical process and slurry chemistry are highlighted.

High compressibility caused by particle breakage: a DEM investigation

This paper summarises the numerical and experimental studies of brittle, hollow, cylindrical particles, called shells. It addresses the influence of shell properties both at the particle and assembly scales. Extreme compressibility has been recorded in the oedometer tests. Due to the large internal porosity of the shell, the breakage phenomena lead to highly compressive deformations with a significant stress dissipation. Using the Discrete Element Method (DEM), we have investigated in depth the micro-mechanical phenomena governing this macroscopic response. By quantifying the breakage and separating the double-porosity of the material, the foundations of a future constitutive model have been established throughout a simple prediction model applicable to the engineering practice.