Influence of the Metal–Semiconductor Interface Model on Power Conservation Principle in a Simulation of Bipolar Devices

The purpose of the study is to present a proper approach that ensures the energy conservation principle during electrothermal simulations of bipolar devices. The simulations are done using Sentaurus TCAD software from Synopsys. We focus on the drift-diffusion model that is still widely used for power device simulations. We show that without a properly designed contact(metal)–semiconductor interface, the energy conservation is not obeyed when bipolar devices are considered. This should not be accepted for power semiconductor structures, where thermal design issues are the most important. The correct model of the interface is achieved by proper doping and mesh of the contact-semiconductor region or by applying a dedicated model. The discussion is illustrated by simulation results obtained for the GaN p–n structure; additionally, Si and SiC structures are also presented. The results are also supported by a theoretical analysis of interface physics.

Direct Derivation of Liénard–Wiechert Potentials, Maxwell’s Equations and Lorentz Force from Coulomb’s Law

In this paper, the solution to long standing problem of deriving Maxwell’s equations and Lorentz force from first principles, i.e., from Coulomb’s law, is presented. This problem was studied by many authors throughout history but it was never satisfactorily solved, and it was never solved for charges in arbitrary motion. In this paper, relativistically correct Liénard–Wiechert potentials for charges in arbitrary motion and Maxwell equations are both derived directly from Coulomb’s law by careful mathematical analysis of the moment just before the charge in motion stops. In the second part of this paper, the electrodynamic energy conservation principle is derived directly from Coulomb’s law by using similar approach. From this energy conservation principle the Lorentz force is derived. To make these derivations possible, the generalized Helmholtz theorem was derived along with two novel vector identities. The special relativity was not used in our derivations, and the results show that electromagnetism as a whole is not the consequence of special relativity, but it is rather the consequence of time retardation.

The energy–momentum conservation law in two-particle system for twist-deformed Galilei Hopf algebras

In this paper, we discuss the energy–momentum conservation principle for two-particle system in the case of canonically and Lie-algebraically twist-deformed Galilei Hopf algebra. Particularly, we provide consistency with the coproducts energy and momentum addition law as well as its symmetric with respect to the exchange of particles counterpart. Besides, we show that the vanishing of total four momentum for two Lie-algebraically deformed kinematical models leads to the discrete values of energies and momenta only in the case of the symmetrized addition rules.

A physical theory of accounting: particular study issues

The subject matter of the paper is related to theoretical and methodological basics of accounting as a field of study. Over many centuries, the laws of economics have been examined dialectically by scholars. In the course of establishing a study of economics, there have been a number of orthodox scholarly traditions, united by a common idea of †development and patterns of performance. For a long time, economists from different countries worked hard in order to understand the essence of economic and social processes, derive and explain economic laws using knowledge and experience acquired by people. The aim of the article is to explore in what way the research methods which are generally applied in natural sciences can be deployed for economic studies, and in particular for describing the nature of accounting. The key objectives of the paper are to develop a methodology for applying methods of physics to the study of economics, and to identify the link between conceptual framework of accounting and physics. In the paper, the following general and specific research methods are used: modeling, algorithmization, formalization, generalization, comparison, analogy, system approach. It is justified that the laws of physics can be prospectively applied for explaining economic phenomena and processes, particularly in accounting, which is viewed as an important source of information. Hence, the correlation between accounting and the field of physics and mathematics is determined through: the use of formal description of accounting items; the consideration in terms of seeing accounting as a specific knowledge field; the interpretation of accounting methods (in particular, the balance method) through algorithmization and parallelism with the laws of physics (for example, the energy conservation principle); the establishment of an information hierarchy of the current state and behavior of assets, capital and liabilities of the enterprise; the examination of balances by means of appropriate algorithmization and justification of advisability of developing a physical nature of accounting theory. It is pointed out, that there is a difference between the balance method and the energy conservation principle (the energy in an enclosed system is constant, which makes it impossible to observe the process of arrival or creation of new energy in enclosed space). The conclusion is based on the positive influence of econophysics on the economy’s performance, and the advisability of its application for a more accurate study of economic processes, and a more qualitative economic analysis of enterprise performance.