Relaxation to magnetohydrodynamics equilibria via collision brackets

Metriplectic dynamics is applied to compute equilibria of fluid dynamical systems. The result is a relaxation method in which Hamiltonian dynamics (symplectic structure) is combined with dissipative mechanisms (metric structure) that relaxes the system to the desired equilibrium point. The specific metric operator, which is considered in this work, is formally analogous to the Landau collision operator. These ideas are illustrated by means of case studies. The considered physical models are the Euler equations in vorticity form, the Grad-Shafranov equation, and force-free MHD equilibria.Comment: Conference Proceeding (Theory of Fusions Plasmas, 2018), 9 pages, 8 figure

Giant dipole resonance with exact treatment of thermal fluctuations

The shape fluctuations due to thermal effects in the giant dipole resonance (GDR) observables are calculated using the exact free energies evaluated at fixed spin and temperature. The results obtained are compared with Landau theory calculations done by parameterizing the free energy. The Landau theory is found to be insufficient when the shell effects are dominating.Comment: 5 pages, 2 figure

B-nodes: a new scalable high level abstraction model

This paper proposes a new modeling technique called B-Nodes. B-Nodes represent a new, high-level abstraction that allows technical detail to be controlled using top-down recursive decomposition. This abstraction. is independent of architectural detail and can therefore accommodate rapid changes in technology. The use of recursive decomposition allows B-Nodes to be used not only for entire e-commerce system but also sub-modules within this system. The use of fundamental units allows the performance of heterogeneous technologies to be compared and other units to be derived. Results to date indicate no comparable model exists. Should further work validate this technique the authors recommend its use as a standard technique in information systems analysis and desig

A case for systems thinking and system dynamics

Systems thinking is a way of thinking that focuses on the relationships between the parts forming a purposeful whole. System dynamics is concerned with building computer models of complex problem situations and then experimenting with and studying the behaviour of these models over time. This paper is a review of systems thinking that considers its unique history and influences, paradigms and methodologies, and presents a case for the system dynamics methodology as the best tool for the most diverse range of problem situation

Comparison of Grain Refinement in Selected Materials Subjected to Hydrostatic Extrusion

The subject of this study was to examine and compare the impact of intense hydrostatic extrusion on grain refinement in three different alloys: duplex stainless steel, commercially used aluminum alloy (6060) and Ag-Cu12 alloy. As a result of the process grain sizes from 370 nm to 90 nm were obtained in aluminum and duplex steel. To analyze the of hydrostatic on mechanical properties tensile tests were also carried out. The highest grain refinement (70 nm) and yield strength increase (over 300%) was observed in duplex steel af-ter hydrostatic extrusion. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3560

Network Security Devices and Protocols Using State Model Diagrams

Network security is concerned with protecting sensitive information, limiting unauthorised access, and reinforcing network performance. An important factor in network security is encryption. Internet Security Protocol (IPSec) is the de facto open standard for encryption and replaces the older Cisco Encryption Technology (CET). Both encryption protocols are typically implemented and managed using the text based Command Line Interface (CLI). A graphical user interface (GUI) is available; however, it is not routinely used. Regardless of whether the CLI or GUI is used, both encryption suites are complex to implement and manage. State Model Diagrams (SMDs) were developed and successfully used as the pedagogical foundation of internetworking technologies. SMDs integrate pertinent output from devices and protocol finite state information. SMDs are modular and hierarchical models thereby providing top down deconstruction as a cascaded structure. In terms of ease of use, hyperlinks may be used to navigate between different state tables and diagrams. Moreover, as hierarchical model characteristics allow technical detail to be presented and integrated to assist in managing devices. In this paper, SMDs were used to evaluate CET and IPSec via experiments in order to determine their potential value as network management tool

Applicability of shape parameterizations for giant dipole resonance in warm and rapidly rotating nuclei

We investigate how well the shape parameterizations are applicable for studying the giant dipole resonance (GDR) in nuclei, in the low temperature and/or high spin regime. The shape fluctuations due to thermal effects in the GDR observables are calculated using the actual free energies evaluated at fixed spin and temperature. The results obtained are compared with Landau theory calculations done by parameterizing the free energy. We exemplify that the Landau theory could be inadequate where shell effects are dominating. This discrepancy at low temperatures and high spins are well reflected in GDR observables and hence insists on exact calculations in such cases.Comment: 10 pages, 2 figure