Minkowski metrics on solutions of the Khokhlov-Zabolotskaya equation

2009 ◽  
Vol 30 (4) ◽  
pp. 333-336 ◽  
Author(s):  
V. Lychagin ◽  
V. Yumaguzhin
Keyword(s):  
Minkowski Metrics

Methods of Interpreting the Results of Vibration Measurements to Locate Damages in Beams

2013 ◽  
Vol 430 ◽  
pp. 84-89 ◽  
Author(s):  
Petru Florin Minda ◽  
Zeno Iosif Praisach ◽  
Andrea Amalia Minda ◽  
Gilbert Rainer Gillich
Keyword(s):  
Structural Changes ◽  
Graphic Representation ◽  
Vibration Measurement ◽  
Vibration Modes ◽  
Precise Localization ◽  
Vibration Measurements ◽  
Measurement Results ◽  
Minkowski Metrics ◽  
Selected Location

This paper deals with methods of interpreting the results of vibration measurement to identify structural changes in beam-like structures. We briefly presented an own developed damage assess method, that consider a large number of frequencies for the weak-axis banding vibration modes; it allows first a precise localization and afterwards evaluation of the damages. For the first step, recognition of the damage position, we introduce an algorithm implemented in C++ with the interface done using EXCEL features, indicating by one number the damage probable position, based on the Minkowski metrics. To avoid uncertainties, a graphic representation of all results is also presented. The method is tested for values determined by calculus for a randomly selected location, with and without measurement results debased by noise, proving its reliability.

scholarly journals Chirality in gravitational and electromagnetic interactions with matter

2018 ◽  
Vol 15 (supp01) ◽  
pp. 1840004
Author(s):  
Robin W. Tucker ◽  
Timothy J. Walton
Keyword(s):  
Finite Energy ◽  
Geodesic Equation ◽  
Einstein Equations ◽  
Analytic Structure ◽  
Astrophysical Jet ◽  
Aspect Ratios ◽  
Test Particles ◽  
Astrophysical Objects ◽  
Minkowski Metrics ◽  
Energy Pulse

It has been suggested that single and double jets observed emanating from certain astrophysical objects may have a purely gravitational origin. We discuss new classes of pulsed gravitational wave solutions to the equation for perturbations of Ricci-flat spacetimes around Minkowski metrics, as models for the genesis of such phenomena. We discuss how these solutions are motivated by the analytic structure of spatially compact finite energy pulse solutions of the source-free Maxwell equations generated from complex chiral eigen-modes of a chirality operator. Complex gravitational pulse solutions to the linearized source-free Einstein equations are classified in terms of their chirality and generate a family of non-stationary real spacetime metrics. Particular members of these families are used as backgrounds in analyzing time-like solutions to the geodesic equation for test particles. They are found numerically to exhibit both single and double jet-like features with dimensionless aspect ratios suggesting that it may be profitable to include such backgrounds in simulations of astrophysical jet dynamics from rotating accretion discs involving electromagnetic fields.

Sign in / Sign up

Export Citation Format

Share Document