Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 4
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

This paper presents novel discrete differential operators for periodic functions of one- and two-variables, which relate the values of the derivatives to the values of the function itself for a set of arbitrarily chosen points over the function’s area. It is very characteristic, that the values of the derivatives at each point depend on the function values at all points in that area. Such operators allow one to easily create finite-difference equations for boundaryvalue problems. The operators are addressed especially to nonlinear differential equations.
Go to article

Bibliography

[1] Richtmayer R.D., Morton K.W., Difference methods for initial-value problems, J.Willey & Sons, New York (1967).
[2] Burden R.L., Faires J.D., Numerical analysis, PWS-Kent Pub. Comp., Boston (1985).
[3] Taflove A., Computational electrodynamics: the finite-difference time-domain method, Artech House, Boston – London (1995).
[4] Strikwerda J.C., Finite Difference Schemes and Partial Differential Equations, Society for Industrial and Applied Mathematics, Second Edition, Philadelphia (2004).
[5] LeVeque R.J., Finite difference methods for ordinary and partial differential equations, Society for Industrial and Applied Mathematics, Second Edition, Philadelphia (2007).
[6] Fortuna Z., Macukow B., Wasowski J., Numerical methods, WNT (in Polish), Warsaw (2009).
[7] Esfandiari R.S., Numerical Methods for Engineers and Scientists Using MATLABr, CRC Press, Taylor & Francis Group (2017).
[8] Zakrzewski K., Łukaniszyn M., Application of 3-D finite difference method for inductance calculation of air-core coils system, COMPEL International Journal of Computations and Mathematics in Electrical Engineering, vol. 13, no. 1, pp. 89–92 (1994).
[9] Demenko A., Sykulski J., On the equivalence of finite difference and edge element formulations in magnetic field analysis using vector potential, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33, no. 1/2, pp. 47–55 (2014).
[10] Huang J., LiaoW., Li Z., A multi-block finite difference method for seismic wave equation in auxiliary coordinate system with irregular fluid–solid interface, Engineering Computations, vol. 35, no. 1, pp. 334–362 (2018).
[11] Chapwanya M., Dozva R., Gift Muchatibaya G., A nonstandard finite difference technique for singular Lane-Emden type equations, Engineering Computations, vol. 36, no. 5, pp. 1566–1578 (2019).
[12] Mawlood M., Basri S., AsrarW., Omar A., Mokhtar A., Ahmad M., Solution of Navier-Stokes equations by fourth-order compact schemes and AUSM flux splitting, International Journal of Numerical Methods for Heat and Fluid Flow, vol. 16, no. 1, pp. 107–120 (2006).
[13] Ivanovic M., Svicevic M., Savovic S., Numerical solution of Stefan problem with variable space grid method based on mixed finite element/finite difference approach, International Journal of Numerical Methods for Heat and Fluid Flow, vol. 27, no. 12, pp. 2682–2695 (2017).
[14] Sobczyk T.J., Algorithm for determining two-periodic steady-states in AC machines directly in time domain, Archives of Electrical Engineering, Polish Academy of Science, Electrical Engineering Committee, vol. 65, no. 3, pp. 575–583 (2016), DOI: 10.1515/aee-2016-0041.
[15] Sobczyk T.J., Radzik M., Radwan-Pragłowska N., Discrete differential operators for periodic and two-periodic time functions, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 38, no. 1, pp. 325–347 (2019).
[16] Sobczyk T.J., Radzik M., A new approach to steady state analysis of nonlinear electrical circuits, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 37, no. 3, pp. 716–728 (2017).
[17] Sobczyk T.J., Radzik M., Tulicki J., Direct steady-state solutions for circuit models of nonlinear electromagnetic devices, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 40, no. 3, pp. 660–675 (2021), DOI: 10.1108/COMPEL-10-2020-0324.
[18] Sobczyk T.J., Jaraczewski M., Application of discrete differential operators of periodic functions to solve 1D boundary-value problems, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 39, no. 4, pp. 885–897 (2020).
[19] Sobczyk T.J., 2D discrete operators for periodic functions, Proceedings IEEE Conference Selected Issues of Electrical Engineering and Electronics (WZZE), Zakopane, Poland, pp. 1–5 (2019), https://ieeexplore.ieee.org/document/8979992.
[20] Jaraczewski M., Sobczyk T., Leakage Inductances of Transformers at Arbitrarily Located Windings, Energies, vol. 13, no. 23, 6464 (2020), DOI: 10.3390/en13236464.

Go to article

Authors and Affiliations

Tadeusz Jan Sobczyk
1
ORCID: ORCID

  1. Department of Electrical Engineering, Faculty of Electrical and Computer Engineering, Cracow University of Technology, 24 Warszawska str., 31-155 Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

A helicopter blade tip vortex generates impulsive noise of high intensity when it impinges upon the following blade. In the present work, the vortex is attenuated by coaxial swirling jet rotating in the opposite direction. The jet issues from a nozzle located at the blade tip. The nozzle was supplied with compressed air transported in the blade channel. The decrement of vortex strength is measured as a function of the compressed air pressure related to the dynamic pressure of the flow in the wind tunnel. It was found that the jet, even of relatively low intensity, considerably effects the blade tip vortex formation.
Go to article

Authors and Affiliations

Andrzej Szumowski
Mieczysław Litwińczyk
Download PDF Download RIS Download Bibtex

Abstract

Tetranychus urticae (Acari: Tetranychidae) infesting many plants but Mentha viridis L., and Mentha piperita L., were low in number of infestation. Therefore the objective of this study was to identify the resistance of M. viridis and M. piperita plants against T. urticae by studying the external shape and internal contents of those plants. For morphological studies, dried leaves were covered with gold utilizing an Edwards Scan coat six sputter-coater. For histological studies, arrangements of Soft Tissue technique were used. For phytochemical studies, the plants were cut, dried and then high performance liquid chromatography (HPLC) was used. While feeding the mites were collected from the area between oily glands, trichomes and respiratory stomata in both mint species. The most important leaf structures in aromatic plants are the oily glands found on the external part of the leaves (both upper and lower epidermis). The number of oil glands in M. viridis leaves was greater than in M. piperita; the trichomes on the epidermis of M. viridis were greater in number than in M. piperita; the spongy mesophyll in M. viridis was much thicker than in M. piperita. The essential oils in the leaves of both mint species contained 71 compounds representing 99.61% of the total oil constituents identified from M. viridis before infestation, and 90.95% after infestation, and about 99.65% from M. piperita before infestation, and 99.98% after infestation.

Go to article

Authors and Affiliations

Sally Farouk Allam
Basem Abdel-Nasser Soudy
Ahmed Salah Hassan
Mahmoud Mohamed Ramadan
Doha Abo Baker
Download PDF Download RIS Download Bibtex

Abstract

The paper presents investigation results of the migration of a chemical compound contained in fly ash deposited on a dry furnace waste landfill site exposed to weather conditions. Climate conditions are able to significantly affect chemical component distribution in a block of deposited, moving chemical compounds to different depths. The main aim of the investigations was to determine the chemical component distribution of deposited fly ash in the landfill. Identification of chemical components based on XRF analysis indicated the existence of differences in both tested storage layer and the fraction of fly ash.

Go to article

Authors and Affiliations

Aleksandra Sambo
Arkadiusz Szymanek

This page uses 'cookies'. Learn more