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Modeling the Movement of Groundwater from the Pits, Surrounded with Tongues of Zhukovsky
Bereslavckii Eduard Naumovich
Issue:
Volume 3, Issue 4, August 2017
Pages:
129-137
Received:
8 May 2017
Accepted:
1 June 2017
Published:
21 July 2017
Abstract: In the hydrodynamic statement the filtration low from ditches, walled tongues of Zhukovsky is considered. The fluid moves through the layer of soil, underlain by a well-permeable pressure aquifer, which is contained waterproof area on the roof. For study the infiltration to the free surface of groundwater is formulated a mixed multi-parameter boundary value problem of the theory of analytic function, which is solved by the Polubarinova-Kochina's method and ways the conformal mapping areas of a special kind, which are characteristic for tasks of an underground hydromechanics.
Abstract: In the hydrodynamic statement the filtration low from ditches, walled tongues of Zhukovsky is considered. The fluid moves through the layer of soil, underlain by a well-permeable pressure aquifer, which is contained waterproof area on the roof. For study the infiltration to the free surface of groundwater is formulated a mixed multi-parameter bound...
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Remodelling of Lee’s Knife Diffraction Loss Model as a Function of Line of Site Percentage Clearance
Swinton C. Nwokonko,
Vital K. Onwuzuruike,
Chibuzo Promise Nkwocha
Issue:
Volume 3, Issue 4, August 2017
Pages:
138-142
Received:
31 October 2016
Accepted:
6 January 2017
Published:
10 October 2017
Abstract: In this paper, remodeling of Lee’s piecewise knife diffraction loss model is presented. The original Lee’s piecewise knife diffraction loss model is expressed as a function of Fresnel-Kirchoff diffraction parameter. The computation of the Fresnel-Kirchoff diffraction parameter requires detailed terrain and link parameters. However, for quick link planning the Fresnel-Kirchoff diffraction parameter can be computed from the knowledge of the line of site percentage clearance alone. Moreover, in line of site link design, the required or acceptable obstruction clearance is specified in terms of line of site percentage clearance. Consequently, in this paper, the Lee’s model is remodeled into new piecewise functions that are entirely functions of line of site percentage clearance. The new version of Lee’s model is validated with the results of knife edge diffraction loss obtained from the original Lee’s piecewise knife diffraction loss model. With the new model it is easier to determine the diffraction loss that will be caused by any obstruction at a given line of site percentage clearance.
Abstract: In this paper, remodeling of Lee’s piecewise knife diffraction loss model is presented. The original Lee’s piecewise knife diffraction loss model is expressed as a function of Fresnel-Kirchoff diffraction parameter. The computation of the Fresnel-Kirchoff diffraction parameter requires detailed terrain and link parameters. However, for quick link p...
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Robust Numerical Resolution of Nakamura Crystallization Kinetics
Issue:
Volume 3, Issue 4, August 2017
Pages:
143-147
Received:
1 December 2016
Accepted:
16 December 2016
Published:
23 October 2017
Abstract: The numerical prediction of crystallization transformation is of great interest in several applications. One such application is the polymer-forming process. In this short communication, the integration of the widely used Nakamura kinetics is discussed. A robust time integration method is proposed. In order to overcome its singularities, the Nakamura function is thresholded. A convergence analysis provides guidelines for the threshold values and time discretization.
Abstract: The numerical prediction of crystallization transformation is of great interest in several applications. One such application is the polymer-forming process. In this short communication, the integration of the widely used Nakamura kinetics is discussed. A robust time integration method is proposed. In order to overcome its singularities, the Nakamu...
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Power System Stabilizer Application for Load Frequency Control in Hydro-Electric Power Plant
Issue:
Volume 3, Issue 4, August 2017
Pages:
148-157
Received:
1 December 2016
Accepted:
12 January 2017
Published:
24 October 2017
Abstract: Renewable energy provides 20% of electricity generation worldwide. Hydroelectric power is the cheapest way to generate electricity today. It provides almost onefifth of the electricity in world. Hydropower is produced in more than 150 countries. The main objective of this paper is modelling and analysis of the effects of the power system stabilizer (PSS) for load frequency control (LFC) system in hydro-electric power plant to damp the frequency oscillations due to different load distributions. LFC is the mechanism by which the energy balance is maintained. PSS is used to increase the system positive damping. The results of small signal stability analysis have been represented employing eigenvalue as well as time domain response.
Abstract: Renewable energy provides 20% of electricity generation worldwide. Hydroelectric power is the cheapest way to generate electricity today. It provides almost onefifth of the electricity in world. Hydropower is produced in more than 150 countries. The main objective of this paper is modelling and analysis of the effects of the power system stabilizer...
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