Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Citation - WoS: 1Citation - Scopus: 2Wave Diffraction by a Thin Lossy Dielectric Half-Plane(Elsevier Gmbh, 2021) Umul, Yusuf ZiyaThe scattering of electromagnetic waves by a thin lossy dielectric half-plane is investigated. With this aim, the interaction process of waves with a dielectric layer is studied. The reflection and transmission coefficients are obtained in the limiting case, which is defined when the thickness of the layer is sufficiently smaller than the wavelength. The diffracted waves by the half-plane are evaluated using the method of transition boundary. Some numerical results are given. We will study the interaction problem of electromagnetic waves by a thin lossy dielectric half-plane in this paper. It will be supposed that the width of the dielectric layer is sufficiently smaller than the wavelength of the incident field. In the literature, such a structure is modeled by the resistive boundary conditions [1]. The scattering of waves by a resistive half-plane has been investigated in the literature by some authors [2-9]. Rawlins [10] solved the diffraction problem of plane waves by a thin dielectric half-screen by using approximate boundary conditions. Anderson [11] studied the same scenario and obtained a solution with the method of dual integral equation. A Wiener-Hopf approach was applied by Chakrabarti [12] to the dielectric half-plane, illuminated by a plane electromagnetic wave. Senior and Volakis [13] derived approximate boundary conditions for a thin dielectric layer and applied them to the diffraction problem, under consideration, for magnetic polarization [14]. We will take into consideration a lossy dielectric layer with finite width d and derive the reflected and transmitted electromagneticArticle Citation - WoS: 1Citation - Scopus: 1Wave Diffraction by a Perfect Magnetic Conductor Half-Plane Between Free Space and Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe diffraction of magnetic polarized electromagnetic plane waves by a perfect magnetic conductor half-screen, located between free space and anisotropic plasma, is studied. The method of transition boundary is used for the solution of the problem. The scattered GO wave is obtained. The diffracted fields are derived with the aid of the scattered GO wave. The uniform expressions of the edge diffracted waves are derived. The behaviors of the evaluated fields are investigated numerically.Article The Standing Matter Waves and Bohm's Quantum Potential(Elsevier Gmbh, 2021) Umul, Yusuf ZiyaThe standing wave type wave functions are investigated in terms of Bohm's decomposition of the Schro spacing diaeresis dinger equation. It is shown that the quantum potential, obtained for the standing matter waves, is always different from zero. However, it is also put forth that the wave function do not satisfy the Bohm's equations except one case, which is defined in the Cartesian coordinates. The Airy type matter wave is also analyzed in terms of the Bohmian approach.Article Citation - WoS: 2Citation - Scopus: 8Scattering of Electromagnetic Waves by an Impedance Sheet Junction in Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe diffraction of electromagnetic plane waves by the edge discontinuity of an impedance sheet junction, which is located in an anisotropic plasma, is investigated. The problem is solved by the integral theory of diffraction. The scattering integral is obtained from the scattered geometric optics wave. The diffracted fields are derived by the edge point evaluation of the scattering integral. The evaluated field expressions are analyzed numerically.Article Propagation and Diffraction of Surface Plasmons on a Resistive Half-Plane(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe propagation, radiation and diffraction characteristics of surface plasmons, on a discontinuous dielectric layer, are investigated. The layer is modeled by a resistive surface. The physical optics based formulation of the surface waves is taken into account. The physical optics integral includes the propagating and diffracting fields. These wave components are evaluated asymptotically and their behaviors are studied numerically.Article Citation - WoS: 3Citation - Scopus: 5On the Reality of the Bohmian Potential(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe existence of the Bohmian quantum potential is investigated in terms of the energy relation of a quantum particle. The derivation process of the quantum potential is applied to the Helmholtz equation and it is shown that a similar term also occurs in this case. The possibility of the existence of a potential term is questioned according to the frequency and wave-number quantities of a wave which is the solution of the Helmholtz equation. By using the same approach, it is shown that the quantum potential should be equal to zero. Some examples are studied in terms of the wave function.Article New Model for Liquid-Based Rapid Prototyping With a Scanning Lorentz Beam(Elsevier Gmbh, 2021) Arpali, C. CaglarIn this work, a new model is proposed to examine the effect of scanning Lorentz beam on a liquid based rapid prototyping scheme. The interaction of a Lorentz laser beam with a photocurable resin is analysed for different kinds of processing parameters such as beam power, beam size, scan speed, cure depth, width of the cured region and critical radiant exposure. The penetration depth profile of curing is obtained while the beam propagates inside the resin. It is shown that the proposed laser scanning model can be used to estimate the depth profile of the cured region that is treated for a certain amount of critical exposure. The Lorentzian beam generates fine and narrow hatch structures along the scan direction. This distinct ability facilitates the development of a low resolution process for fabricating complex patterns.Article Citation - WoS: 63Citation - Scopus: 70New Fractional Signal Smoothing Equations With Short Memory and Variable Order(Elsevier Gmbh, 2020) Shiri, Babak; Wu, Guo-Cheng; Baleanu, Dumitru; Ma, Chang-YouIn this paper, systems of fuzzy fractional differential equations with a lateral type of the Hukuhara derivative and the generalized Hukuhara derivative are numerically studied. Collocation method on discontinuous piecewise polynomial spaces is proposed. Convergence of the proposed method is analyzed. The superconvergent results on the graded mesh are studied. Examples are provided to support theoretical results. Finally, the effect of uncertainty in a diabetes model and its resulting complications is investigated as a practical application.Article Citation - WoS: 3Citation - Scopus: 3Diffraction of Electromagnetic Waves by an Anomalously Transmitting Metasurface Half-Plane in Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf Z.The paper deals with the scattering of magnetic polarized electromagnetic plane waves by a anomalously transmitting metasurface half-plane, located in anisotropic plasma. Such a medium occurs for cold magnetized plasma, in which a static magnetic field exists. In this case the permittivity of the medium is expressed as a tensor, the elements of which are functions of the magnetostatic field, electron's mass and charge and angular frequency of the plasma. The metasurface half-plane transmits part of the incoming electromagnetic wave with a different angle from the angle of incidence, absorbing the remaining part. First of all, we will obtain the scattered geometric optics wave by subtracting the incident field from the total geometric optics wave. Then the kernel of a physical optics type scattering integral will be constructed with the aid of the integral theory of diffraction. The uniform diffracted magnetic field will be obtained from the physical optics integral. The total magnetic field will be evaluated as a sum of the total geometric optics and diffracted waves. The behaviours of the derived fields will be analyzed numerically.Article Diffraction in Time in the Relativistic Domain(Elsevier Gmbh, 2021) Umul, Yusuf ZiyaThe diffraction of matter waves in time is investigated by using the kinetic energy based relativistic wave equation for the quantum shutter problem. The differential equation is solved with the aid of the Fourier integral transform according to the spatial coordinate. A new Green's function is obtained and a scattering integral is composed for the wave function. The boundary condition of the quantum shutter problem is expressed in the kernel of the integral. Two field components are derived by the asymptotic evaluation of the scattering integral. The behavior of the scattered matter waves is studied in the relativistic and non-relativistic domains numerically.