Hellenic Navy Petty Officers Academy

Skaramagkas, Greece

Hellenic Navy Petty Officers Academy

Skaramagkas, Greece
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Stavrou V.N.,Hellenic Navy Petty Officers Academy | Stavrou V.N.,University of Iowa | Veropoulos G.P.,Hellenic Navy Petty Officers Academy
Semiconductor Science and Technology | Year: 2011

We have theoretically and numerically studied nitride-based quantum well (QW) laser structures. More specifically, we have used a QW made with III-nitride where the width of the barrier region is large relative to the electron mean free path, and we have calculated the electron surface capture velocities by considering an electron flux which is captured into the well region. The process is assisted by the emission of the longitudinal optical phonons as predicted by the hybrid (HB) model. The results of surface capture velocities via the emission of HB phonons are compared to the emission of the dielectric continuum phonons (Zakhleniuk et al 1999 Phys. Status Solidi a 176 79). Our investigation shows that the two different phonon models predict almost the same results for the non-retarded limit. Furthermore, the surface capture velocities strongly depend on the size of the structure and the heterostructure materials. Lastly, a comparison to the recent experimental values shows that our model could accurately describe the experimentally measured parameters of the quantum capture processes. © 2011 IOP Publishing Ltd.


Veropoulos G.P.,Hellenic Navy Petty Officers Academy
IET Microwaves, Antennas and Propagation | Year: 2010

Plane-wave excitation fields are by far the most commonly used in field-to-wire coupling computations. Nevertheless, such excitations are not always adequate for the immunity assessment of wire-type structures operating in the contemporary man-made environment. To reinforce this conjecture, this study examines two-wire transmission lines excited by common non-uniform fields. Numerical results for the induced load voltages show notable deviations from those obtained under the assumption of plane-wave incidence. © 2010 The Institution of Engineering and Technology.


Kardaras I.S.,University of Ioannina | Stavrou V.N.,Hellenic Navy Petty Officers Academy | Tsoulos I.G.,University of Ioannina | Kosmas T.S.,University of Ioannina
AIP Conference Proceedings | Year: 2012

We present a numerical approach of calculating the wave functions of μ-. particles bound in muonic atoms due to an extended nuclear Coulomb potential. A genetic algorithm has been employed to solve numerically the Schrödinger and Dirac equations and subsequently to estimate the binding energies in heavy nuclei like the 208Pb and the 124Sn for these particles. The comparison of the present results with those of previously reported numerical algorithms shows that our μ- binging energies and wave functions are well matched. One of the main goals of such exact calculations is to systematically study the rates of exclusive μ- capture processes in nuclei as well as those of the exotic μ- → e± conversions in the presence of nuclei. The latter rates are extremely suppressed. © 2012 American Institute of Physics.


Papakanellos P.J.,Hellenic Air Force Academy | Veropoulos G.P.,Hellenic Navy Petty Officers Academy
Progress In Electromagnetics Research M | Year: 2013

Plane-wave excitation fields are not always sufficient for the immunity characterization of wire-type structures operating in the contemporary manmade environment. Following a previous work dealing with straight-wire transmission lines in the presence of nonuniform fields, the present paper examines twisted-wire pairs. Numerical results for the induced load voltages reveal the importance of field nonuniformity for assessing the immunity behavior of twisted-wire transmission lines on a firmer basis.


Markopoulos A.P.,National Technical University of Athens | Fragkou A.,Hellenic Navy Petty Officers Academy | Kasidiaris P.D.,Hellenic Navy Petty Officers Academy | Davim J.P.,University of Aveiro
International Journal of Mechanical Engineering Education | Year: 2015

The incorporation of game mechanics and dynamics in non-gaming applications is a subject of interest in various sectors such as education, marketing, medicine and military, in the last few years. It is believed that engineering education in a pre-graduate level and in professional practice will bring high pay-offs. The role of the academia is to develop new methodologies and tools to produce, apply and use digital games and gamification techniques in contemporary industry and present scientific evidence on the value and the benefits derived from this technology. In this paper, the relative literature is evaluated and a discussion on the gamification status today is given, by examining various aspects of this novel term. Furthermore, game techniques, gamification practices in education and e-learning are considered. Special discussion on engineering games, gamification platforms and empirical surveys is presented with focus on manufacturing. © 2015 The Author(s).

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