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The optical characteristics of GaAs/AlGaAs double anharmonic oscillator potentials are investigated across various quantum well parameters and applied electromagnetic probes, including electric field, magnetic field, and intense laser field (α0). The study employs the effective mass approximation and diagonalization method to determine the band alignment of the structure and solve the one-dimensional time-independent Schrödinger equation. Intersubband energies, total optical absorption coefficients (TOACs), and total relative refractive index changes (RRICs) are numerically evaluated under the influence of the structural parameters and the applied external electric field. Structural parameters and applied electric fields induce separations in energy levels and variations in dipole moment matrix elements, leading to shifts in resonant peaks. It is demonstrated that alterations in structural parameters and external electric fields result in either red or blue shifts in the resonant peak positions of TOAC and RRIC coefficients. [ABSTRACT FROM AUTHOR]

Purpose: (1) A mathematical model for the Hybrid nanofluids flow is used as carriers for delivering drugs. (2) The flow conditions are controlled to enable drug-loaded nanofluids to flow through the smaller gap between the two tubes. (3) Hybrid nanofluids (HNFs) made from silver (Ag) and titanium dioxide (TiO2) nanoparticles are analyzed for applications of drug delivery. (Ag) and (TiO2) (NPs) are suitable candidates for cancer treatment due to their excellent biocompatibility, high photoactivity, and low toxicity. (4) The new strategy of artificial neural networks (ANN) is used which is machine-based and more prominent in validation, and comparison with other techniques. Design/methodology/approach: The two Tubes are settled in such a manner that the gap between them is uniform. The Control Volume Finite Element Method; Rk-4 and Artificial Neural Network (ANN). Findings: (1) From the obtained results it is observed that the dispersion and distribution of drug-loaded nanoparticles within the body will be improved by the convective motion caused by hybrid nanofluids. The effectiveness and uniformity of drug delivery to target tissues or organs is improved based on the uniform flow and uniform gap. (2) The targeting efficiency of nanofluids is further improved with the addition of the magnetic field. (3) The size of the cylinders, and flow rate, are considered uniform to optimize the drug delivery. Research limitations/implications: (1)The flow phenomena is considered laminar, one can use the same idea through a turbulent flow case. (2) The gap is considered uniform and will be interesting if someone extends the idea as non-uniform. Practical implications: (1) To deliver drugs to the targeted area, a suitable mathematical model is required. (2) The analysis of hybrid nanofluids (HNFs) derived from silver (Ag) and titanium dioxide (TiO2) nanoparticles is conducted for the purpose of drug delivery. The biocompatibility, high photoactivity, and low toxicity of (Ag) and (TiO2) (NPs) make them ideal candidates for cancer treatment. (3) Machine-based artificial neural networks (ANN) have a new strategy that is more prominent in validation compared to other techniques. Social implications: The drug delivery model is a useful strategy for new researchers. (1) They can extend this idea using a non-uniform gap. (2) The flow is considered uniform, the new researchers can extend the idea using a turbulent case. (3) Other hybrid nanofluids flow, in the same model for other industrial usages are possible. Originality/value: All the obtained results are new. The experimental thermophysical results are used from the existing literature and references are provided. [ABSTRACT FROM AUTHOR]

In this work, we study the electric and magneto-optical absorption coefficients (ACs) and relative refractive index changes (RRICs) in W x Mo 1 − x S2 ternary alloys under the control of tungsten contents using the compact density matrix approach. With the influence of external electric and magnetic fields, the results show that there are a series of resonant peaks for both intra-band and inter-band transitions. With an increase in W-concentration and electric and magnetic fields, the resonant peaks give a blue (red) shift and reduce (increase) their amplitudes. These results suggest a potential application of monolayer W x Mo 1 − x S2 in future nanoscale electronic and magneto-optical devices. [ABSTRACT FROM AUTHOR]

The current work scrutinizes electro-magnetized mixed convective flow of radiative fourth-grade nanofluid over a stretchable surface with bioconvection mechanism, thermophoretic body force, Brownian motion and activation energy for both nanoparticles (NPs) and motile microorganisms. Also, features of viscous dissipation, fluctuating fluid viscosity, Joule heating, suction/injection, heat source/sink and convective heat-mass-microbial conditions are included in the flow model. By employing suitable dimensionless variables, the set of model equations has been transformed into non-dimensional ordinary differential equations, which are subsequently tackled using quasilinearization-based spectral collocation approach applied in overlapping grids. For different flow parameters, numerical results of flow profiles and quantities of engineering intrigue are discussed. The results reveal that the inclusion of Biot numbers for heat, mass and microbes transfer helps to enhance flow profiles along with quantities of engineering interest. The material parameters enhance the magnitude of velocity, which is also higher for the fourth-grade nanomaterial model. Better heat transfer attributes can be achieved through strong thermophoretic force, thermal radiation, heat generation, viscous dissipation and NP Brownian motion. Activation energy increases NP concentration, while a decreasing trend is notable for higher chemical reaction and NP Brownian diffusion parameters. Bioconvection parameters reduce the motile microbes concentration, while enhancing the rate of motile microbes transfer. Microbial Brownian motion and microbial reaction play a crucial role in the dynamics of microorganisms, and that is confirmed by their noticeable effect on the flow properties.

The paper presents the nonlinear optical rectification, second and third harmonic generation properties of a quantum well-formed within AlGaAs/GaAs heterostructures under the Razavy potential function. The effects of well parameters as well as applied external fields such as electric, magnetic, and non-resonant intense laser on these parameters are examined. The energies of sub-bands and dipole moment matrix elements related to wave function probabilities are obtained by solving the Schrödinger equation within effective mass and parabolic band approximations. Optical coefficients are calculated in the framework of the density matrix approach. The findings point out that the potential distribution parameters strongly affect the magnitudes as well as the locations of nonlinear optical rectification, second and third harmonic generation peaks on the corresponding incident photon energies. Besides the influences of potential parameters, subjecting the system to intense laser field leads noticeable changes on the NOR, SHG, and THG coefficients. However the changes on these properties are quite slight when the system subjected to the external electric or magnetic field. Razavy potential parameters are more effective in controlling the optical properties in comparison to the electric and magnetic field perturbations. [ABSTRACT FROM AUTHOR]

In this study, we investigated the exciton binding energy and interband transition between the electron and heavy-hole for the single and double quantum wells which have different hyperbolic-type potential functions subject to electric, magnetic, and non-resonant intense laser fields. The results obtained show that the geometric shapes of the structure and the applied external fields are very effective on the electronic and optical properties. In the absence of the external fields, the exciton binding energy is a decreasing function of increasing well sizes except for the strong confinement regime. Therefore, for all applied external fields, the increase in the well widths produces a red-shift at the absorption peak positions. The magnetic field causes an increase in the exciton binding energy and provides a blue-shift of the absorption peak positions corresponding to interband transitions. The effect of the electric field is quite pronounced in the weak confinement regime, it causes localization in opposite directions of the quantum wells of the electron and hole, thereby weakening the Coulomb interaction between them, causing a decrease in exciton binding energy, and a red-shift of the peak positions corresponding to the interband transitions. Generally, an intense laser field causes a decrease in the exciton binding energy and produces a red-shift of the peak positions corresponding to interband transitions. [ABSTRACT FROM AUTHOR]

Waveguides are devices that allow the propagation of directional electric magnetic waves. Guided waves occur when the wave equation is satisfied considering the boundary conditions in the waveguide. Besides its practical issue, studying electric and magnetic fields is highly relevant in electromagnetism and microwave device courses. In this article, we present and provide a numeric code for an animated visualization of the electromagnetic waves in a rectangular wave guide. For this, the waveguide propagation equations for TE and TM mode are reviewed. This code, in Matlab®, allows the user to select wave guide dimensions, wave and mode type, view type and operation frequency. An example for the TEi0 and TM2i wave modes propagating through the commercial WR-90 waveguide is presented. This program is a highly relevant open-source educational object when it comes to learning electromagnetism. [ABSTRACT FROM AUTHOR]

In this present study, the effect of external static electric and magnetic field on the binding energy of hydrogenic donor impurity associated with the ground state in Rosen-Morse quantum well were theoretically investigated by using a variational method in the effective-mass approximation. The impurity-related nonlinear optical properties in this structure were calculated by using the compact-density-matrix approach. The numerical results of nonlinear optical properties were presented as functions of incident photon energy for two different values of the static electric and magnetic field for on-center donor impurity. Moreover, the binding energy of the hydrogenic donor impurity was shown as a function of static electric and magnetic field. As a result, it was found that the nonlinear optical properties of the structure were significantly affected by the impurity atom and the magnitude of static electric and magnetic fields. [ABSTRACT FROM AUTHOR]

We investigate the generalized Klein–Gordon (KG)-oscillator under the Lorentz symmetry breaking effects, where a linear electric and constant magnetic field is considered, and analyze its effects on the relativistic quantum oscillator. Furthermore, the behavior of the quantum oscillator in the presence of a Cornell-type scalar potential is analyzed and the solution of the bound state is obtained. We see that the analytical solution to the generalized KG-oscillator can be achieved and the angular frequency of the oscillator depends on the quantum numbers of the system. [ABSTRACT FROM AUTHOR]

Excitation of novel graphene plasmons is examined using finite-element analysis via COMSOL RF module 5.6. The theoretical model is simulated with graphene grating on the glass substrate having fixed periodicity (Λ = 700 nm) by illumination with transverse magnetic (TM) polarized light through the substrate side. The effect of thickness variation on SPPs excitation has been acquired from transmission spectra while keeping the periodicity and slit width of grating structure constant via analyzing the trend followed by the resonance dips. The electric and magnetic field behavior has also been analyzed for each thickness, and a specific grating thickness of 10 nm was taken into consideration owing to the thickness constraints regarding graphene. Slit width variation of the grating structure has been investigated using far-field analysis to observe the formation of SPPs from transmission spectra and near-field analysis for understanding the underlying physics. These analyses resulted in SPP excitation more appreciable at slit widths in between 250 and 350 nm. The slit width range regarding the chosen periodicity supports the most efficient plasmonics mode and many applications of such devices are found in real life. [ABSTRACT FROM AUTHOR]

Copyright of Erzincan University Journal of Science & Technology is the property of Erzincan Binali Yildirim Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Freezing has been widely recognized as the most common process for long-term preservation of perishable foods; however, unavoidable damages associated with ice crystal formation lead to unacceptable quality losses during storage. As an alternative, supercooling preservation has a great potential to extend the shelf-life and maintain quality attributes of fresh foods without freezing damage. Investigations for the application of external electric field (EF) and magnetic field (MF) have theorized that EF and MF appear to be able to control ice nucleation by interacting with water molecules in foods and biomaterials; however, many questions remain open in terms of their roles and influences on ice nucleation with little consensus in the literature and a lack of clear understanding of the underlying mechanisms. This review is focused on understanding of ice nucleation processes and introducing the applications of EF and MF for preservation of food and biological materials. [ABSTRACT FROM AUTHOR]

In Lithuanian and Polish electric power supply systems, the power transmission lines of 400 kV voltage represent one of the most potential sources of electric and magnetic fields generation. The 400 kV double-circuit overhead power transmission line and its surrounding environment were herby described and simulated through Finite Element Method using COMSOL Multiphysic software package. This study includes magnetic and electric field calculations. The study shows that the values of magnetic field strength and electric field strength present in the vicinity of a 400 kV overhead power transmission line tend to exceed limit values established in the Normative. Measurements are suggested to be taken for the purpose of finding maximum values of magnetic and electric field strength. To reduce these values, it is recommended to increase the height of supports, and restrict human personal and economic activities.

Abstract On 25 August 2018, the China Seismo‐Electromagnetic Satellite (CSES) encountered the first intense geomagnetic storm event since its launch on 2 February 2018. The main purpose of this work is to check in‐flight performance of the assembled payloads onboard CSES, as well as to investigate the ionosphere perturbations induced by this geomagnetic storm. The study shows that all investigated parameters simultaneously respond to the different phases of the geomagnetic storm, verifying the measuring capabilities of the assembled payloads onboard CSES. Specifically, the magnetic field obtained from the high‐precision magnetometer fits well with that obtained by the Swarm satellite, clearly demonstrating the development phase of the storm; joint analysis using the Langmuir probe, plasma analyzer, electric field detector, and GNSS occultation receiver data demonstrate that this is a positive storm event and that electric field penetration is the possible mechanism for the disturbance in the ionosphere. During this storm event, some significant ELF/VLF waves are also excited and there is enhancement of the energetic electron flux (of energy

In the present paper, we report a theoretical investigations on the linear and nonlinear optical properties of a GaAs-based quantum well with the Kratzer-Fues confining potential, including the effects of external applied static electric, magnetic, and intense THz laser fields. The electronic structure of this system is obtained by using the effective-mass and envelope wave function approaches. Then, the coefficients of linear, third-order nonlinear, and total optical absorption (OACs) and relative refractive index changes (RICs) are calculated by using the iterative solutions of the compact-density matrix approach (CDMA). The obtained numerical results are reported as functions of the incident photon energy taking into account several values of static electric, static magnetic, and intense THz laser fields. These results show that the nonlinear optical properties of this structure are significantly affected by the magnitude of the external applied fields. [ABSTRACT FROM AUTHOR]

Abstract We have investigated the binding energies of the s -symmetric ground and first excited shallow donor impurity states and the total 1 s → 2 s absorption coefficient, including the first and third order corrections, in "12-6" tuned GaAs/GaAlAs double quantum well as a function of the impurity position, size of the structure, and the electric and magnetic field intensities. The obtained results show that the electronic and optical properties of tuned GaAs/GaAlAs double quantum well can be adjustable by an appropriate choice of the sample geometry, material parameters and applied external fields which will lead to new potential applications in optoelectronics. Highlights • Donor impurity states in "12-6" tuned double quantum well. • Nonlinear optical absorption related to s-symmetric states. • Electromagnetic field is used to tune the optical absorption. • The impurity binding energy depends on the double well parameter. [ABSTRACT FROM AUTHOR]

The propagation of nonlinear three-dimensional dust-ion-acoustic solitary waves in a magnetized two-ion-temperature dusty plasma is analyzed. Modified extended mapping method is further modified to discover dust-ion-acoustic solitary wave solutions of the nonlinear three-dimensional extended Zakharov-Kuznetsov dynamical equation. Consequently, different kinds of solitary wave solutions representing electric potential, electric and magnetic fields, and electron fluid pressure, are obtained with the help of Mathematica. The new dispersive solitary wave solutions are found in various shapes such as bright and dark solitons, periodic solitary wave solutions, and dark and bright solitary waves, that are expressed in different forms such as hyperbolic, rational, exponential, and trigonometric functions. These results demonstrate the efficiency and accuracy of the proposed method that can be applied to other nonlinear models. The results are shown graphically. [ABSTRACT FROM AUTHOR]

The quantum Langevin formalism is used to study the charge carrier transport in a two-dimensional sample. The center of mass of charge carriers is visualized as a quantum particle, while an environment acts as a heat bath coupled to it through the particle–phonon interaction. The dynamics of the charge carriers is limited by the average collision time which takes effectively into account the two-body effects. The functional dependencies of particle–phonon interaction and average collision time on the temperature and magnetic field are phenomenologically treated. The galvano-magnetic and thermo-magnetic effects in the quantum system appear as the results of the transitional processes at low temperatures. [ABSTRACT FROM AUTHOR]

Propagation of three-dimensional nonlinear solitary waves in a magnetized electron–positron plasma is analyzed. Modified extended mapping method is further modified and applied to three-dimensional nonlinear modified Zakharov–Kuznetsov equation to find traveling solitary wave solutions. As a result, electrostatic field potential, electric field, magnetic field and quantum statistical pressure are obtained with the aid of Mathematica. The new exact solitary wave solutions are obtained in different forms such as periodic, kink and anti-kink, dark soliton, bright soliton, bright and dark solitary waves, etc. The results are expressed in the forms of trigonometric, hyperbolic, rational and exponential functions. The electrostatic field potential and electric and magnetic fields are shown graphically. The soliton stability of these solitary wave solutions is analyzed. These results demonstrate the efficiency and precision of the method that can be applied to many other mathematical physical problems. [ABSTRACT FROM AUTHOR]

In this paper, we used tight-binding model to calculate the thermal properties of tetragonal silicene (T-Si). T-Si has a zero band gap with two Dirac points and linear dispersion around them. When a vertical electric field is applied to the T-Si, the band gap opens up as the strength of the electric field increases. This suggests that T-Si could potentially be used in electronic and optoelectronic devices that require a tunable band gap. Applying a magnetic field leads to split of the density of states (DOS) peaks, which increases in intensity as the strength of the magnetic field increases. The band gap, position and height of each DOS peak are influenced by the magnetic field strength. Due to the dependence of the electronic properties of T-Si on external fields, its thermal properties are significantly affected by external parameters such as electric and magnetic fields and chemical potential. The electric field decreases the thermal conductivity of T-Si and this is attributed to the opening of the band gap, which creates a barrier for charge excitation and reduces the number of available electronic states that can contribute to the thermal transport. The results show that the thermal conductivity of T-Si increases with magnetic field and chemical potential due to the reduction in the band gap and the increase in the charge carrier density. The thermal conductivity in terms of chemical potential (μ), decreases with electric field strength in the presence of the magnetic field. The thermal conductivity (κ(T)) is highest at μ = 0 and decreases as μ increases. The Lorentz number, which relates the electrical conductivity and thermal conductivity, decreases with increasing chemical potential and magnetic field strength, but increases with increasing electric field strength. [Display omitted] • The electronic properties of T-Si are influenced by bias voltage, due to its buckling structure. • The band structure of T-Si splits into multiple levels in the presence of a magnetic field, due to the Zeeman Effect. • The thermal and electrical conductivity of T-Si increase with temperature due to rise in thermal energy of charge carriers. • T-Si thermoelectric properties: decrease with bias voltage, increase with mag field and chemical potential. [ABSTRACT FROM AUTHOR]

In this study we have attempted, firstly, to describe programming protocols developed for the teaching of an Electromagnetism course in the university degrees of Electrical Engineering and Energy Engineering, and secondly, to evaluate students’ satisfaction with the simulation practices through MATLAB® programming. The main objective of the protocols is to allow students to model and visualize the electric field and magnetic field (both static) and understand the approximation that is made when considering certain distributions of electric charges and electric currents. To evaluate the usefulness of this computational methodology, eighteen students from the two engineering degrees answered a questionnaire with seven questions related to the Electromagnetism course and to the benefits of using computer programming. Their answers are measured by a Likert scale. From the analysis of the results, we can conclude, in a general way, that the use of this methodology has positive effects in the learning of Electromagnetism in these two degrees.

Abstract In framework of the adiabatic approximation the energy states of electron as well as direct light absorption are investigated in strongly oblate and strongly prolate ellipsoidal quantum dots (QDs) at presence of electric and magnetic fields. Analytical expressions for particle energy spectrum are obtained. The dependence of energy levels’ configuration on QD geometrical parameters and field intensities is analytically obtained. The energy levels of electrons are shown to be equidistant both for strongly oblate and prolate QDs. The effect of the external fields on direct light absorption of a QD was investigated. The dependence of the absorption edge on geometrical parameters of QDs and intensities of the electric and magnetic fields is obtained. Selection rules are obtained at presence as well as absence of external electric and magnetic fields. In particular, it is shown that the presence of the electric field cancels the quantum numbers selection rules at the field direction, whereas in radial direction the selection rules are preserved. Perspectives of practical applications for device manufacturing based on ellipsoidal quantum dots are outlined.

In the framework of S3 project "Short term earthquake forecasting" supported by Department of Civil Protection (DPC) and National Institute of Geophysics and Volcanology (INGV), a magnetotelluric (MT) station was installed in the Pollino area (southern Italy) during September 2012 by the Institute of Methodologies for Environmental Analysis (IMAA-CNR, Italy) in order to investigate possible correlation between electromagnetic signals and seismicity. For the last two years Pollino area has been characterized by swarm-type seismicity, culminating with the earthquake occurred on October 25, 2012 of magnitude MW=5.0. After the mainshock, the INGV installed a seismic station close to the MT station. In this paper, we focus the analysis on the largest event (ML=3.6) recorded during the colocated electromagnetic and seismic experiment. We applied time-frequency misfit criteria based on the continuous Morlet wavelet transform to compare the electric and seismic homologous components: this analysis confirms an overall good waveform similarity between the signals, but also some interesting differences in amplitude for frequencies above 1 Hz in correspondence of the arrival of particular seismic phases that need further investigations. [ABSTRACT FROM AUTHOR]

In this study, the electric and magnetic fields occurred around the medium voltage power distribution lines (MV-PDL) in the residential area have been analyzed, and different MV and LV power distribution lines (PDL) in Antalya were selected in order to investigate the electromagnetic field exposure according to yearly-based current load on power lines. Knowledge of magnetic field levels determined around power lines is so important for completing acceptable epidemiological studies, and medium voltage power lines established in the residential area close to the apartments have been investigated. There are houses and apartments in a distance of 10m or less which have potential for child leukemia, since magnetic field levels are around 0.4 µT and up. [ABSTRACT FROM AUTHOR]

In this paper, the effects of optimum phase conductor arrangement and compaction of tower for electric and magnetic fields minimization of 400 KV double circuit lines are investigated by using of Finite Element Analysis Software ANSYS. Two typical types of compact and conventional transmission lines are modeled by FEM with symmetrical and optimum phase conductor arrangement. The electric and magnetic fields produced by both lines are calculated by analytical and 2D finite element method at the mid-span. To consider the catenary effect along the whole span, 2D finite element analysis is developed by APDL programming in order to achieve 3D distribution of electric and magnetic fields between adjacent towers. Finally, some aspects concerning the necessary ROW (Right of Way) are pointed and the necessary ROW width of the compact and conventional overhead lines with the symmetrical and the optimum phase conductor arrangement are determined based on finite element results and the ICNIRP standard. [ABSTRACT FROM AUTHOR]

Background: Various studies in vitro suggest that low electric and magnetic fields may modify cancer cell growth and recent studies in vivo have revealed anti-tumoral effects. After screening different tumor cell lines, we identified specific sequences of localized magnetic and electric fields (MESQ) that reduce cancer cell survival in vitro. This finding led us to design an experiment to determine the actual efficacy of above sequences in selectively destabilizing tumor cells and their effect on healthy cells. Materials and Methods: We exposed the MCF7 cancer cell line and normal fibroblasts to MESQ for 1, 2, 3 and 6 hours, evaluating cell survival and induction of apoptosis. Results: Exposure to MESQ reduced MCF7 survival, inducing apoptosis in a timedependent way, whereas fibroblasts were completely unaffected. Conclusion: These results have promising implications for the treatment of cancer and warrant further research. [ABSTRACT FROM AUTHOR]

ording to the 20/20/20 strategy by European Union for green energy by 2020 priority should be given to the Renewable Energy Sources. The energy generated from the wind has proven to be of interest for several reasons-wind is available, it is a cheap, and virtually inexhaustible source of energy. In this relation in the last years, many wind power stations were built all around the country. They are being located in proximity of populated areas. Their work besides the generation of electricity is connected to emission of physical factors in the environment that could be essential for human health. In order to avoid overexposure to electromagnetic fields, noise, and vibration to the general public minimal safety distance is being determined theoretically for 'worst case' conditions basing on the technical characteristics of the generators. After the mounting of installations, measurements have to be performed to determine whether the national and European safety limits for the factors of environment are being kept. The paper presents results of measurement of electromagnetic fields, additionally noise and vibration around one of the biggest wind power parks in Bulgaria. The measurements were made in the close proximity of the generators both for the personnel working conditions and for the population in the closest living areas. [ABSTRACT FROM AUTHOR]

Electromagnetic exposure of the general public due to large substations transforming voltages of 150 and 36 kV to 11 kV is investigated and safety distances for these substations have been determined. In total, 142 field measurements were executed for two substations: 91 measurements of the magnetic field and 51 measurements of the electric field. Measured momentary magnetic field values are within the range of 0.051 to 13.17 μT. The levels of the electric field are within the range of 0.095 to 270.0 V/m. The cumulative distribution function of the measured magnetic-field values has been determined, and it is shown that the fields excellently follow a lognormal distribution. The maximal magnetic and electric-field values for all the investigated substations are below 100 μT (values over a day and year) and 5 kV/m, respectively. When comparing the average exposure with the value of 0.4 μT, safety distances of maximally 8.1 m (average day) and 7.1 m (average year) are obtained. [ABSTRACT FROM AUTHOR]

In this present work, the effect of applied external fields and well width on the optical absorption and refractive index change coefficient of a GaAs quantum well with Razavy confinement potential is theoretically presented. For this, firstly, the confined subband energy levels of the structure and the envelope wave functions corresponding to these states have been computed using the diagonalization method within the framework of effective mass and parabolic band approximation. Then, by using this information, the coefficients of total – linear plus nonlinear – intersubband optical absorption (TOAC) and relative refractive index changes (RRIC) of the structure are evaluated. The obtained numerical results show that the increase in the magnitude of the applied external fields creates a blue shift in TOAC and RRIC. Also, contrarily to the applied external fields, an increment of the quantum well width have induced a red shift in the TOAC and RRIC. We discuss in detail the variation of the diagonal matrix elements and the energy difference (E2–E1) which are responsible for the change of amplitudes of the calculated coefficients. We believe that the obtained numerical results can be useful in the design and application of the next generation devices used in the optoelectronics field. • The magnitude of the TOACs peak decrease with the static electric field. • The magnitude of the TOACs peak increase with the ILF. • The magnitude of the RRICs decrease with the ILF. • The increase of ILF leads to important effects on the optical properties of Razavy QW. [ABSTRACT FROM AUTHOR]

Simultaneous effects of electric, magnetic, and non-resonant intense laser field on the nonlinear optical properties of a GaAs quantum well with an anharmonic confinement potential profile are theoretically investigated. Energy eigenvalues and eigenfunctions of the system are determined using the diagonalization method within the framework of the effective mass and parabolic band approximation. Nonlinear optical properties associated to the inter and intra band transitions are evaluated. Our numerical results for the intra-band response show that the resonance peak positions of the total optical absorption coefficients and relative refractive index changes shift towards higher energy levels (blueshift) by increasing the strength of the applied external electric, magnetic, and non-resonant intense laser field. The analysis of inter-band (electron-heavy hole) transitions reveals that the optical coefficients has a pronounced redshift induced by the electric field while a blueshift is caused by the magnetic and laser signals. It is seen that the nonlinear optical properties of such structures can be adjusted according to the purpose by changing the external perturbations and could be used in new optoelectronic device designs. [ABSTRACT FROM AUTHOR]

• Conical shaped quantum dots under electric and magnetic field. • Electron-hole Coulomb correlation via perturbative and variational calculations. • Several orders of magnitude for the ground state exciton lifetime. • Evolution from quantum dot to quantum ring via electric field effects. • Oscilations of the ground state energy via magnetic field effects. Using the effective mass and parabolic band approximations, and the finite element method, we calculate the combined effects of axially applied electric and magnetic fields on the electronic properties of cone-shaped quantum dots. Once the one particle eigenvalue equations have been solved, both for electrons and holes, the available information on energies and wave functions is used as input in order to calculate the electron and hole positions along the axial axis, the overlap integral, the ground state exciton lifetime, and the exciton Coulomb interaction; all these properties are obtained as a function of the applied electric and magnetic fields. The main findings are: (i) the electric field separates the electrons and holes in opposite positions of the structure, giving rise to indirect excitons with a quite significant lifetime, (ii) the magnetic field is a useful tool to increase by several orders of magnitude the exciton lifetime, mainly when it is superimposed on the electric field effect, (iii) for spatially direct excitons, the magnetic field reinforces the Coulomb integral giving rise to a redshift of the photoluminescence energy transition, (iv) the magnetic field effects are much more visible on electrons than on the holes, and finally (v) the electric field allows to tune the evolution of the structure from a quantum dot to a quantum ring. Our results on the photoluminescence energy transition are in excellent agreement with previously reported experimental measurements [Phys. Status Solidi RRL 2018 (2018) 1800245 (4pp)..]. [ABSTRACT FROM AUTHOR]

On 25 August 2018, the China Seismo‐Electromagnetic Satellite (CSES) encountered the first intense geomagnetic storm event since its launch on 2 February 2018. The main purpose of this work is to check in‐flight performance of the assembled payloads onboard CSES, as well as to investigate the ionosphere perturbations induced by this geomagnetic storm. The study shows that all investigated parameters simultaneously respond to the different phases of the geomagnetic storm, verifying the measuring capabilities of the assembled payloads onboard CSES. Specifically, the magnetic field obtained from the high‐precision magnetometer fits well with that obtained by the Swarm satellite, clearly demonstrating the development phase of the storm; joint analysis using the Langmuir probe, plasma analyzer, electric field detector, and GNSS occultation receiver data demonstrate that this is a positive storm event and that electric field penetration is the possible mechanism for the disturbance in the ionosphere. During this storm event, some significant ELF/VLF waves are also excited and there is enhancement of the energetic electron flux (of energy <1 MeV). These main features are consistent with results from previous works, indicating the excellent performance of the search coil magnetometer and high‐energy particle detector. Key Points: The comprehensive parameters from CSES are presentedThe measuring capabilities of the assembled payloads onboard CSES are demonstrated through an intense geomagnetic storm eventCSES observation shows that a positive storm event and the electric field penetration should play important role [ABSTRACT FROM AUTHOR]

In this study we have attempted, firstly, to describe programming protocols developed for the teaching of an Electromagnetism course in the university degrees of Electrical Engineering and Energy Engineering, and secondly, to evaluate students' satisfaction with the simulation practices through MATLAB® programming. The main objective of the protocols is to allow students to model and visualize the electric field and magnetic field (both static) and understand the approximation that is made when considering certain distributions of electric charges and electric currents. To evaluate the usefulness of this computational methodology, eighteen students from the two engineering degrees answered a questionnaire with seven questions related to the Electromagnetism course and to the benefits of using computer programming. Their answers are measured by a Likert scale. From the analysis of the results, we can conclude, in a general way, that the use of this methodology has positive effects in the learning of Electromagnetism in these two degrees. [ABSTRACT FROM AUTHOR]