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By using the reductive perturbation method, the existence of dust acoustic shock waves is given for a dusty plasma considering the dust size distribution. The effects of both the dust size distribution and the dust charge variation on the characteristics of the shock wave are discussed. It is shown that the amplitude of a shock wave in plasmas considering a dust size distribution is larger than that in the case of a mono-sized dusty plasma, while its width considering the dust size distribution is smaller than that of the mono-sized dusty plasma. The speed of the shock waves also depends on different dust size distributions.

The propagation of dust-acoustic waves in a dusty plasma bounded in finite symmetrical cylindrical geometry has been theoretically investigated. By using the reductive perturbation method, we obtain a quasi-nonlinear Schrodinger equation. It is shown that there is a dark envelope soliton under certain conditions, while its amplitude will decrease with the time. The dependence of both the dispersion relation and group velocity of envelope solitary waves on the radius of cylinder has been given. Moreover, we define the duration time of dark envelope solitons and give the theoretical ones. It is found that the duration time increases as the radius of cylinder increases, while it decreases as the viscosity coefficient of dusty plasmas increases.

It is well known that the ponderomotive force of a relatively high-frequency magnetosonic wave (HMSW) can excite the low-frequency magnetosonic wave (LMSW). By using the coupled system of dynamical equations of LMSW in the presence of a ponderomotive force of HMSW (pump wave), we have studied the modulational instability of the coupled waves between the HMSW and the LMSW. It is found that there are instabilities for the coupled waves between the HMSW and the LMSW. It is also found that the growth rate depends on several system parameters, such as the frequency of HMSW, the perturbation wave vector, and the background magnetic field.

By using a Korteweg-deVries-Burgers(KdV-Burgers) equation and considering the dust size distribution, we have studied effects of the dust size distribution on the shock wave in dusty plasma. The dependence of characteristics of the shock wave on different dust size distributions has been given. It is found that the speed and amplitude of a shock wave considering the dust size distribution are larger than that of the dusty plasma with the averaged dust size. However, the width of a shock wave considering the dust size distribution is smaller than that of the dusty plasma with the averaged dust size.

The recent legalization of cannabidiol (CBD) to treat neurological conditions such as epilepsy has sparked rising interest across global pharmaceuticals and synthetic biology industries to engineer microbes for sustainable synthetic production of medicinal CBD. Since the process involves screening large amounts of samples, the main challenge is often associated with the conventional screening platform that is time consuming, and laborious with high operating costs. Here, a portable, high-throughput Aptamer-based BioSenSing System (ABS

Theoretical investigations are carried out for the cylindrical magnetosonic solitary waves in dissipative, hot electron–positron–ion plasma. By the reductive perturbation technique the modified Korteweg–de Vries–Burgers equation (mKdVB) is obtained and its approximate analytical solution is given. Using this solution, the effects of different physical parameters on magnetosonic solitary wave in cylindrical geometry are discussed. The results may have applications in laboratory and space plasmas.

Theoretical results are given in the present paper, which can well explain the experimental observations performed under microgravity conditions in the PK-3 Plus Laboratory on board the International Space Station about the propagation of a solitary wave across an interface in a binary complex plasma. By using the traditional reductive perturbation method and the continuity conditions of both the electric potential and the momentum at the interface, we obtain the equivalent ``initial conditions'' for both the transmitted wave and the reflected waves from the incident wave. Then we obtain the numbers of the reflected and the transmitted solitary waves as well as all the wave amplitudes by using the inverse scattering method. The ripples of both reflection and transmission have also been given by using the Fourier series. The number of the reflected and the transmitted solitary waves produced by interface, as well as all the solitary wave amplitudes, depend on the system parameters such as the number density, electric charge, mass of the dust particles, and the effective temperature in both regions. The analytical results agree with observations in the experiments.

The Kelvin–Helmholtz instability on the ionopause of Venus with different density ratios and magnetic Reynolds numbers has been simulated numerically by using the magnetohydrodynamics equations. For the special case of a Venus-like planet, the plasma density increases from the magnetosheath to the ionosphere. The numerical simulation shows that the density increasing toward the planet has more important effects than the magnetic Reynolds number on the Kelvin–Helmholtz instability. And during the evolution of the Kelvin–Helmholtz instability, there are three different phases, the linear growth phase, followed by a nonlinear phase with vortex-like structure, and finally, the turbulent phase. During the nonlinear evolution of the Kelvin–Helmholtz instability, the spatial scale of the vortex has a width of about $\sim 12a$ , where $a$ is the half width of the shear layer located at the Venusian ionopause. For each phase, the vorticity of the system also has different characteristics. Supersonic flow could appear at the position where the vorticity is stronger in both nonlinear and turbulent phases.

Present paper studies the contribution of both the quantum effect and the dust size distribution effect on the shock wave characters. It is concluded that the quantum effect of dust particles is negligible, while the quantum effects of both electrons and ions on the shock wave of a quantum dusty plasma cannot be neglected in certain cases. It is found that the speed and the amplitude of the shock wave, considering the dust size distribution, are larger than that of the quantum dusty plasma with the average dust size of a monosized dust plasma. Furthermore, the speed and the amplitude of the shock wave increase, while the width of the shock wave decreases as the ratios of the maximum dust size to the minimum one increases. The quantum effects may affect both the amplitude and width of the shock wave, while it has no effect on the shock wave speed. The width of the shock wave increases, while its amplitude decreases as $$H_e$$ and $$H_i$$ increase.

Theoretical investigations are carried out for the cylindrical and spherical dust-ion acoustic solitary waves with the kinematic viscosity. By the reductive perturbation technique the damped KdV-Burgers equation is obtained, and an approximate analytical solution is given. Using this solution, the effects of different physical parameters on dust-ion acoustic solitary wave are discussed. The results may have applications in laboratory and space plasmas.

This paper proposes a design of 2 × 1 printed monopole antenna array for 5G C-Band (3.3 — 4.2 GHz) applications. The size of the printed monopole antenna array is 95 × 47.5 × 0.8 mm3, which is fabricated on an FR4 substrate of permittivity of 4.4, and loss tangent of 0.0245. Also a 5 × 3 H-type EBG is integrated to the antenna array placed at 8 mm below, and the size of single H-type EBG is 20 × 20 × 1.6 mm3, which is also implemented on FR4 substrate. The simulated antenna gain of 2 × 1 printed monopole array can be achieved to 12.8 dBi by integrating the H-type EBG. Compared with the original 2 × 1 printed monopole antenna array, the gain can be improved by 8.8 dBi.

The paper proposes a design of MIMO antennas with broadband effect for laptop computers. The antenna is a use stereoscopic bending-coupled of architecture. The coupled-fed antenna is composed of a grounded inverted L-shaped arm, two short metal arms connected to the feed. The structure of isolation mechanism is a T-type metal strip with multi-arms to reduce the interaction between the two antennas. The overall size of the design is (LxWxH) is 6.2 × 50 × 4.2 mm3. The design antennas and isolation element made of 0.8mm FR-4 substrate is placed on upper left corner of the system ground with a size of (L× W) 200 × 260mm2. From the results, this design of MIMO antennas can be applied to the bands of WLAN2.4/5.2 /5.8GHz (2.4-2.484 GHz, 5.15-5.35 GHz, 5.725-5.825 GHz), and 5G NR SUB-6GHz (3.3- 4.2 GHz, 4.8-5 GHz).

The head-on collision between two dust-acoustic solitary waves in a non-magnetized, collisionless and strongly coupled dust plasma has been studied. The application scope of the analytical solution of the head-on collision is given in the present paper by using the particle-in-cell simulation method. It is noted that the analytical results are valid if the amplitudes of both of the solitary waves are small enough. The effects of the coupling parameters on both the head-on collision and the waveform are also studied in the present paper.

Theoretical investigations are carried out for the properties of small amplitude dust-acoustic solitary waves in plasmas consisting of extremely massive, high negatively charged inertial dust grains, Boltzmann distributed electrons and trapped ions, for one-dimensional case and three-dimensional case. An energy integral equation involving the Sagdeev potential is derived. The dependence of the critical Mach number corresponding to maximum amplitude on other parameters is obtained. It is observed that the magnitude of the external magnetic field has no effect on the amplitude of the solitary waves.

We translate three-dimensional magnetohydrodynamic equations describing the bounded plasma into a one-dimensional case and obtain an equivalent damping force that resulted from both the bounded geometry and the viscosity of the plasma by averaging all the physical quantities on the cross section, which is perpendicular to the wave propagation direction. A damping solitary wave propagating in a viscous bounded plasma is also verified by the particle-in-cell simulation method. The results in the present paper may be useful in the study of charged beam and particle acceleration, etc. Moreover, we can devise an experiment to obtain the viscosity coefficient of the plasma by measuring the ratio of two amplitudes at two different points.

This work investigates the envelope solitary wave (ESW) in magnetized power law distribution dusty plasma consisting of free electrons and nonthermal ions. A (3+1)-dimensional nonlinear Schr $$\ddot{o}$$ dinger equation (NLSE) through the reductive perturbation technique is derived. The nonlinear dispersion relation $$\omega =\omega (k )$$ and coefficients of NLSE are analyzed in detail by the numerical simulation method under the effect of nonthermal ions. It is indicated that the frequency increases as the number density of nonthermal ions increase. It can be seen that the frequency with higher unperturbed ion number density is larger than that with lower case. Moreover, the effects of amplitude and width on ESW are discussed with different plasma parameters. The present results can be important in understanding the characteristics of ESW for a magnetized three component plasma system.

The propagation of q -Gaussian laser beam in a preformed plasma channel is investigated by means of the variational method. A differential equation for the spot size has been obtained by including the effects of relativistic self-focusing, ponderomotive self-channeling and preformed channel focusing. The propagation behaviors and their corresponding physical conditions are identified. The comparison of the propagation between q -Gaussian and Gaussian laser beams is done by theoretical and numerical analysis. It is shown that, in the same channel, the focusing power of q -Gaussian laser beam is lower than that of Gaussian laser beam, i.e., the q -Gaussian laser beam is easier to focus than Gaussian laser beam.

Supersoliton (SS) can be mainly featured in two ways, namely, by focusing on subsidiary maxima on its electric field or by meeting the requirement that the appropriate Sagdeev pseudopotential (SP) has three local extrema between the equilibrium conditions and its amplitude. In this paper, by using the SP method, double layers and ion-acoustic SSs are studied in a plasma with Maxwellian cold electrons, nonthermal hot electrons, and fluid ions. The existence of the SS regime in parameter space is obtained in a methodical fashion. The existence domains for positive solitary waves are also presented. It is found that there is no SSs at the acoustic speed.

Theoretical studies are carried out for ion acoustic solitons in multicomponent nonuniform plasma considering the dust size distribution. The Korteweg−de Vries equation for ion acoustic solitons is given by using the reductive perturbation technique. Two special dust size distributions are considered. The dependences of the width and amplitude of solitons on dust size parameters are shown. It is found that the properties of a solitary wave depend on the shape of the size distribution function of dust grains.

An antenna design of smart-watch device with a metal frame structure is proposed. The dimension is $\mathbf{35}\mathbf{mm\ x} \mathbf{35mm}\ \mathbf{x}\ \mathbf{5mm}$ . There are four antennas designed on a metal frame of smart-watch. The four antennas are fed by 4 microstrip lines to drive slots by using matching circuit. To achieve the required application band for GPS (1.575 GHz), WLAN 2.4 (2.4-2.484 GHz), C-band (3.4-3.6 GHz). For the port 1, it uses capacitive element to adjust matching and achieve for GPS band. For the port 2, it uses the direct feed the slot to reach the WLAN 2.4 band. For the port 3 and 4, they use the LC element to activate the slot to achieve wideband characteristic, and a symmetric MIMO architecture for 5G C-band application is also designed. Detailed results for antenna design of smart-watch will be discussed in the article.

In this paper, a design of 8-ports MIMO slot antennas for 5G application is proposed. The design is composed of 4 printed slot and 8 port microstrip lines. The overall size of the design MIMO antennas is 120 × 120 × 20 mm3. The four printed slots are printed on the FR4 substrate with thickness of 0.8mm, relative permittivity of 4.4, and loss tangent of 0.0245. The design uses X-Shaped metal strip protruded the edge of the printed slot to achieve good isolation; the 4 thin slots connected to all 4 printed slots to enhance the isolation effect in the design. The obtained bandwidth of the design covering 3.3 to 3.8 GHz can cover the 5G C-band. Simulated and measured Sii (i=1 – 8) results are all below of -10dB and Sij ( i= 1 – 8, when i is not equal to j) for eight antenna are also less than -20dB. Measured antenna gains achieve 8.5 - 8.8dBi. This design has the advantage of high antenna gain, good radiation efficiency, and stable radiation pattern. Therefore, it is a good candidate for 5G wireless system at C-band.

This paper proposes a design of MIMO IFA antennas for laptop computers. The antenna size is 7 mm × 35 mm × 3.8 mm, and the ground plane size is 200 mm × 260 mm. The two antennas are fed by 50-ohm mini-coaxial cables. The design of MIMO antennas cover the bands of WLAN 2.4/5.2/5.8GHz (2.4 – 2.484, 5.15 – 5.825 GHz), WRC-15 C-band (3.4 – 3.6 GHz), and China 5G C-band (4.8 – 5 GHz). By adding a grounded loop element between the two antennas, the isolation of the MIMO antennas can be improved. The simulated and measured S11 and S22 are all below -10dB, and the S12 is also less than -15dB.

By using particle-in-cell(PIC) simulation method, the proton beam confinement in a magnetic mirror is investigated in the present paper. We define two physical quantities to describe the confinement effects of mirror for proton beam. One is loss rate χ=Nlost/N0, where Nlost is the number of leaked particles from the mirror and N0 is the number of initial particles. The other is confinement time τm. Dependences of loss rate and confinement time on the parameters of both magnetic mirror and proton beam is given. It is found that the larger the mirror ratio, the less the loss rate, and the longer the confinement time. The appropriate proton beam velocity and other parameters of the protons can significantly improve the confinement time of the mirror and the efficiency of confinement.

By using the traditional perturbation technique, a focusing nonlinear Schrödinger equation (NLSE) for the one-dimensional bead chain with the initial prestress is first obtained. The Peregrine soliton, called the rogue wave in the present paper, and the super rogue wave are investigated both numerically and analytically. It is noted that both the rogue wave and the super rogue wave do exist in the one-dimensional bead chain. The solutions from the NLSE can correctly describe the real rogue wave as well as the real super rogue wave in the limiting case of small amplitude. Both the rogue wave and the super rogue wave propagate in the granular bead chain as if they are solitary waves.

We investigate atomic interaction induced localization of a spin–orbit coupled Bose-Einstein condensate loaded in a double-well potential. We confirm the existence of the localization in the presence of the spin–orbit coupling for differences between the spin-dependent nonlinear atomic interaction strength between intraspin and interspin. We find a quantum phase transition from spin balance to spin localization for the different strengths of nonlinear atomic interaction strength. We also obtain the parametric dependence of the transitions to spin localization. The results play a constructive role to control spin localization of spin–orbit coupled Bose-Einstein condensate in a double-well potential.

In order to offer simultaneously switching noise (SSN) mitigation for dual WLAN bands in PCB of only two metal layers, this paper proposes a novel flipped stepped-impedance-resonator electromagnetic bandgap (FSIR-EBG) structure with its $2\times 2$ modified non-periodic combination. An equivalent circuit model is also developed to investigate the EBG design concept, whose stopband performance is enhanced by the theory of stepped-impedance resonator and the slot resonance. The unit cell of $2 \times 2$ modified non-periodic EBG combination can suppress SSN of both 2.4-3.1 GHz and $ 4.5\sim 6$ GHz bands with best suppression level up to 30 dB and 50 dB, respectively, and the simulation results agree well with the measurement.

By using the equation of the state of P = α d + β d T d, we studied a shock wave propagation in a strongly coupled complex plasma. A Korteweg-de Vries–Burgers equation is obtained to describe a shock wave in strongly coupled complex plasma. Dependence of the shock wave speed on the piston velocity and the plasma parameters such as the screening parameter of the strongly coupled complex plasma are given analytically for a weak shock wave. It is in good agreement with previous results. It shows in the present paper that there are density oscillations in the postshock region which is similar to that found in the previous works. Dependence of the length between two first peaks of the density oscillation on the piston velocity and the plasma parameter are also given analytically which is also in agreement qualitatively with previous results.

By using the PIC simulation method and theoretical investigation from both the magnetohydrodynamic equations and the Vlasov equation of the dusty plasma produced by the relative streaming of the dust fluid and the background ionospheric plasma, we investigate the instability of the waves excited by this kind of the dust beam in the ionosphere. It is found that the waves are stable in both the electron and ion vibration time scales, while they are unstable in the dust grain vibration time scale. It is inferred that the wave is the high hybrid wave in the electron vibration time scale. The dispersion relations of the perturbed waves in both the electron vibration and ion vibration time scales are obtained. As the time increases until it arrives at the dust grain vibration time scale, the instability appears for the perturbed wave. Such instabilities may drive plasma irregularities that could affect radar backscatter from the clouds, when the wave satisfies the Bragg condition for backscatter. By using the dispersion relation of waves in both electron vibration and ion vibration time scales, we can infer what kind of radar backscatter can be possibly affected by the instability of the perturbed waves.

Both the linear and the nonlinear magnetosonic wave in a multi-component dusty plasma are studied in the present paper. The dependence of the dispersion relation of the linear waves on the dust size distribution are given. It seems that the larger the difference between the maximum and the minimum radius of the dust grains, the lower the wave frequency for all cases of the dust size distribution. Furthermore, it is noted that the width, the amplitude and the propagation velocity of the KdV solitary wave depend on the dust size distribution, especially it depend on whether the number density of the larger sized dust grain is larger or smaller than that of the smaller sized dust grain. For the power law dust size distribution, the width and the propagation velocity of the KdV solitary wave between the maximum and the minimum radius of the dust grains is larger than that of mono-sized dusty plasma.

A multi-ion dusty plasma containing hot isothermal electrons, ions (both positive and negative ones), extremely and negatively charged dust grains and its corresponding dust negative ion acoustic waves are studied by using the reductive perturbation method in this paper. It is noted that they can be determined by parameters of the dust size distribution and the number densities of the ion and electrons.

The solitary waves of a viscous plasma confined in a cuboid under the three types of boundary condition are theoretically investigated in the present paper. By introducing a three-dimensional rectangular geometry and employing the reductive perturbation theory, a quasi-KdV equation is derived in the viscous plasma and a damping solitary wave is obtained. It is found that the damping rate increases as the viscosity coefficient increases, or increases as the length and width of the rectangle decrease, for all kinds of boundary condition. Nevertheless, the magnitude of the damping rate is dominated by the types of boundary condition. We thus observe the existence of a damping solitary wave from the fact that its amplitude disappears rapidly for a → 0 and b → 0, or v' → + ∞.

1-D particle-in-cell simulations are used to investigate the propagation and decomposition of the ion acoustic solitary waves (IASWs) in plasmas. Our results show that for small-amplitude conditions, IASWs are stable and the simulation results are consistent with the theoretical predictions of the reductive perturbation method. As the amplitudes of IASWs increase, the waves become unstable and trains of oscillating waves are emitted behind the main waves. When the amplitude is large enough, the wave cannot exist and will decay into a series of waves with a small amplitude. By comparing our simulations with the theoretical solutions of Kortewag–de Vries soliton, the upper limitation of the amplitude of IASWs in plasmas is found. Moreover, our results show that although the reductive perturbation method is valid only for small perturbations, the application scope of the reductive perturbation method can be expanded to describe the potential profiles of IASWs with any amplitude. Meanwhile, the application scope for the density profiles is still limited in the perturbation cases.

Evolution of both low-frequency harmonic Alfvén wave train and Alfvén solitary wave is studied by using the compressible MHD fluid model. A critical point is found at which linear wave theory should be replaced by a nonlinear one. A small, but finite amplitude Alfvén solitary wave is numerically found. The head-on collision between an Alfvén wave train and an Alfvén solitary wave is also numerically investigated. An interesting result is that there is no phase shift for both colliding waves which is different from that between two KdV solitary waves.

The finite-amplitude circularly polarized Alfven envelope solitary waves are numerically studied in the present paper. It is verified that the left-hand polarized Alfven envelope solitary wave can ...

A general small amplitude wave equations are proposed for the granular material. It is shown that the wave is localized in a certain region which is in agreement with that found in both the analytical and the simulation results. The localization region depends on the wave frequency and the parameters of the granular material such as the bead radius, the magnitude of the initial prestress, the Young’s modulus and the bead mass. Several examples are given which indicate that the attenuation rate of the wave depend on the permutation of the bead. It also depends on whether the wave is longitudinal or tangential.

The combined effect of the cylindrical boundary and the adiabatic variation in dust charges on the spatiotemporal evolution of the overlapping soliton in a dusty plasma is studied in detail. We derive the mathematical expression of the overlapping soliton and investigate the effect of dust charging and the influence of its adiabatic variation on the evolution process of the soliton structure. Numerical results indicate that the basic properties of the merged pulse are partially similar to the recent experimental results reported for the interaction of planar solitons in strongly coupled dusty plasmas by Harvey et al., Phys. Rev. E 81, 057401 (2010) and Sharma et al. Phys. Rev. E 89, 013110 (2014). Moreover, it is found that the soliton amplitude and the occurrence time of its peak value increase with the increase in Rn and RT, and the increasing rate of the peak amplitude decreases with the increase in Rn and increases with the increase in RT. As time t increases, the overlapping soliton moves to the inside-traveling direction (i.e., r → 0); before reaching the peak amplitude, the merged pulse gradually increases its amplitude and decreases its width and traveling velocity; after reaching the peak amplitude, the soliton gradually decreases its amplitude and increases its width and velocity. It is also noted that when dust charge variation is considered, solitons with bigger values of Rn (or RT) experience longer phase delays. Comparatively speaking, Rn has a more remarkable effect on the physical properties of the overlapping soliton.

By the reductive perturbation method, we investigate the Rogue waves in a fluid-filled elastic tube. Based on a nonlinear Schrodinger equation obtained from a fluid-filled elastic tube, the rouge wave solution in the fluid-filled elastic tube is discussed. The characteristics of a single rouge waveare studied for this system. Then, the effects of the system parameters, such as the wave number k, the parameters \begin{document}$\epsilon$\end{document}, the density of the fluid, the thickness of the elastic tube, the Yang's modulus of the elastic tube, and the radius of the elastic tube on the rouge wave are also investigated. Finally, the model is applied to the blood vessels of both animal and the human to ascertain the effects of the rouge wave in different arteries and vessels. The results of the present study may have potential applications in medical science.