Wave Phenomena Research Articles

On‐Demand Subwavelength‐Scale Light Sculpting Using Nanometric Holograms

AbstractSpatially or temporally structured light has attracted considerable attention for its intriguing beam characteristics, which have found extensive applications in classical and quantum optics. Extending structured light from macroscale and microscale to nanometricscale brings more prospects both for fundamental and applied science. However, sculpting light at the subwavelength scale remains a challenge since its transverse structure is fragile in the nanometric scale. Here a novelholography for arbitrary light sculpting at the subwavelength scale is demonstrated. A wave phenomenon of diffractive focusing from an amplitude‐only nanometric (50‐nm‐thick) film is introduced, and use of the induced high‐spatial‐frequency waves as carriers to encode information of an object is considered. Using this technique, nanometric holograms are designed and fabricated for generating the well‐defined eigen modes including the zero‐order Bessel beam, vortex beam, vector beam, Airy beam, as well as an arbitrary light pattern, with feature sizes on the deep‐subwavelength scale. The broadband performance of the hologram is examined, and a white‐light nondiffracting beam at the deep‐subwavelength scale is realized. This demonstration paves a way toward on‐demand light sculpting at the nanometric scale, which may find applications such as optical super‐resolution imaging, nanoparticle manipulation, and precise measurements.

Optimization of the chamber of OWC to improve hydrodynamic performance

Nearly 71% of Earth's surface area is occupied by the ocean, which is abundant in energy, with wave energy being one of its essential components. As a result, the investigation of wave energy generation devices is a crucial matter. This paper analyzes the performance of the oscillating water column (OWC) wave energy conversion device under the influence of unidirectional regular waves and optimizes the OWC device accordingly. The impact of different structural dimensions on the first-stage conversion efficiency of the OWC device is determined. Moreover, to evaluate the performance of the OWC device in real sea conditions, the wave climate at Sanmen Gorge is employed as the experimental parameter. The study examines the performance and characteristic response of the OWC device regarding the air chamber width, thickness of the front wall, and draught of the front wall. The findings reveal that the width of the OWC air chamber and the draught of the front wall significantly affect the OWC performance. Decreasing the width of the air chamber results in a stable horizontal plane, eliminating the occurrence of standing wave phenomena. As the draft of the front wall increases, the reflection coefficient of the air chamber gradually increases, and it becomes difficult for the wave to penetrate into the air chamber section. The Latin hypercube design experiment method was used to select experimental points and establish quadratic polynomial response functions. The OWC device was optimized based on multi-island genetic algorithm. The simulation and fault tolerant optimization methods presented in this paper can be widely used to improve system performance.

Applying a transformation-based method to extract optical traveling waves from the Kundu–Mukherjee–Naskar equation

Optical solitons are solitary waves that propagate without changing shape due to a balance between dispersion and nonlinearity in the medium. Therefore, solitary optical waves are important solutions to nonlinear partial differential equations for modeling pulse propagation in optics. Our work derives new solitary wave solutions to the Kundu–Mukherjee–Naskar (KMN) equation, which governs complex nonlinear optical wave phenomena. Using innovative logarithmic transformation-based analytical techniques, various solution forms are obtained and expressed in closed form via elementary functions. The solutions are validated through direct substitution into the original KMN equation. Our new solutions provide fresh perspectives into the intricate soliton landscape described by this model. Since the KMN equation finds use in fiber optic communications, fluid dynamics, and other domains, these findings have broad implications. The methods showcase promising new pathways for unraveling soliton behaviors by fractional- and integer-order nonlinear models alike. Researchers can build upon these techniques to further advance understanding of the profound mathematical structures underlying real-world physical systems.

A graduate laboratory experiment to study the dynamics of an acoustically levitated particle

The comprehension of physical wave phenomena is imperative for students in the fields of engineering and basic sciences. Laboratory experiments that involve generation of acoustic waves can be used to explain advanced nonlinear wave phenomena. Acoustic levitation is a method for stably suspending and trapping objects in mid-air using acoustic radiation forces. This paper discusses an experimental apparatus that offers an economical means to demonstrate the acoustic levitation of polystyrene particles while enabling the investigation of stability and nonlinear dynamics of the trapped particles. Additionally, this platform offers the potential to examine other phenomena, such as the interaction forces between multiple acoustically levitated particles. The mechanical design of the system along with the data acquisition and control techniques are thoroughly explained.

Electro-momentum coupling tailored in piezoelectric metamaterials with resonant shunts

Local microstructural heterogeneities of elastic metamaterials give rise to non-local macroscopic cross coupling between stress–strain and momentum–velocity, known as Willis coupling. Recent advances have revealed that symmetry breaking in piezoelectric metamaterials introduces an additional macroscopic cross coupling effect, termed electro-momentum coupling, linking electrical stimulus and momentum and enabling the emergence of exotic wave phenomena characteristic of Willis materials. The electro-momentum coupling provides an extra degree of freedom for controlling elastic wave propagation in piezoelectric composites through external electrical stimuli. In this study, we present how to tune the electro-momentum coupling arising in 1D periodic piezoelectric metamaterials with broken inversion symmetry through shunting the inherent capacitance of the individual piezoelectric layers with a resistor and an inductor in series forming a resistor–inductor–capacitor circuit. Guided by the effective elastodynamic theory and homogenization method for piezoelectric metamaterials, we derived a closed-form expression of the electro-momentum coupling in shunted piezoelectric metamaterials. Moreover, we demonstrate the ability to tailor the electro-momentum coupling coefficient and control the amplitudes and phases of the forward and backward propagating waves, yielding tunable asymmetric wave responses. The results of our study hold promising implications for applications involving asymmetric wave phenomena and programmable metamaterials.

Probing Chiral Magnetic Wave phenomena in Pb–Pb collisions with ALICE at the LHC

The interplay of the chiral anomaly and the strong magnetic field ( ∼1015 T) created in non central heavy-ion collisions could give rise to a collective excitation in the quark-gluon plasma called the Chiral Magnetic Wave (CMW), which can be experimentally sought through the charge asymmetry (A ch) dependence of the elliptic flow v 2 of positively and negatively charged hadrons. However, non-CMW mechanisms such as local charge conservation (LCC) interwined with collective flow can also lead to a similar dependence of v 2 on A ch. The measurement of triangular flow (v 3) thus serves as a reference as it is not expected to be affected by the CMW. In this study the slope parameters of Δv 2 vs A ch and Δv 3 vs A ch are estimated and compared with each other and with theoretical models to probe the CMW background.

Modelling Symmetric Ion-Acoustic Wave Structures for the BBMPB Equation in Fluid Ions Using Hirota’s Bilinear Technique

This paper investigates the ion-acoustic wave structures in fluid ions for the Benjamin–Bona–Mahony–Peregrine–Burgers (BBMPB) equation. The various types of wave structures are extracted including the three-wave hypothesis, breather wave, lump periodic, mixed-type wave, periodic cross-kink, cross-kink rational wave, M-shaped rational wave, M-shaped rational wave solution with one kink wave, and M-shaped rational wave with two kink wave solutions. The Hirota bilinear transformation is a powerful tool that allows us to accurately find solutions and predict the behaviour of these wave structures. Through our analysis, we gain a better understanding of the complex dynamics of ion-acoustic waves and their potential applications in various fields. Moreover, our findings contribute to the ongoing research in plasma physics that utilize ion-acoustic wave phenomena. To show the physical behaviour of the solutions, some 3D plots and their respective contour level are shown, choosing different values of the parameters.

The Effect of the Korean Wave Phenomenon toward Imitation Intention: Korean Product Purchase Intention in the Global Market

The Effect of the Korean Wave Phenomenon toward Imitation Intention: Korean Product Purchase Intention in the Global Market

AI in Gravitational Wave Analysis, an Overview

Gravitational wave research presents a range of intriguing challenges, each of which has driven significant progress in the field. Key research problems include glitch classification, glitch cancellation, gravitational wave denoising, binary black hole signal detection, gravitational wave bursts, and minor issues that contribute to the overall understanding of gravitational wave phenomena. This paper explores the applications of artificial intelligence, deep learning, and machine learning techniques in addressing these challenges. The main goal of the paper is to provide an effective view of AI and deep learning usage for gravitational wave analysis. Thanks to the advancements in artificial intelligence and machine learning techniques, aided by GPUs and specialized software frameworks, these techniques have played a key role over the last decade in the identification, classification, and cancellation of gravitational wave signals, as presented in our results. This paper provides a comprehensive exploration of the adoption rate of these techniques, with reference to the software and hardware involved, their effectiveness, and potential limitations, offering insights into the advancements in the analysis of gravitational wave data.

Human Life of Korean University Students

Purpose: The Korean wave phenomenon is closely related to university students in Korea, and university students are greatly influenced by the Korean Wave phenomenon and experience and develop positive changes and opportunities through it. The Korean Wave phenomenon is contributing to university students introducing and promoting Korean wave contents abroad, contributing to Korean language education and cultural exchange, and becoming Korea's representative soft power factor through cultural event planning and international leadership. Through these roles, university students can gain opportunities to promote Korean culture and values to the world and form an international network, which has created a need for research on the lives of Korean university students.
 Method: In this study, 150 Korean university students were surveyed by convenience sampling method. A valid questionnaire was analyzed for 136 people, and the data were analyzed using the SPSS 23.0 program. Frequency analysis, t-test, and One Way ANOVA were used as analysis methods. According to the purpose of the analysis, differences in stress by gender, difference in organizational commitment by presence or absence of friends of the opposite sex, differences in empowerment by religious type, and differences in organizational commitment by friends of the opposite sex and dwelling type were explored.
 Results: First, as a result of examining the difference in stress according to gender in Korean university students, males answered Q7(I feel the need to reduce part of my role in my team) and Q8(I feel my role is too much in my team). It was found that women experience higher levels of stress than women. Second, as a result of verifying differences in empowerment according to religious types of Korean university students, in Q8(I decide the goal of my training by myself), the result was that Christian believers experienced higher empowerment than other religions(non-religious). And as a result of examining the difference in organizational commitment according to the presence or absence of friends of the opposite sex among Korean university students, those who have friends of the opposite sex were Q1(I feel a strong sense of belonging to the team I am currently training for), Q2(I think the current team is worth putting my heart and soul into), and Q3(I look forward to life in the team more positively in the future).
 Conclusion: First, Korean university students showed different role burdens and stress levels according to gender. Second, Christians tended to feel greater self-determination and control through religious values and belief systems. Third, those who have friends of the opposite sex tend to feel a strong sense of belonging and passion within the organization. Fourth, students living in university dormitory dormitories showed higher organizational commitment than students who commute to school. The university dormitory provides an environment that encourages the formation of relationships with classmates and communication with the outside world.

Generalized exponential rational function method to the fractional shallow water wave phenomena

In this study we introduce the fractional shallow water wave phenomena, namely, the new extended (2 + 1)-dimensional fractional Boussinesq equation and in the following we apply the generalized exponential rational function for extracting the soliton solutions to the Ex-FBe (extended (2 + 1)-dimensional fractional Boussinesq equation) by using Maple tools for calculating and Mathematica for graphical behaviors. Many types of exact soliton solutions for the fswwp equation have been derived by the erf method. Physical interpretations of some of the obtained solutions are also included. It can be easily concluded that the new proposed method is very efficient and finds the exact solutions of the equation in a relatively easy way.

Abundant time-wavering solutions of a modified regularized long wave model using the EMSE technique

This research article presents the application of the enhanced modified simple equation integral technique to obtain abundant time-wavering solutions of the modified regularized long wave (RLW) model. The model is known for its significance in exploring wave phenomena in various fields, including shallow water dynamics, pressure waves in liquids and gas bubbles, nonlinear transverse waves in magneto-hydrodynamics, and ion-acoustic waves in plasma. By implementing the enhanced modified simple equation integral technique, we construct arbitrary time-varying wave solutions for the model, resulting in a diverse range of solitonic waveforms. These solutions include kink waves, anti-kink waves, bright and dark bell waves, double periodic waves, and combinations of solitons and periodic waves. The obtained solutions are visually presented through 2D and 3D density and contour plots. Our findings demonstrate the effectiveness and potential of the enhanced modified simple equation integral technique in identifying innovative time-varying soliton solutions within the modified RLW model.

Addressing the Impact of Surface Roughness on Epsilon-Near-Zero Silicon Carbide Substrates.

Epsilon-near-zero (ENZ) media have been very actively investigated due to their unconventional wave phenomena and strengthened nonlinear response. However, the technological impact of ENZ media will be determined by the quality of realistic ENZ materials, including material loss and surface roughness. Here, we provide a comprehensive experimental study of the impact of surface roughness on ENZ substrates. Using silicon carbide (SiC) substrates with artificially induced roughness, we analyze samples whose roughness ranges from a few to hundreds of nanometer size scales. It is concluded that ENZ substrates with roughness in the few nanometer scale are negatively affected by coupling to longitudinal phonons and strong ENZ fields normal to the surface. On the other hand, when the roughness is in the hundreds of nanometers scale, the ENZ band is found to be more robust than dielectric and surface phonon polariton (SPhP) bands.

On the Solitary Waves and Nonlinear Oscillations to the Fractional Schrödinger–KdV Equation in the Framework of the Caputo Operator

The fractional Schrödinger–Korteweg-de Vries (S-KdV) equation is an important mathematical model that incorporates the nonlinear dynamics of the KdV equation with the quantum mechanical effects described by the Schrödinger equation. Motivated by the several applications of the mentioned evolution equation, in this investigation, the Laplace residual power series method (LRPSM) is employed to analyze the fractional S-KdV equation in the framework of the Caputo operator. By incorporating both the Caputo operator and fractional derivatives into the mentioned evolution equation, we can account for memory effects and non-local behavior. The LRPSM is a powerful analytical technique for the solution of fractional differential equations and therefore it is adapted in our current study. In this study, we prove that the combination of the residual power series expansion with the Laplace transform yields precise and efficient solutions. Moreover, we investigate the behavior and properties of the (un)symmetric solutions to the fractional S-KdV equation using extensive numerical simulations and by considering various fractional orders and initial fractional values. The results contribute to the greater comprehension of the interplay between quantum mechanics and nonlinear dynamics in fractional systems and shed light on wave phenomena and symmetry soliton solutions in such equations. In addition, the proposed method successfully solves fractional differential equations with the Caputo operator, providing a valuable computational instrument for the analysis of complex physical systems. Moreover, the obtained results can describe many of the mysteries associated with the mechanism of nonlinear wave propagation in plasma physics.

Indonesian Generation Z’s Intention to Visit South Korea: The Mediating Role of Tourist Attitude on Travel Motivation and Celebrity Endorser Credibility

Objective: This study examined the effect of travel motivation and celebrity endorser credibility in influencing the intention of the Indonesian Generation Z to visit South Korea, with involved a mediating role of tourist attitude, which refers to the Korean Wave Phenomenon. Design/Methods/Approach: This study was done by quantitative approach with Partial Least Square Structural Equation Modeling (PLS-SEM) analysis procedure using SmartPLS 4. The data collection technique was purposive sampling, aimed at the Indonesian Generation Z as the target respondent. There were 385 data collected using the online questionnaires. Findings: The results show that travel motivation and celebrity endorser credibility positively and significantly affect the visit intention to South Korea. Tourist attitude also mediates the relationship between travel motivation and celebrity endorser credibility in affecting the visit intention to South Korea. Originality: The existing literature discovered the direct effect of travel motivation and celebrity endorser credibility on visit intention in the tourism industry. This study contributes to the existing literature by involving tourist attitude as a mediation variable in the relationship between tourist motivation and celebrity endorser credibility in affecting visit intention to South Korea. Practical/Policy implication: This study contributes to proposing recommendations for a more effective marketing and promotion strategy for tourism products in South Korea by looking at trends in tourist preferences and involving the role of celebrities as an endorser. Research also contributes to developing literature on marketing and promoting tourism products and tourist behavior literature.

Exploring source region of 3-min slow magnetoacoustic waves observed in coronal fan loops rooted in sunspot umbra

ABSTRACT Sunspots host various oscillations and wave phenomena like umbral flashes, umbral oscillations, running penumbral waves, and coronal waves. All fan loops rooted in sunspot umbra constantly show a 3-min period propagating slow magnetoacoustic waves in the corona. However, their origin in the lower atmosphere is still unclear. In this work, we studied these oscillations in detail along a clean fan loop system rooted in active region AR 12553 for a duration of 4 h on 2016 June 16 observed by Interface Region Imaging Spectrograph and Solar Dynamics Observatory. We traced foot-points of several fan loops by identifying their locations at different atmospheric heights from the corona to the photosphere. We found presence of 3-min oscillations at foot-points of all the loops and at all atmospheric heights. We further traced origin of these waves by utilizing their amplitude modulation characteristics while propagating in the solar atmosphere. We found several amplitude modulation periods in the range of 9–14, 20–24, and 30–40 min of these 3-min waves at all heights. Based on our findings, we interpret that 3-min slow magnetoacoustic waves propagating in coronal fan loops are driven by 3-min oscillations observed at the photospheric foot-points of these fan loops in the umbral region. We also explored any connection between 3- and 5-min oscillations observed at the photospheric foot-points of these loops and found them to be weakly coupled. Results provide clear evidence of magnetic coupling of the solar atmosphere through propagation of 3-min waves along fan loops at different atmospheric heights.

Waves propagation of optical waves through nonlinear media; modified Kawahara equation

The focus of this study is to investigate novel and precise solitary wave solutions of the modified Kawahara (MK) equation using recent and accurate computational techniques. The MK equation, a nonlinear partial differential equation, has significant applications in various fields, including fluid dynamics and plasma physics The comprehension of nonlinear wave phenomena relies heavily on solitary wave solutions, making it necessary to develop accurate and efficient computational techniques for their identification. In this study, the Khater II method is employed as a computational technique, while the variational iteration method is used as a numerical scheme.The Khater II method is a powerful computational technique that has exhibited promising outcomes in solving nonlinear wave equations. It uses an analytical framework to transform the partial differential equation into a set of ordinary differential equations that are amenable to straightforward solutions, thereby enabling the construction of exact solutions. Conversely, the variational iteration method is a numerical scheme that enhances solution accuracy through iterative approximations.By using the Khater II method as a computational technique and the variational iteration method as a numerical scheme, this study identifies novel and precise solitary wave solutions of the MK equation. These solutions provide valuable insights into the dynamics and behavior of nonlinear waves across various applications. The effectiveness of the employed techniques is demonstrated by comparing them with other commonly utilized computational methods for solving the MK equation. The results indicate that the combined application of the Khater II method and the variational iteration method yields more accurate and efficient solutions. This heightened accuracy and efficiency are critical for comprehending and predicting the behavior of the studied model in real-world applications. Thus, this study underscores the significance of employing recent and accurate computational techniques, such as the Khater II method and the variational iteration method, to identify novel and precise solitary wave solutions of the MK equation. The obtained solutions contribute to an improved understanding of the model’s behavior and hold practical implications across diverse scientific and engineering domains.

Magnitude‐Controlled Phase Based on Euler's Formula

AbstractPhase manipulation plays a fundamental role in electromagnetic (EM) and optics research, i.e., the wavefront shaping depends heavily on phase modulation. However, the previous phase manipulation methods are limited to phase‐angle dimensionality, and the magnitude and phase are generally deemed as two distinct characters that should be controlled separately. Herein, a phase manipulation method in which phase is modulated by magnitude is proposed that follows an EM expression of Euler's formula. A rotation phase of linearly‐polarized waves is presented. Using this method, several unique applications in this research are demonstrated. First, a Hall effect of non‐angular‐momentum waves is obtained; second, an interdigital topology model with a unique topological‐charge control strategy is presented; and finally, the method is applied to holographic imaging, of which information of the hologram is recorded as a distribution of magnitude. Furthermore, as this method is applicable to all forms of harmonic waves, it can be potentially applied to other areas of wave phenomena such as acoustics and mechanics.

The effect of the eruption of mount Hunga-Tonga on density altitude, air pressure and flight operations in eastern Indonesian

There was an eruption of the Hunga Tonga volcano in the Pacific Ocean on January 15, 2022 and produced the phenomenon of Shock Waves in the atmosphere, in addition to sonic booms, and tsunami waves that spread to various parts of the world. Data from the automated weather observing system (AWOS) in several Airports in Indonesia were analyzed to assess the impact of the eruption of Mount Tonga on the Indonesian atmosphere. There are sudden changes in air pressure (QNH) at locations (Airports) including Sorong, Wamena, Ternate, Sumbawa, Biak, Geser, Lombok, Sabu, and Kupang, with a range between 0.6 to 1.9 Mb. These atmospheric waves propagate at a speed of about 1248 km/hour. This drastic change in air pressure is not followed by a significant change in density altitude which affects the effectiveness of the aircraft’s lift, but a sudden change will cause a change in air pressure (QNH) in the altimeter which can cause a change in aircraft altitude. This sudden change has high probability to result in a plane crash due to a stall or undershoot or collision with aircraft.

High-order mode interface states of surface water waves based on non-Bragg resonances

In this paper, we connect two periodic channels with bandgaps of different physical properties to form a heterojunction of surface water waves, which realize a high-order mode water wave interface state and concentrate the water wave energy near the heterojunction interface. By introducing a spatial symmetry breaking mechanism, we obtain a periodic channel with non-Bragg bandgaps due to different mode resonances. At a similar central frequency of the gap, another periodic channel is designed to generate Bragg bandgaps of the same mode resonances. The results of the mode analysis indicate that the localized region of the interface state in the frequency range of the non-Bragg bandgap contains a high-order mode component, which is dominant. The interface states induced by the high-order modes are much more efficient in wave accumulation. By introducing defect structures with different lengths, the frequency tuning of the high-order mode interface states is also achieved. The high-order mode interface state provides a different way for wave aggregation, and its implementation is also applicable to other classical wave systems due to the ubiquity of wave phenomena.