Phase Shift Of Wave Research Articles

Mechanisms of medicine-induced effect on organism

One of the key issues in modern medicine-based therapy is the mechanisms of medicine-induced effects on the body. The generally acknowledged chemical paradigm can’t offer an explanation for the therapeutic effect, in case of treatment with ultra-high diluted (UHD) medicines.
 At the same time studies of the homeopathic phenomenon elicited the electromagnetic wave nature of the interaction between drugs (including allopathic medicines) and the organism. Correspondence of the medicine and gene wave indicators leads to the resonance of the waves and stimulates attenuated genetic activity demonstrating a therapeutic effect.
 Wave actions of an allopathic remedy target a certain weak gene, the weakness of which causes a certain symptom. The gene activation results in the symptom elimination which is symptomatic treatment.
 Homeopathic preparations have an effect on control centres containing a certain set of genes. Stimulation of such centres leads to normalization of the functions of a relevant body system, as well as of the biochemical processes controlled by the centre. On the other hand, counter-propagating amplitudes of medication waves and pathogenic beams helps to reduce their effect and stop the disease process.
 UHD of medicinal substances used in homeopathy demonstrates coherency - phase shift of the preparation wave. Its value is essential for the homeopathic phenomenon realization as it allows approximation of the medicine wave indicators to those of the ‘target’.
 Therefore, today’s level of scientific apprehension of a medicine healing effect on the organism, as well as subsequent studies and active implementation of obtained study results into practical work make it possible to identify a way out of the critical situation, which exists in the modern medication-based therapy, ensure medicine-based therapy efficiency and optimize costs of therapy and prevention of many diseases.
 Keywords: homeopathic phenomenon, coherency, mechanisms of medicine-induced effect on organism, wave actions, gene, therapeutic effect.

Partial Wave Analysis of $$\pmb {K^+N}$$ Scattering and the Possibility of Pentaquark $$\pmb {\Theta ^+(1540)}$$

Elastic $K^+ n\to K^+ n$ and charge exchange $K^+n\to K^0p$ reactions at low momenta are investigated using the partial wave analysis. Isospin relation gives constrains for the partial $s$- and $p$-waves among elastic $K^+p$, $K^+n$ and charge exchange $K^+n\to K^0p$ amplitudes. Two sets of the phase shift for these partial waves in the isoscalar channel are obtained from the fit of experimental data on total and differential cross sections. Polarization observable leads to a good criterion to decide which set is valid. Differential cross section data near $P_{\rm Lab}=434$ MeV/$c$ suggests a possibility of a resonance, e.g., the exotic $\Theta^+(1540)$ baryon around $\sqrt{s}\simeq$ 1.54GeV.

Simulation of high-power microwaves gas breakdown with a modified multi-physical model

In this paper, a modified multi-physics method for transient analysis of high-power microwaves (HPM) gas breakdown is proposed. Distinguished from previous works, the proposed method couples the plasma fluid equations with Maxwell's equations to fully consider the interaction between plasma and electromagnetic waves. To perform the numerical simulation, the spectral-element time-domain method is employed, which has the advantages of spectral accuracy and block diagonal mass matrix. Numerical simulations are conducted to demonstrate the accuracy of the proposed method. Moreover, with an external DC magnetic field, HPM breakdown can be effectively delayed by increasing its breakdown threshold. Simultaneously, the phase shift of electromagnetic waves during the HPM breakdown can also be controlled by the external DC magnetic field, which can improve the quality of the phase-modulated signal in HPM illumination. This proposed framework is expected to provide an effective numerical tool for analyzing the microwave propagation characteristics and suppressing the HPM breakdown in gas-filled microwave devices.

Using differential phase for 3D localization of tracer particles in digital inline holographic microscopy PIV/PTV (DIHM-PIV/PTV)

Digital inline holographic microscopy PIV/PTV (DIHM-PIV/PTV) has the ability to provide 4-dimensional (4D), i.e. time-resolved, 3-component 3-dimensional (3C-3D) flow measurement with high spatial and temporal resolution, compact optical setup and minimal calibration Sun et al. (2020) compared to most other volumetric techniques such as tomo-PIV, defocusing PIV, etc. Despite all these advantages DIHMPIV/PTV has not yet developed into a standard laboratory tool due to some major limitations such as the extended depth-of-focus (DOF) problem and the virtual image effect which cause artefacts in the standard reconstruction volume limiting the seeding concentration and thus the achievable velocity spatial resolution. In order to mitigate the above-mentioned limitations we present a novel particle localization and extraction methodology which allows the minimization of these artefacts from the standard reconstruction and perform PIV/PTV analysis on the particle volume fields only. The proposed algorithm is based on the differential phase, which is the axial phase shift of the object wave compared to the reference plane wave propagation.

Effect of wave shift of porous slab on thermo-hydraulic transport characteristics of laminar flow through a wavy channel

In the present numerical study, the finite element method is adopted to investigate the thermo-hydraulic transport characteristics of two-dimensional, steady, Laminar flow of Newtonian fluid through partially porous wavy channel. The wavy channel consists a porous wavy slab at the center. Water is taken as working fluid with Prandtl number Pr = 6.93 and Reynolds number Re = 700 considered for all simulations. Results are investigated in the form of average Nusselt number (Nuavg), Enhancement ratio (ER), Pressure drop (Δp), Pressure ratio (PR), and Performance factor (PF) for different wave amplitudes (α=0.06, 0.12, and 0.18) and wave phase shifts (φ = 00, 45°, 90° and 180°) of porous slab at different Darcy numbers range (Da = 10-6 to 10-2). Results reveal a significant increment in average Nusselt number with decreasing in Darcy number on the pressure drop penalty. The maximum value of ER found for geometry configuration α = 0.18 and φ = 900 at Darcy number Da = 10-6, and on the other end, maximum PF is obtained at Darcy number Da = 10-2 irrespective of geometry configurations. The lower value of ER was obtained at φ = 1800 irrespective of wave amplitude and Darcy number. There is a significantly less effect of porous slab wave phase shift of φ = 450 and φ = 900 for given Da on PR at fixed wave amplitude.

All optical half subtractor based on linear photonic crystals and phase shift keying technique

Abstract In this work, the authors investigate the new structure of all optical half subtractor in a two dimensional photonic crystal based on wave interference and phase shift keying technique. The suggested structure is designed using 10 optical waveguides and one defect in the basic structure. The numeral methods such as plane wave expansion and finite difference time domain are used to analyze the proposed structure. According to obtained results, the rise and fall times, the working bit rate, the minimum and maximum values of the normalized power at ON and OFF states for output ports are 0.1 ps, 0.05 ps, 5 Tbit/s, 77 and 17%, respectively. According to results, high switching speed, compactness, low power consumption and ultra-fast operation are the main advantages of designed optical half subtractor compared with the previous structures.

Research on the method of dual-frequency microwave diagnosis of plasma for solving phase integer ambiguity

In this work, microwaves and terahertz waves have performed a dual-frequency combined diagnosis in high-temperature, large-scale plasma. According to the attenuation and phase shift of electromagnetic waves in the plasma, the electron density and collision frequency of the plasma can be inversely calculated. However, when the plasma size is large and the electron density is high, the phase shift of the electromagnetic wave is large (multiple times 2π period). Due to the limitations of the test equipment, the true phase shift is difficult to test accurately or to recover reality. That is, there is a problem of phase integer ambiguity. In order to obtain a phase shift of less than 180°, a higher electromagnetic wave frequency (terahertz wave with 890 GHz) is used for diagnosis. However, the attenuation of the terahertz wave diagnosis is too small (less than 0.1 dB), only the electron density can be obtained, and the collision frequency cannot be accurately obtained. Therefore, a combined diagnosis was carried out by combining two frequencies (microwave with 36 GHz, terahertz wave with 890 GHz) to obtain electron density and collision frequency. The diagnosis result shows that the electron density is in the range of (0.65–1.5) ×1019 m−3, the collision frequency is in the range of 0.65–2 GHz, and the diagnostic accuracy is about 60%.

Einstein–de Haas phase shifts in surface acoustic waves

We demonstrate the phase shift of the Rayleigh-type surface acoustic wave (RSAW) in a ferromagnetic ${\mathrm{Ni}}_{81}{\mathrm{Fe}}_{19}$ film based on the gyromagnetic Einstein--de Haas (EdH) torque that can be attributed to the back action of spin-wave excitation. The EdH torque modulates the transverse velocity of the bulk acoustic wave that causes the bipolar phase shift of RSAW. When compared with a magnetoelastic torque, the phase shift can be more prominently enhanced by increasing the frequency. The gyromagnetic torque in the RSAW paves the way for controlling spin-mechatronics devices without magnetoelastic torque which is specific to a certain material.

Experimental investigation of optically controlled topological transition in bismuth-mica structure

The hyperbolic materials are strongly anisotropic media with a permittivity/permeability tensor having diagonal components of different sign. They combine the properties of dielectric and metal-like media and are described with hyperbolic isofrequency surfaces in wave-vector space. Such media may support unusual effects like negative refraction, near-field radiation enhancement and nanoscale light confinement. They were demonstrated mainly for microwave and infrared frequency ranges on the basis of metamaterials and natural anisotropic materials correspondingly. For the terahertz region, the tunable hyperbolic media were demonstrated only theoretically. This paper is dedicated to the first experimental demonstration of an optically tunable terahertz hyperbolic medium in 0.2–1.0 THz frequency range. The negative phase shift of a THz wave transmitted through the structure consisting of 40 nm (in relation to THz wave transmitted through substrate) to 120 nm bismuth film (in relation to both THz waves transmitted through substrate and air) on 21 µm mica substrate is shown. The optical switching of topological transition between elliptic and hyperbolic isofrequency contours is demonstrated for the effective structure consisting of 40 nm Bi on mica. For the case of 120 nm Bi on mica, the effective permittivity is only hyperbolic in the studied range. It is shown that the in-plane component of the effective permittivity tensor may be positive or negative depending on the frequency of THz radiation and continuous-wave optical pumping power (with a wavelength of 980 nm), while the orthogonal one is always positive. The proposed optically tunable structure may be useful for application in various fields of the modern terahertz photonics.

Broadband tunable elastic metastructure based on one-dimensional phononic crystal

Considering the manufacturing difficulty and tunability, a one-dimensional phononic crystal-type metastructure is proposed in this paper. By adjusting the distance between the mass oscillators installed on the connecting bar, that is, changing the length of the phononic crystal unit, the phase shift of the flexural wave can span over a full range of 0–2π and then the phenomena such as abnormal refraction, beam focusing, and self-acceleration can be realized based on the generalized Snell’s law. In addition, the method of multiple mass oscillator array design is used to broaden the operating frequency domain by increasing or decreasing the number of mass oscillators. This proposed method provides an innovative concept for realizing broadband tunable metastructures and has potential applications in the fields of vibration control, energy harvesting, and noise isolation.

Research on phase shift characteristics of electromagnetic wave in plasma

The phase shift characteristics reflect the state change of electromagnetic wave in plasma sheath and can be used to reveal deeply the action mechanism between electromagnetic wave and plasma sheath. In this paper, the phase shift characteristics of electromagnetic wave propagation in plasma were investigated. Firstly, the impact factors of phase shift including electron density, collision frequency and incident frequency were discussed. Then, the plasma with different electron density distribution profiles were employed to investigate the influence on the phase shift characteristics. In a real case, the plasma sheath around the hypersonic vehicle will affect and even break down the communication. Based on the hypersonic vehicle model, we studied the electromagnetic wave phase shift under different flight altitude, speed, and attack angle. The results indicate that the phase shift is inversely proportional to the flight altitude and positively proportional to the flight speed and attack angle. Our work provides a theoretical guidance for the further research of phase shift characteristics and parameters inversion in plasma.

Continuous manipulation of acoustic wavefront using a programmable acoustic metasurface

Conventional passive acoustic metasurfaces (AMSs) can hardly reconfigure their topologies or structural parameters, which limits their wide applications. In this paper, a programmable AMS which contains an array of reconfigurable subwavelength unit cells, regulated by a set of stepper motors with lead screws and a cost-effective control system is presented. The unit of the AMS is composed of a parallel one-dimensional daisy-chained slit with five Helmholtz resonators. The phase shift of the transmission wave through the AMS units can be precisely controlled over the full phase range and continuously tuned by varying the slit width at high transmission efficiency. Benefitting from such a mechanism, the designed AMS is able to achieve continuous versatile wave manipulation functions in simulation and in experiment by engineering the phase and amplitude of transmission waves, including tuneable acoustic refraction, tuneable acoustic focusing and tuneable acoustic self-bending. Thus, this proposed AMS holds a great potential for a wide range of applications including diagnostic sonography, active non-destructive evaluation, acoustic holography, noncontact micro-particles manipulation and energy harvesting.

P -wave nucleon-pion scattering amplitude in the Δ(1232) channel from lattice QCD

We determine the $\Delta(1232)$ resonance parameters using lattice QCD and the L\"uscher method. The resonance occurs in elastic pion-nucleon scattering with $J^P=3/2^+$ in the isospin $I = 3/2$, $P$-wave channel. Our calculation is performed with $N_f=2+1$ flavors of clover fermions on a lattice with $L\approx 2.8$ fm. The pion and nucleon masses are $m_\pi =255.4(1.6)$ MeV and $m_N=1073(5)$ MeV, and the strong decay channel $\Delta \rightarrow \pi N$ is found to be above the threshold. To thoroughly map out the energy-dependence of the nucleon-pion scattering amplitude, we compute the spectra in all relevant irreducible representations of the lattice symmetry groups for total momenta up to $\vec{P}=\frac{2\pi}{L}(1,1,1)$, including irreps that mix $S$ and $P$ waves. We perform global fits of the amplitude parameters to up to 21 energy levels, using a Breit-Wigner model for the $P$-wave phase shift and the effective-range expansion for the $S$-wave phase shift. From the location of the pole in the $P$-wave scattering amplitude, we obtain the resonance mass $m_\Delta=1378(7)(9)$ MeV and the coupling $g_{\Delta\text{-}\pi N}=23.8(2.7)(0.9)$.

Confined variational calculations of low-energy electron-helium scattering

The $S\text{\ensuremath{-}},$ $P\text{\ensuremath{-}},$ and $D\text{\ensuremath{-}}\mathrm{wave}$ elastic scattering of electrons by atomic helium with the scattering energy between 0.136 and $16.463\phantom{\rule{4pt}{0ex}}\mathrm{eV}$ is studied using the confined variational method. Our calculated phase shifts improve the best published results by at least one order of magnitude. The finite nuclear mass effect on the $S$-wave phase shift at very low scattering energy between 0.022 and $0.067\phantom{\rule{4pt}{0ex}}\mathrm{eV}$ is investigated, and the accurate $S$-wave scattering length is determined to be $1.1723{a}_{0}$, where ${a}_{0}$ is the Bohr radius. The results reported here can serve as a benchmark for other theoretical and experimental studies.

Numerical comparison of time-, frequency- and wavelet-domain methods for coda wave interferometry

SUMMARYTemporal changes in subsurface properties, such as seismic wave speeds, can be monitored by measuring phase shifts in the coda of two seismic waveforms that share a similar source–receiver path but that are recorded at different times. These nearly identical seismic waveforms are usually obtained either from repeated earthquake waveforms or from repeated ambient noise cross-correlations. The five algorithms that are the most popular to measure phase shifts in the coda waves are the windowed cross correlation (WCC), trace stretching (TS), dynamic time warping (DTW), moving window cross spectrum (MWCS) and wavelet cross spectrum (WCS). The seismic wave speed perturbation is then obtained from the linear regression of phase shifts with their respective lag times under the assumption that the velocity perturbation is homogeneous between (virtual or active) source and receiver. We categorize these methods into the time domain (WCC, TS, DTW), frequency domain (MWCS) and wavelet domain (WCS). This study complements this suite of algorithms with two additional wavelet-domain methods, which we call wavelet transform stretching (WTS) and wavelet transform DTW, wherein we apply traditional stretching and DTW techniques to the wavelet transform. This work aims to verify, validate, and test the accuracy and performance of all methods by performing numerical experiments, in which the elastic wavefields are solved for in various 2-D heterogeneous half-space geometries. Through this work, we validate the assumption of a linear increase in phase shifts with respect to phase lags as a valid argument for fully homogeneous and laterally homogeneous velocity changes. Additionally, we investigate the sensitivity of coda waves at various seismic frequencies to the depth of the velocity perturbation. Overall, we conclude that seismic wavefields generated and recorded at the surface lose sensitivity rapidly with increasing depth of the velocity change for all source–receiver offsets. However, measurements made over a spectrum of seismic frequencies exhibit a pattern such that wavelet methods, and especially WTS, provide useful information to infer the depth of the velocity changes.

Envelope-Based Sparse-Constrained Deconvolution for Velocity Model Building

Full waveform inversion is often troubled by falling into a local minimum due to cycle-skipping problem when missing low-frequency seismic data. According to the dynamics of seismic waves, the travel-time information will not change due to the variation in the frequency band of seismic data, which is the working mechanism of travel-time inversion. However, the current travel-time inversion method often requires various assumptions for the convenience of calculation, resulting in limited inversion effects. We present a novel velocity building method based on travel-time information. First, we use the sparse-constrained deconvolution (SCD) to convert travel-time information of seismic data into reflection sequences, which greatly reduces the complexity of the travel-time inversion. Then, the phase-independent characteristic of the envelope is introduced into the SCD to deal with the phase shift of the seismic wave. The combination of SCD and envelope greatly improves the reconstruction accuracy of the reflection sequences. Finally, the reconstructed reflection sequences are convolved with the full-band source wavelet to obtain full-band seismic data, and thus, the envelope-based SCD (E-SCD) inversion method is proposed. The results of numerical experiments on the partial basic tracking (BP) model and SEG/EAGE overthrust model verify the performance of the E-SCD inversion method. The limitations of the method and the direction of future development are also briefly discussed.

Confined variational calculation of positronium-hydrogen scattering below the positronium excitation threshold

The confined variational method is used to study $S$-, $P$-, and $D$-wave positronium-hydrogen scattering with the scattering energy between 0.068 and 3.333 eV. Accurate phase shifts and $S$-wave scattering lengths are calculated and compared with other theoretical methods. Existing discrepancies for the $D$-wave phase shifts are resolved. According to collision momentum, total orbital angular momentum, and spin configuration, the distortion effects of positronium are quantitatively studied. Finally, the finite nuclear mass effects are investigated.

Characterization of fracture process in polyolefin fibre-reinforced concrete using ultrasonic waves and digital image correlation

This study explores the monitoring of the fracture process in concrete beams and aims to characterize the evolution of damage in polyolefin fibre-reinforced concrete beams by utilizing the integrated application of two measurement techniques, digital image correlation and ultrasonic testing. The interpretation of registered wave time histories data was provided by the calculation of the magnitude-phase-composite metrics. An efficient procedure for the determination of strain field and the identification of crack height was subsequently developed. The results of the study show that the energy and phase shifts of ultrasonic waves can be used as autonomous damage indicators in a system for the real-time monitoring of a fracture process.

Strangeness S=−3 and S=−4 baryon-baryon interactions in relativistic chiral effective field theory

The strangeness $S=-3$ and $-4$ baryon-baryon interactions are investigated in the relativistic chiral effective field theory at leading order. First, the potentials are derived from the $S=-1$ sector assuming that the corresponding low-energy constants are related to each other via SU(3) flavor symmetry. The comparison with the state-of-the-art lattice QCD simulations, show, however, that SU(3) flavor symmetry breaking effects can not be neglected. In order to take into account these effects, we redetermine two sets of low-energy constants by fitting to the lattice QCD data in the $\Xi\Sigma$ and $\Xi\Xi$ channels respectively. The fitting results demonstrate that the lattice QCD $S$-waves phase shifts for both channels can be described rather well. Without any additional free low-energy constants, the predicted phase shifts for the ${}^3D_1$ channel and the mixing angle $\varepsilon_1$ are also in qualitative agreement with the lattice QCD data for the $S=-3$ channel, while the results for the $S=-4$ channel remain to be checked by future lattice QCD simulations. With the so-obtained low-energy constants, the $S$-wave scattering lengths and effective ranges are calculated for these two channels at the physical point. Finally, in combination with the $S=0$ and $-2$ results obtained in our previous works, we study the evolution of the irreducible representation $27$ in the baryon-baryon interactions as a function of increasing strangeness. It is shown that the attraction decreases dramatically as strangeness increases from $S=0$ to $S=-2$, but then remains relatively stable until $S=-4$. The results indicate that the existence of bound states in the $\Xi\Sigma$ and $\Xi\Xi$ channels is rather unlikely.

Interaction of Dust-Acoustic Shock Waves in a Magnetized Dusty Plasma under the Influence of Polarization Force

The interaction of dust-acoustic (DA) shock waves in a magnetized dusty plasma under the influence of nonextensively modified polarization force is investigated. The plasma model consists of negatively charged dust, Maxwellian electrons, nonextensive ions, and polarization force. In this investigation, we have derived the expression of polarization force in the presence of nonextensive ions and illustrated the head-on collision between two DA shock waves. The extended Poincaré–Lighthill–Kuo (PLK) method is employed to obtain the two-sided Korteweg–de Vries–Burgers (KdVB) equations and phase shifts of two shock waves. The trajectories and phase shifts of negative potential dust-acoustic shock waves after collision are examined. The combined effects of various physical parameters such as polarization force, nonextensivity of ions, viscosity of dust, and magnetic field strength on the phase shifts of DA shock waves have been studied. The present investigation might be useful to study the process of collision of nonlinear structures in space dusty plasma such as planetary rings where non-Maxwellian particles such as nonextensive ions, negatively charged dust, and electrons are present.