Potential Wave Research Articles

Influence Of Lithospheric Scale Basement Faults On Seismicity In The Himalayan Orogenic System

The Himalayan system is the result of a continental collision that occurred approximately 55 million years ago between the Indian and Asian tectonic plates1,2. The collision resulted in the underthrust of the Indian crust beneath Asia, and a deformed crustal wedge3,4. The Indian plate records a complex pre-Himalayan geological history that includes several basement faults that reach depths of 70 kilometres and are oriented at a high angle to the Himalayan front5. These basement faults bound topographic basement highs that are interpreted to limit the rupture of Himalayan earthquakes6. Recent research suggests the basement faults control the distribution and magnitude of seismicity along the Himalaya7. 
 The Himalayan system serves as a prototype for novel three-dimensional numerical modelling to understand if and how inherited basement structures influence seismicity in orogenic settings. Models are generated using the Coreform Cubit meshing software and are run on the supercomputer platform hosted at the University of Toronto. The initial model contains three crustal blocks: the Indian crust, a deformed orogenic wedge, and the Asian crust, all cut at a high angle by a lithospheric scale basement fault. The 2015 7.9 MW Gorkha earthquake is simulated, and slip is generated along the Himalayan basal detachment. Seismograms, shear wave potential, and compressional wave potential movies are created to understand if and how the inherited basement faults influence seismicity within orogenic systems. Understanding how these regionally significant basement faults influence seismicity in the densely populated regions of northern India and Nepal is of utmost societal importance. 
 References 
 1. Najman, Y., et al., (2010). Timing of India‐Asia collision: Geological, biostratigraphic, and palaeomagnetic constraints. Journal of Geophysical Research: Solid Earth, 115. 
 2. Hodges, K. V. (2000). Tectonics of the Himalaya and southern Tibet from two perspectives. Geological Society of America Bulletin, 112(3), 324-350. 
 3. Godin, L., et al., (2019). Influence of inherited Indian basement faults on the evolution of the Himalayan Orogen, in Crustal Architecture and Evolution of the Himalayan-Karakoram-Tibet Orogen, R. Sharma, I. M. Villa, and S. Kumar, Editors, Geological Society of London Special Publication, 481, 251-276. 
 4. Chung, S.-L. et al. (2005). Tibetan tectonic evolution inferred from spatial and temporal variations in post-collisional magmatism. Earth-Science Reviews 68, 173–196. 
 5. Godin, L., & Harris, L. B. (2014). Tracking basement cross-strike discontinuities in the Indian crust beneath the Himalayan orogen using gravity data – relationship to upper crustal faults. Geophysical Journal International, 198, 198-215. 
 6. Gahalaut, V. K., & Kundu, B. (2012). Possible influence of subducting ridges on the Himalayan arc and on the ruptures of great and major Himalayan earthquakes. Gondwana Research, 21(4), 1080-1088. 
 7. Gahalaut, V, K., & Arora, B. R. (2012). Segmentation of seismicity along the Himalayan Arc due to structural heterogeneities in the under-thrusting Indian plate and overriding Himalayan wedge. Episodes Journal of International Geoscience, 35(4), 493-500.

Interaction of a Flexural-Gravity Wave with a Vertical Rigid Plate Built in a Floating Elastic Plate

The linear two-dimensional problem of interaction between an hydroelastic wave propagating along an elastic floating ice plate with built-in vertical rigid plate is studied. The fluid under the ice is inviscid and incompressible. The fluid depth is finite. The deflection of the ice plate is described by the linear theory of thin elastic plates. The flow under the ice is potential. The total velocity potential is decomposed into the potential of the incident wave, even potential caused by the vertical motion of the rigid plate, and an odd potential caused by the rotation of the rigid plate. The vertical mode method is used. The third potential is obtained by solving a mixed boundary-value problem numerically using Chebyshev polynomials. The solution is validated by analysis of its convergence. The first and second potentials, and the corresponding deflections and strains of the ice plate, are obtained analytically. The motions of the rigid plate, as well as deflection and strains in the floating plate, are numerically analyzed. It is shown that the rotation of the rigid plate due to the incident wave is the main factor of increasing strains in the ice plate.

New insights into the reactivity of the triscyclopentadienyl monothiolate uranium(IV) complexes: CS2 and CO2 insertion and redox properties. A DFT theoretical approach

The structural properties of a series of triscyclopentadienyl monothiolate uranium(IV) complexes [U(Cp)3(SR)] (Cp = η5–C5H5; R = Me (1), iPr (2), Ph (3), tBu (4)) as well as their reactions with CO2 or CS2 leading to their insertion into the US bond, have been investigated using relativistic Density Functional Theory (DFT) calculations. The computed activation barriers of these reactions show that insertion of CO2 into the US bond of the thiolate complexes is easier and faster than that of CS2, in agreement with the experimental observation. The study brings to light the electrostatic interactions and steric hindrance effects that play an important role in these processes. The redox behavior of the thiolate [U(Cp)3(SR)] complexes has also been investigated, permitting to find a very nice linear correlation (R2 = 0.99) between the computed electron affinities and the experimental reduction half–wave potentials E1/2. This correlation allowed to estimate the reduction potentials of [U(Cp)3(SMe)] (1) and [U(Cp)3(StBu)] (4) for which the electrochemical measurement failed. Several population analyses were carried out, among them Nalewajski–Mrozek Bond Orders (NMBO) and Hirshfeld charges Analysis (HA) allowing to rationalize the insertion reactions and redox processes and to highlight the driving role of the uranium 5f orbitals.

PEDOT:PSS‐bacterial cellulose bilayer actuators: From the movement of ions to deflection

AbstractHere, the role of the voltage waveform and the electrolytic ions in the actuation mechanism of Poly (3,4‐ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS)/bacterial cellulose bilayer actuator is reported. PEDOT:PSS/bacterial cellulose‐based bilayer actuator was fabricated, and its mechanism under a square and triangular wave potential at multiple frequencies was studied. The actuation was performed with HCL, KCl, and LiCl electrolytes. The deflection of the actuator was found to be dependent on the time period of the voltage waveform. The deflection for opposite biases showed frequency‐dependent asymmetry. Further, the actuator deflection was found to be related to the hydrodynamic size of cations present in electrolytes. The results indicate a cation‐dominated actuation mechanism for PEDOT:PSS/bacterial cellulose bi‐layer actuator.

Numerical investigations on seakeeping and added resistance in head waves based on nonlinear potential flow methods

A fully nonlinear potential flow (FNPF) method and a body-exact (BE) method based on the time-domain desingularized-Rankine panel (DRP) method have been developed to compute the motion responses and added resistance for ships traveling in regular head waves. In the present methods, the disturbed wave potential is separated from the incident potential, and the boundary value problem (BVP) for the disturbed potential is established in each method. To validate the present FNPF and BE methods, different hull forms are adopted, including two Wigley hulls and the S-175 containership. The results of radiation, diffraction, and free motion simulations are presented and systematically compared with the experimental data and linear solutions using the double-body (DB) and Neumann–Kelvin (NK) methods. Through comparison, we demonstrate that the present FNPF method can accurately predict the motion responses and added resistance of ships. For the ships with large flare angles, the FNPF and BE methods give better predictions of peak motion responses than those using DB and NK. In addition, the FNPF method can well predict the added resistance, and has significant advantages over the other numerical methods at high forward speed (Fn=0.3). The analyses also confirm that, compared with the heave and pitch motions, the added resistance and the total wave elevations are more sensitive to the incident wave amplitude. The dimensionless added resistance decreases with the increase of incident wave amplitude, which is mainly driven by the total wave elevations along the waterline in the bow region. As the incident wave amplitude increases, the 1st harmonic amplitudes of the heave and pitch motions and the total wave elevations in the bow region decrease, while the 2nd harmonic amplitudes increase.

Dissipation of incident wave energy by two floating horizontal porous plates over a trench type bottom

ABSTRACT This work investigates the scattering of oblique incident waves by two floating horizontal porous plates over a trench-type sea bed to study the role of different pairs of barriers in dissipating the incident wave energy. This problem is modelled based on Darcy's law for flow past a porous structure. Havelock's expansions of water wave potentials, suitable matching conditions, and the algebraic least-square method handle the boundary value problem. The role of the horizontal porous plates is studied by analysing the scattering coefficients, energy loss, hydrodynamic wave force and free surface elevation through graphs which show a periodic oscillatory pattern as a function of gap length. The study reveals that if the porous effect parameter of plates or the length of plates is increased, more energy is dissipated and the plates experience less wave force, and the free surface elevation on the lee side is decreased. The present results also signify that as compared to rigid plates, significant changes are found in wave scattering coefficients, hydrodynamic force and free surface elevation due to the consideration of one porous plate along with one rigid plate and also two porous plates, where a pair of porous plates are more effective as compared to one porous plate. The present study reveals that the scattering of water waves by two floating horizontal porous plates over uneven bottom topography plays a vital role in constructing floating structures having more staying power in harsh wave environments.

Observation of Bohm trajectories and quantum potentials of classical waves

In 1952 David Bohm proposed an interpretation of quantum mechanics, in which the evolution of states results from trajectories governed by classical equations of motion but with an additional potential determined by the wave function. There exist only a few experiments that test this concept and they employed weak measurement of non-classical light. In contrast, we reconstruct the Bohm trajectories in a classical hydrodynamic system of surface gravity water waves, by a direct measurement of the wave packet. Our system is governed by a wave equation that is analogous to the Schrödinger equation which enables us to transfer the Bohm formalism to classical waves. In contrast to a quantum system, we can measure simultaneously their amplitude and phase. In our experiments, we employ three characteristic types of surface gravity water wave packets: two and three Gaussian temporal slits and temporal Airy wave packets. The Bohm trajectories and their energy flows follow the valleys and bounce off the hills in the corresponding quantum potential landscapes.

One−Step Synthesis of a Non−Precious−Metal Tris (Fe/N/F)−Doped Carbon Catalyst for Oxygen Reduction Reactions

Advancements in inexpensive, efficient, and durable oxygen reduction catalysts is important for maintaining the sustainable development of fuel cells. Although doping carbon materials with transition metals or heteroatomic doping is inexpensive and enhances the electrocatalytic performance of the catalyst, because the charge distribution on its surface is adjusted, the development of a simple method for the synthesis of doped carbon materials remains challenging. Here, a non-precious-metal tris (Fe/N/F)-doped particulate porous carbon material (21P2-Fe1-850) was synthesized by employing a one-step process, using 2-methylimidazole, polytetrafluoroethylene, and FeCl3 as raw materials. The synthesized catalyst exhibited a good oxygen reduction reaction performance with a half-wave potential of 0.85 V in an alkaline medium (compared with 0.84 V of commercial Pt/C). Moreover, it had better stability and methanol resistance than Pt/C. This was mainly attributed to the effect of the tris (Fe/N/F)-doped carbon material on the morphology and chemical composition of the catalyst, thereby enhancing the catalyst's oxygen reduction reaction properties. This work provides a versatile method for the gentle and rapid synthesis of highly electronegative heteroatoms and transition metal co-doped carbon materials.

Impact of Different Lignin Sources on Nitrogen-Doped Porous Carbon toward the Electrocatalytic Oxygen Reduction Reaction.

Lignin is an ideal carbon source material, and lignin-based carbon materials have been widely used in electrochemical energy storage, catalysis, and other fields. To investigate the effects of different lignin sources on the performance of electrocatalytic oxygen reduction, different lignin-based nitrogen-doped porous carbon catalysts were prepared using enzymolytic lignin (EL), alkaline lignin (AL) and dealkaline lignin (DL) as carbon sources and melamine as a nitrogen source. The surface functional groups and thermal degradation properties of the three lignin samples were characterized, and the specific surface area, pore distribution, crystal structure, defect degree, N content, and configuration of the prepared carbon-based catalysts were also analyzed. The electrocatalytic results showed that the electrocatalytic oxygen reduction performance of the three lignin-based carbon catalysts was different, and the catalytic performance of N-DLC was poor, while the electrocatalytic performance of N-ELC was similar to that of N-ALC, both of which were excellent. The half-wave potential (E1/2) of N-ELC was 0.82 V, reaching more than 95% of the catalytic performance of commercial Pt/C (E1/2 = 0.86 V) and proving that EL can be used as an excellent carbon-based electrocatalyst material, similar to AL.

Ricca’s factors as mobile proteinaceous effectors of electrical signaling

Leaf-feeding insects trigger high-amplitude, defense-inducing electrical signals called slow wave potentials (SWPs). These signals are thought to be triggered by the long-distance transport of low molecular mass elicitors termed Ricca's factors. We sought mediators of leaf-to-leaf electrical signaling in Arabidopsis thaliana and identified them as β-THIOGLUCOSIDE GLUCOHYDROLASE 1 and 2 (TGG1 and TGG2). SWP propagation from insect feeding sites was strongly attenuated in tgg1 tgg2 mutants and wound-response cytosolic Ca2+ increases were reduced in these plants. Recombinant TGG1 fed into the xylem elicited wild-type-like membrane depolarization and Ca2+ transients. Moreover, TGGs catalyze the deglucosidation of glucosinolates. Metabolite profiling revealed rapid wound-induced breakdown of aliphatic glucosinolates in primary veins. Using invivo chemical trapping, we found evidence for roles of short-lived aglycone intermediates generated by glucosinolate hydrolysis in SWP membrane depolarization. Our findings reveal a mechanism whereby organ-to-organ protein transport plays a major role in electrical signaling.

Large amplitude electrostatic solitary waves in anisotropic plasma

The propagation of nonlinear ion-acoustic solitary waves (IASWs) is investigated in a magnetized anisotropic electron ion plasma with Cairns distributed electrons. The ions are warm and exhibit pressure anisotropy due to the external magnetic field. The energy integral equation for the wave potential is derived via Sagdeev approach. The effect of various physical plasma parameters (nonthermality, ion pressure anisotropy) on the characteristics of IASWs is investigated in detail. The present investigation could be of interest to space and astrophysical plasma systems having ion pressure anisotropy, for instance, in the magnetosphere and near earth magnetosheath.

Baselining Activity and Stability of ORR Catalysts and Electrodes for Proton Exchange Membrane Fuel Cells for Heavy-Duty Applications

Activity and stability of electrodes with Pt and PtCo alloy catalysts supported on high surface area carbon, hereafter to as a-Pt/C and d-PtCo/C, were evaluated for heavy-duty applications. Both catalysts had nearly identical Pt loading (50-wt% Pt on carbon and 0.25 mgPt cm−2) and had undergone thermal treatment to stabilize them by growing the average particle size to 4–5 nm. Both were subjected to 90,000 (90 k) standard accelerated stress tests (AST) cycles consisting of 0.6–0.95 V square wave potentials, 3-s hold at upper and lower potential limits in H2/N2 at 1.5 atm, 80 °C and 100% RH. Test protocols were developed to monitor the performance losses and characterize them in terms of activity for the oxygen reduction reaction (ORR), oxygen transport in the electrode and proton transport in the membrane and cathode catalyst layer. Despite the nearly double initial ORR activity, the PtCo/C electrode degraded faster due to the leaching of Co from the catalyst that had started even before the imposition of the AST potential cycles. Commensurate with Co leaching, Co poisoning of ionomer is responsible for the inferior performance of d-PtCo/C electrode at high current densities both before and after AST.

ERP components analysis of selective attention to auditory signals in meaningful or meaningless noise using adaptive correlation filter.

Open offices that make effective use of limited space and encourage dialogue, interaction, and collaboration among employees, are becoming an increasingly. However, productive work-related conversation might actually decrease the performance of other employees within earshot more so than other random, meaningless noises. On the other hands, it is well known that the Event-Related Potential (ERP) in the brain wave elicited by internal or external stimuli are related to the operation of selective attention. The present experiment was designed to determine the effects of meaningfulness of external noise on ERP in the auditory odd-ball paradigms. First, in order to decide on a template of adaptive correlation filter, multivariate analysis such as the Principal Component Analysis (PCA) for ERP components was performed. Next, performance of algorithm on adaptive correlation filter for estimating average waveform of ERPs was evaluated. Furthermore, differences in the ERP components due to the meaningfulness of external noise were examined.

Potato-derived N-doped carbon nanoparticles incorporated with FeCo species as efficiently bifunctional electrocatalyst towards oxygen reduction and oxygen evolution reactions for rechargeable zinc-air batteries

An N-doped carbon-based bifunctional catalyst (Po-FeCo-N-C) is prepared. Biomass potato is utilized a sustainable material and the OER performance of the catalyst is positively regulated. Potato is carbonized to N-doped carbon nanoparticles with the facilitation of carbon black to anchor more nitrogen, generating pyridinic N and graphitic N dominated ORR active sites. The Po-FeCo-N-C with 3:1 of Fe/Co ratio exhibits 0.830 V of ORR half wave potential and 5.19 mA cm−2 of current density in 0.1 M KOH. Meanwhile, 85 mV of improvement on OER potential is achieved with regulation of Co(OH)2, demonstrating the remarkably bifunctional catalytic activity. The rechargeable zinc-air battery of Po-FeCo-N-C outputs higher open circuit voltage, and delivers higher specific capacities, larger power densities and excellent cyclic durability. This work provides a feasible method for the preparation of nonprecious metal-based bifunctional catalyst to ORR and OER from sustainable biomass material with low cost and wide resources.

Phase properties of several nonlinear optical waves described by rational solutions

Phase plays an essential role in both classical and quantum wave dynamics, which has motivated many scientists to study the phases of many different nonlinear waves. Among those nonlinear waves, the ones described by rational solutions have been given much attention, partly because some of them can describe rogue wave dynamics. We revisit the phase of several well-known one-dimensional rational solutions and clarify that sudden phase inversion processes indeed exist for rogue waves, in contrast to the ones reported before. Moreover, we investigate the phase properties of rogue waves and rational W-shaped solitons in the Hirota and Sasa-Satsuma model, for which some high-order physical effects are considered, i.e., the third-order dispersion delayed nonlinear response and self-steeping effects. The quite distinctive phases are uncovered for the rational W-shaped solitons with similar density profiles in the two models, by limitation analysis on the underlying topological vector potentials of other related nonlinear waves. These results indicate that the underlying topological vector potentials can be used to identify the phases of nonlinear waves, especially for localized waves with abrupt phase jumps.

Ab Initio Theoretical Study of DyScO3 at High Pressure

DyScO3 is a member of a family of compounds (the rare-earth scandates) with exceptional properties and prospective applications in key technological areas. In this paper, we study theoretically the behavior of DyScO3 perovskite under pressures up to about 65 GPa, including its structural and vibrational properties (with an analysis of the Raman and infrared activity), elastic response, and stability. We have worked within the ab initio framework of the density functional theory, using projector-augmented wave potentials and a generalized gradient approximation form to the exchange-correlation functional, including dispersive corrections. We compare our results with existing theoretical and experimental published data and extend the range of previous studies. We also propose a candidate high-pressure phase for this material.

Asymptotic Formulation for the Rayleigh Wave on a Nonlocally Elastic Half-Space

This paper deals with the Rayleigh wave, propagating on a nonlocally elastic, linearly isotropic half-space, excited by a prescribed surface loading. The consideration develops the methodology of hyperbolic–elliptic models for Rayleigh and Rayleigh-type waves, and relies on the effective boundary conditions formulated recently, accounting for the crucial contributions of the nonlocal boundary layer. A slow-time perturbation scheme is established, leading to the reduced model for the Rayleigh wave field, comprised of a singularly perturbed hyperbolic equation for the longitudinal wave potential on the surface, acting as a boundary condition for the elliptic equation governing the decay over the interior. An equivalent alternative formulation involving a pseudo-differential operator acting on the loading terms, with parametric dependence on the depth coordinate, is also presented.

Unlocking the Wave's Potential: Dynamic Numeric Simulation Response of Hexagon Buoy and Ring Heave Plate in a Shared Wave Environment

Wave electricity extraction technology in advanced international locations holds to advance. One of the strategies used is a point absorber, which extracts electricity from the response of its system. The essential machine includes a floating buoy and a response management tool referred to as a heave plate. This look discusses the impact of the heave plate's floor location variant at the hydrodynamic parameters of a hexagonal-fashioned buoy (heave and pitch Response Amplitude Operator (RAO), brought mass, and radiation damping). The evaluation changed into performed the usage of the industrial software program ANSYS AQWA. The effects of the evaluation display that the presence of the heave plate at the buoy version affects the RAO values, mainly for the heave and pitch modes. Increasing the ratio of the heave plate's floor location results in a growth withinside the RAO heave price however decreases the RAO pitch price. Additionally, the presence of the heave plate influences the values of brought mass and radiation damping. The maximum ratio of heave plate location effects withinside the maximum brought mass price. This price gradually decreases because the ratio of the heave plate location decreases, and the buoy without a heave plate has the bottom price. This is reversed for the radiation damping price, wherein the best heave plate ratio corresponds to the bottom damping price. The damping price will gradually increase because the heave plate ratio decreases, with the buoy without a heave plate having the best price. The presence of the heave plate in the buoy model influences the RAO values, particularly in the observed motion modes of heave and pitch.

Time-resolved measurements of sub-optical-cycle relativistic electron beams

We propose an all-optical technique to record the time information of relativistic electron beams with sub-optical-cycle duration. The technique is based on the interaction of the electron beam with the ponderomotive potential of an optical traveling wave generated by two counter-propagating circularly polarized optical fields at different frequencies in vacuum. One of the optical pulses is a vortex laser pulse, and the other is a normal Gaussian laser pulse. The time information of the electron beam is mapped into the angular information, which can be converted into a spatial distribution after a drift section. Thus, the temporal profile and arrival time of the electron beam can be retrieved from the spatial distribution of the electron beam. The measurement has a dynamic range comparable to the period of the optical intensity grating formed by two counter-propagating laser pulses. This technique may have wide applications in many research fields that require sub-optical-cycle electron beams.

Destructive Potential of Planetary Meteotsunami Waves beyond the Hunga Tonga–Hunga Ha‘apai Volcano Eruption

Abstract Worldwide tsunamis driven by atmospheric waves—or planetary meteotsunami waves—are extremely rare events. They mostly occur during supervolcano explosions or asteroid impacts capable to generate atmospheric acoustic-gravity waves including the Lamb waves that can circle the globe multiple times. Recently, such ocean waves have been globally recorded after the Hunga Tonga–Hunga Ha‘apai volcano eruption on 15 January 2022, but did not pose any serious danger to the coastal communities. However, this study highlights that the mostly ignored destructive potential of planetary meteotsunami waves can be compared to the well-studied tsunami hazards. In practice, several process-oriented numerical experiments are designed to force a global ocean model with the realistic atmospheric response to the Hunga Tonga–Hunga Ha‘apai event rescaled in speed and amplitude. These simulations demonstrate that the meteotsunami surges can be higher than 1 m (and up to 10 m) along more than 7% of the world coastlines. Planetary meteotsunami waves thus have the potential to cause serious coastal damages and even human casualties during volcanic explosions or asteroid impacts either releasing intense acoustic energy or producing internal atmospheric gravity waves triggering the deep-ocean Proudman resonance at a speed of ∼212 m s−1. Based on records of catastrophic events in Earth’s history, both scenarios are found to be realistic, and consequently, the global meteotsunami hazards should now be properly assessed to prepare for the next big volcanic eruption or asteroid impact even occurring inland.