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A general asymptotic approach involving multimode long-wave approximations is illustrated by a 2D time-harmonic scalar problem for the dynamic antiplane shear of a viscoelastic coating. For the first time, a 1D equation of motion with the coefficients depending on frequency parameters is derived. The associated dispersion relation also seems to be a fresh development approximating its exact counterpart near the vicinities of all the cut-off frequencies. As might be expected, the developed formulation is not valid for short wavelength patterns. At the same time, as it is shown for a δ -type loading, it proves to be robust for various scenarios dominated by long-wave response. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper discusses some comparative analysis between the pattern of economic performances in Asia and Western Europe during 1950s-2020s through political economies perspective. The Asian and Western European economic performances are investigated through some stylized facts in the sense of economic factors. Three analyses are used to explain the general pattern of these regions. First, this study examines the pattern of GDP growth per capita during the 1950s-2020s, focusing on several countries in this region. Second, the analysis captures the pattern of linkages of economic variables in this region related to the principle of Circular and Cumulative causation (CCC) and contradiction. Third, the analysis employs a historical perspective underpinned by the results in the second analysis. This third analysis is crucial to appreciating Asia’s global economic performance and also the process of Western deterioration phenomenon through long wave, including the occurrence recession and financial crises. The institutions of globalization and neoliberalism that put the power of capital promoted a financial crisis several times during the decades of 1980s-2020. The financial crisis is depicted by contradictions in the structural linkages among economic factors in Western Europe over the period.

The transition of sea power from the battleship-dominated Royal Navy of the First World War to the carrier-dominated United States Navy of the Second is a much discussed topic in current historiography. This article investigates a small but important part of that transition, elements of which have been previously researched but where important connections have not been made and where, in current British historiography, the full picture has perhaps been hidden behind the achievements of one man – Guglielmo Marconi. The contribution of wireless to the transition of sea power had its roots in the immediate aftermath of the First World War. This research reveals that it involved a somewhat clandestine effort by the United States Navy to undermine British dominance in global communications, at that time based on submarine cables. It reveals how Britain's imperial obligations and a post-war need for greater control over their communications by Britain's colonies also contributed to undermining the Royal Navy position. By a thorough review and new interpretations of existing historiography, plus some additional archive material, this work identifies connections between geography, economics, technology and political will that were key in the United States Navy attaining a superior post-war position in wireless technology. It shows how these connections enabled the United States Navy to benefit from Marconi's discovery of the practical use of short-wave radio. [ABSTRACT FROM AUTHOR]

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

In this paper, a (2 + 1)-dimensional generalized breaking soliton system, for the interactions of the Riemann wave with a long wave, is investigated. Via the Hirota method, bilinear forms different from those in the existing literatures are derived. N -soliton solutions are constructed via the Wronskian technique. Solitons with the crest curves being curvilineal are constructed, whose shape changes with the propagation. Parallel solitons have been obtained. Directions of the soliton propagation change, and speeds of the solitons are different: The higher the amplitude of the soliton is, the faster the soliton propagates. Breathers are constructed. Solutions consisting of a lump and two solitons are derived: Two solitons propagate in the same direction and the lump occurs in the region of the interaction between the two solitons. [ABSTRACT FROM AUTHOR]

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

A solitary wave is commonly used in tsunami study for both physical and numerical models. A tsunami is categorized as a long wave which drastically changes its shape and speed when propagates in shallow water and land. In this paper, a physical model test of tsunami propagation based on Dam Break system to produce a tsunami-like wave was carried out. In a flume, finite reservoir length is set to sufficiently provide downstream length for propagation and run-up area. The downstream part is divided into two sections of bed configuration where it has flatbed as shallow water region and 1:20 of sloping beach model. The effect of the ratio of the reservoir depth to the initial downstream depth ( ) is discussed. In addition, the tsunami inundation depth and run-up in land were also investigated. For comparison of results, numerical model similar to the physical one was conducted. The numerical model was based on a set of nonlinear shallow water equation that employed second-order explicit leap-frog finite difference scheme. The use of numerical approach using shallow water equation may not yield realistic results since the wave evolution in shallow water and coastal area has not sufficiently accommodated. The comparison between the models suggested that the numerical model consistently produce slightly higher run-up than its counterpart. This was probably due to the application of shallow water equation (SWE) in the numerical model which could not entirely solve vertical convection problems, breaking waves, and turbulence-related aspects that reduced run-ups energy. A finetuning method to improve the numerical model run-ups is necessary by introducing proper artificial energy reduction mechanism in the numerical model especially at breaking condition.

An asymmetric three-layered laminate with prescribed stresses along the faces is considered. The outer layers are assumed to be much stiffer than the inner one. The focus is on long-wave low-frequency anti-plane shear. Asymptotic analysis of the original dispersion relation reveals a low-frequency harmonic supporting a slow quasi-static (or static at the limit) decay along with near cut-off wave propagation. In spite of asymmetry of the problem, the leading order shortened polynomial dispersion relation factorises into two simpler ones corresponding to the fundamental mode and the aforementioned harmonic. The associated 1D equations of motion derived in the paper are also split into two second-order operators in line with the factorisation of the shortened dispersion relation. Asymptotically justified boundary conditions are established using the Saint-Venant's principle modified by taking into account the high-contrast properties of the laminate. [ABSTRACT FROM AUTHOR]

Since the end of the expansionary period after the Second War, the world economy went through a long period of mediocre growth with a major recession in 2009 and another in 2020. This period is examined following As Time Goes By, the last contribution by Chris Freeman, with the cooperation of this co-author. As a long period of readjustment after the beginning of a structural crisis is imposed by the mismatch between the capabilities of the emerging techno-economic paradigm and the socio-institutional framework, my argument is that the duration of this transition is explained by the difficult process of replacing a successful institutional setting, that which supported the post-War expansion, by the new accumulation regime that is being constituted. Instead of most of the literature on long waves, which tries to uncover some mechanics of succession of radical technological innovations, this paper addresses different questions: how does the socio-institutional adaptation proceed, and how relevant is this process to explain the length of the downswing since the turning point of the 1970s. In order to investigate such process of readjustment, the conditions for the new rule of financial accumulation are discussed, including the forms and duration of the process of selection, reproduction, and education of the elite, and changes in institutions, norms, and social networks. [ABSTRACT FROM AUTHOR]

Aiming to obtain better topcoat appearance, the conventional procedure was adjusted. The DOI (distinctness of image), short wave, and long wave of the topcoats obtained after adding a polishing step for the whole electrodeposition coating, an extra varnish layer prior to basecoat spraying, and a wet-on-wet extra varnish respectively were compared. The effects of related operations on topcoat appearance were discussed. The optimal improvement scheme was determined as follows: spraying an extra varnish layer prior to basecoat spraying and polishing, and spraying an extra varnish layer on the original wet topcoat. [ABSTRACT FROM AUTHOR]

Meteotsunamis are long waves generated by displacement of a water body due to atmospheric pressure disturbances that have similar spatial and temporal characteristics to landslide tsunamis. NAMI DANCE that solves the nonlinear shallow water equations is a widely used numerical model to simulate tsunami waves generated by seismic origin. Several validation studies showed that it is highly capable of representing the generation, propagation and nearshore amplification processes of tsunami waves, including inundation at complex topography and basin resonance. The new module of NAMI DANCE that uses the atmospheric pressure and wind forcing as the other inputs to simulate meteotsunami events is developed. In this paper, the analytical solution for the generation of ocean waves due to the propagating atmospheric pressure disturbance is obtained. The new version of the code called NAMI DANCE SUITE is validated by comparing its results with those from analytical solutions on the flat bathymetry. It is also shown that the governing equations for long wave generation by atmospheric pressure disturbances in narrow bays and channels can be written similar to the 1D case studied for tsunami generation and how it is integrated into the numerical model. The analytical solution of the linear shallow water model is defined, and results are compared with numerical solutions. A rectangular shaped flat bathymetry is used as the test domain to model the generation and propagation of ocean waves and the development of Proudman resonance due to moving atmospheric pressure disturbances. The simulation results with different ratios of pressure speed to ocean wave speed (Froude numbers) considering sub-critical, critical and super-critical conditions are presented. Fairly well agreements between analytical solutions and numerical solutions are obtained. Additionally, basins with triangular (lateral) and stepwise shelf (longitudinal) cross sections on different slopes are tested. The amplitudes of generated waves at different time steps in each simulation are presented with discussions considering the channel characteristics. These simulations present the capability of NAMI DANCE SUITE to model the effects of bathymetric conditions such as shelf slope and local bathymetry on wave amplification due to moving atmospheric pressure disturbances. [ABSTRACT FROM AUTHOR]

As long waves propagate over an island, wave energy can be trapped in the shallow water near the coastline due to the effect of refraction and diffraction. However, in some particular situations extremely huge near-shore waves can be excited due to the resonance of edge waves. This study focuses on the occurrence condition of the resonance phenomenon, and mainly investigates the effects of geometric parameters of underwater topography around island, especially the curvature of island profile. Based on an analytical solution of long waves over an idealized circular island, resonance of long waves around islands has been investigated. The island profile is described as a function with three independent parameters. The influences of average slope and curvature of island profile on the resonance frequency and amplification factor have been discussed. It is found that not only the average slope but also the curvature parameter greatly affects the resonance frequency and amplification factor of resonance peaks. The resonance frequency shifts to lower frequency with decrease of the average slope and increase of the curvature parameter of island profile. The milder slope and larger curvature parameter are associated with a larger resonance peak and a narrower resonance bandwidth. By comparison with the existing edge wave theory, the resonance peaks are confirmed to relate to edge waves. The resonance peaks appear when the frequency of incident long wave is close to the edge wave that the perimeter of island is an integral multiple of its wave length. An approach to estimate the resonance frequency considering the curvature of island profile is given, which agrees well with the result of the complex analytical solution. • Resonance of long waves around an island is theoretically shown. • A formula to predict the resonance frequency is proposed based on edge wave theory. • The curvature of island profile has obvious influence on waves around an island. [ABSTRACT FROM AUTHOR]

Modelling of tides and tsunami waves propagation is important problem for the hydraulic engineering practice since it allows to predict characteristics of these phenomena (load, values of run up and flooding zones, propagation times to structures and so on) and to make reasonable choice of design solution for coastal structures. Numerical modeling is effective way to simulate tides and tsunami waves propagation. Results of simulations of tides and tsunami waves propagation on the basis of shallow water model are presented and analyzed in the article. It was considered explicit and implicit numerical scheme for solution of shallow water model equations, which were verified on the number of experimental results including experimental data on distribution of dam-break wave propagation on a dry and sloping bottom. It is shown that the numerical data of tides in Persian Gulf are well co-ordinated with the data of tidal tables, both on time and on level of tides in various points. Numerical results of tsunami waves propagation in the Krasheninnikov Bay and Kozmino Bay are presented at various angles of tsunami at open boundary of computed area. Numerical results of tide currents for Krasheninnikov Bay are presented for various velocities of a wind. Developed programs may be used, particular, for numerical calculations of impact characteristics of tsunami waves on structures in coastal and offshore zones according requirements of Russian normative documents.

Hydraulics resistance is commonly used to simulate or replace drag and inertia forces due to vegetation when modeling tsunami run-up. A new numerical method was proposed which was named Combined Roughness and Reflected Model (CRRM). This method accommodates the reflection process of tsunami flow by tree surfaces. A series of experimental work was performed in laboratory to verify the numerical results. The physical process of laboratory work was discussed to explain the interaction between tsunami and vegetation models. The relation of some notable parameters was reviewed for both models. The physical model verified that the deviations between the physical and the numerical model were below 20%. With such numerical method, more challenging forest layout such as zigzag arrangement can be studied more accurately. It is concluded that the zigzag arrangement of trees layout and higher density of trees were capable of reducing tsunami run-up on land significantly.

The article shows the current state of small and medium entrepreneurship in the Russian Federation. The comparison of innovation figures of business of different size in Russia and EU countries was conducted. The research was able to identify the long-term laws of the development of small and medium business in conditions of cyclic renewal of the technological base of industry and achievements that take into account such laws of supply in upgrading the system of state support. During investigation of figures of small business development it was empirically confirmed that there was a link between the level and character of innovation activity of small and medium enterprises and stages of developing a new technological structure in economy. On the basis of statistical data the role of business of different sizes was identified on phases of the long wave of economic development. The article describes the present system of state support of small and medium enterprises in the Russian Federation and shows drawbacks of such support of small and medium business and puts forward steps aimed at its improvement in conditions of necessity to form a new technological base of industry. The author substantiates the approach to the development of the system of state support of small and medium enterprises, which take into account the specific features of its development on certain stages of the long wave under the influence of renewal of the technological base of industry.

Long-wave propagation on a uniformly sloping beach is formulated as a transient-response problem, with initially stationary water subjected to an incident wave. Both the water surface elevation and the horizontal flow velocity on the slope can be represented as convolutions of the rate of displacement of the water surface at the toe of the slope with a singular kernel function of time and space. The kernel, which is typically expressed in the form of an infinite series, accommodates the dynamic processes of long waves, such as shoaling, reflection, and multiple reflections over the slope and yields exact solutions of the linear shallow water equations for any smooth incident wave. The kernel convolution can be implemented numerically by using double exponential formulas to avoid the kernel singularity. The kernel formulation can be extended readily to nonlinear dynamics via the hodograph transform, which in turn enables the instantaneous prediction of nonlinear wave properties and of the occurrence of wave breaking in the near-shore area. This general description of long-wave dynamics provides new insights into the long-studied problem. [ABSTRACT FROM AUTHOR]

We report upon a series of laboratory experiments and complementary (two-dimensional) direct numerical simulations that explore the lock release of a fixed volume of dense fluid into a two-layer density-stratified ambient. By initial condition, the lock release experiments/simulations fall into one of two categories: full-depth and partial-depth. Our particular focus is on the "tailwaters" limiting case where the lock fluid density matches that of the lower ambient layer. In either case the front speed of the advancing lock fluid is less than that of the excited interfacial disturbances. Consequently, the internal front propagates at constant speed for less time than, say, the downstream-propagating interfacial disturbance, which we term the dense gravity current (or GC1). Complementing GC1, there is an analogue flow of light ambient fluid into the lock, and this we refer to as the light gravity current (or GC2). Measured speeds for GC1, GC2 and the internal front are compared against analogue predictions from shallow water (SW) theory. From this comparison, positive agreement is noted in the case of GC1 and the internal front. Meanwhile, the speed of GC2 post reflection from the lock end wall is under-predicted by 10–20% depending on the initial depth of dense fluid within the lock. This under-prediction is believed to result from a mismatch between where the SW prediction is made (immediately following GC2 reflection from the back of the lock) and where the experimental GC2 speed is measured, usually 0.5–2.5 lock lengths downstream by which point the GC2 height has decreased due to dispersion. Although the GC1 height also undergoes a dispersive decrease in height, generally more positive agreement is noted when comparing measured and predicted gravity current heights. The distance travelled by the internal front prior to being arrested by the reflected GC2 agrees robustly with SW theory. Laboratory and DNS experiments exhibiting a thick ambient interface are also reported upon. We observe that the speed of the internal front and the downstream distance it travels at a constant speed increase with interface thickness. The insights gained from this investigation can be applied to realistic environmental flows such as nocturnal thunderstorm outflows. [ABSTRACT FROM AUTHOR]

This paper is devoted to the WKB analysis of the three coupled long wave–short wave interaction (LSI for short) equations. We consider the zero-dispersion limit of the LSI for initial data with Sobolev regularity, before the shocks appear in the limit system. For the smooth solution, the limit system is given by the two fluids equations. The split-step Fourier method is also employed to justify the numerical simulation of the small dispersion limit. [ABSTRACT FROM AUTHOR]

The research is aimed at reviewing two numerical methods for modeling the effect of coastal forest on tsunami run-up and to propose an alternative approach. Two methods for modeling the effect of coastal forest namely the Constant Roughness Model (CRM) and Equivalent Roughness Model (ERM) simulate the effect of the forest by using an artificial Manning roughness coefficient. An alternative approach that simulates each of the trees as a vertical square column is introduced. Simulations were carried out with variations of forest density and layout pattern of the trees. The numerical model was validated using an existing data series of tsunami run-up without forest protection. The study indicated that the alternative method is in good agreement with ERM method for low forest density. At higher density and when the trees were planted in a zigzag pattern, the ERM produced significantly higher run-up. For a zigzag pattern and at 50% forest densities which represents a water tight wall, both the ERM and CRM methods produced relatively high run-up which should not happen theoretically. The alternative method, on the other hand, reflected the entire tsunami. In reality, housing complex can be considered and simulated as forest with various size and layout of obstacles where the alternative approach is applicable. The alternative method is more accurate than the existing methods for simulating a coastal forest for tsunami mitigation but consumes considerably more computational time.

This study addresses the linear and nonlinear resonance of the film flow on an inclined slippery topography plate in the frame of long-wave theory. The influence of the surface tension is taken into account. The fluid flow is assumed to be steady, and confined to the limit of a small amplitude of the wall corrugation. The influence of the slip condition is the main factor in the study. The effects of various parameters on the flow properties, and the instability criteria through some numerical applications were investigated. [ABSTRACT FROM AUTHOR]

Abstract Despite the recognized impact of tidal bores on estuarine ecosystems, the large scale mechanism of bore formation in convergent alluvial estuaries is still under investigation. So far, field data exist only for a small number of estuaries, while numerical simulations employ the shallow water equations mainly focusing on the small-scale and local processes. In this work, firstly we apply the fully nonlinear weakly dispersive Serre–Green–Naghdiequations to simulate the tide propagation in a convergent estuary of idealized form, verifying that the local dispersion effects, responsible for the appearance of the secondary waves, do not influence the tidal bore onset, which only results from the large scale processes of amplification/damping and distortion of the incoming wave. In a second part, we numerically investigate (225 runs) the estuarine parameter space in order to identify the physical conditions that lead to tidal bore generation. In this parameter space, we determine a critical curve which divides estuaries according to tidal bore occurrence. As a result of this investigation we have shown that bore formation is controlled by the competition between two physical processes: (a) the knee-shaped distortion of the tidal wave, with flood dominance and eventually bore inception; (b) the dissipation of the tidal wave, which is unfavorable to bore formation. We also provide evidence that amplification due to topographic convergence is not a necessary condition for tidal bore generation and that there exist estuaries which display both wave damping and bore development. Finally, the validity of the results has been also assessed in the presence of freshwater river discharge, showing that for low river discharge, its effect on estuarine dynamics can be neglected. [ABSTRACT FROM AUTHOR]

An experimental study is conducted using a pneumatic long-wave generator (also known as a Tsunami Generator). Scaled tsunami waveforms are produced with periods in the range of 5–230 s and wave amplitudes between 0.03 and 0.14 m in water depths of 0.7–1.0 m. Using Froude similitude in scaling, at scale 1:50, these laboratory waves are theoretically dynamically equivalent to prototype tsunami waveforms with periods between 1 and 27 min and positive wave amplitude between 1.5 and 7.0 m in water depths of 50 m. The purpose of these tests is to demonstrate that the pneumatic method can generate long waves in relatively short flumes and to investigate their runup. Standard wave parameters, (free-surface, wave celerity and velocity profiles) are used to characterise the waveforms. It is shown that for the purpose of runup and onshore ingression, minimal interference from the re-reflected waves is observed. By generating tsunami waveforms with periods greater than ≈ 80 s ( ≈ 9.5 mins prototype scale) the available experimental data set is expanded and used to develop a new runup equation. Contrary to the shorter waves, shoaling of these longer waves is insignificant. For waveforms with periods greater ≈ 100 s the runup is best described by wave steepness not potential energy. When tested against available runup equations the results are mixed; most perform poorly for scaled tsunami length periods. A segmented regression analysis is performed on the data set and an empirical runup relationship is provided based on a new parameter termed the ‘Relative Slope Length’. The tests show the definition of offshore wave amplitude is non-trivial and may greatly affect the predicted relative runup of a given wave. It is noted that this appears to be a general issue for all types of tsunami simulation in the laboratory. Together these observations and proposed runup model provide a framework for future numerical studies of the topic. [ABSTRACT FROM AUTHOR]

In this work, formulas for the reflection and transmission coefficients of linear long water waves propagating along a slender harbour composed of an asymmetric convergent/divergent region connected to uniform inlet and outlet regions are obtained. The governing equation is solved using the Wentzel-Kramers-Brillouin singular perturbation technique. A better sheltering function of the harbour is found for a divergent harbour with asymmetric variations in width. For convergent harbours, the largest values of the reflection coefficient are obtained for the limit in which the length of the harbour is of the same order of magnitude as the wavelength. A zero-reflection phenomenon occurs for a convergent symmetric harbour with a linearly varying width and a parabolic depth profile. The results reveal that in the presence of a linear transition in either width or depth, the reflection coefficients exhibit oscillating behaviour. The present mathematical model is compared with a simple numerical solution and with another analytical solution expressed in terms of Bessel functions. The formulas are also checked by considering an energy identity, which is satisfied to very good accuracy. Therefore, the deduced formulas can serve as a preliminary means of identifying which harbour geometries can significantly amplify or attenuate the amplitudes of water waves. [ABSTRACT FROM AUTHOR]

A debate exists in literature between the Goldstein's theory that Kondratieff-waves (K-waves) or Long Waves (LWs) are linked to hegemonic wars occurring in the final phase of ascending long cycles and studies that do not support this pattern. However, current theoretical frameworks have trouble explaining the sources of LWs with comprehensive and consistent arguments. This study proposes a theory that LWs are due to structural change of warfare that generates huge demand-side effects and powerful supply-side effects to support the evolution of General Purpose Technologies (GPTs) and clusters of innovation. In particular, the analysis here seems to reveal a sequential historical process that runs from wars performed by great powers, occurring in phases of instability of LWs (peak and/or trough), to GPTs and clusters of innovation in the trough of K-waves, which trigger the upward phase of new K-waves. Overall, then, the theory here can be useful for bringing a new perspective to explain, whenever possible one of the general sources of the evolution of LWs, rooted-in-war, that generates technological and economic change in society. [ABSTRACT FROM AUTHOR]

Vertical track irregularities over viaducts in high-speed rail systems could be possibly caused by concrete creep if pre-stressed concrete bridges are used. For bridge spans that are almost uniformly distributed, track irregularity exhibits a near-regular wave profile that excites car bodies as a high-speed train moves over the bridge system. A long-wavelength irregularity induces low-frequency excitation that may be close to the natural frequencies of the train suspension system, thereby causing significant vibration of the car body. This paper investigates the relationship between the levels of car vibration, bridge vibration, track irregularity, and the train speed. First, this study investigates the vibration levels of a high-speed train and bridge system using 3D finite-element (FE) transient dynamic analysis, before and after adjustment of vertical track irregularities by means of installing shimming plates under rail pads. The analysis models are validated byin situmeasurements and on-board measurement. Parametric studies of car body vibration and bridge vibration under three different levels of track irregularity at five train speeds and over two bridge span lengths are conducted using the FE model. Finally, a discontinuous shimming pattern is proposed to avoid vehicle suspension resonance. [ABSTRACT FROM PUBLISHER]

We solve the nonlinear shallow water-wave equations over a linearly sloping beach as an initial-boundary value problem under general initial conditions, i.e., an initial wave profile with and without initial velocity. The methodology presented here is extremely simple and allows a solution in terms of eigenfunction expansion, avoiding integral transform techniques, which sometimes result in singular integrals. We estimate parameters, such as the temporal variations of the shoreline position and the depth-averaged velocity, compare with existing solutions, and observe perfect agreement with substantially less computational effort. [ABSTRACT FROM AUTHOR]

The study of internal waves has become important because they are associated with the energy transfer mechanism across continental shelf edges. In addition, they also can cause strong localized departures from the surrounding ocean conditions, resulting in increased shear stresses on underwater structures and large variations in acoustic transmission properties of the ocean. Therefore, the internal waves cause problems in many areas such as offshore oil recovery, acoustic propagation in the ocean, and deep water outfall. Hence, this paper is conducted to study the two-layer long-waves propagation through submerged humps using analytical solution. Equation involved in this study are mild slope equation and the methods involve are separation of variables and a series solution. In this study the effect of the geometry of the hump when water waves propagating through the humps are also studied. Besides, the density ratio also give significance effect to the surface wave elevation. An analytical solutions obtained in this study is useful in reviewing applications and condition of the wave amplitude on submerged hump. [ABSTRACT FROM AUTHOR]

A new instrument has been setup at the Centre de Recherche Public-Gabriel Lippmann to measure spectral emissivity values of typical earth surface samples in the 8 to 12 μm range at a spectral resolution of up to 0.25 cm−1. The instrument is based on a Hyper-Cam-LW built by Telops with a modified fore-optic for vertical measurements at ground level and a platform for airborne acquisitions. A processing chain has been developed to convert calibrated radiances into emissivity spectra. Repeat measurements taken on samples of sandstone show a high repeatability of the system with a wavelength dependent standard deviation of less than 0.01 (1.25% of the mean emissivity). Evaluation of retrieved emissivity spectra indicates good agreement with reference measurements. The new instrument facilitates the assessment of the spatial variability of emissivity spectra of material surfaces—at present still largely unknown—at various scales from ground and airborne platforms and thus will provide new opportunities in environmental remote sensing.

We studied the influence of the topography on the oceanic response to a traveling atmospheric disturbance and the relevance of its propagation direction on the generation of seiche oscillations. A primitive equation ocean model was used to analyze the response of two harbors located in insular systems to a pressure disturbance. The spectral component at the frequency of fundamental harbor resonance was determined from these data for different propagation directions of the incoming atmospheric disturbance. A conceptual model of interferences of resonantly generated ocean waves was introduced in order to explain energy maxima obtained by the numerical model close to the most affected areas.

The transformation of long water waves arriving at a sloping beach is investigated. An approximate theory is presented for plane periodic waves propagating in water of non-uniform depth. The theoretical description of the phenomenon, based on certain kinematic assumptions, is formulated in the material variables, and the solution is constructed by applying the Hamilton variational principle. In order to assess the accuracy of the formulation and to learn more about long wave transformation, experimental measurements were carried out in a laboratory flume. In the experiments, a water wave, generated by a piston-type wave maker placed at one end of the flume, propagated towards a rigid inclined ramp installed at the other end of the flume. The wave transformation along the direction of its propagation was recorded by a set of wave gauges installed along the flume. The wave run-up on the sloping beach was measured with a special conductivity gauge placed alongside the ramp. Comparison of the theoretical results with experimental data indicates that the proposed theoretical formulation provides a good description of the main features of wave transformation behaviour over a sloping beach, except in the vicinity of the shore point, where some discrepancies occur.

The development, testing, and implementation of a real-time tsunami forecast model, the method of splitting tsunami (MOST), is described. MOST is now used as an operational forecast model for the National Oceanic and Atmospheric Administration's TsunamiWarning System, and as a tsunami hazard assessment tool in the United States and in many countries around the world. Every step in the development of MOST marked new scientific challenges, improvements of technological and computational capabilities, and new demands of the engineering and hazard mitigation communities for applied and benchmark modeling tools for tsunami hazard assessment. [ABSTRACT FROM AUTHOR]

We consider the displacement of one fluid by a second immiscible fluid through a long, thin permeable channel whose thickness and permeability decrease away from the axis of the channel. We build a model that illustrates how the shape of the fluid-fluid interface evolves in time. We find that if the injected fluid is of the same viscosity as the original fluid, then the cross-channel variations in permeability and thickness tend to focus the flow along the centre of the channel. If the viscosity of the injected fluid is smaller than the original fluid, then this flow focusing intensifies, leading to very poor sweep of the original fluid in the system, with the injected fluid bypassing much of the channel. We also show that if the viscosity ratio of the injected fluid to the original fluid is sufficiently large, then a blunt nose may develop at the leading edge of the injected fluid, whereas the remainder of the fluid-fluid interface becomes stretched out along the edges of the channel. This leads to a much more efficient sweep of the original fluid from the channel. We generalize the model to illustrate how buoyancy forces and capillary pressure affect the evolution of the system and compare our model predictions with some simple laboratory experiments. This partial stabilization of a fluid interface in a channel of non-uniform width represents a generalization of the classical Saffman- Taylor instability, and our nonlinear solutions for the evolution of the interface highlight the importance of cross-channel variations in permeability and thickness in modelling flow in channelled reservoirs. [ABSTRACT FROM AUTHOR]

Experimental studies on tsunami are carried out since many years, most of them by generating solitary waves with a piston type wave maker. However, today it is more and more appreciated that these kinds of waves actually do not represent a real tsunami very well, as particularly for the shallow waters at the coast the wave length becomes comparably far too short. Recently new generation methods for scaled down real tsunami experiments were suggested, as it was doubted that sufficiently long waves could be generated with a classical wave maker. The present paper shall disprove these arguments by providing results of a study carried out in the Large Wave Flume (Großer Wellenkanal, GWK), where waves of periods between 30 s and more than 100 s at 1 m water depth were successfully generated with a piston type wave maker. Results for elongated solitary waves, trough led N-waves and real tsunami records as a combination of a different number of general solitons (sech 2 waves) are presented. Finally, the requirements and limitations to bring a “real” tsunami into the laboratory are discussed. [ABSTRACT FROM AUTHOR]

Park, J.H.; Yoo, C.I. and Yoon, H.S., 2016. Use of groundwater-table to establish a buffer zone In a barrier Island, Nakdong river estuary, South Korea. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 113-117. Coconut Creek (Florida), ISSN 0749-0208. A barrier island works as a buffer zone against wave and tidal forces, especially in river estuaries. To quantitatively analyze the buffer zone mechanism, understanding the wave, tide precipitation and groundwater-table by using long-term field observation is necessary. This study presents a coastal buffer zone mechanism in a barrier island (Jinudo) of the Nakdong river estuary in Busan, South Korea. For establishing a coastal buffer zone in a barrier island, we measured the groundwater at five observation points for 26 months from March 2012 and obtained wave and tidal data from a national observation station near the river mouth. We constructed a wave transformation numerical model and extracted breaking wave conditions, and then we compared data from the numerical model with a real-time groundwater data. According to the results, the buffer zone maximized up to 166.3 m from the shoreline with a wave height and period of 0.05 m and 12 sec, respectively, for 8 hours. Considering seawater infiltration, the buffer zone was observed to reduce to 125.0 m. The critical values are likely to define a coastal protection zone and vegetation distribution characteristic. [ABSTRACT FROM AUTHOR]

The paper starts by reviewing some recent contributions on long waves, arguing that the present technological revolution in ICT is part of the broad phenomenon of a newlong wave. It follows that the main focus of economic policy should be to support the diffusion of the new technology and to favour the institutional changes required by such an objective. Four broad guidelines are suggested: i) a Keynesian policy for demand going beyond the straitjacket of the Maastricht criteria and improving the income distribution in favour of employees; i) a policy to re-establish the primacy of productive capital through systematic concerted open market operations to regulate financial liquidity; iii) a reconstruction of the employment relationship that preserves the essential features of the "European social model" and a targeted flexibility of labour, that contrasts with the neoclassical all-out market flexibility; and iv) a regime for intellectual property rights that avoids the drawbacks--both ethical and economic--of current US practices.

Long waves are amplified as short-wave groups shoal and break over reefs, therefore, having significant impacts on coastal inundation, structure stability, and sediment transport. This study investigated the cross-reef variation of long-wave energy exchange with short-wave group over a reef using fully nonlinear analysis of simulation results by the non-hydrostatic model SWASH. The objective was to elucidate the mechanisms of long-wave transformation under nonlinear short-wave group forcing over a reef, and to assess the consequences of simplifications in linear and weakly nonlinear analyses in this problem. The energy transfer between short and long waves is the work done by radiation stress on long-wave velocity. Unlike conventional linear and weakly nonlinear analysis, the Stokes transport and long-wave modulation of local water depth are included in the fully nonlinear analysis. It was found that only the long-wave energy flux gradient given by the fully nonlinear analysis was balanced by the work done by wave radiation stress over a shallow reef. The fully nonlinear analysis showed that strict mass conservation has to be used to extract long wave velocity properly. In contrast, in linear and weakly nonlinear analysis, the long-wave velocity is extracted from single-point velocity measurements. The fully nonlinear analysis demonstrated that the generation and growth of incoming breakpoint-forced long waves overcame the dissipation of bound long waves in the surf zone, leading to amplification of incoming long-wave energy flux. This phenomenon occurred even when short waves mainly broke over the horizontal reef flat with large submergence, indicating that long-wave evolution is not locally controlled but dependent on wave spatial evolution history. Outgoing breakpoint-forced long waves were dissipated considerably during de-shoaling over the forereef due to substantial energy transfer to incoming short waves, though both of them are free waves. The consistent phase coupling between outgoing long waves and incoming short-wave groups at all frequencies was found to be the primary driving mechanism for the energy transfer. According to the fully nonlinear analysis, the reef-flat submergence may affect the long wave in a complex fashion, i.e. , reducing the submergence may enhance the energy transfer from short waves to long waves or suppress long-wave growth by increasing its frictional dissipation at the same time. • Long-wave energy balance is achieved with fully nonlinear analysis. • Strict mass conservation has to be used to extract long-wave velocity properly. • Long wave amplitude is dependent on short-wave spatial evolution history. • Radiation stress does positive work on incoming long waves in surf zone. • Free outgoing long waves transfer energy to incoming short waves in shoaling zone. [ABSTRACT FROM AUTHOR]

Longwave response in a reef-lagoon bathymetry adjacent to a shore is studied by performing a series of numerical experiments. We consider the problem such that the length scale of the lagoon is comparable to the reef. A series of offshore reefs is formed periodically in the alongshore direction, parallel to the shoreline; adjacent reefs are separated with aperture channels. We impose cnoidal waves for the incident longwave train with the length scale comparable to the reef and lagoon dimensions. Our results reveal that the incident waves amplify in the region behind the reef, and attenuate in the region directly exposed to the aperture; the resulting variation of wave amplification along the shore is found to be substantial. This somewhat counterintuitive outcome is caused by a combination of diffraction and refraction of the long waves interacting with the reef-lagoon bathymetry of comparable length scale. We also found that the pattern of the offshore wavefield may not identify the reef bathymetry characteristics; it is because the pattern of offshore wave formation is influenced by a complex combination of wave reflection from the reef-lagoon system. The induced residual currents are also examined. The results show that notable offshore-directed residual currents are formed in the aperture channel only when the reef height is high with respect to the ambient water depth and when the aperture width is narrow compared with the reef's alongshore breadth. Otherwise, the residual currents in the onshore direction are formed, although the magnitude is very small. It is demonstrated that the residual currents are induced by a combination of the gradients of the mean water surface and the time average of horizontal momentum flux. • Substantially amplified runup directly behind the reef and attenuated runup in the area exposed to the aperture channel. • Difficult to characterize the reef formation from the offshore wave field. • Notable residual currents through the aperture channel only when the reef height is higher than one-half the water depth. [ABSTRACT FROM AUTHOR]

Wave-induced pore pressure in the seabed may cause seabed liquefaction and lead to geohazards such as submarine landslides. Under natural conditions, waves generally consist of different components with various frequencies, and the seabed response to each wave component can vary considerably. However, little is known concerning these differences. In this study, a series of flume experiments were conducted to investigate the pore pressure responses in a silty seabed to various components of random waves. According to the experimental results, the short wave (SW) component had high energies, but the SW-generated high-frequency hydrodynamic pressure (HF p0) decayed rapidly in the seabed. The long wave (LW) component had low energies, but the LW-generated low-frequency hydrodynamic pressure (LF p0) was effectively propagated in the seabed. The transmittance coefficient of the low-frequency pore pressures (LF p) was two times that of the high-frequency pore pressures (HF p). The energy ratio of LF p /HF p was enhanced with increasing soil depth, and the energy of LF p was greater than that of HF p at soil depths ≥15 cm, indicating that the contribution of LWs to the cumulative pore pressure is enhanced with an increase in soil depth. An important implication of our findings is that the use of statistical wave parameters (e.g., significant wave height and average wave period) to determine pore pressure responses of the seabed can underestimate liquefaction risk, and in turn, lead to unsafe engineering designs. • Long wave component generates significantly stronger pore pressure. • High-frequency pore pressures propagated poorly in the seabed. • Low-frequency pore pressures readily propagated within the seabed. • Long wave component had significantly larger contribution to deep soil pore pressure. [ABSTRACT FROM AUTHOR]

Shih, R.-S. and Weng, W.-K., 2016. A study of long wave attenuation over composite undulating breakwaters. In this study, the wave attenuation of multiple impermeable sinusoidal profile breakwaters is investigated by a physical experiment conducted in a 21-m wave flume with a combination of breakwaters collocated with various widths ( w) and heights ( D). The breakwaters were arranged in different permutations and combinations (from one to three sets) on the bottom of various undulating slopes. The attenuation effect when waves propagated through the periodic-gradational undulating terrain was explored, and the optimization of various sinusoidal breakwaters was analyzed. This article discusses the properties of wave reflectance ( Kr), transmittance ( Kt), the energy loss coefficient ( KL), and the attenuation of composite terrain, including the optimal combinations of obstacles. The values of Kr, Kt, and KL were diverse because of various breakwater combinations and various wave conditions. The results indicated that the attenuation of long waves was effective and was affected by nonlinearity and dispersion. Wave decomposition occurred when a wave passed through the breakwaters; a high-frequency fluctuation appeared and dissipated the energy of long waves. The transmittance indicated that a composite of rapidly varying combinations was more favorable than a gradually varying section. Increasing the quantity of composite breakwaters also improved the attenuation effect on both the rapidly varying cases and the segmented gradually varying cases. The optimal combination required to eliminate the energy of long waves was also examined and confirmed using a solitary wave test. [ABSTRACT FROM AUTHOR]

This article identifies the differences and common features of two global crises: the Great Depression of 1929 and the international financial crisis of 2008. The circumstances of the two crises differ in terms of the demographic structure, the technological conditions, the economic and social systems in developed countries, the extent of globalization and other global economic situations. Among the common features, both crises were preceded by unprecedented economic booms, laisse-faire regulatory policies, easy monetary and credit policies, asset bubbles and yawning income gaps. Moreover, the crises had a strong redistribution effect, which would cause shifts of power among large countries and major changes in international economic order. [ABSTRACT FROM AUTHOR]

Analysis of water level and river discharge time series collected at three locations in the St. Johns River, FL reveals that subtidal variability with periods of several days is associated with long waves propagating from the ocean into the river channel. These dynamics are similar to tidal wave propagation: both tidal and subtidal frequency bands have the same ratio of free surface-to-discharge standard deviations, which is not the case on oceanic shelves. However, important differences also emerge: as waves pass through the river mouth, tidal oscillations exhibit much stronger attenuation, while subtidal oscillations propagate at a lower speed. Further upstream, where the channel cross-sectional area contracts (between Palatka and Buffalo Bluff), the waves in two frequency bands adjust differently: tidal waves are amplified and continue upstream, while a significant fraction of subtidal energy is reflected. The amplification of tidal waves occurs mostly through the generation of overtides. Also, tidal wave attenuation in the river relative to the mouth is nearly constant over the observation period, while the attenuation of subtidal waves exhibits strong changes. Variations in subtidal attenuation are linked to the influence of the river discharge: higher discharge (relative to the subtidal water level variability) causes stronger attenuation of subtidal waves. [ABSTRACT FROM AUTHOR]