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Despite being known for decades the chemical reactivity of homoatomic seven‐atom phosphorus clusters towards small molecules remains largely unexplored. Here, we report that neutral tris(silyl) functionalised heptaphosphane (P7(SiR3)3) cages are capable of heteroallene capture between the P−Si bonds of the cluster. A range of isocyanates and an isothiocyanate were investigated. In the case of isocyanates, silyl bonding at oxygen or nitrogen is regioselectively directed by the functional group on the isocyanate and substituents on the silyl moiety. Above all, we find that captured isothiocyanate molecules can be exchanged for isocyanate molecules, indicative of small molecule catch and release. Small molecule catch and release at these Zintl‐derived clusters reveals their potential application as chemical storage materials or as reusable probes. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive methodology that addresses climate change–induced coastal erosion at the regional scale O (100 km). The use of climate data with high space-time resolution enabled the reconstruction of the shoreline response to cross-shore forcing both historically and throughout the twenty-first century. Cross section–based equilibrium models were combined to assess beach erosion induced by local waves, storm surge, astronomical tide and mean sea-level rise. The approach incorporates the potential impacts that tidal inlets could have on the long-term evolution of adjacent beaches as sink terms in the beaches’ budget. The methodology provides probabilistic estimates of coastline recession while accounting for sea level rise uncertainty, both of which are essential aspects for establishing adaptation priorities and efficient fund allocation. The outlined assessment was undertaken on 57 sandy beaches along a 345 km coastline stretch in Asturias, a region in the northwest of Spain open to the Atlantic. [ABSTRACT FROM AUTHOR]

This study presents the design, development, scheme and field validation of an early-alert ocean wave system. It is designed to automate, improve, analyse, design and manage the daily construction activities of any harbour at construction stage. The objective is threefold: a) maximise construction safety, with regards to well-known hazards which occur during construction, especially breakwaters that interact with high-energy sea states, b) optimise the transport, by means of specialised vessels, of the refill material, and c) to minimise the construction delay and disruption on a daily basis, thanks to short-term construction forecasting (96 h). The system, known as PATO, offers short-term sea states characteristics, at any point near harbour structures, and relevant wave-structure interaction parameters at any harbour construction stage. The system is able to assist harbour project managers by providing accurate ocean wave data through a user-friendly interface. [ABSTRACT FROM AUTHOR]

The mathematical modeling of the interaction of water waves with porous coastal structures has continuously been among the most relevant challenges in coastal engineering research and practice. Finding a tool to better predict essential processes, relevant to the functionality and stability of breakwaters and jetties, and how they are affected by permeability, has been hampered by computational limitations that are being overcome. Over the last 60 years, the Journal of Waterway, Port, Coast, and Ocean Engineering has witnessed gradual developments leading from linearized solutions based on wave theories and constant friction coefficients to very sophisticated Eulerian or Lagrangian solvers of the Navier-Stokes (NS) equations, including turbulence within porous media. Today, although not without difficulty, the first steps are being made toward addressing the simulation of a fully three-dimensional interaction of complete sea states with porous structures at prototype scale. In this paper, after posing the mathematical foundations of the problem, the solution techniques available in the literature are reviewed. Linear solutions based on potential theory; depth-integrated solutions, including Boussinesq approximations; and solutions based on the NS equations, in both the Eulerian and Lagrangian frameworks, are covered. Then, turbulence modeling on porous media is discussed. Conclusions and a discussion of future research directions close the paper. It is shown that, after so many years, some fundamental questions still remain unanswered, leaving challenges open for future research. [ABSTRACT FROM AUTHOR]

In this work the numerical model IHFOAM is extended to incorporate moving-boundary wave generation and absorption capabilities. The goal is to obtain a solver that includes free surface flow through porous media, able to replicate the wave generation procedures of physical wave basins. For this purpose a new boundary condition to mimic the action of multi-paddle piston wavemakers is developed and the dynamic mesh capabilities present in OpenFOAM ® are enhanced. A set of experiments is carried out in the laboratory and is reproduced numerically to validate the correct operation of the new module. Additional numerical experiments are carried out to test the efficiency of active wave absorption. The results indicate a high degree of accordance between the experimental and numerical results and a correct performance of active wave absorption at the moving boundary. [ABSTRACT FROM AUTHOR]

Abstract: The contribution of seagrasses to coastal protection is examined through the review of the most relevant existing knowledge. Seagrasses are the largest submerged aquatic vegetation ecosystem protected in Europe and it is worth examining their contribution to coastal protection. The review performed highlights incident energy flux, density, standing biomass and plant stiffness as the main physical and biological factors influencing the efficiency of the protection provided by seagrasses. The main conclusion achieved is that seagrass meadows cannot protect shorelines in every location and/or scenario. The optimal conditions for enhancing the protection supplied might be achieved in shallow waters and low wave energy environments, with high interaction surface, at the vertical and horizontal dimension, between water flow and seagrasses. Likewise, the most favorable protection might be provided by large, long living and slow growing seagrass species, with biomass being largely independent of seasonal fluctuations and with the maximum standing biomass reached under the highest hydrodynamic forcings. It is shown that seawater warming, increasing storms and sea level rise, together with the increasing population and anthropogenic threats in the coastal area may lead to rates of change too fast to allow seagrasses to adapt and keep their coastal defense service. Finally, to amend the decline of seagrasses and consequent coastal protection loss, different artificial and natural adaptation measures are provided. [Copyright &y& Elsevier]

Abstract: Solitary wave evolution over a shelf including porous damping is investigated using Volume-Averaged Reynolds Averaged Navier–Stokes equations. Porous media induced damping is determined based on empirical formulations for relevant parameters, and numerical results are compared with experimental information available in the literature. The aim of this work is to investigate the effect of wave damping on soliton disintegration and evolution along the step for both breaking and non-breaking solitary waves. The influence of several parameters such as geometrical configuration (step height and still water level), porous media properties (porosity and nominal diameter) or solitary wave characteristics (wave height) is analyzed. Numerical simulations show the porous bed induced wave damping is able to modify wave evolution along the step. Step height is observed as a relevant parameter to influence wave evolution. Depth ratio upstream and downstream of the edge appears to be the more relevant parameter in the transmission and reflection coefficients than porosity or the ratio of wave height–water depth. Porous step also modifies the fission and the solitary wave disintegration process although the number of solitons is observed to be the same in both porous and impermeable steps. In the absence of breaking, porous bed triggers a faster fission of the incident wave into a second and a third soliton, and the leading and the second soliton reduces their amplitude while propagating. This decrement is observed to increase with porosity. Moreover, the second soliton is released before on an impermeable step. Breaking process is observed to dominate over the wave dissipation at the porous bottom. Fission is first produced on a porous bed revealing a clear influence of the bottom characteristics on the soliton generation. The amplitude of the second and third solitons is very similar in both impermeable and porous steps but they evolved differently due to the effect of bed damping. [Copyright &y& Elsevier]

Abstract: The numerical model COBRAS-UC [Losada, I.J., Lara, J.L., Guanche,R., Gonzalez-Ondina, J.M. (2008). Numerical analysis of wave overtopping of rubble mound breakwaters. Coastal Engineering, Vol 55 (1), 47–62.] is used to carry out a two-dimensional analysis of wave induced loads on coastal structures. The model calculates pressure, forces and moments for two different cross-sections corresponding to a low-mound and a conventional rubble-mound breakwater with a crown-wall under regular and irregular incident wave conditions. Predicted results are compared with experimental information provided in Losada et al. [Losada, I.J., Lara, J.L., Guanche,R., Gonzalez-Ondina, J.M. (2008). Numerical analysis of wave overtopping of rubble mound breakwaters. Coastal Engineering, Vol 55 (1), 47–62.] and Lara et al. [Lara, J.L., Losada, I.J., Guanche, R. (2008). “Wave interaction with low mound breakwaters using a RANS model”. Ocean engineering (35), pp 1388–1400; doi:10.1016/j.oceaneng.2008.05.006.] on a 1:20 scale. Good agreement is found, and the differences between both typologies are explained in detail. Additionally, numerical results are also compared with several semi-empirical formulae recommended for design at both the 1:20 model scale and two prototype cross-sections. Results suggest that COBRAS-UC is able to provide realistic stability information that can be used to complete the approach based on currently existing methods and tools. [Copyright &y& Elsevier]

Abstract: The purpose of this work is to a present a numerical model to solve a set of modified Boussinesq equations to analyse nonlinear resonance of semi-enclosed water bodies. The equations are solved on a finite element unstructured grid in order to achieve an optimal mesh resolution with the local geometry. The model is able to simulate long time lapses and realistic forcing in real bathymetries with a reasonable computational cost. To validate the numerical results, a set of experiments was carried out in a physical model of two adjacent elongated basins. Comparisons between numerical and experimental results for different geometries and nonlinear conditions show that the model is able to simulate with an excellent agreement the transient nonlinear resonant process. [Copyright &y& Elsevier]

Abstract: The paper describes the results of a two-dimensional (2-D) numerical modelling investigation of the functionality of rubble mound breakwaters with special attention focused on wave overtopping processes. The model, COBRAS-UC, is a new version of the COBRAS (Cornell Breaking Waves and Structures) based on the Volume Averaged Reynolds Average Navier–Stokes (VARANS) equations and uses a Volume of Fluid Technique (VOF) method to capture the free surface. The nature of the model equations and solving technique provides a means to simulate wave reflection, run-up, wave breaking on the slope, transmission through rubble mounds, overtopping and agitation at the protected side due to the combined effect of wave transmission and overtopping. Also, two-dimensional experimental studies are carried out to investigate the performance of the model. The computations of the free surface and pressure time series and spectra under regular and irregular waves, are compared with the experimental data reaching a very good agreement. The model is also used to reproduce instantaneous and average wave overtopping discharge. Comparisons with existing semi-empirical formulae and experimental data show a very good performance. The present model is expected to become in the near future an excellent tool for practical applications. [Copyright &y& Elsevier]

Abstract: A description of the progress achieved within DELOS (environmental DEsign of LOw-crested coastal defence Structures) EU project in the modelling of wave interaction with low-crested structures (LCS) is presented in this paper. Emphasis is put on the description of the near-field flow, especially the velocity and turbulence distribution around and inside LCS, as required by other researchers in the project. Two-dimensional (VARANS) and three-dimensional (LES) numerical modelling has been considered. The two-dimensional model has been extensively validated with DELOS laboratory data as shown in Garcia et al. [Garcia, N., Lara, J.L., Losada, I.J., 2004. 2-D Numerical analysis of near-field flow at low-crested breakwaters. Coastal Engineering, ELSEVIER, 51 (10) 991–1020.]. A system of flow recirculation is included in both the experimental and numerical set-ups for a correct description of the 2DV velocity field in the vicinity of the structure. Further validation is presented in this paper. Laboratory tests on two values of crest width have been simulated in order to analyse relevant near-field flow features related to a variation of the geometric configuration of the structure. The width of the breakwater crest is seen to significantly influence the wave breaking-induced flow pattern at the structure. Magnitudes such as turbulent kinetic energy (TKE), TKE dissipation rate, shear stresses and Reynolds stresses are computed around and inside the breakwater. The three-dimensional model numerical results are compared with results of wave basin experiments, showing a good agreement for instantaneous free surface. Numerical results of the flow over the breakwater and around the breakwater head are also presented. [Copyright &y& Elsevier]

In this work, a model for wave transformation on vegetation fields is presented. The formulation includes wave damping and wave breaking over vegetation fields at variable depths. Based on a nonlinear formulation of the drag force, either the transformation of monochromatic waves or irregular waves can be modelled considering geometric and physical characteristics of the vegetation field. The model depends on a single parameter similar to the drag coefficient, which is parameterized as a function of the local Keulegan–Carpenter number for a specific type of plant. Given this parameterization, determined with laboratory experiments for each plant type, the model is able to reproduce the root-mean-square wave height transformation observed in experimental data with reasonable accuracy. [Copyright &y& Elsevier]

A simple and innovative method to solve explicitly the dispersion equation for water waves over dissipative media is presented. The roots of this equation are themselves complex and difficult to obtain by standard numerical methods. A general structure for the dispersion relation is given, the dimensionless wave number, x, depending on the value of a dissipation parameter, φ, which is a function of the dissipative medium. Based on the hypothesis that a small perturbation in the dissipation parameter, δφ, produces a small variation in the dimensionless wave number, δx, a simple approach is proposed to calculate explicitly in an iterative manner the complex roots. The new method improves upon the unreliability of standard numerical schemes in the calculation of the roots in dissipative media. [Copyright &y& Elsevier]

A new probability density function (pdf) for the transformation of depth-limited wave height distributions is presented. Assuming the bore approach for modeling the energy dissipation in the inner surf zone to be valid, an analytical expression for the transformation of wave height distribution including shoaling and breaking on a planar beach is obtained. The resulting expression for the pdf is formulated with a single function and only one shape parameter, which is calibrated as a function of the local root-mean-square (rms) wave height-to-water depth ratio and the local Iribarren number. The transformed pdf is able to reproduce the shape of field and laboratory measured wave height histograms and the sharp change in the shape of the wave height distribution in depth-limited breaking conditions for low exceedance probability. Results show that the theory is appropriate to represent wave height distribution transformation over shallow foreshores or in the surf zone. Alternatively, a combination of the new model with existing state-of-the-art wave energy propagation models allows the complete definition of the wave height distribution transformation on a planar beach. [Copyright &y& Elsevier]

Presents information on a study which analyzed the influence of wave reflection and energy dissipation induced by a permeable submerged breakwaters on second-order mean quantities. Methodology of the study; Results and discussion on the study; Conclusions.

Presents information on a study which obtained an analytical solution for waves propagating through a horizontal porous plate of finite thickness. Formulation of the problem; Extension to irregular waves; Interaction of a wave group with the horizontal porous plate; Results.

Despite being known for decades, the solution-state molecular chemistry of heptapnictogen ([Pn7]3−; Pn = P, As) clusters is not well established. Here we study heavy element derivatives of tetrel functionalized heptapnictogen clusters towards heteroallene capture, specifically isocyanates, an isothiocyanate and CO2 are probed. Clusters (Me3Ge)3P7 (1), (Et3Ge)3P7 (2), (nBu3Sn)3P7 (3), and (Me3Si)3As7 (4) were all found to capture isocyanates between all three of their tetrel–pnictogen bonds. In the case of phenyl isocyanate insertion, tetrel coordination at the isocyanate nitrogen atoms is preferred, while in the case of p-toluenesulfonyl isocyanate insertion, tetrel coordination at oxygen is preferred. Furthermore, the reaction of (Me3Si)3P7 with CO2 gave NMR spectra consistent with the capture of the greenhouse gas. Heteroallene insertion at these clusters was also studied using density functional theory. [ABSTRACT FROM AUTHOR]

Mono‐ and bis‐salen functionalised [2]rotaxanes have been synthesised from the esterification of [2]rotaxanes containing phenol‐terminated threads (salen=N,N′‐bis(salicylidene)ethylenediamine). The [2]rotaxanes have general formula [RH][Cr7NiF8(O2CtBu)16], where [RH]+ is a thread with a central secondary ammonium site that templates a [Cr7NiF8(O2CtBu)16]− ring. The threads are terminated at one or both ends by carboxylic acid functionalised salen groups. The {M(salen)} groups can be free‐base [M=(H+)2] or metallated [M=Cu2+, Ni2+, (VO)2+]. The [2]rotaxanes have been characterised by single crystal XRD and solid‐ and solution‐state EPR spectroscopy. Where two paramagnetic M ions are involved [M=Cu2+ and/or (VO)2+] the [2]rotaxanes contain three electron spin S=1/2 ${{ 1/2 }}$ centres, since the {Cr7Ni} ring has an S=1/2 ${{ 1/2 }}$ ground state which is well isolated at low temperatures. These three‐spin [2]rotaxanes have been characterised in solution by pulsed dipolar EPR spectroscopies (DEER, also known as PELDOR, and RIDME). The M⋅⋅⋅M and M⋅⋅⋅{Cr7Ni} interactions measured are consistent with dipolar interactions and also with the distances from single crystal XRD. The authors declare no competing financial interest. [ABSTRACT FROM AUTHOR]

In the design of dynamic supramolecular systems used in molecular machines, it is important to understand the binding preferences between the macrocycle and stations along the thread. Here, we apply 1H NMR spectroscopy to investigate the relative stabilities of a series of linear alkylammonium templated pseudorotaxanes with the general formula [H2NRR'][Cr7CoF8(O2CCH2tBu)16] by exchanging the cation in solution. Our results show that the pseudorotaxanes are able to exchange threads via a dissociative mechanism. The position of equilibrium is dependent upon the ammonium cation and solvent used. Short chain primary ammonium cations are shown to be far less favourable macrocycle stations than secondary ammonium cations. Collision‐induced dissociation mass spectrometry (CID‐MS) has been used to look at disassembly of the pseudorotaxanes in a solvent‐free environment and stability trends compared to those in acetone‐d6. The energy needed to induce 50 % of the precursor ion loss (E50) is used and shows a similar trend to the equilibria measured by NMR. The relative stabilities of these hybrid inorganic‐organic pseudo‐rotaxanes are different to those of host‐guest compounds involving crown ethers and this may be valuable for the design of molecular machines. [ABSTRACT FROM AUTHOR]

Reduction of copper(II) chloride using sodium ascorbate in the presence of pure sodium 5-nitro-tetrazolate (NaNT) forms copper(I) 5-nitrotetrazolate – a known initiatory explosive (DBX-1) – and the novel mixed-ligand copper(I) chloride 5-nitrotetrazolate coordination polymer Cu3Cl(N4C-NO2)2, as well as mixtures of both. The reaction is controlled by the presence of seed crystals and transition metal compounds other than CuCl2. Cu3Cl(N4C-NO2)2 is obtained as a wine-red, air stable, water-insoluble, crystalline and highly sensitive explosive material with a greater crystal density, lower thermal stability and a higher sensitivity toward hydrolysis and shock than DBX-1. Efforts to obtain the stable and pure starting material are improved by crystallisation of NaNT as a tetrahydrate. Cu3Cl(N4C-NO2)2 and Na(H2O)4(NT) were characterised by single crystal and powder XRD, IR spectroscopy, magnetic and thermal measaurements, elemental analysis, particle size measurements, mass spectrometry, and by drop weight testing. [ABSTRACT FROM AUTHOR]

A synthetic strategy is demonstrated to prepare two distinct trimers of antiferromagnetically coupled {Cr7Ni} rings, substantially varying the magnetic interactions between the spin centres. The interactions were studied using multi‐frequency cw EPR: in a trimer linked via non‐covalent H‐bonding interactions no measurable interaction between rings was seen, while in a trimer linked via iso‐nicotinate groups isotropic and anisotropic exchange interactions of +0.42 and −0.8 GHz, respectively, were observed. The latter are the same as those for a simpler hetero‐dimer system, showing how the spin‐spin interactions can be built in a predictable and modular manner in these systems. [ABSTRACT FROM AUTHOR]

We present conductivity data for a newly synthesised metal–organic framework FeQ, Fe(C14H6O4).H2O demonstrating significant electronic transport. The electrical conductivity of the material is expected to be through the π–π interaction of the ligand-quinizarin and is measured to be 1.73 × 10−2 Scm−1. Its potential role as supercapacitor electrodes is discussed. [ABSTRACT FROM AUTHOR]

Global wave hindcasts provide wave climate information for long time periods which helps to improve our understanding of climate variability, long term trends and extremes. This information is extremely useful for coastal studies and can be used both directly or as boundary conditions for regional and local downscalings. This work presents the GOW2 database, a long-term wave hindcast covering the world coastline with improved resolution in coastal areas and along ocean islands. For developing the GOW2 hindcast, WAVEWATCH III wave model is used in a multigrid two-way nesting configuration from 1979 onwards. The multigrid includes a global grid of half degree spatial resolution, specific grids configured for the Arctic and the Antarctic polar areas, and a grid of higher resolution (about 25 km) for all the coastal locations at a depth shallower than 200 m. Available outputs include hourly sea state parameters (e.g. significant wave height, peak period, mean wave direction) and series of 3-h spectra at more than 40000 locations in coastal areas. Comparisons with instrumental data show a clear improvement with respect to existing global hindcasts, especially in semi-enclosed basins and areas with a complex bathymetry. The effect of tropical cyclones is also well-captured thanks to the high resolution of the forcings and the wave model setup. The new database shows a high potential for a variety of applications in coastal engineering. [ABSTRACT FROM AUTHOR]

A three dimensional numerical approach based on IHFOAM to study the interaction of tsunami waves with mangrove forest is presented. As a first approximation, the problem is modelled by means of solitary waves impinging on emergent rigid cylinders. Two different conceptual approaches are implemented into IHFOAM. Solving the URANS equations provides a direct simulation of the flow field considering the actual geometry of the array of cylinders. A modified version of the volume-average URANS equations by introducing a drag force to model the momentum damping created by the cylinders is used in the second approach. Both the direct and macroscopic simulations are validated against laboratory experiments for wave damping with very high agreement. A large set of numerical experiments to analyse flow parameters and uniform and random cylinder array distributions are analysed and use to compare pros and cons of the different approaches. Large differences are found in the forces exerted on the vegetation for uniform and random distributions. Generalizations obtained from uniform arrangements could lead to underestimation of wave-exerted forces, especially for low dense configurations. Wave forces calculated with the macroscopic approach by means of the drag coefficient yields clear underestimations. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive methodology for the reanalysis, characterization and propagation of wave bound infragravity waves (1/300 Hz to 1/30 Hz) in the nearshore. A deep water short wave reanalysis has been modified analytically to include the energy input associated with infragravity waves (full spectrum), through the decomposition and energy balance of the radiation stress of waves in deep water. A hybrid clustering-numerical wave propagation downscaling technique was used, forced by the modified full wave spectra previously obtained, resulting in hourly series of high spatial resolution nearshore ocean waves, including short and bound long waves. The methodology has been applied to the northern coast of Spain and validated by comparing buoy and pressure gauge records in the coast, for short wave (agitation) and infragravity wave (resonance) responses in open harbours, with very satisfactory results. [ABSTRACT FROM AUTHOR]

A [2]rotaxane was produced through the assembly of a picolinaldehyde, an amine, and a bipyridine macrocycle around a CuI template by imine bond formation in close-to-quantitative yield. An analogous [3]rotaxane is obtained in excellent yield by replacing the amine with a diamine, thus showing the suitability of the system for the construction of higher order interlocked structures. The rotaxanes are formed within a few minutes simply through mixing the components in solution at room temperature and they can be isolated through removal of the solvent or precipitation. [ABSTRACT FROM AUTHOR]

A [2]rotaxane was produced through the assembly of a picolinaldehyde, an amine, and a bipyridine macrocycle around a CuI template by imine bond formation in close-to-quantitative yield. An analogous [3]rotaxane is obtained in excellent yield by replacing the amine with a diamine, thus showing the suitability of the system for the construction of higher order interlocked structures. The rotaxanes are formed within a few minutes simply through mixing the components in solution at room temperature and they can be isolated through removal of the solvent or precipitation. [ABSTRACT FROM AUTHOR]

We report a method for routine crystal structure determination on very small (typically 0.1 mg or less) amounts of crystalline material using powder X-ray diffraction data from a laboratory-based single-crystal diffractometer. The solved structures span a wide range of molecular and crystallographic complexity. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents laboratory and numerical simulations of run-up induced by irregular waves breaking on a gentle-sloping planar beach. The experimental data are well reproduced by a numerical model based on the nonlinear shallow water equations. By extending the incoming wave conditions considered in the laboratory experiments, the model is applied to study the run-up variability under highly energetic incoming conditions. The numerical results support the idea that, for cases characterized by the same incident peak frequency, infragravity run-up increases almost linearly with the offshore significant wave height. Moreover, the most energetic conditions lead to an upper limit of the swash similarity parameter of about 1.8. [Copyright &y& Elsevier]

Abstract: In this paper and its companion (Higuera et al., 2014--this issue), the latest advancements regarding Volume-averaged Reynolds-averaged Navier–Stokes (VARANS) are developed in OpenFOAM® and applied. A new solver, called IHFOAM, is programmed to overcome the limitations and errors in the original OpenFOAM® code, having a rigorous implementation of the equations. Turbulence modelling is also addressed for k-ϵ and k-ω SST models within the porous media. The numerical model is validated for a wide range of cases including a dam break and wave interaction with porous structures both in two and three dimensions. In the second part of this paper the model is applied to simulate wave interaction with a real structure, using an innovative hybrid (2D–3D) methodology. [Copyright &y& Elsevier]

Abstract: This paper and its companion Higuera et al. (2014--this issue) introduce the formulation of Volume-Averaged Reynolds-Averaged Navier–Stokes (VARANS) equations in OpenFOAM® to simulate two-phase flow through porous media. This new implementation, so-called IHFOAM, corrects the limitations of the original OpenFOAM® code. An innovative hybrid methodology (2D–3D) is presented to optimize the simulation time needed to assess the three-dimensional effects of wave interaction with coastal structures. The combined use of a 2D and a 3D model enables the practical application of the 3D VARANS code to simulate real cases, contributing to a significant speed-up. This is highly convenient and especially suitable for non-conventional structures, as it overcomes the limitations inherent to applying semi-empirical formulations out of their range or 2D simulations only. A detailed study of stability and overtopping for a 3D porous high-mound breakwater at prototype scale subjected to oblique irregular (random) waves is carried out. Pressure around the caissons, overtopping discharge rate and turbulent magnitudes are presented in three dimensions. The mean pressure laws present a high degree of accordance with the formulation provided by Goda–Takahashi. Furthermore, local effects due to three-dimensional processes play a significant role, especially close to the breakwater head. [Copyright &y& Elsevier]

Abstract: This work presents a new model for wave and submerged vegetation which couples the flow motion with the plant deformation. The IH-2VOF model is extended to solve the Reynolds Average Navier–Stokes equations including the presence of a vegetation field by means of a drag force. Turbulence is modeled using a k–ε equation which takes into account the effect of vegetation by an approximation of dispersive fluxes using the drag force produce by the plant. The plant motion is solved accounting for inertia, damping, restoring, gravitational, Froude–Krylov and hydrodynamic mass forces. The resulting model is validated with small and large-scale experiments with a high degree of accuracy for both no swaying and swaying plants. Two new formulations of the drag coefficient are provided extending the range of applicability of existing formulae to lower Reynolds number. [Copyright &y& Elsevier]

Abstract: In the present work, the OpenFOAM® newly developed wave generation and active absorption boundary condition presented in the companion paper (Higuera et al., submitted for publication) is validated. In order to do so the simulation of some of the most interesting physical processes in coastal engineering is carried out and comparisons with relevant experimental benchmark cases presented. Water waves are found to be generated realistically and agreement between laboratory and numerical data is very high regarding wave breaking, run up and undertow currents. [Copyright &y& Elsevier]

Abstract: The present paper and its companion (Higuera et al., 2012) introduce OpenFOAM® as a tool to consider for coastal engineering applications as it solves 3D domains and considers two-phase flow. In this first paper, OpenFOAM® utilities are presented and the free surface flow solvers are analysed. The lack of specific boundary conditions for realistic wave generation is overcome with their implementation combined with active wave absorption. Wave generation includes all the widely used theories plus specific piston-type wavemaker replication. Also standalone active wave absorption implementation is explained for several formulations, all of which are applicable to 3D cases. Active wave absorption is found to enhance stability by decreasing the energy of the system and to correct the increasing water level on long simulations. Furthermore, it is advantageous with respect to dissipation zones such as sponge layers, as it does not increase the computational domain. The results vary depending on the theory (2D, Quasi-3D and 3D) but overall performance of the implemented methods is very good. The simulations and results of the present paper are purely theoretical. Comparisons with laboratory data are presented in the second paper (Higuera et al., 2012). [Copyright &y& Elsevier]

Abstract: This paper presents the validation results for the IH-3VOF model presented in Part I (del Jesus et al., 2011) of this paper. Initially the validation procedure is focused on wave-breaking conditions. A dam-break interacting with a prism is considered as a simplified approach to the study and analysis of wave-breaking conditions. Two different turbulence models are used in order to investigate flow separation prediction and its influence on the net forces exerted on the prism. Single and two-phase flow simulations are carried out to investigate the importance of trapped air within the fluid in the development of the forces acting on the prism. In addition, both a porous and a solid prism are considered for the study. Surface gravity waves interacting with a vertical structure in a narrow flume are presented next. Comparisons between experimentally and numerically obtained free surface elevation, pressure distribution and velocity around the structure are carried out. The hydrodynamics around the structure are studied in detail and compared with the numerical model predictions. Finally, the interaction of regular and solitary waves with a vertical breakwater in a wave basin is studied. The comparison between the laboratory tests and the numerical simulations are carried out for free surface elevation and pressure distribution over the structure under solitary and regular waves. The different results show a good performance of the IH-3VOF model, reproducing the most important processes that appear in the interaction of surface gravity waves with porous structures; therefore validating the new equations and the numerical implementation of the model. [Copyright &y& Elsevier]

Abstract: This paper and its companion paper () describe the capability of a new model, called IH-3VOF, to simulate wave–structure interaction problems using a three-dimensional approach, when porous structures are present. The lack of a universal approach for the formulation of porous media flow equations has motivated a new derivation in the present work. Applications dealing with heterogeneous media, where porosity varies along the porous body, such as the study of multilayered rubble-mound breakwaters, are the final objective of the study. In this first paper, a new derivation of the equations, eliminating the limitations imposed by previous approaches is presented. The model integrates a new set of equations which covers physical processes associated with flow interaction with porous structures. The model considers the multiphase VARANS equations, a volume-averaged version of the traditional RANS (Reynolds-Averaged Navier–Stokes) equations. Turbulence is modeled using a k–ε approach, not only at the clear fluid region but also inside the porous media. A VOF technique is used to track the free surface. In this first paper, the model has been validated using laboratory data of a two-dimensional flow. In the companion paper the model is further validated with new experimental data sets, considering porous and solid structures as well as the presence of air. The model predictions present an excellent agreement with the laboratory measurements. [Copyright &y& Elsevier]

Tsunami wave interaction with coastal regions is responsible for very important human and economic losses. In order to properly design coastal defenses against these natural catastrophes, new numerical models need to be developed that complement existing laboratory measurements and field data. The use of numerical models based on the Navier-Stokes equations appears as a reasonable approach due to their ability to evaluate complex flow patterns around coastal structures without the inherent limitations of the classical depth-averaged models. In the present study, a Navier-Stokes-based model, IH-3VOF, is applied to study the interaction of tsunami waves with porous and impermeable structures. IH-3VOF is able to simulate wave flow within the porous structures by means of the volume-averaged Reynolds-averaged Navier-Stokes VARANS equations. The equations solved by the model and their numerical implementation are presented here. A numerical analysis of the interaction of a tsunami wave with both an impermeable and porous vertical breakwater is carried out. The wave-induced three-dimensional wave pattern is analysed from the simulations. The role paid by the porous media is also investigated. Finally, flow around the breakwater is analyzed identifying different flow behaviors in the vicinity of the breakwater and in the far field of the structure. [ABSTRACT FROM AUTHOR]

This paper presents the numerical modelling of the cross shore propagation of infragravity waves induced by a transient focused short wave group over a sloping bottom. A dataset obtained through new laboratory experiments in the wave flume of the University of Cantabria is used to validate the Reynolds averaged Navier-Stokes type model IH- 2VOF. A new boundary condition based on the wave maker movement used in the experiments is implemented in the model. Shoaling and breaking of short waves as well as the enhancement of long waves and the energy transfer to low-frequency motion are well addressed by the model, proving the high accuracy in the reproduction of surf zone hydrodynamics. Under the steep slope regime, a long wave trough is radiated offshore from the breakpoint. Numerical simulations conducted for different bottom slopes and short wave steepness suggest that this low-frequency breakpoint generated wave is controlled by both the bed slope parameter and the Iribarren number. Moreover, the numerical model is used to investigate the influence that a large flat bottom induces on the propagation pattern of long waves. [ABSTRACT FROM AUTHOR]

Abstract: This work aims to demonstrate an advancement towards the integrated modelling of surf zone hydrodynamics by means of a VOF-type numerical model (COBRAS-UC) based on the Reynolds-Averaged Navier–Stokes equations. In this paper, the numerical model is adapted and validated for the study of nearshore processes on a mildly-sloping beach. The model prediction of wave energy transformation and higher order statistics (skewness and asymmetry) are in good agreement with detailed laboratory observations from a barred beach [Boers, M. (1996). “Simulation of a surf zone with a barred beach; Report 1: Wave heights and wave breaking”. Tech. Rep.96-5, Comm. on Hydrol. and Geol. Eng., Dept. of Civil Engineering, Delft University of Technology]. Moreover, the numerical model allows us to study the low-frequency motions inside the surf zone. It is found that in order to achieve a satisfactory simulation of both short- and long-wave transformation, the numerical model must achieve: (i) the simultaneous second-order wave generation and absorption, (ii) the energy transfer between triad of components, (iii) the short- and long-wave energy dissipation inside the surf zone, and (iv) the wave reflection at the shoreline. Comparisons between numerical and experimental results demonstrate the model capability to satisfactorily simulate all the aforementioned processes. [Copyright &y& Elsevier]

Menendez, M., Mendez, F. J., and Losada, I. J. 2009. Forecasting seasonal to interannual variability in extreme sea levels. – ICES Journal of Marine Science, 66: 1490–1496.A statistical model to predict the probability of certain extreme sea levels occurring is presented. The model uses a time-dependent generalized extreme-value (GEV) distribution to fit monthly maxima series, and it is applied for a particular time-series record for the Atlantic Ocean (Newlyn, UK). The model permits the effects of seasonality, interannual variability, and secular trends to be identified and estimated in the probability distribution of extreme sea levels. These factors are parameterized as temporal functions (linear, quadratic, exponential, and periodic functions) or covariates (for instance, the North Atlantic Oscillation index), which automatically yield the best-fit model for the variability present in the data. A clear pattern of within-year variability and significant effects resulting from astronomical modulations (the nodal cycle and perigean tides) are detected. Modelling different time-scales helps to gain a better understanding of recent secular trends regarding extreme climate events, and it allows predictions to be made (for example, up to 2020) about the probability of the future occurrence of a particular sea level. [ABSTRACT FROM PUBLISHER]

This paper compares the output from four methods used to predict the mean overtopping discharge at the root of the South Breakwater of Póvoa de Varzim Harbour (Portugal): two numerical models AMAZON, based on solving the nonlinear shallow-water equations, and COBRAS-UC, based on the Reynolds averaged Navier–Stokes equations, Pedersen’s empirical formula, and the neural network tool NN_Overtopping. Output from the methods is considered alongside data from two-dimensional (2D) physical model tests. The results show that rather accurate predictions can be obtained with COBRAS-UC. Agreement between the data and the AMAZON output depends principally on the impact of porosity on overtopping: agreement is very good when the impact is limited (for high overtopping discharges) and it worsens as porosity plays a more important role (for small discharges). NN_Overtopping estimates the mean discharges with a degree of accuracy similar to AMAZON. Pedersen’s results are those which deviate more from the data, substantially overpredicting the mean discharges for the conditions analyzed. [ABSTRACT FROM AUTHOR]

Abstract: In the last years, new tools have been developed to describe wave climate. In particular, wave hindcast models allow a very detailed description in time and space. However, the data bases generated from these models require calibration with instrumental observations. In this work, a methodology for spatial calibration of wave hindcast data bases is developed. It is based on an Empirical Orthogonal Function decomposition and a non-linear transformation of the spatial–time modes. The method is applied to monthly long-term distribution of significant wave height in the Western Mediterranean. The calibration (transformation of the modes) is carried out using existing buoys in the area. After calibration, the validation with satellite data shows that this methodology is useful to better define wave climate from hindcast data bases. [Copyright &y& Elsevier]

Abstract: This paper was initially presented during the scientific workshop of the French society for child and adolescent psychiatry and allied professions (SFPEADA), devoted to psychomotricity and its current bonds with child and adolescent psychiatry (Paris, September 29, 2005). The authors are a child and adolescent psychiatrist, using daily psychoanalytical psychotherapies in a universitary public hospital and two psychomotricians, who work in a child and adolescent public department, in a private activity and in a specialized institute (therapeutic, educational and teaching institute or ITEP). They present here the results of their clinical practices, exchanges and thoughts about a complex and discussed subject, which touches in more than one way with the bases of our clinical and therapeutic practices with children and adolescents: how do we choose the differential indications between psychotherapies and psychomotor therapies? [Copyright &y& Elsevier]

This paper reviews mainly conceptual models and experimental work, in the field and in the laboratory, dedicated during the last decades to studying turbulence of breaking waves and bores moving in very shallow water and in the swash zone. The phenomena associated with vorticity and turbulence structures measured are summarised, including the measurement techniques and the laboratory generation of breaking waves or of flow fields sharing several characteristics with breaking waves. The effect of air entrapment during breaking is discussed. The limits of the present knowledge, especially in modelling a two- or three-phase system, with air and sediment entrapped at high turbulence level, and perspectives of future research are discussed. [Copyright &y& Elsevier]

With the recent increase in research into ferroelectric, anti‐ferroelectric and piezoelectric materials, studying the solid‐state properties in situ under applied electric fields is vital in understanding the underlying processes. Where this behaviour is the result of atomic displacements, crystallographic insight has an important role. This work presents a sample environment designed to apply an electric field to single‐crystal samples in situ on the small‐molecule single‐crystal diffraction beamline I19, Diamond Light Source (UK). The configuration and operation of the cell is described as well as its application to studies of a proton‐transfer colour‐change material. [ABSTRACT FROM AUTHOR]

MFM-722(Pb)-DMA undergoes a single-crystal-to-single-crystal (SCSC) transformation to give MFM-722(Pb)-H2O via ligand substitution upon exposure to water vapour. In situ single crystal impedance spectroscopy reveals an increase in proton conductivity due to this structural transition, with MFM-722(Pb)-H2O showing a proton conductivity of 6.61 × 10−4 S cm−1 at 50 °C and 98% RH. The low activation energy (Ea = 0.21 eV) indicates that the proton conduction follows a Grotthuss mechanism. [ABSTRACT FROM AUTHOR]

Historic coastal structures have played a key role in small- to medium-size ports, being the driving force for the local development of coastal communities. Because coastal managers require reliable risk-based analysis of the whole life cycle of these coastal structures, previous lifetimes should be studied. This is a differentiating factor with respect to the newly built breakwaters. For this reason, in this work, a methodology for assessing how the hydraulic performance of an expired lifetime has evolved over the years is presented. It is performed following a probabilistic approach due to the uncertainty related to both the involved variables (wave climate, geometrical and structural breakwater variables) and the hydraulic response of the structure. The first ones are characterized by reliable probability distribution functions. The second ones are characterized by reliable formulae for the analysis of the hydraulic response. However, their non-conventional designs located in shallow-water locations require site-dependent formulae. To overcome this problem, a novel methodology to apply CFD numerical models is presented. Finally, it is integrated in a high-resolution time-dependent probabilistic methodology which takes into account the stochastic behaviour of all the involved variables, coastal and structural processes with a good uncertainty level. This article is part of the theme issue 'Environmental loading of heritage structures'. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the stability analysis of a non-conventional breakwater cross-section integrating an overtopping wave energy converter, named OBREC. The device consists of a traditional rubble-mound breakwater in which the upper part of the armour layer is replaced by a smooth ramp and a reservoir. The analysis of the structure is carried out by combining model scale experiments and numerical simulations based on the Volume-Averaged Reynolds Averaged Navier-Stokes (VARANS) equations. The numerical analysis is used to complete and extend the results of the physical model test campaign, providing a deeper understanding of the pressure distribution and resultant force behaviour in locations where laboratory measurements were difficult to obtain or not available. Results show that the maximum vertical and horizontal total forces on the device are not simultaneous. At the time instant of the maximum total horizontal force, the vertical force is zero or directed downward, due to the significant positive contribution of the force acting on the sloping ramp. Additional numerical simulations show the influence of the submerged ramp length on the forces acting on the structure using the global and local stability analysis. The presence of the shaft contributes positively to the global stability against the sliding failure mode by reducing the uplift force exerted on the horizontal base. Moreover, the stability analysis shows that the critical conditions for the global failure modes occur at different time instants. Highlights • The stability analysis of a non-conventional breakwater integrating an overtopping wave energy converter is studied. • A combination of model scale experiments and numerical simulation based on the Volume-Averaged Reynolds Averaged Navier-Stokes (VARANS) equations is carried out. • Detailed analysis of pressure distribution and wave loads on a non-conventional breakwater is carried out. [ABSTRACT FROM AUTHOR]

Abstract: [2] and [3] hybrid rotaxanes are reported based on {Ti7M} rings (M is a trivalent metal such as FeIII or GaIII). NMR studies show that [2]rotaxanes can act as molecular shuttles, while EPR studies of [3]rotaxanes show weak interactions between the paramagnetic components of the supramolecular assemblies. [ABSTRACT FROM AUTHOR]