bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the effect of spur dikes on beach protection based on physical model experiment
Authors: CHEN FUYUAN , HE ZHIGUO , KUN HE , QIUSHUN WANG
Published: May 2024

The Qiantang River is a typical strong tide estuary, the world-famous tidal bore have huge turbulent energy and causes damage to the sea wall. Spur dike is an important engineering to prevent the seawall foundation from tidal bore. But the tidal bore occurs at the low tide level, strong turbulence, high flow velocity, water level rises sharply. The spur dike height, length, inclination angle need to be determined by physical model according to the specific bore dynamic conditions. In the tests, the fixed-bed model was used to study the tidal current velocity reduction rate and region, the falling current circulation characteristics in dike field. The movable-bed model test is used to study the effect of each test on protecting the beach. This physical model study reveals the rule of spur dike influence on tidal bore dynamics so the effect of spur dike on protecting the beach is clear.
Wave Loads On Hydraulic Structures
Authors: ALMEIDA ERMANO DE , TUIN HENRY , STOETEN KASPER , HOFLAND BAS
Published: May 2024

Hydraulic structures are essential for flood protection, water management and navigation in coastal, delta and lake regions. Their importance will continue to grow in the coming years and decades, because of two main factors. Firstly, because of the consequences of climate change and sea level rise. Secondly, because of the continuous development and urbanization of coastal, delta and lake regions, with an increase in the value of the assets and activities in those locations combined with more strict safety requirements. Those factors will lead to the construction of a series of new hydraulic structures and the renovation of several existing structures around the world.
Wave loads acting on such hydraulic structures are crucial for their design and safety assessment. This study addresses two different types of wave loads acting on hydraulic structures: confined wave impact loads and bimodal wave loads. To this end, a series of laboratory experimental test campaigns were carried out in a wave flume.
Short-Term Coastal Impact Of Lakeshore For Natural Reserve Protection
Authors: DREGER CHARLOTTE , BOLLAERT ERIK
Published: May 2024

The site of Grangettes, which is registered as a natural reserve of national and international importance for waterowl and migratory birds (i.e. OROEM site), is considered the last part of the Swiss lakeshore of Lake Geneva that remains natural. This area hosts a wide variety of coastal ecosystems, containing significant natural values located both in aquatic and in terrestrial areas of the reserve. Because of repetitive localized dredging activities of the lake bottom since the last century, a severe withdraw of the shoreline and its associated natural values has been observed between 1964 and 2001 close to the « Gros Brasset » dredge pit.
Tsunami Debris Damming Drag Forces And Associated Coefficients On Elevated Coastal Structure Columns
Authors: DOYLE KELLEN , KOH MYUNG-JIN , JAYASEKARA RAVINDU , COX DANIEL , LOMONACO PEDRO , PARK HYOUNGSU , KAMESHWAR SABARETHINAM
Published: May 2024

Tsunami overland flow induces hydrodynamic loads on coastal structures and may transport various objects located within the inundation zone, which could become debris and exacerbate hydrodynamic loading. In the process of adopting “the first national, consensus-based standard for tsunami resilience” (Chock, 2016) in the form of ASCE 7-16 Chapter 6: Tsunami Loads and Effects, emphasis was placed on evaluating debris transport and impact forces. This is evidenced by the robust body of literature regarding physical model experiments of these processes and thorough design procedures for both load considerations in current structural engineering standards (ASCE, 2022). Debris damming forces, resultant of debris being transported and accumulating against structures, are less thoroughly studied, having only recently begun to transition from steady flow experiments to transient flow conditions representative of coastal inundation events. A recent pair of experiments bridges this gap, comparing debris damming via steady-state, subcritical flow conditions to that caused by a dam-break style hydraulic bore (Stolle et al., 2018). That paper aimed to study debris dam formation, stability, and loading as well as runup of the flow onto idealized structural columns. Another study varied debris quantity, orientation, and arrangement to determine the effect had on damming and impact loads (Shekhar et al., 2020), however neither compared findings to current standards.
The experimental work presented herein represents initial findings of a multi-year experimental campaign to better understand the mechanisms that lead to debris damming and increased structural loading. This work builds upon previous studies by using larger scale debris elements, more numerous debris fields, and more trials to better model such a stochastic process as debris damming. Three different incident wave conditions also led to varied hydrodynamics at the column specimen. In later phases, this campaign will also investigate the debris damming consequences of heterogeneous debris, which more accurately represent highly variable debris fields observed in post-event site surveys (Nistor et al., 2017).
This paper aims to compare experimental debris dam loading parameters to those in the current ASCE 7-22 standard (ASCE, 2022). Namely, evaluating conservatism of ASCE 7-22 design values for: overall drag force on buildings, minimum closure ratios used in load determination, and empirical rectilinear structure drag coefficients during both debris accumulation and quasi-steady debris damming phases.
Physical Modelling Of Propeller Jet Induced Scour Near Quay Walls
Authors: NIEUWENHUIZEN C. VAN , VAN DER HOUT A.J. , NOGUEIRA H.I.S. , BAKKER W. , BROCCA G. , PIETRO P. DI
Published: May 2024

Ship propellers cause high flow velocities near quay walls, jetties, locks and other hydraulic structures which can lead to scour of the bed near these structures and potentially result in instabilities of the construction. Bed protection is commonly applied as a measure to prevent damage and increase the life span of such hydraulic structures. When designing bed protection, the existing guidelines e.g. (PIANC 2015, BAW 2010) may not always result in optimal designs due to simplifications made in jet-flow schematizations and uncertainty of propeller-induced loads. To improve these design guidelines and optimize bed protection, a working group led by CROW and the Dutch Government was formed, and a joint research programme was initiated aiming at developing knowledge on propeller jet-induced scour by combining field measurements (Tukker 2021), scale model tests (Deltares 2023), and numerical modelling. The objective of the presentation during the Coastlab24 conference is to provide an overview of the various measurement techniques applied in the present research.
Reefense: Design Of A Porous Modular Hybrid Reef For Coastal Protection
Authors: GHISALBERTI MARCO , LOWE RYAN J. , GELDARD JUSTIN , BOOTH BAILEY , ELLWOOD GEORG , GOAD ALEX , MORRIS REBECCA
Published: May 2024

Hybrid artificial reef structures can be designed to promote the development of a self-sustaining habitat for reef organisms while simultaneously enhancing the extent to which they provide coastal protection. Such hybrid structures offer many additional ecosystem benefits over conventional engineering structures that are used to provide coastal protection. Here, we investigate the wave attenuation capacity of engineered oyster reef modules that have been designed through the DARPA initiative Reefense: A Mosaic Oyster Habitat for Coastal Defense. The modules are designed with significant porosity (through misaligned holes), shelves to facilitate oyster recruitment, and an interlocking mechanism to maximise reef stability.
Local Head Losses And Drag Coefficients Characterization In Coastal Infrastructures
Authors: TOMÁS ANTONIO , VIDAL CESAR , BLANCO DAVID , BARAJAS GABRIEL , BENGOCHEA PABLO , REGUEIRA DELIA , RODRÍGUEZ BEATRIZ , ÁLVAREZ ÁLVARO
Published: May 2024

Some coastal infrastructures (i.e. intakes, outfalls, gates) incorporate singular elements (meshes, nets or grids) which, through their interaction with the water flow, can produce large changes in the water level (upstream and downstream) and forces on them. Therefore, an accurate definition of local head losses (to characterize water level changes) and drag coefficient (to characterize drag forces) allows to optimize their designs (configuration and geometric definition).
Large-Scale Experimental Model Of Edge Treatments For Constructed Salt Marshes
Authors: PROVAN MITCHEL , MURPHY ENDA , RAHMAN AMANJ , MORRIS ERIC , MATFIN ALLISON
Published: May 2024

Large stretches of Canada’s coastlines are lined with legacy dykes (or levees) to provide protection against coastal flooding and erosion. However, future sea-level rise presents a risk to these structures, which may result in the dykes being under designed when exposed to future water levels and wave conditions. Under certain conditions, these dykes can be augmented with a coastal saltmarsh to create a living dyke, which allows for the existing dyke to be more resilient against sea level rise without the need to retrofit the dyke with a higher crest elevation or larger armour stone. The coastal saltmarsh is able to attenuate storm waves, resulting in lower wave energy at the dyke, while also attracting and retaining sediment to combat coastal erosion.
The Living Dyke project in Boundary Bay, Canada is a pilot project being used to test the living dyke concept by placing sediment and planting salt marsh vegetation in the foreshore combined with upgrades to the existing dyke. Kerr Wood Leidal Associates Ltd. prepared a preliminary design which incorporated four different edge treatment features that are to be installed at the offshore edge of a newly constructed salt marsh platform in order to attenuate wave energy and retain the placed sediment before the planted vegetation can be established. The proposed edge treatment features included a natural sand edge, a rounded gravel berm, an oyster-shell filled bag berm, and a brushwood dam. Large scale (full scale for all edge treatment feature tests except for the brushwood dam which was conducted at half-scale) physical model experiments were carried out by the National Research Council of Canada’s Ocean, Coastal and River Engineering Research Centre in their Large Wave-Current Flume to investigate the performance, including stability of the edge treatment features, wave attenuation ability, and stability of the salt marsh platform, of these edge treatment features under varying water level and wave conditions that are present at Boundary Bay.
Scour Hole Evolution Near A Detached Low-Crested Rubble-Mound Breakwater
Authors: PINTO FRANCISCO , ROSA-SANTOS PAULO , LARA JAVIER LOPEZ , RAMOS JOSÉ VICTOR
Published: May 2024

Low-crested detached breakwaters are affected by coastal hydro- and morphodynamics, due to complex wave-structure- seabed interactions, which impact their stability, namely due to scour effects. The scour phenomenon has been under study in several mobile-bed physical model research studies (e.g., Fredsøe et al., 1997, Sumer et al., 2000 and Sumer et al., 2005). However, scour phenomenon near detached rubble-mound breakwaters is still far from being well understood.
Therefore, the present research work comprises an innovative and comprehensive analysis of the local morphodynamics around a detached low-crested rubble-mound breakwater, with a special focus on the quantitative characterization of scour phenomena, namely the scour depth.
Physical Modelling Of The Wave Field Around An Array Of Centrally Controlled Wave Energy Converters
Authors: HERBST MAXIMILIAN , KERPEN NILS B. , SCHLURMANN TORSTEN , SCHOONEES TALIA
Published: May 2024

Stepped revetments have shown to be effective in limiting wave overtopping and wave run-up compared to sloped revetments. However, literature on wave impact pressures and comprehensive design guidelines for these structures is scarce. Laboratory experiments support establishing design recommendations. So far, studies for wave impacts at stepped revetments were mainly performed at small scales. Results from these tests are likely to be subjected to scale effects and therefore inaccurately replicate the wave-structure interaction at full scale. This study quantifies scale effects of wave impact characteristics for design cases based on a comparison to small-scale tests (Kerpen et al., 2018). Full-scale flume experiments were studied with a slope of 1:3 and uniform step heights of 0.17 m and 0.50 m in the Large Wave Flume (GWK) in Hannover, Germany. Horizontal and vertical wave impacts were measured at 15 locations in the plunging region of the revetment for a range of wave steepnesses (). The results show that previous small-scale tests underestimate design wave impact pressures by a factor of up to 7.7. Impact loadings occur considerably faster than at small scale with relative peak rising times decreasing by a factor of up to 5.6. Prediction formulae are derived for the vertical distribution of horizontal impact pressures (Figure 1b) as well as for temporal characteristics of these pressures at stepped revetments.
Tsunami Runup Attenuation By Onshore Obstacles
Authors: VAN BALEN IVO , CELS JONAS , ADAMS KEITH , BAIGUERA MARCO , ROSSETTO TIZIANA , ANTONINI ALESSANDRO , WÜTHRICH DAVIDE , ISTRATI DENIS , BULDAKOV EUGENY , CHANDLER IAN , MCGOVERN DAVID
Published: May 2024

In a time of climate emergency due to global warming, nature-based coastal defence systems are attractive solutions for flood mitigation and adaptation. Coastal forests such as mangroves have received a growing interest for their disaster mitigation effectiveness such as water flow energy dissipation, hence helping communities to become more resilient (Iimura & Tanaka, 2012). The role of coastal forests as a defence measure was highlighted in the aftermath of the 2004 Indian Ocean Tsunami, which claimed the lives of more than 200,000 people and displaced millions more across fourteen countries. Post-disaster damage observations indicated that forests, particularly mangroves, reduced the impact of the tsunami wave in some locations. As a result, significant international relief and reconstruction efforts focused on extensive forest replantation of coastlines (Satake, 2014).
The role of coastal vegetation in reducing the severity of tsunami waves has been studied since. Several studies using physical modelling and computational approaches have provided insights into the wave attenuation provided by coastal vegetation, in terms of relationships between incident hydrodynamic conditions, forest configurations and wave height decay. However, there are still many gaps in knowledge, particularly in quantifying the efficacy of coastal forests in reducing inland hydrodynamic conditions (Tomiczek et al., 2020). It is therefore essential to improve the understanding on how wave heights, velocities and runup are influenced by the characteristics of the “obstacles”, e.g. the forest density, as well as the incident hydrodynamic conditions, e.g. the wave period. This study aims to address these questions conducting physical experiments using the novel pneumatic Tsunami Simulator (TS) developed by HR Wallingford together with UCL (Rossetto et al., 2011).
Air-Water Flow Properties In Highly Unsteady Flows
Authors: REGOUT DORETTE , WÜTHRICH DAVIDE , MATSCH JONAS
Published: May 2024

Recent catastrophic events caused by tsunamis, storm surges, flood waves, and the failure of dams (e.g. in Ukraine and Libya) have shown to be a significant threat to densely populated coastal communities. Interactions with built environments can lead to violent wave impacts that may have severe consequences, including significant infrastructural damage and potential loss of life. The frequency of these water-related disasters is increasing globally due to climate change and sea level rise, resulting in a rising demand for deeper knowledge related to the physical processes of such hazards.
The dynamic behaviour of these type of wave phenomena is described by long-period, high translatory waves, where the on-shore propagation or inland inundation is associated with sudden free-surface deformations. This results in a steeping of the slope at the leading edge, causing non-linear flow behaviour to prevail and inducing the wave to collapse. The breaking process generates a breaking roller at the wave front, containing a rapidly fluctuating mixture of air and water, associated with a strong recirculation. The high degree of air-water interaction in these unsteady flows has a significant impact on the flow properties as it influences many dynamic processes, including viscous and surface tension effects at air-bubble level, as well as larger scale gravitational effects associated with the turbulent flow and eddy formation (Brocchini and Peregrine, 2001). New innovative measurement techniques have allowed experimental studies to more precisely quantify the air-water interactions in multiphase flows. However, most experimental research focused on air-water flow properties in hydraulic jumps and other steady flows (e.g. spillway flows, plunging jets). Currently, limited research is available for unsteady flows and mostly based on small datasets and limited flow conditions. This lack of availability and diversity of experimental data restricts the understanding of how these multi-phase flows behave under different conditions, hence the need for future research.
Marelab: The Lab Of The Mediterranean Sea For Marine Renewable Energy
Authors: Russo SARA , BARDAZZI ANDREA , LUCARELLI ALESSIA , PILLOTON CHIARA , AZZELLINO ARIANNA , CONTESTABILE PASQUALE , VICINANZA DIEGO , LUGNI CLAUDIO
Published: May 2024

This work aims to describe the testing capabilities of the Mediterranean Marine Renewable Energy Laboratory for mid-to-full scale devices. As an illustrative example, it presents various experimental campaigns conducted in recent years on a hybrid breakwater – wave energy converter and a floating wind turbine.
LOW-CRESTED AND EMERGENT BREAKWATERS WITH ECO-FRIENDLY ARMOUR UNITS
Authors: SAYAR SERIM DOGAC , NISTOR IOAN , BAKER SCOTT , MARTÍNEZ JORGE GUTIÉRREZ
Published: May 2024

Artificial coastal defense systems (such as concrete armour units) frequently host less diverse aquatic populations than natural environments and feature higher concentrations of invasive species (Dafforn et al., 2009). Therefore, coastal structures need to be designed or refitted to achieve sustainable goals through the application of ecological engineering solutions applied to coastal defence structures and for the ecosystem, marine habitat, and biodiversity improvement. Ecological engineering, which integrates ecosystems with engineering principles to construct coastal structures that benefit both humans and the ecosystem, is growing as a means of reducing the adverse ecological impacts of coastal infrastructure (Mitsch & Jorgensen, 2003). Thus, creating new eco-friendly breakwater design guidelines is critical and will benefit from the multidisciplinary involvement of marine biologists and ecologists.
The purpose of this experimental modelling study was to provide data on the hydraulic performance and stability of low-crested and emergent rubble mound breakwaters (RMBW) constructed using ecologically friendly armour units under various wave conditions. The University of Ottawa, the National Research Council of Canada (NRC), and ECOncrete collaborated to develop and conduct the physical testing program.
Several breakwater models were tested to evaluate their performance, as the idea of an eco-friendly breakwater is still a new area of research. Thus, this experimental program is essential to promote environmentally-friendly armour units in the design of new coastal structures (such as Baker et al., 2018), as well as ecological retrofitting of existing coastal structures. The physical tests were conducted between June 2023 and August 2023 in the Large Wave Flume of NRC’s Ocean, Coastal, and River Engineering Research Center in Ottawa, Canada. ECOncrete's Coastalock armour units were tested in various configurations at a 1/15 scale using two-dimensional low-crested and emergent RMBW models. The hydraulic performance and failure mechanisms of these environmentally-friendly breakwater models were tested under severe wave conditions.
Decay Of Bow Thruster Induced Near-Bed Flow Velocities At A Vertical Quay Wall: A Field Measurement
Authors: TUKKER JIM W.T. , RUIJTER MICHEL , VAN DER VORM-HOEK CHARLOTTE V.A. , HOFLAND BAS
Published: May 2024

During berthing operations vessels use bow thruster(s) to improve their manoeuvrability, making them less dependent on the assistance of tugboats. While manoeuvring, the transversal bow thruster jet can reflect on the quay wall and partially be directed towards the bed. At the intersection between the quay wall and the bed, the jet reflects again leading to a highly turbulent and complex flow field (Figure 1). When the bed is left unprotected scour may occur, which can eventually lead to instability of the quay wall (Roubos et al., 2014).
Over the years, the shipping industry has been developing continuously, characterized primarily by the upscaling in size of inland- and sea-going vessels (OECD, 2015; Weenen et al., 2020; Looye, 2021). As a result, vessels have larger draughts, more power and larger thruster diameters leading to higher hydraulic loads on quay walls and bed protections of berthing facilities (Roubos & Verhagen, 2007). To complicate the matter even more, the jet from a transversal bow thruster is confined by the hull of the vessel, the quay wall and the bed. Leading to a complex flow field of the reflected jet and an unknown decay in near-bed flow velocities. Resulting in uncertainties in the design of bed protections, especially in the required width.
A New Formulation For Vegetation Induced Damping Under Waves And Currents Based On Their Standing Biomass
Authors: MAZA MARIA , GALLEGO ISABEL
Published: May 2024

Estimation of the flow energy dissipation induced by an ecosystem that accounts for its characteristics (i.e. biomechanical properties, morphology, density) and the incident hydrodynamic conditions is crucial if ecosystem-based coastal protection measurements want to be implemented. Characterization of a vegetated ecosystem by measuring leaf traits, biomechanical properties of plants and the number of individuals per unit area involves a lot of effort and is case-specific. Previous studies have shown that wave height attenuation positively correlates with standing biomass (Maza et al., 2022) highlighting the crucial role played by this variable that can be used to estimate the ecosystem wave damping capacity without using calibration coefficients. In addition, this variable has been already characterized for many ecosystems and it can be estimated by aerial images (Doughty and Cavanaugh, 2019) and remote sensing techniques. However, this new approach has not been extended to conditions where waves and currents are simultaneously present. These conditions are very relevant to habitats like saltmarshes that are commonly affected by tidal currents or wave-induced currents flowing simultaneously with wind or swell waves. Then, to further explore this new approach based on the ecosystem standing biomass, a new set of experiments using real vegetation with contrasting morphology and biomechanical properties, and subjected to different combinations of waves and currents, is proposed. The obtained standing biomass-attenuation relationships will help to quantify the expected coastal protection provided by different vegetated ecosystems based on their standing biomass under the combined effect of waves and currents.
Experimental Comparison Of The Hydraulic Performance Of Overhanging And Vertical Parapets Under Limited Wave Breaking Conditions: The Case Of The New Offshore Ravenna Lng Terminal (It)
Authors: CASTELLINO MYRTA , ALDERSON JOHN , RAULT THIERRY , LANZA GABRIELE P. , CABRA ANGELO , Russo PIERLUIGI , CAPOZZI FABIO , DEL BIANCO MARCO , GIROLAMO PAOLO DE
Published: May 2024

Harbors play a pivotal role in global trade, serving as vital gateways for the transportation of goods, fostering economic growth. These essential coastal infrastructures are subjected to relentless forces (e.g. wave action, storm surges, and sea level variation induced by climate change) which can jeopardize their functionality and safety. Safe working conditions are mandatory for the operability of all kinds of harbors. However, particular attention must be paid in the case of terminals dedicated to dangerous goods, as for example Liquefied Natural Gas (LNG). Composite vertical breakwaters may be efficiently used to protect this kind of terminal and have both advantages and disadvantages over rubble mound breakwaters.
This work presents the results of a 2D experimental campaign carried out to optimize, from a hydraulic point of view, the parapet wall of the new composite vertical breakwater that will be built to protect the new offshore LNG terminal located in in the North Adriatic Sea in the South-East of the Port of Ravenna (Italy). In particular, two types of parapets walls have been compared: one overhanging (recurved in the shape of one fourth of a circumference with a ray of one meter) and one vertical. For each type of parapets, three different heights were evaluated for a total of six different configurations. The typical water depth in the area where the new terminal will be built is approximately -15.0 m with respect to the MSL and the total range of the astronomical tides does not exceed one metre. The terminal is located about 8.0 km far from the coast and is positioned on a very mild seabed foreshore slope of less than 0.05°
Parametric Analysis Of Wave-Induced Forces And Overtopping On Composite Vertical Breakwaters With Retreated Crown Wall
Authors: CENTORAMI MATTEO , ROMANO ALESSANDRO , CECIONI CLAUDIA , FRANCO LEOPOLDO , BELLOTTI GIORGIO
Published: May 2024

Composite vertical breakwaters are monolithic structures often used to protect port basins, especially in deep-water conditions. At present, the design of these structures is mainly based on Goda's formulae (Goda, 2010) or on the probabilistic design tools (PROVERBS) proposed by Oumeraci et al. (2001), while their hydraulic performance in terms of overtopping can be predicted by using the tools described in the EurOtop Manual (EurOtop Manual, 2018).
Due to the size of these structures, the optimization and the improvement of the hydraulic performances (e.g. reduction of wave loads, wave overtopping, etc.) of these breakwaters can lead to significant economic saving. Typically, designers try to make small geometric changes without modifying the main geometrical dimensions of these structures. One of these technical solutions consists in placing the cast-in-situ concrete crown wall at a retreated position with respect to the front caisson face. It is assumed that the retreat of the crown wall, for geometric reasons, induces a time lag between the loads acting on the lower front external seawall face and on the crown wall of the caisson; furthermore, this could introduce a change in the pulsating nature of the loads, introducing also turbulent dissipations, consequently reducing the reflection coefficient and modifying the wave overtopping. To the best authors’ knowledge, in the literature there is a lack of guidelines to consider the effects of crown wall retreat in terms of wave actions and hydraulic performance of the structure. Recently, Romano & Bellotti (2023), based on physical model tests, provided a first experimental insight on the increase/reduction of the wave loads acting on deep water vertical breakwaters with retreated crown wall.
Lagrangian Measurements Of Surface Water Waves: Relation Between Drift Velocities And Set-Down
Authors: MELITO LORENZO , KHORBATLY BASHAR , MARCONI ALESSANDRO , POSTACCHINI MATTEO , BLANDFORT DANIEL , BROCCHINI MAURIZIO , BUCKLEY MARC , KALISCH HENRIK
Published: May 2024

Since the work of Stokes on steady progressive surface waves (Stokes, 1847), there has been interest in fluid particle trajectories and associated mass flux. The original result obtained by Stokes was based on linear theory, and implied that there is a net forward drift in the fluid beneath a propagating surface wave. In the non-dimensional case, the drift velocity for a sinusoidal wave on a fluid of depth h is given by
Recent works suggest that in many cases, particularly in waves propagating over a shear flow, a net Eulerian flow may develop, which is opposed to the Stokes drift. Monismith et al. (2007) suggested that in a deep-water setting, the net Eulerian backflow may cancel the Lagrangian Stokes drift on a pointwise basis. Further, Grue & Kolaas (2017) found good agreement with the theoretical findings of Longuet-Higgins (1953), except near the bottom and near the free surface, where boundary layers have a discernable impact on the induced flow.
In recent field measurements, it was observed that the drift velocity correlates positively with the local average fluid depth (Bjørnestad et al., 2021). In other words, a wave with a set-up features a large forward drift, while a wave with a set-down features a negative net drift. The present work aims at investigating what observed in the field by means of laboratory experiments carried out in a wave flume, where monochromatic and bichromatic waves of different characteristics have been run.
Physical Model Study Of Standing Wave Impact Loads On Gates And Decks Of The Existing Discharge Sluices In The Afsluitdijk The Netherlands
Authors: KORTLEVER W.C.D. , CAPEL A. , DER WERF I. VAN , JANSEN P.L.M. , LOUWERSHEIMER W.F. , VERVOORN H.A.
Published: May 2024

To anticipate the rising sea level and to meet the increased flood safety standards the Afsluitdijk in the northwest of The Netherlands is currently being reconstructed. The Afsluitdijk is the dam, with a length of 30 km, that closes the IJsselmeer basin, the former Zuiderzee. Outside the dam lie the Waddenzee and the North Sea. The reconstruction of the dam includes the reinforcement of  the dam and the raising of the crest level, the renovation of the existing discharge sluices and the building of new pumping stations, discharge sluices and flood gates. Higher design waves and water levels, including the effects of sea level rise, present determining loads for drawing up the strength and stability of these hydraulic structures. One of these loads is the wave impact load on the gates, supporting beams and bridge decks of the discharge sluices. At first, these loads have been calculated using a design approach which has been based on analytical models, only partially validated (Almeida and Hofland, 2020). It showed that these loads due to vertical wave impacts can be higher than the strength of the gates and the existing bridge decks. Therefore, load reduction measures are required. To better predict the wave impact loads, which strongly depend on the configuration of the gates and decks, a physical model study in a wave flume has been carried out at Deltares (Capel and van der Werf, 2023). This abstract is about the results of this model study, focusing on the wave impacts on the existing discharge sluices near Kornwerderzand, because at this location these loads are the highest.
The application of flexible and porous concrete structures in training works and scour protection
Authors: RUWIEL TIM , REEDIJK BAS , MEIJER MARTIJN , SCHOONEES TALIA , VAN RIJSWIJK TOM
Published: May 2024

Concrete armour units such as Xbloc have been applied as armour layer for breakwaters and bank protections for years. These smartly shaped blocks were invented to offer efficient protection at more exposed locations by applying blocks that work together with neighbouring units to withstand high wave loads (Interlocking). Also material use was lowered since steeper slopes could be realized compared to conventional rock structures.
Xstream and Xstone can be applied in a large range of applications that are traditionally built with loose rock, pitched rock or smooth block revetments such as:
-     Bed protection (e.g. offshore wind foundations)
-     River training works
-     Detached breakwaters
-     Quay wall protection in harbours
-     Revetment structures
This  abstract elaborates on why flexible and porous structures made of these small-scale [0.2 – 0.6m] concrete armour units are an interesting, low CO2 and eco-friendly alternative for bed protections and river training works.
Breakwaters In A Living Environment
Authors: MEDINA JOSEP R.
Published: May 2024

Breakwaters protecting harbors and coastal areas are key to the economic and social development of many countries, but they are also infrastructures which may result in relevant environmental and social impacts. The construction of new breakwaters in developing countries, together with the dismantling, rehabilitation or repair of old breakwaters in developed countries, should be adapted to the principles of sustainability to produce efficient and resilient systems. Global mean temperatures and sea levels are rising due to climate change, and many environmental variables and numerous ecosystems are evolving. The hypothesis of stationarity, widely assumed in the last century when estimating the wave climate for the design of maritime structures, is now questionable, and new methodologies are required to design breakwaters in this changing environment. Marine life and ecosystems are affected by construction processes and structures, but the interactions are not well known; marine growth and enhanced biodiversity are usually considered positive environmental impacts of most breakwaters but materials, carbon footprint and energy consumption are negative impacts. The two main challenges in breakwater design are (1) to develop sound design methods valid in a changing wave climate and with rising sea levels, and (2) to adapt design guidelines to build-up, to repair and to dismantle breakwaters in a living environment.
DESIGN AND DEVELOPMENT OF CAMPUS ROOM USE MONITORING APPLICATION BASED ON ANDORID WITH MAGNETIC DOOR LOCK IN THE DEPARTMENT OF INFORMATICS AND COMPUTER ENGINEERING UNM
Authors: Nur Annisaa Badia  , Zulhajji Zulhajji , Gunawan Zain Satria
Published: May 2024

The condition of campus room doors that are often open has the potential for misuse of campus rooms that do not comply with the schedule set in the room and affect the security of the room facilities. This research aims to produce an Android-based campus room usage monitoring application using magnetic door locks at JTIK FT UNM as well as knowing the results of functional testing and performance testing or system performance. This research uses the Research and Development method with the Rapid Application Development Development model with stages: needs analysis, system design, system building, validation, testing, and final product. The final product of this research is a system developed in an Android-based room usage monitoring application that is integrated with a magnetic door lock using the QR Code feature. In this case, the system utilizes the ESP32 microcontroller as a chip that receives and provides signals according to the program in the system. The test results obtained validation of the Android-based campus room usage monitoring application using magnetic door locks can be said to be valid and suitable for use.
محددات دعم وتعزيز ولاء الخطوط الملاحية بمحطات تداول الحاويات المصرية (بالتطبيق على محطة دمياط لتداول الحاويات والبضائع)
Authors: عسل محمد عبد الله , عبد الحافظ مصطفى , السمان أمير
Published: May 2024

المستخلص تهدف الدراسة إلى التعرف على تأثير محددات دعم وتعزيز ولاء الخطوط الملاحية بمحطات تداول الحاويات المصرية (بالتطبيق على محطة دمياط لتداول الحاويات والبضائع) حيث قام الباحث بصياغة فرض رئيسي ومنه حدد مجموعة فروض فرعية وكذا مجموعة من التساؤلات لتغطية كافة جوانب هذا البحث. وقد تم الاعتماد على المنهج الوصفي التحليلي لهذا الغرض، حيث استخدم الباحث قوائم الاستقصاء كأداة رئيسية لجمع البيانات حيث تمثل مجتمع الدراسة في عينة المديرين (الخطوط الملاحية ) وذلك باستخدام أسلوب المسح الشامل لعدد (120) مفردة وقد تم استعادة (93) استمارة بنسبة (77.5 %) من جملة الاستمارات الموزعة، وكذلك عينة من مجتمع العاملين بمحطة دمياط لتداول الحاويات والبضائع موضوع الدراسة والبالغ عددهم (1015) عامل وقد تم اختيار عينة عشوائية بسيطة بعدد (279) مفردة من العاملين وذلك لأن مجتمع البحث يعبر عنه بوحدة واحدة بغض النظر عن مستوياتهم الوظيفية ولقد تم استعادة (217) استمارة بنسبة (80%) من الاستمارات الموزعة. ولتحليل بيانات الدراسة ومعالجتها واختبار فروض الدراسة تم استخدام برنامجSPSS vr 25) ) كرزمة إحصائية لإدخال ومعالجة وتحليل البيانات. وخلصت الدراسة إلى مجموعة من النتائج أهمها: أن هناك تأثيرا ذات دلالة إحصائية لكل من (جودة الخدمة – رضا العميل – إدارة علاقات العملاء) على ولاء الخطوط الملاحية في محطة دمياط لتداول الحاويات من وجهة نظر العملاء.
Developments and research directions for collision avoidance in mixed navigation environment for MASS: A systematic literature review with bibliometric analysis.
Authors: Basal Mahmoud , Ammar Alaa
Published: May 2024

ABSTRACT: The integration of advanced technologies, data-driven processes, and automation under the Industry 4.0 revolution is fostering increased connectivity among ships and maritime infrastructures, particularly with the emergence of Maritime Autonomous Surface Ships (MASS) and the imperative for safe navigation. Despite existing studies delving into collision regulations (COLREG), autonomous navigation, and risk assessment for MASS navigation, a comprehensive systematic literature review and bibliometric analysis of academic research studies addressing collision avoidance in the context of MASS within mixed navigational environments has, to our knowledge, not been undertaken. This review aims to provide a concise overview of academic research advancements concerning the challenges associated with MASS and the safety of navigation in mixed navigational environments. To achieve this objective, we conducted a bibliometric analysis of pertinent studies, utilizing metrics and analysis tools to discern academic research topics, primary challenges, and directions in this domain. Our approach adhered to the principles outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) for systematic literature reviews, incorporating tailored keywords in a Scopus search. The results revealed that China, Norway, Poland, and South Korea are the leading countries in MASS collision avoidance, based on the weighted number of authors. Additionally, Ocean Engineering and the Journal of IFAC-Papers Online emerged as the principal journals for publications on this topic. Through the analyzed literature, specific challenges were identified, paving the way for suggested avenues for future research.
Perception of Accent Modification Programs: Assimilation or Racism?
Authors: Kabala Aimee , Montalvan Eleazar , Luna Hinojosa Mariel , Al-Hadel Amher , Sotto-Santiago Sylk
Published: May 2024

Background: International medical graduates (IMGs) represent approximately 25% of practicing physicians in the United States (US), including residents and fellows. Unfortunately, often non-American English accents often challenge professional credibility. In fact, many healthcare providers and scholars in the US face linguistic discrimination. This type of discrimination has not been examined in great depth, especially in academic medicine. Objective: The objective of this study is to examine IMG perspective as they relate to linguistic accent, explore accent modification programs, and analyze the message such programs may send to trainees. Methods: The authors utilized semi-structured interviews. The interviews took place virtually for 30 to 45 minutes. Interviews were transcribed and all response summaries were relayed back to the participant to assure correct meaning. Data was analyzed by 3 authors using the constant comparative method to extract recurrent themes. Secondary data specifically explores accent modification programs. Selection of institutions was purposeful and derived from web searches. We selected eight institutions, which allowed for a content analysis of each institutional website. A final thematic analysis was performed via discussing the themes as a group, inclusive of the publicly available institutional messages. Results: We identified three main themes: (1) perception of accent modification as racist and as forced assimilation, and (2) accent as linguistic discrimination and deficit-based thinking (3) hidden message in accent modification programs. Conclusions: Our research highlights an unsettling sentiment among IMGs: accent modification programs might harbor a racist undertone, potentially suggesting forced assimilation and covert biases. A significant number of participants expressed that perceived accents can be a source of discrimination.
The Climate Migrant: Health Risks Before, During, and After Migration
Authors: Liebman Amy K. , Seda Claire H. , Pagan-Santana Marysel
Published: May 2024

The climate crisis and migrant health are closely intertwined. Climate change is rapidly altering the planet, and migrants are experiencing new and overlapping health consequences as a result. In this article, three subsets of migrants affected by the climate crisis are identified, and the health needs of each are delineated. Climate-precipitated migrants were forced to move as a result of a climate impact like a hurricane or drought. Climate-impacted migrants may have migrated initially for reasons unrelated to the climate crisis, but the social and occupational factors they encounter increase their risk of climate-related health effects during and after migration. Climate workers, the third type of migrant identified, move into regions affected by climate disasters to aid in clean-up and rebuilding, facing significant occupational and environmental health risks. All three types of climate migrants are increasing, but little attention is given to the health and safety of these migrants. Frontline clinicians and community health centers play an increasingly important role regarding climate-related health conditions; up-to-date training of and support for clinicians can reduce climate-related morbidity and mortality, but clinicians on their own are unprepared to systematically address climate health inequity. Regulation needs to anticipate the health impacts of the advancing climate crisis by reinforcing the migration system to enable movement after a crisis and increasing worker protections to facilitate faster and safer climate response and post-disaster recovery.
Case Study: Urgent Medical Care for Asylum-Seeking Infant at US-Mexico Border
Authors:   Migrant Clinicians Network, Garcia Deliana , Seda Claire H. , Madaras Laszlo
Published: May 2024

A 22-month-old male presented at a triage facility within an immigration shelter with wounds, inflammation, and swelling across legs and arms; bloody and pus-filled discharge; skin discoloration, scaling, and swelling; and significant pain. His family had been released from immigration detention after migrating from Central America to the U.S. southern border. The attending triage nurse-midwife immediately transferred the patient to a local hospital for emergency care, in addition to signing the patient’s family into Specialty Care Action Network (SCAN), a pediatric component of Health Network, a virtual system for medical care coordination. After transfer to another hospital for higher level care, where he received a diagnosis of Carvajal syndrome, the patient was sufficiently stable for transport to a hospital in California, his family’s final destination. The resident physician in San Antonio, a SCAN case manager, a network of clinicians, and the medical director in California arranged for his extensive and diverse subspecialty care, through nonprofit funding and charity care in the absence of case management or care for migrants provided by federal immigration and/or health systems.
Migrant Clinicians Network: Championing Health Equity
Authors:   Migrant Clinicians Network, Nolte Kim M. , Madaras Laszlo , Garcia Deliana , Liebman Amy K. , Seda Claire H.
Published: May 2024

As with many underserved populations, migrants, immigrants, and asylum seekers encounter barriers to access culturally responsive high-quality health care in the United States. Clinicians dedicated to serving them struggle to reach them, and lack strategies, resources, and technical assistance to remove barriers to care. Migrant Clinicians Network advocates for these populations’ health needs, develops both patient-facing and clinical resources, and provides services and technical assistance to support clinical care on the frontlines. Migrant Clinicians Network’s goal is to create practical solutions at the intersection of vulnerability, migration, and health. In this article, the authors examine the underserved populations in the United States that Migrant Clinicians Network seeks to serve, and the efforts built to meet their basic health needs.
Sensitivity Plot of cy:{(m4 + 3* m2)*10-4} - Cycle of Money
Authors: Challoumis Constantinos
Published: May 2024

In this work, financial liquidity predominates over escape savings. The velocity of financial liquidity is twice as high as the velocity of escape savings. It uses mathematical definitions by the cycle of money and shows the sensitivity plot of cy: {(m4 + 3*m2)*10-4}. In this case, financial liquidity is identical to the cycle of money. The applied methodology is the S.M. (Sensitivity Method).
The Influence of STEM Learning (Science, Technology, Engineering, Mathematics) Assisted with Android Media on Students' Learning Interest
Authors: Deviana Deviana
Published: May 2024

This research aims to determine the significant influence of STEM learning assisted by Android media on students' interest in learning. This type of research is quantitative research, with a Quasi Experimental Design, Non Equivalent Control Group Design. The instruments used were learning outcomes tests and questionnaires, then analyzed using prerequisite tests in the form of normality tests, linearity tests and hypothesis tests using the t-test. The results of the research show that there is a significant influence of STEM learning assisted by Android media on students' interest in learning at X SMAN 2 Tabanan. This result can be seen from the results of the Independent sample t-test with ????ℎ???????????????????? 2.720 and ???????????????????????? 2.211 so that we get ????ℎ???????????????????? > ???????????? ???????????? with a significant value of 0.028 is smaller at the 5% significance level. The learning outcomes obtained by the experimental class were higher than those in the control class.
Risk Factors Associated with the incidence of ISPA in Toddlers (1-5 Years) in the Working Area of North Singkil Health Center, Aceh Singkil Regency
Authors: Syahriazi  , Fahdhienie Farrah , Ariscasari Putri
Published: May 2024

Upper respiratory tract infection (ARI) is a disease of the upper or lower respiratory tract, which is contagious and can cause a wide spectrum of diseases from asymptomatic to severe and deadly disease. The research aimed to determine the risk factors associated with the incidence of ISPA in toddlers in the North Singkil Community Health Center Working Area, Aceh Singkil Regency. This research is analytical with a case-control research design. Data collection was carried out by interviews using questionnaires. The population in this study was 116 toddlers with a sampling technique, namely Simple Random Sampling. Data collection was carried out on 18-26 July 2023. The analysis used was univariate and bivariate using the Chi-Square and OR statistical tests. The research results show that cigarette smoke is associated with the incidence of ARI with a p-value of 0.001, OR 4.424, LBW p-value 0.004, and OR 3.367, knowledge with a p-value of 0.002, and OR 3.670, immunization status with a p-value of 0.001, and OR 3.868, breastfeeding with p value 0.005, and OR 3.148. Conclusion There is a relationship between cigarette smoke, LBW, immunization status, and breastfeeding with ARI in toddlers. It is hoped that research sites will provide health education about ISPA by holding health education.