bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the effect of Lake Erie dredged sediment on soil properties and specialty crops development
Authors: Sequeira Juan Pablo , Vázquez‐Ortega Angélica , Oyewumi Olusola , Signorini Guilherme
Published: August 2024

To maintain harbour navigability, significant quantities of sediments are annually dredged and disposed of in the vicinities of Lake Erie. This study aimed to assess the impact of Lake Erie sediment on the productivity of tomatoes, lettuce, and carrots. Using a greenhouse setting, this experiment evaluates different sediment‐farm soil ratios: 100% farm soil (Farm Soil), 100% lake sediment (Sediment), and a blend of 10% dredge sediment and 90% farm soil (Mixture). We evaluated the chemical and physical composition of the treatments and the development of the roots, leaves, and fruit production for each crop. Additionally, Total Organic Carbon (TOC), Total Nitrogen (TN), and Total Phosphorus (TP) were assessed post‐harvest for each crop's roots, leaves, and fruit biomass. The Sediment treatment showed higher pH, Cation Exchange Capacity (CEC), Calcium, and TOC but lower magnesium, phosphate, and potassium compared to Farm Soil. The Sediment and Mixture treatments exhibited higher root and leaf dry weights for lettuce compared to Farm Soil, with the Sediment treatment showing the longest roots. Sediment and Mixture treatments in carrots led to greater root weight and length. Tomatoes submitted to the Sediment treatment excelled in all variables except stem diameter. Lettuce and carrot biomass analysis revealed no statistical differences in TOC and TN among the treatments. Tomato biomass analysis showed no differences among the three treatments. The use of Lake Erie dredged sediment led to increased crop biomass in the greenhouse production of tomatoes, carrots, and lettuce.
Transfusion Camp: The UK experience and its value in improving knowledge of transfusion medicine among postgraduate trainees
Authors: Aggarwal Asha , Kaushik Kunaal , Morton Suzy , Danaee Anicee , Gurung Kamala , Robinson Susan , Kapitany Casey , Charge Sophie , Lin Yulia , Desborough Mike , Murphy Michael F.
Published: August 2024

Objectives

To report the UK experience of rolling out Transfusion Camp.

Background

Transfusion Camp is a structured education programme developed in Toronto, with the aim of reducing knowledge gaps in transfusion medicine in postgraduate trainees. It consists of didactic lectures viewed online by the participants, then interactive, locally delivered seminars. Since 2015, it has been rolled out in the United Kingdom, and is now available in four centres. Here, we report the UK experience of Transfusion Camp and outcomes.

Methods

Trainees are recruited via the training programme directors in each region. Pre‐ and post‐course assessments are administered using the validated BEST (Biomedical Excellence for Safer Transfusion) test, with possible scores 0–20, and confidence measured on an A‐E Likert scale.

Results

Since 2015, 130 trainees have participated in Transfusion Camp in the United Kingdom. Trainees from all specialties significantly improved their BEST‐test scores after attending the course (mean score 11.6/20 before the course, compared with 14.3/20 after the course), and confidence in managing transfusion‐related issues was also significantly improved.

Conclusion

We recommend that all centres consider offering Transfusion Camp to trainees in haematology and other specialties that frequently use blood transfusions, such as anaesthesia/ICU, Internal Medicine and others.
Stability of immunohaematological reagents used for blood typing of recipients in the tube technique
Authors: Hermes Julia , Carloto Mariane Stefanes , Leal Amanda , Martinello Flávia
Published: August 2024

Background and Objectives

The storage temperature of immunohaematological reagents generally ranges from 2 to 8°C, and they should be utilised at room temperature. This study aimed to analyse the stability of immunohaematological reagents used in ABO and RhD typing.

Methods

The evaluation encompassed the potency, specificity, and integrity of anti‐A, anti‐B, anti‐D, RhD control sera, and A1 and B red blood cells (RBC) reagents after long (8 h) and short (4 h) daily periods of exposure to room temperature (20–24°C), 5 days a week for 4 weeks. Additionally, the A1 and B RBC reagents were exposed daily for 11 h and 30 min at room temperature, including 30 more minutes at room temperature with simultaneous homogenisation through equipment. For the control, an aliquot of each reagent was constantly stored at refrigeration temperature, while another was exposed to room temperature for 12 h daily. Tests conducted included reaction intensity, titration, and avidity for antisera, reaction intensity, free haemoglobin determination, and electrical conductivity for the RBC reagents.

Results

The antisera maintained the reaction intensity. The titre and avidity of the antisera satisfied the minimum Brazilian requirements after different exposure periods. A higher free haemoglobin concentration was noted in the RBC reagents subjected to room temperature and simultaneous homogenisation, although this did not affect the potency and specificity. The electrical conductivity average of the RBC reagent remained consistent.

Conclusion

The findings indicate that the immunohaematological reagents from a specific manufacturer are stable under the tested temperature, ensuring the quality of the results under these conditions.
Simplified medial canthoplasty: Technique and early postoperative complications in 601 dogs (1180 eyes)
Authors: Allgoewer Ingrid
Published: August 2024

Purpose

To present a novel modified medial canthoplasty (MCP) technique, the application in 601 dogs (1180 eyes), and a review of the early postoperative complications related to the technique.

Introduction

Macroblepharon and nasal entropion is a common presentation in many brachycephalic dog breeds promoting chronic keratitis. The previously described MCP techniques limit the medial shortening of the eyelids to the location of the lacrimal puncta. A novel technique was developed allowing for a more extensive eyelid shortening nasally.

Methods

The modification of the here described technique includes the longitudinal splitting of the lacrimal canaliculi allowing for an extensive shortening of the lids beyond the lacrimal puncta. Records of 601 dogs which underwent the modified MCP were reviewed regarding breed, indications for surgery, follow‐up, and early postoperative surgical complications. Descriptive statistics were applied.

Results

Six hundred one dogs (1180 eyes) were included in this study. Twenty‐four different breeds underwent the simplified MCP with the Pug (n = 403) being the most represented breed. Indications were macropalpebral fissure, medial entropion, pigmentary keratitis, trichiasis by haired caruncle, strabismus after globe prolapse, and facial nerve paralysis. The overall complication rate was 1.01% (12/1180) and consisted of wound dehiscence 0.59% (7/1180), corneal ulceration caused by suture material 0.25% (3/1180), and wound infection (2/1180). None of the 601 operated dogs developed serious complications related to the surgical technique.

Conclusions

The simplified MCP is a novel technique with a very low complication rate.
Autoequivalences of blow‐ups of minimal surfaces
Authors: Hu Xianyu , Krah Johannes
Published: August 2024

Let be the blow‐up of in a finite set of very general points. We deduce from the work of Uehara [Trans. Amer. Math. Soc. 371 (2019), no. 5, 3529–3547] that has only standard autoequivalences, no non‐trivial Fourier–Mukai partners, and admits no spherical objects. If is the blow‐up of in 9 very general points, we provide an alternate and direct proof of the corresponding statement. Further, we show that the same result holds if is a blow‐up of finitely many points in a minimal surface of non‐negative Kodaira dimension which contains no ‐curves. Independently, we characterize spherical objects on blow‐ups of minimal surfaces of positive Kodaira dimension.
Tracking Algorithm Application Integrating Visual and Radar Information in Intelligent Vehicle Target Tracking
Authors: Wang Yu , Shi Jianfei , Zhao Yu
Published: August 2024

With the continuous development of various automobile technologies, the concept of intelligent automobile automatic driving has been introduced into people's lives, and it has great research value in traffic safety, traffic efficiency, and other aspects. Intelligent vehicles can accurately identify and track the target vehicle, which is one of the important preconditions for safe driving. However, a single tracking algorithm is often used in traditional intelligent vehicles with a low tracking accuracy under adverse circumstances. To solve this problem, a fusion tracking algorithm combining visual tracking and radar tracking algorithm is proposed, and intelligent vehicle target-tracking technology is constructed based on the fusion algorithm. Through the performance comparison test, it was found that the fusion algorithm proposed in the study had the highest accuracy of 93% and the highest F measure of 0.98, both of which were superior to the comparison algorithm. Then, an empirical analysis is made of the target-tracking technology proposed in the study. The results showed that the error range of yaw angle velocity of the target vehicle was −0.48 to 0.36, and the maximum root-mean-square error of lateral and longitudinal distance of the target vehicle detected by the technology was 0.03, which was superior to other tracking technologies. To sum up, the intelligent vehicle target-tracking technology proposed in the research can improve the accuracy of intelligent vehicle target tracking and provide a guarantee for the safe driving of intelligent vehicles.
Process-Induced History Effects on the Mechanical Behavior of Additively Manufactured IN718 Alloys
Authors: Sharma Saurabh , Beura Vikrant Kumar , Darling Kris , Solanki Kiran
Published: August 2024

The design complexities with advancements in technology limit the operational efficiency and conventional manufacturing ability of Nickel-based superalloy 718 (IN718). Additive manufacturing (AM) can overcome these drawbacks by producing near-net shape components; however, a thorough understanding of mechanical behavior at elevated temperatures and different loading conditions (i.e., tension and compression) is required before its actual use. In this work, process-induced history effects on the mechanical behavior in an additively manufactured IN718 alloy were investigated. In particular, two different heat treatment routes were chosen to tailor the microstructure by having the specific dissolution of precipitated phases. Quasi-static (QS) and creep experiments were performed in both as-build and postprocessed conditions. The build directions and the nature of the phases present were observed to be the governing factors. Results showed that the horizontal orientation had higher yield strength compared to the vertical orientation, irrespective of loading condition. Compression and tensile creep experiments indicated that the creep life was dependent on the orientation of δ/Laves phases. Furthermore, a tension-compression asymmetry was observed in both QS and creep testing. Overall, postprocessing proved to be advantageous in improving mechanical behavior and reducing the anisotropy related to the build direction.
A Cyberphysical Structural Health Monitoring Framework for Threshold-Free Active Signal Detection and Classification on the Edge
Authors: Gullapalli Anirudh , Aburakhis Taha , Featherston Carol , Pullin Rhys , Morini Lorenzo , Kundu Abhishek
Published: August 2024

The increased focus on predictive maintenance of safety-critical engineering structures requires an onboard structural health monitoring system, which is reliable and robust to provide accurate predictions of health metrics of structures while also being efficient and streamlined to facilitate autonomous data processing and real-time decision-making capabilities. An onboard structural health monitoring system with the capability to continuously monitor and interrogate a structure, describe its current state, and assess the operational risks of the degraded structure needs to be developed and matured so that it can be deployed in practical, real-time monitoring scenarios. This would constitute a cyberphysical system in structural health monitoring. A cyberphysical system is a mechanism that is controlled by computer-based algorithms integrated with the Internet and working with users. There exists a physical domain that is under examination and its digital counterpart, which is informed by data from the physical as well as simulation models. While there exist multiple surveys on the overarching advantages, limitations, and potential of realizing a cyberphysical system, innovation on structural systems, in-line signal processing, and damage event detection in the context of a cyberphysical system, especially from an experimental point of view is still in its infancy. In this work, we implement a versatile cyberphysical framework—CyberSHM using a sparse network of transducers and an edge computing device. Hosted on the structure of interest, the transducers possess the capability to interrogate the structure continuously, periodically, on-demand or autonomously when triggered by damage or an unplanned acoustic event. In addition, the device also possesses efficient on-edge feature extraction and signal classification capabilities, which serve as crucial starting points for further damage analysis and characterization on the digital layer.
Constituting and Investigation of Ion-Implanted Protective Layer on NiTi Alloy for Mechanical and Tribological Applications
Authors: Levintant-Zayonts N. , Starzynski G. , Kucharski S.
Published: August 2024

NiTi exhibits an excellent wear resistance, which can be further enhanced by ion implantation. However, there are some limitations to the implantation effects: only a thin layer of about 100 nm can be created. In this paper, the effect of nitrogen ion implantation on the NiTi wear response is investigated. The different loads and durations of tests are taken into account to show that the implanted layer has the most beneficial effect only in a certain range of contact pressure. It was found that the wear volume changes in a non-linear manner with respect to the load and sliding length, for both non- and implanted samples. For the latter, two distinct stages can be distinguished in the wear process: an initial stage characterized by a low wear-rate and a low coefficient of friction, and a second stage in which the wear-rate drastically increases. The duration of the first stage is longer for lower loads. This specific behavior is explained by differences in the hardness distribution, energy dissipation due to the normal load, and differences in the microstructure of the wear tracks. Our results show that the lifetime of NiTi can be improved by ion implantation, thus boding well for applications in harsh environments.
Study of the Influence of Pre-Drilled Holes on Weakening the Rocks and Enhancing the Rate of Penetration
Authors: Abugharara Abdelsalam N. A. , Alwaar Abourawi , Futheiz Ibrahim , Butt Stephen D.
Published: August 2024

Improving the drilling Rate Of Penetration (ROP) is a target for oil and gas drilling companies. However, efficient drilling performance is not only measured by the improvement of ROP, but it is also measured by minimizing the mechanical specific energy, minimizing the bit wear rate, minimizing the NonProductive Time (NDP) impacted by the pre-mature bit wear and failure, as well as by reducing the overall drilling cost. Another approach of improving drilling performance is sought through optimal applications of drilling parameters including sufficient fluid flow rate for efficient hole cleaning and bit ball prevention, applying adequate Weight On Bit (WOB) that induces effective Depth Of Cut (DOC) without negatively inducing the bit wear rate to increase, and at optimal rotary speed. This research focuses on applying various techniques through multi stage drilling and coring in high strength formation using PDC bits and natural diamond impregnated coring bits to investigate potential micro cracks generation. The analysis of drilling and coring data includes evaluation of input drilling parameters such as WOB and rotational speed as well as the output data of ROP, DOC, torque, etc. The drilling experiments were laboratory based using a large lab scale of a fully instrumented drilling simulator. A high strength rocks were drilled, and water flow rate was used. Different applied WOB and rotational speeds were applied. The results of the analyzed data indicated variation in ROP (increasing and decreasing) when drilling different stages at the same conditions of the applied parameters. ROP was increased parallel to the predrilled section, where the ROP was found decreases when drilling the un-predrilled section. Corresponding data of torque also supported the ROP increase vs. which was influenced by possible rock weakened due to possible micro cracks generation in the predrilled section. Data analysis, results, and conclusions are reported.
Dashpot-Enhanced RVE Model for Simulating Bending of Three-Core Submarine Power Cables
Authors: Li Xiao , Jiang Xiaoli , Hopman Hans , Bai Yong , Liu Zhuangjian
Published: August 2024

This study presents a Representative Volume Element (RVE) model for predicting the bending stiffness of three-core submarine power cables used in offshore wind farms. The RVE model, developed with constant curvature and periodic conditions, incorporates a dashpot technique to address stick-slip challenges associated with cable bending. Bending tests were performed on one-core and three-core cables to serve for model calibration and validation, separately. The dashpot coefficient in the RVE is first calibrated through the one-core bending test. Subsequently, the calibrated model is validated using the three-core bending test. This work demonstrates the capability of the dashpot-enhanced RVE in predicting bending stiffness of three-core cables.
On the Performance of a Novel Hinged Type Wave Energy Converter
Authors: Jin Siya , Guo Bingyong , Chen Lifen , Xu Sheng , Yang Kunde
Published: August 2024

This paper aims at carefully studying the performance of a novel two-body hinged wave energy converter (WEC). Two different types of WEC are investigated: a counterpart using the generic two-body hinged-type WEC composed of two cubic floating bodies and a designed novel two-body hinged WEC composed of floating bodies with wave channels. The wave channel consists of two side walls, an inclined base and an end wall connected to the main floating body. Physical tank tests, CFD simulations and WEC-Sim modelling are employed in the study. Validated by the physically obtained data (including wave elevation, torque force, surge force and heave force acting on the body), the CFD modelling is shown to be capable of presenting the hydrodynamic interaction between the wave and the novel body with wave channel. Additionally, unlike the traditional cubic body, the body with wave channel is able to receive the incoming wave to change the mass properties of the WEC. As a result, the resonance frequency of the designed hinged WEC can vary under different wave conditions, leading the WEC device to have a broader wave capture band. Moreover, a CFD numerical wave tank is built to model the interaction between the wave and the hinged-type WEC with expensive computation however. A fast-solving WEC-Sim modelling is, therefore established to simulate the hydrodynamic response of this novel hinged-type WEC. The results show that the designed hinged type WEC with wave channels has better hydrodynamic performance compared to the generic hinged WEC.
Numerical Analysis of Structured Sheet Material in Flexible Oscillating Water Column Wave Energy Converter
Authors: Huang Yang , Idarraga Guillermo , Xiao Qing , Yang Liu , Dai Saishuai , Abad Farhad , Brennan Feargal , Lotfian Saeid
Published: August 2024

To improve the power output and reduce the stress levels for Flexible Wave Energy Converters (FlexWECs), a structured material using a sheet of natural rubber with a specific pattern called NR937 is developed in this research. Mechanical characterisation tests are conducted to determine the material properties, and the YEOH hyper-elastic model is employed to capture the nonlinear behaviour of this material. Fluid-structure interaction simulations are performed for a FlexWEC using a CFD-FEA tool. The responses of the Poly-A-OWC model equipped with both the innovative NR937 material and a conventional sheet of Natural Rubber (NR) are compared, and the deformation of flexible membrane, stress distribution, flow field, and power output are all fully explored. The results indicate that at resonance, the deformation amplitude of the flexible membrane using NR937 is increased by 1.3 times compared to that using NR, while the maximum stress increases by only 12%. Additionally, the peak power output of the Oscillating Water Column (OWC) Wave Energy Converter (WEC) utilizing NR937 is approximately 2.6 times higher than that of the WEC using NR. This suggests that structured sheet materials possess potential for improving the performance of FlexWECs, including increasing power output, reducing stress levels in flexible membrane and extending the service life.
Design Analysis of Shared Mooring for Floating Offshore Wind Farm
Authors: Li Binbin , Wang Chenyu , Yang Lei , Zhao Wenhua
Published: August 2024

The development of wind energy in deeper waters presents numerous advantages; however, floating offshore wind turbines (FOWTs) face challenges, primarily in terms of their higher levelized cost of energy (LCOE) compared to onshore and fixed offshore turbines. To address this, the concept of a shared mooring system has emerged as a potential solution to reduce costs. However, practical application and validation of this concept in real-world engineering projects are yet to be realized. Consequently, there is a lack of design methodology, specialized analytical tools, and industrial rules for the design and analysis of shared mooring systems. This study aims to summarize the latest research efforts in developing a methodology for the design and analysis of shared mooring systems. Various levels of dynamic models, including the spring-mass model, quasi-dynamic model, and fully coupled sub-model, are discussed. A dedicated module for shared mooring analysis has been developed within the in-house software KraKen. The study explores design constraints, considerations, modal characteristics, global performance, transient effects resulting from sudden line loss, adaptability of different mooring line models, and structural redundancy of the entire system. These aspects are examined through numerical simulations and a survey of existing rules. By consolidating these research findings, the authors aim to contribute towards establishing a comprehensive framework for the design and analysis of shared mooring systems of floating wind farm.
Dynamic Response Analysis of Bio-Inspired TSUSUCA DOLPHINPatented
Authors: Chandrasekaran Srinivasan , Patil Basanagouda I. , A. Meher Prasad
Published: August 2024

The devastating impacts of tsunamis on humans and strategic infrastructure for naval defence emphasize the requirements for coastal protection. Further, offshore floating platforms are deployed extensively to accommodate the expanding need for oil and gas exploration and wave and wind energy extraction. They are commissioned for limited applications, making them uneconomical. In the present study, a novel attempt is made to combine the functional aspects of coastal protection with energy harvest. The current study focuses on dynamic response analysis of one such novel platform TSUSUCA DOLPHINPatented to act as a tsunami barrier in addition to a wave energy extracting device. Apart from wave energy extraction, solar panels are placed on the deck for additional energy capture. The design follows a bio-inspired geometry to attract tourists under normal sea states. The dynamic response of the multi-body by considering 2 TSUSUCAs is presented. The suggested platform’s dynamic response under regular and irregular waves is being studied numerically and experimentally. The design’s proposed motion characteristics, notably heave and pitch, aid in the capture of wave energy for a wide variety of wave amplitudes. This allows the TSUSUCA body to move in an oscillating motion in the vertical plane, one of the platform’s critical activities: tsunami protection.
Development and Application of a Digital Tool for Real-Time Corrosion Monitoring and Decision Support in Well Integrity Management
Authors: Wu Bohong , Wang Bei , Shi Shuzhe , Nie Zhen , Chen Yingfeng
Published: August 2024

Well integrity management is essential for preventing well leakage and ensuring the optimal performance of oil and gas wells. Existing downhole monitoring tools are complex to install and unable to monitor the corrosion condition along the wellbore. These drawbacks limit the effective support for well integrity management and increase potential HSE risks.

Therefore, a new digital and visual corrosion management platform was developed to overcome these challenges and enhance well integrity management. This dashboard links to the oilfield database to obtain dynamic real-time data, integrating it with static data through manual integration to form a wellbore integrity database with over 46 types of data. Advanced corrosion rate prediction models were established based on this database, developing modules for single well corrosion rate monitoring, remaining wall thickness and life prediction for tubing, and early warning of corrosion status in oil and gas fields. This dashboard is currently the only tool capable of calculating corrosion rates for gas lift wells, dynamically displaying corrosion risk and integrity parameters for various types of wells, providing support for intelligent decision-making in oil and gas fields. It also offers quick recommendations for material selection through simple parameter input to support wellbore integrity management.
Numerical Investigation of Mooring System and First-Year Ice Ridge Keel Interaction
Authors: Chen Jiaming , Zhou Li , Ding Shifeng , Ding Yi
Published: August 2024

This work focuses on develop a new mooring cable-keel interaction model to investigate the dynamic response of mooring system for moored structures in Arctic regions. Since the ice ridge volume change during failure process of cohesion, it is more practicable to use a constitutive model considering deformation accumulation and stiffness decay in the interaction between slender body and ice ridge keel. A formula for the relationship between the contact index and the porosity between the brash ice is presented, and the breaking condition of the ice ridge keel is described according to the relevant critical state. The simulation results are compared with model test data to verify the accuracy of the new interaction model. The plastic failure mode can be directly applied to predict the ice ridge load on the mooring cable, and the mooring cable gradually breaks the ridge keel as the ridge drifts motion. The result of tension distribution and dynamic response on the mooring cable can provide some significant hints for the design of mooring system for moored structures.
Long Horizontal Slim-Hole Cementing Technologies for Cost-Effective Development in a Middle East Ultra Low Permeability Reservoir
Authors: Nie Zhen , Shi Shuzhe
Published: August 2024

The Sadi ultra-low permeability reservoir accounts for more than 25% geological reserves of a giant Middle East Oilfield. 70 horizontal wells with more than 5000m MD have been planned and the infinite stage cementing fracturing technique are proposed in 1000m-2000m horizontal section for Sadi reservoir cost-effective development. The liner cementing quality in long horizontal section is the key to the success of good zonal isolation and premises of effective hydraulic fracture operation.

To improve the efficiency and performance of 4 1/2″ liner cementing, a comprehensive series of numerical simulation of cementing process and experimental research of core additives have been carried out to overcome slim-hole cementing challenges such as poor centralization, insufficient mud removal or displacement, and low cement bond quality. The cementing operation procedure was optimized including centralizer selection, cementing liquid volume design, Rheological property design and cementing operation parameters. The integrity mechanical model of cement sheath was established so that to design the high efficiency washing space fluid and flexible cement slurry based on experimental results.

By simulating mud removal and cement slurry placement process, integral elastic centralizer and centralization program was recommended, sequence of cementing fluid with appropriate density and volume was determined. the rheology property of Spacers/ Lead slurry / tail slurry was determined in view of the friction resistance hierarchy concept, and variable pumping procedure has been optimized to achieve better effective mud displacement. Meantime, the mechanical properties of the cement sheath was demonstrated by integrity analysis under the condition of multistage fracturing in horizontal section, and concluded that cement sheath shall meet the requirements of Elastic modulus < 6.5GPa, Poisson’s ratio > 0.18, Compressive strength > 24MPa, Tensile strength < 2MPa. In terms of cementing fluid. A new toughening agent was also developed to improve the mechanical property of cement sheath to meet the requirements of infinite stage cementing fracturing operation.

Liner cementing key techniques has been developed to achieve effective zonal isolation and good cement bond quality in challenging long horizontal slim-hole cementing and application in-site horizontal well cementing job and achieved the good cement bond quality, this technology is expected to deliver a successfully optimized liner cementing operation for future horizontal wells cementing.
Deterministic Sea Wave Prediction Based on Radar Images Via End-To-End Deep Learning Methods
Authors: Zheng Yaokun , Lin Zhiliang
Published: August 2024

Deterministic sea wave prediction (DSWP) based on radar images is meaningful in ocean engineering. Achieving accurate and efficient methods for predicting nonlinear waves remains a challenge. In this paper, spatiotemporal reconstruction and prediction based on radar images via deep learning methods are investigated. The radar images are synthetic and based on the 2nd order Lagrange wave model. The Fourier neural operator (FNO), which integrates Fourier transform and deep learning, and ConvLSTM, which is a classical spatiotemporal forecasting network, are tested. The direct prediction approach and multitask learning approach are introduced and evaluated. The results show that the FNO with multi-task learning approach performs effectively in the presence of noise and under multiple wave steepness. The results confirm the feasibility and performance of deep learning method for DSWP based on radar images.
Elastic-Plastic Buckling Analysis of a Ship Circular Hollow Pillar Under Compression and Bending Loads: Analytical Resolution and Comparison to Finite Element Analysis
Authors: Nicolas Aurélien , Conti Fabien
Published: August 2024

Pillars have various applications in ships and maritime structures. They can undergo bending, torsion and compression loads. Their limit state can be determined through finite element analysis, considering their geometric characteristics, material and applied stresses. However, finite element modelling can be less easy to handle than an analytical solution, especially when large numbers of calculations are needed.

In this study, we present the results from 1D analytical analysis considering an initial compression stress and two different moments at each end of the pillar — implying that a transverse force was applied at one end. This represents a typical ship pillar between two consecutive decks.

The physical problem statement consists of the resolution of a first order coupled differential system of four equations. Solving this problem numerically accounting for large displacements and elastic material behavior yields solutions very close to the finite element modelling. We finally developed an elastic-plastic analysis of the same problem. Analytical resolution consisted of the derivation of a moment-curvature law including elastic and perfectly plastic behaviors. To derive this law, compression and moment are applied on a cross section of the beam. In the elastic behavior, bending stress and curvature are related through Young’s modulus and inertia, whereas once yield stress is attained no additional stress can be carried in the yielded surface and a new moment-curvature relationship must be developed: In a given cross section, bending stress varies linearly around the neutral fiber (which position depends on the compression stress and curvature) until yield stress is eventually attained. Above and below the position where the yield stress is attained, bending stress remains constant and equal to the material yield stress.

The full analytical procedure is the following: let us first apply the compression stress in a uniform manner in the beam cross section. Then, curvature is increased step by step, and we let plasticity arise and penetrate from the inner part of the curved beam. Integrating the moment over the cross section at each curvature step allows to build the moment-curvature relationship. Analytical results were compared to finite elements analysis; and turned out to be similar with a discrepancy falling within a few percents for both full and hollow pipes.

Finally, we used the moment-curvature relation that was developed to derive the full elastic-perfectly plastic solution with a numerical model; and compared to FEA results.
Exploring the Use of Field Data to Improve Predictions of Pipeline As-Laid Embedment
Authors: Taner Yasar , Hou Zhechen , Bransby Fraser , Watson Phil , Low Han Eng
Published: August 2024

Reliable prediction of as-laid embedment for surface-laid offshore pipelines is important for predicting seabed resistance during operation. However, the accuracy of existing methods can be limited by various challenges: difficulties in determining representative, very near-surface soil properties (either by field or laboratory investigation), inherent seabed variability including bathymetry, and changing/ complex lay conditions.

Given significant experience across the offshore sector with installing offshore pipelines, this study explores the potential to predict as-laid embedment directly from field cone penetration test (CPT) results. Part of the ARC ITRH Transforming energy Infrastructure through Digital Engineering (TIDE), the installation data for two parallel flowlines from a single project on the Northwest Shelf of Australia are used to show that correlations can be made between cone resistance and pipeline embedment — if the cone data is used appropriately. By comparing the observation based correlations with predictions made using current industry practice, the potential to develop a data informed method to predict pipeline as-laid embedment is demonstrated — with the current study to now be extended to other sites, and (if relevant) to consider parameters other than cone resistance to improve the approach.
Validation of a Time Domain Panel Code for Prediction of Impulsive Wave Loads on Container Ships
Authors: van Walree Frans , Grin Rob
Published: August 2024

The focus of the paper is on the prediction of wave loads experienced by a 20kTEU container ship. The principles of the potential flow panel method to predict motions and loads are briefly described. A description of scale model tests is given. A number of validation cases are discussed, whereby experimental and simulated time traces and frequency spectra of accelerations, shear forces, torsion and bending moments in regular and irregular waves are compared. Particular attention is paid into the prediction of whipping and springing phenomena.
Digital Twin for Floating Offshore Wind Foundations Operation and Maintenance Management
Authors: Halme Jari , Souza Ramos Ieza , Mikkola Eeva
Published: August 2024

In the offshore industry, environmental conditions typically have a significant effect on operation performance, maintenance, and total costs.

In this study, predictive maintenance tools were developed in the context of a floating testbed structure (FTB), a cylindrical buoy with features representative of the maintenance needs of floating offshore wind foundations. The FTB was measured dynamically and statistically over the local weather conditions at a harbor in Portugal. A digital twin of the FTB was constructed using the data to assess mooring line loads and hydrodynamic responses at a different place in the Atlantic Ocean.

One major factor restricting operation and maintenance is exposure to dynamic motion. A limiting criterion was demonstrated for heavy manual work based on short-length moving root-mean-square (RMS) values of vibration, acceleration, and roll/pitch. For operational state, history, and statistical analysis, RMS values were profiled as to time-at-level to evaluate the probability of a maintenance weather window and the suitability for maintenance deployment.

FTB digital twin data was used to analyze mooring line loading and remaining useful life (RUL) to provide deterministic decision-making support for justified inspections and structural health monitoring (SHM) under different marine sea state conditions. The approaches shown can also be used for flagging sea-state conditions that are leading to premature failures and reduced lifetime.
Examination of an Analytical Approach for Load-Displacement Behavior of Drag Embedment Anchors and Their Geometrical Optimization
Authors: Dao Duy Anh , Grabe Jürgen , Chmelnizkij Alexander
Published: August 2024

Floating offshore renewables require anchorage to the seabed, often applying drag embedment anchors (DEAs). Industry standards use analytical solutions for evaluating DEA holding capacity and displacement behavior, but their complexity causes challenges in interpretation. This research provides a parametric and graphical analysis of a key analytical solution used internationally to predict the load-displacement behavior of DEAs in clay. It aims to clarify this solution’s calculations and identify optimal DEA geometry. Optimal shaft and fluke lengths for a simplified DEA are determined based on weight and cost-effectiveness (minimum volume) and safety (maximum bearing capacity and penetration depth). A solution set is presented, showing various optimal solutions tailored to predefined objectives. Comparative examination of ten DEA configurations reveals that no single design is universally optimal. Instead, strategic balancing of objectives, such as operational efficiency, cost-effectiveness, and safety margins, is essential. This approach underscores the need for a holistic view in DEA design, accommodating diverse objectives to achieve effective anchorage solutions. In conclusion, the study validates the applicability of established analytical solutions in predicting DEA behavior and in determining optimal geometries. These insights are crucial for economic efficiency and safety, offering guidance for future sustainable and reliable offshore infrastructure design.
Experimental Study of Deflector on Scour Reduction Around Artificial Reef
Authors: Liu Xianyi , Wang Xinxin , Zhao Fenfang , Tang Yanli
Published: August 2024

Artificial reefs play a vital role in marine ecosystem restoration, yet their effectiveness is compromised by local scouring, leading to settlement and burial. This study focuses on mitigating scouring around a cubic artificial reef (CAR) (100mm × 100 mm × 100 mm) through the strategic installation of deflectors. A series of 17 local scour model experiments were conducted by varying deflector shapes (flat plate, curved plate), quantities (1, 4 (full-enclosed)), deflector angles of attack (30°, 45°, 60°), and deflector heights (3 mm, 0 mm, −10 mm, −20 mm) from the sand bed. The experiments were carried out in a 15000 mm × 400 mm × 500 mm scour flume, and were scaled per Froude’s criterion (λ = 1:20), with an average velocity u0 = 0.246 m/s and clear water scour conditions. The main findings include: (1) The angle of attack significantly influences the extent of scour holes upstream of the artificial reef with a single-sided deflector, with minimum scour observed at 60°; (2) Deflector height significantly impacts the distribution of scour holes, with the −10 mm height inducing more serious downstream accumulation and larger upstream scour hole range than those with 3 mm and 0 mm height; (3) Full-enclosed deflectors demonstrate superior scour prevention, which decrease the maximum scour depth by 28.0%. So it provides an essential support to prevent reef overturning. In terms of scour topography, sand beds on both sides of reefs with full-enclosed deflectors exhibit pile-up, contrasting with minimal accumulation around reefs with single deflectors. Finally, the range analysis results show that the deflector shape has a more significant impact on the maximum scour depth and length of the scour hole compared to the installation height of the deflector. Our research explores the use of a flow-altering method as a scour countermeasure for the CAR, demonstrating that a specially designed deflector can effectively reduce local scour.
Numerical Investigation on Hydroelastic Response of a Model Ship in Regular Head Waves
Authors: Zhang Han-Wen , Zhu Ling , Liang Qi-Yu , Dai Shao-ling
Published: August 2024

With the increasing size of ships, their flexibility plays a more and more important role in ship motion predictions. However, existing numerical prediction of ship motion in regular waves usually does not consider the elastic response of the ship, which often regards the ship as a rigid body. Therefore, hydroelastic effects on ship motion need to be taken into account in the research. With the continuous progress of advanced research, many studies on ship hydroelastic response have emerged, but most of them still stay in the hydroelasticity theories based on potential flow theory or the one-way coupling numerical simulation based on RANS/CFD and FEM. To strengthen the interaction between fluid and structure, this paper uses the two-way coupling between fluid solver Star-CCM+ and finite element software Abaqus to calculate the vertical motion RAOs of a model ship at different measuring points in regular head waves. The two-way coupling method exchanges real-time data of pressure and nodal displacements between the fluid domain in Star-CCM+ and the three-dimensional structural model in Abaqus, and uses the mesh morphing method to simulate the motion of the ship. The computational results are compared with the solution of the rigid body calculated by Star-CCM+, the results predicted by fluid solver ANSYS-AQWA based on three-dimensional potential flow theory and model test results, which verifies the feasibility of the two-way coupling method.
Design and Optimization of Layout and Dimensions of the M4 Wave Energy Converter System Under Regular and Irregular Waves
Authors: Wang Wei , Xie Yonghe , Zhang Jiping , Li Gangqiang
Published: August 2024

In this paper, we discuss the dimension optimization of a single floater and the layout and geometry optimization of the M4 wave energy converter system. The M4 system has a single bow float and one or more middle floats in a rigid connection. The stern float is connected to the center floats by a transom, and the hinge above the center floats carries a damper for power conversion. For the calculation of the hydrodynamic coefficients, the FHLAN hydrodynamic coefficient solver is used to calculate the single-floater hydrodynamics, and the commercial software WADAM is used to calculate the coefficients of the hydrodynamics of the multi-floater hydrodynamics. In this paper, with a given configuration (the number of floaters is constant), a constrained optimization problem is well established. An optimal distance between each floater and the optimal geometric shape will be obtained by running a simulation. In this paper, the single floating body and the M4 system are studied, and the optimum dimensions of the single floating body and the optimum layout and geometry of the M4 system are given for regular and irregular waves.
Vibroacoustic Performance of a Stiffened Plate With Perforation Under the Excitation of Turbulent Boundary Layer
Authors: Li Piao , Li Yukun , Zhang Jingyu , Chen Meixia , Wang Ting
Published: August 2024

Perforated plate is an essential part of underwater vehicles. Investigation on its sound and vibration characteristics has significant influences on the performance of the underwater vehicles. Premised on the fluid-solid interaction, this article presents the vibroacoustic performance of a stiffened plate with perforation under the excitation of turbulent boundary layer (TBL) with the finite element approach. The TBL excitation in the form of dynamic pressure is calculated by using the CFD technique. By analyzing the properties of the excitation at different location versus frequency, the intrinsic frequency and mode shapes, and vibration and sound radiation of the stiffened perforated plate, it is found that the dynamic pressure attenuates dramatically along with the frequency, multiple natural modes of the stiffened perforated plates are evoked which radiates sound to the adjacent fluids. Due to the strong stiffeners, there are several vibration modes which strongly radiate sound within the areas among the stiffeners. The mechanism of the radiation peaks is stated that the radiation efficiency of a surface vibration mode is much higher than that of a dipole and quadrupole vibration mode. This work provides guidance for the optimization and implementation for the stiffened perforated plate in underwater vehicles.
Colorimetric Determination of Amine-Based Shale Inhibitors in Water-Based Drilling Fluids
Authors: Wagle Vikrant , Pal Omprakash , Al-Yami Abdullah , Safran Ali , Pino Rafael , Olivares Tulio
Published: August 2024

Formations that contain hydratable shale or mixed layers of reactive clay can lead to wellbore instability issues during drilling operations. Shale inhibitors are used to limit the interaction of water with clay particles. Amine-based compounds are commonly used shale inhibitors in water-based drilling fluids. Amine-based shale inhibitors are typically added in predetermined concentrations in water-based drilling fluids. The shale inhibitors prevent the swelling and disintegration of shales, preventing problems during the drilling process, such as wellbore instability, viscosity build-up, high torque and drag, bit balling and stuck pipe, and wellbore caving. During the drilling process, the shale inhibitors are either consumed or may be lost to the formation. Accordingly, there exists a need for quantifying and tracking active concentrations of amine-based shale inhibitors in drilling fluids in real-time conditions.

The paper describes a method for quantifying and tracking an amine-based shale inhibitor in a drilling fluid through UV-visible spectrophotometry. The method involves reacting the amine-based shale inhibitor with a complexing agent and then measuring the absorption intensity of the residual complexing agent solution using a portable UV-visible spectrophotometer. For varying concentrations of an amine-based shale inhibitor, a correlation between a concentration of the amine-based shale inhibitor in a water-based drilling fluid and an ultraviolet (UV)-visible absorption intensity is determined. A calibration plot is generated from the correlations. Samples of a circulating drilling fluid having unknown concentrations of amine-based shale inhibitor are collected. The concentrations of amine-based shale inhibitor in the samples of the circulating drilling fluid are estimated using the calibration plot.

The method of colorimetric determination of amine-based shale inhibitors in water-based drilling fluids was field validated successfully. The method was successful in tracking the depletion rates and any addition of the amine-based shale inhibition in the water-based drilling fluids during drilling.