bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Treated Sulfur Water on the Microbial Content of the Soil and the Extent of Resistance of These Bacteria to Antibiotics
Authors: Farhan Muthana B , Ali Hala A 
Published: August 2023

Abstract
The research began on March 7, 2021, as the regions of Ain Al-Wusta and Ain Jarura were chosen to take soil samples. The sulfuric water was treated using laboratory batch reactors. Locally manufactured glass tubes were used, with dimensions 17 * 17 * 55 in length, width and height, respectively, Subsequently, microbiological and chemical analyzes of the soil were performed. The results of the study showed success of the physical treatment process that was used to reduce the levels of sulfur in the water Depending on the source of water and the type of material used, the triple-magnetic treatment achieved the highest removal rate of 73% in Ain Al-Wusta soil, 40% in soil sample B1, and 27% in soil sample B2 of Ain Jarura. The results of bacterial culture showed that Gram-negative bacteria were dominant by 100% in soil samples from Ain Jarura region treated with untreated sulfuric water (WA1, WA2, WA3) (Table- 4), as well as for the same soil samples treated with sulfuric water treated with sand filter (GB1), charcoal filter (GB2) and magnetic field filter. (GB3) Soil samples treated with untreated sulfur water were dominated by Pseudomonas aeruginosa with a percentage of 66.7% and Acinetobacter lwoffii with a percentage of 33.3%.The results of the bacterial count of soil samples from the Ain Jarura region showed that there were significant differences between the bacterial number with sulfuric water treated with the three filters, As for soil samples from Ain Al-Wusta region, only soil samples added to sulfuric water treated with charcoal filter (WB2) gave significant differences with a significant decrease of number (84×102 CFU) for the species Aerococcus viridans. The results of the antibiotic sensitivity test showed that Elizabethkingia meningoseptica gave the highest rate of resistance to antibiotics about 66%. The results of the study showed that the resistance of bacterial isolates to antibiotics did not show significant differences between soil samples treated with treated and untreated sulfur water, except for the GB2 isolate.
Maritime Emergency Preparedness – Drifting Ships
Authors: Berg T E , Selvik Ø , Indergård R , Ringen E 
Published: August 2023

Abstract
The Norwegian Coastal Administration registers maritime incidents in Norwegian waters. Drifting ships and drifting objects may cause serious incidents and possible disasters. By analysing ship traffic in Norwegian waters, it is documented that the frequency of drifting ships has been approximately 0.15% of the registered ship transits, or 150–165 drifting cases annually. In addition to a possible grounding when a vessel reaches the coastline, the increased use of the ocean space for wind farms, floating solar installations, and fish farming structures (moving from sheltered coastal sites to exposed locations) increase the risk of collision with different types of ocean structures, including offshore oil and gas installations. The need for adequate emergency preparedness to prevent drifting ships from colliding with different types of ocean structures or a final grounding can be solved through different types of mitigating measures. One measure could be to have dedicated emergency towing vessels for handling vessels drifting towards ocean structures or on a course leading to a possible grounding. A reliable tool for predicting a drifting vessel’s path is important for planning an emergency towing operation. Systems to provide a fast and safe setup of an emergency towing connection under different environmental conditions are needed, while the competence of the crew on the emergency towing vessel and the ship to be towed is a critical factor for a successful emergency towing operation under adverse conditions.
Numerical PMM test in shallow water using CFD method
Authors: Zhu Zhang , Kim Yonghwan , Choi Jun-Hoi 
Published: August 2023

Abstract
This study aims to the estimation of the ship manoeuvrability in shallow water by using the numerical PMM approach, which analyses the hull hydrodynamic responses and manoeuvring performance from the viewpoint of coefficients. The test model is a scaled KVLCC2 tanker operating at a low Froude number of 0.0514. Static drift test and pure yaw test are considered, and the water depths vary from deep water to very shallow water of 20% under-keel clearance. The numerical tank is built based on an OpenFOAM+ package. The free surface is modelled by volume-of-fraction method, and the k-ω SST model associating with wall functions is applied for turbulence. After the convergence tests and validation works, the numerical tank is employed to investigate the wave-depth effect on hydrodynamic forces and manoeuvring coefficients. The present results show that the forces of static drift test, particularly sway force, can be significantly changed as the water depth decreases.
A numerical investigation on ship-ship overtaking interactions in confined waterways
Authors: Zheng Z Q , Zou L , Zou Z J 
Published: August 2023

Abstract
The whole process of a KCS container ship overtaking a low-speed Neo-Panamax container ship is numerically simulated by solving the unsteady Reynolds Averaged Navier-Stokes (URANS) equations. The dynamic overset mesh technique is adopted to simulate the relative motions between the two ships and the ship attitude variations. The free-surface elevations, ship attitudes, as well as hydrodynamic forces and moments on the two ships are predicted. In order to discuss the effects of different navigation parameters on the ship-ship interactions, a set of ship speeds, lateral distances and water depths are simulated. The results illustrate that the overtaken ship is more significantly impacted by the interaction than the overtaking ship, and the drawdown generated by the overtaking ship is the key factor during the overtaking process. The increase of ship speed, the decrease of lateral distance or water depth can lead to more intense drawdown, and hence even more significant ship-ship interaction effects.
Towards accurate stereo-video based free-surface reconstruction for wave tank experiments
Authors: Page Sacha Le , Tassin Alan , Caverne Julien , Gall Yves Le , Gomez Benoit , Ducrozet Guillaume 
Published: August 2023

Abstract
Measuring accurately the shape of the free surface in medium-scale hydrodynamic testing facilities is challenging with conventional wave gauges. To overcome this problem, it is necessary to go towards higher resolution measurement systems. For this purpose, we investigate the ability of stereo-video acquisition systems to reconstruct free surface waves in laboratory conditions. This technique has been proven to give satisfactory results in open sea conditions, although it is dependent on the environmental conditions (weather, solar incidence angle). At sea, the stereo-video reconstruction algorithm makes profit of the short waves generated by the wind in order to correlate the points from the left and right images. The main challenge of adapting this technique to laboratory conditions, i.e. in absence of sun and wind, is to overcome the absence of texture on the free surface. This paper presents recent work aiming at developing a stereo-vision measurement system for laboratory conditions. Our efforts have been devoted to finding an adapted lighting system and generating a texture suitable for the reconstruction algorithm. Different lighting configurations have been tested in order to understand its impact on the reconstructions. For the texture generation, we have investigated different means of generating short surface waves (water droplets, air blowing, circulation current, underwater acoustic emissions) in different experimental facilities. Our conclusions show that it is possible to reconstruct the shape of surface gravity waves in the presence of short surface waves and that the effects of lighting and texture on the quality of the reconstruction are strongly coupled.
Hydroelastic analysis of wave diffraction by multiple flexible porous plates
Authors: Sasmal Anjan , De Soumen 
Published: August 2023

Abstract
The study investigates the phenomenon of wave diffraction by multiple poroelastic plates in infinitely deep water using the two-dimensional linearized potential theory. The study focuses on numerically computing the reflection and transmission coefficients using Galerkin approximations specifically designed for two nonidentical vertical poroelastic plates. By varying the separation lengths, porosity, and flexural rigidity of the plates, the study explores the hydrodynamic quantities associated with the wave-plate interaction. These quantities are then represented graphically to visualize their behavior under different conditions. The results of the study show that the flexural rigidity of the porous plates has a significant effect on wave reflection and transmission. The correctness of the method used in the study is confirmed by comparing the results available in the literature. Overall, the study provides valuable insights into the behavior of waves interacting with multiple poroelastic plates and highlights the importance of considering the flexural rigidity of the plates in such systems. The numerical approach used in the study can also be applied to other similar problems and can provide a useful tool for predicting the behavior of waves in complex systems.
Coupled Lattice Boltzmann and Discrete Element Simulations of Ship-Ice Interactions
Authors: Watanabe Seiya , Hu Changhong , Aoki Takayuki 
Published: August 2023

Abstract
Evaluating ice loads acting on ships is essential for the safety of ships navigating in ice-covered seas. In this study, we develop a CFD method to handle ship, ice, and fluid interaction. The lattice Boltzmann method, capable of large-scale calculations, is applied to the simulation of free-surface fluids. The ice motion is computed by solving the equations of motion of a rigid body, and the discrete element method models the ice-ice and ice-ship contact interactions. A momentum exchange scheme couples the lattice Boltzmann method and particle-based rigid body simulation. We introduce tree-based adaptive mesh refinement and multiple GPU computing to improve grid resolution and computational time. The proposed method is applied to model scale simulations of ship navigation in a brash ice channel. Simulations were performed for various conditions with different ice concentrations and ship velocities, and we observed that ice resistance increased with the ice concentration and the ship velocity increased. The ice motions and resistances obtained from our simulations are reasonable compared to model equations of Finnish-Swedish ice class rules (FSICR) and numerical analyses of a previous study.
Ship motions and unsteady pressures on ship hull in oblique waves estimated by potential-based solvers
Authors: Suzuki K , Takeda K , Iida T , Yanagimoto F 
Published: August 2023

Abstract
The seakeeping performances in oblique wave conditions, such as ship motions and unsteady pressures on a ship hull, are getting more important, recently. These physical quantities are used for estimating loads induced by waves and evaluating the safety of a ship. Thanks to the evaluation of various incident wave angles, a rational ship design with sufficient safety and less construction cost can be realized. Therefore, the estimation by numerical schemes in those conditions is demanded for the ship design. However, schemes were usually validated through the comparison with experimental data in only heading wave conditions because few towing tanks can carry out the experiment for a ship advancing in oblique waves. The computed results in oblique waves should be validated well before the industrial usage of schemes. Although Computational Fluid Dynamics is useful to know the seakeeping performance in oblique waves thanks to the development of computer performance in these years, it takes much longer time than the schemes based on a potential theory. For this reason, three solvers based on the potential theory, the Salvesen-Tuck-Faltinsen method, the Green function method, and the Rankine panel method, are validated by comparing ship motions and unsteady pressure on the ship hull obtained from towing tank tests in oblique wave conditions.
Optimization of a coupled launching process considering hydrodynamic interaction effects
Authors: Altenbach L , Wermbter M , Marleaux P , Abdel-Maksoud M 
Published: August 2023

Abstract
Crane-assisted launching and recovering of small boats from a large vessel is common in a wide range of operational scenarios and may be required during research missions or in emergency situations for rescue boats. As the mothership moves in natural irregular seas, the resulting accelerations and motions of the small boat can lead to dangerous situations, such as a collision between the mothership and the small boat or a slamming of the small boat onto the free water surface can occur, posing a great danger to the people involved. In the paper, the development of a coupled simulation method for the motions of the mothership and the small boat during the launching in the time-domain is described. The developed simulation method is based on the impulse response function. The implementation of the suspension on a crane is realised by a holonomic constraint and a Lagrange’s equation. The parameter influencing the launching operation include the current sea state, the stationary wave field induced by the motherships forward speed, at which the small boat is launched and the initial position of the small boat relative to the water surface. By varying the above mentioned parameters, the process can be optimised for different sea states in terms of forces and accelerations. In considering the forward speed of the mother boat during the launching process, it can be observed that in many cases the small boat is operated at high Froude numbers of greater than 0.4. This leads to an exceedance of the operational limits of the programmes used in this paper.
An attempt to predict planing hull motions using machine learning methods
Authors: Shehata Ahmed , Dashtimanesh Abbas 
Published: August 2023

Abstract
Designing a high-speed craft for better seakeeping in waves can contribute significantly to higher safety and human comfort. Early in the design process, mathematical models such as the 2D+T method are commonly used, while high-fidelity computational fluid dynamics (CFD) and experimental models are used later in the process. Some of the limitations of such models are that they are not fast enough to be used in the ship’s system for real-time monitoring or to develop a digital twin. Recently, machine learning methods have demonstrated great promise in building surrogate models from data. These methods include deep learning and recurrent neural network (RNN). In this paper, a systematic investigation of the network architectures and the used optimizers to train the network is presented. Adam, Adagrad, RMSprob and SGD are investigated in training the network. To train the model almost 35000 data points were collected for Fridsma hull operating in 18 regular waves using a 2D+T model. The result showed that gated recurrent unit (GRU) outperformed long short-term memory (LSTM) and RNN in predicting the heave motion. Also, one hidden layer with 5 neurons was enough to achieve mean absolute error of 0.000298 and to predict unseen waves when trained with more than 24000 data points.
Numerical simulations of towing a jacket foundation with triple buckets
Authors: Tan Lei , Hu Changhong , Liu Yingyi 
Published: August 2023

Abstract
Offshore wind energy is developing fast as a promising renewable energy resource that can be helpful in achieving the global net-zero emissions goal. In recent years, offshore wind turbine projects have gradually moved towards far-offshore sea areas, where massive jacket foundations with suction buckets are suitable options. To reduce transportation costs, the wet-towing method is usually favourable since the required buoyancy of the foundation can be provided by the air cushions in the suction buckets. This engineering background brings us a research topic that involves towing and air cushions in waves. This study considers the towing problem of a jacket foundation with triple suction buckets. First, numerical analysis in the frequency domain is conducted using WAMIT®. In particular, the NEWMODES subroutine is extended to consider three separate motion modes in the buckets. Numerical predictions of the natural period show satisfactory agreement with the available experimental data in the literature. Moreover, a time-domain numerical model is developed to simulate towing of the jacket foundation in regular waves based on the potential flow theory. The time-domain model numerically solves the towing force in regular waves, the body motions and the air pressures in the buckets. The simulation results generally agree well with the published experimental data. Besides, the present simulation results suggest that the transit towing force and the forward speed of towed triple-bucket jacket may be considerable in the initial towing stage.
Experimental study on the hydrodynamic characteristics of a Bragg breakwater with triple vertical plates
Authors: Wu Jing-Ping , Luo Hong-Ye , Zou Zao-Jian , Chen Peng , Qi Jing-Jing , Xu Xing-Yu 
Published: August 2023

Abstract
The hydrodynamic characteristics of a Bragg breakwater with triple vertical plates in monochromatic regular waves are experimentally studied. The two spacings between the every two adjacent plates are denoted by S
1 and S
2 respectively which are both wide enough for the necessary of Bragg reflection, and S
2 is equal or unequal to S
1. A series of experiments are carried out in the wave flume equipped with a piston-type wave generator, and the hydrodynamic performance are analysed with the variation of the spacing S
2, the plate draft d
1 and freeboard d
2, the wavelength L and the wave steepness H/L (H is the wave height). Special attention is paid to the effects of nonuniform spacings on the hydrodynamic performance and the characteristics of Bragg reflection. In addition, the comparisons between the fixed and the unrestrained positioning are also presented. The results show that the transmission coefficients of the two unequal spacings mostly are smaller than the two equal spacings, and the intensity and bandwidth of Bragg reflection are increased by the non-uniform spacings. Under the unrestrained positioning, the movements have no serious effects on the wave attenuation performances of the breakwater. Moreover, the trough of transmission coefficient occurs at the left of the primary Bragg reflection condition due to both of Bragg resonance and wave energy dissipation not just Bragg resonance.
An experimental and numerical hydrodynamic study on the Argentinian fishing vessels
Authors: Oyuela S , Sosa R , Otero A D , Arribas F P , Diaz-Ojeda H R 
Published: August 2023

Abstract
The purpose of this work is the validation of the hydrodynamic resistance for a small fishing vessel providing more details about the ship’s hydrodynamics. The selected ship is a traditional vessel that has been sailing in Argentina for more than 20 years without a previous numerical resistance evaluation. Because of the absence of previous numerical optimization, the ship might be a non-efficient vessel from a consumption, operating and polluting point of view. For this reason, in order to bring a more detailed evaluation of the flow around this hull, numerical studies are carried out with the open source OpenFOAM code and validated with experimental results obtained at the University of Buenos Aires towing tank. Reynolds Averaged Navier Stokes (RANS) method together with volume of fluid (VOF) are used for the numerical procedure. Once the resistance results are validated, the total resistance coefficient is split into viscous and wave coefficients in order to provide insight into ship hydrodynamics. Pressure distributions on the hull and wave patterns will be also presented for different ship loading conditions, focusing on the flow around the hull that might give information for a future hull optimization.
Numerical study on wave-induced drift forces and motions of a DTC ship in head and oblique waves using functional decomposition model
Authors: Fang Xianjin , Yu Jiawei , Yao Chaobang , Zhang Zhiguo , Wang Xianzhou 
Published: August 2023

Abstract
It is imperative to investigate the adequacy of propulsion power and steering mechanisms in order to maintain the manoeuvrability of ships in adverse wave conditions, as the drift forces caused by wave can result in deviation from the desired course. The primary objective of this research is to develop a hybrid approach, combining potential and viscous flows, known as SWENSE (Spectral Wave Explicit Navier-Stokes Equations), to accurately assess the wave-induced drift forces and motions experienced by ships in waves. SWENSE is a hybrid approach based on the functional decomposition model, in which the total field is composed of the incident field and complementary field. In this study, the incident filed waves are calculated by the Airy wave theory and the complementary field is solved by the SWENSE model. The wave conditions are selected according to the benchmark cases of the European Union research project SHOPERA (Energy Efficient Safe Ship Operation). The wave-induced loads and motions of DTC in head and oblique waves are calculated. Results of CFD (Computational Fluid Dynamics) are compared with those of EFD (Experimental Fluid Dynamics) and other numerical methods. In addition, the wave-induced drift forces of the fixed/3DOF (Degrees of Freedom) ships are compared with each other (3DOF includes heave, roll and pitch). SWENSE model is proven to be reliable for the predictions of the wave-induced drift forces and motions of ships in waves.
Numerical simulations of water-air-bubble mixed flows around hydrofoil and propeller
Authors: Mao Tianyi , Li Xinyi , Wan Decheng 
Published: August 2023

Abstract
Water-air-bubble mixed flow is a complex multiphase flow usually generated due to the intense interaction between the sailing ship and the free surface[1]. A large number of bubbles scour down along the ship which gather around the propulsion system, making a significant effect on the hydrodynamic performance of propeller and hydrofoil. In this paper, the hydrodynamic performance of two-dimensional hydrofoil and three-dimensional propeller in uniformly mixed water-air-bubble incoming flow is studied by using the Computational Fluid Dynamics (CFD) method. Euler-Euler two-fluid model is used to simulate the uniformly mixed water-air-bubble incoming flow with the open-source CFD software OpenFOAM. The feasibility of numerical simulation is verified by comparing the numerical simulation results with experimental data. On this basis, the changes of physical fields around two-dimensional hydrofoil and three-dimensional propeller caused by water-air-bubble flow under multiple air fraction conditions are discussed. In addition, the differences in dimensionless coefficients are compared between single-phase flow conditions and two-phase flow. Furthermore, the Population Balance Model (PBM) is used in the simulation of two-dimensional hydrofoil to observe the coalescence and break of bubbles.