bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drought Assessment Using Two-Variate Modelling
Authors: Hasan Ihsan F , Kamal Nurul Hana M , Awchi Taymoor A , Abdullah Rozi 
Published: August 2023

Abstract
Drought is a natural hazard that mainly threatens water resources and food security. Due to climate change, an increase in drought events that may adversely affect various sectors is expected. Therefore, a reliable analysis of drought events is important. However, there is a deficiency in research works which deals with two-variate drought assessment and monitoring. This paper focused on drought assessment based on modelling the effective precipitation and runoff variables simultaneously. Drought indices are widely utilized to assess droughts in many regions around the world. The copula method was used to modelling a two-variate drought index based on the effective precipitation and runoff variables in northern Iraq as a case study. It was found that Frank is the optimal copula function to model the joint cumulative distribution function of effective precipitation and runoff. To assess the performance of the proposed two-variate index, it was compared with the widely used standardized precipitation index SPI and Standardized Runoff Index SRI. Where the Pearson correlation coefficients between 2-variate index and SPI, SRI were 0.78 and 86, respectively, for 3-month time scale, and were 0.83 and 82, respectively, for 6-month time scale. The results revealed that the proposed index is applicable and can comprehensively and effectively characterize drought events.
Effect of Application Different Combinations of Phosphogypsum and Humic Acids Mixed With Saline Irrigation Water on Broccoli Yield and NPK Concentration
Authors: Al-Falahi Muneer N , Al-Esawi Jabbar S , Salih Salih M , Mansoor Saif S , Jweer Khamees A 
Published: August 2023

Abstract
Long-term irrigation with saline water causes detrimental effects on the soil-crop system. The study aimed to determine the best combination of Phosphogypsum and humic acid can mitigate the negative effects of saline water irrigation on broccoli growth. Therefore, two-factorial field experiment was conducted according to a randomized complete block design with three replications during autumn season of 2021 in Fallujah district /Anbar governorate in sandy loam soil. The first factor included three levels of saline water irrigation, namely 2.5, 5.0 and 7.0 dS.m-1. while the second factor involved three levels of humic acids i.e., 0.0, 0.25 and 0.50 g/l mixed with three levels of phosphogypsum that is 0.0, 0.25 and 0.50 g/l. Fruits weight, height, yield, plant nitrogen content, plant phosphorus, and plant potassium content were measured. The results showed that the combinations under study ( humic acids and phosphogypsum) had a crucial role in reducing the negative effects of irrigation salinity. Moreover, the macronutrients availability increased with increasing humic acids concentration in irrigation water. The observed results show a significant increase in the weight of broccoli fruit and yield at T8 by giving 325 g. plant-1and 8.66 t.h-1 respectively under effect of the combination under study. Also, the studied combinations led to increase the N,P,and K concentration in plant tissues. Where the highest observed averages of nitrogen and potassium were 3.96% and 2.56% at T8 treatment. While The highest concentration of phosphorus was observed at treatment T9 reached 0.47%.
Evaluation the Suitability of Irrigation Water in Karma Island for Agriculture
Authors: Al-Bayati Ali H , Al-Azawi Hayder H , Al-Rawi Muthana K 
Published: August 2023

Abstract
To evaluating the suitability of surface and groundwater which used in agriculture in Karma Island in Anbar Governorate, eight wells depending on the topographical variation in the area as well as the surface water (Euphrates River) were selected. The water samples were collected during the winter and summer seasons at period 2021-2022. The tests included some chemical measurements of the water, its classification, and assessment of its suitability for agricultural purposes and its quality according to the Baber classification. The results showed significant difference between water sources and date of sampling in terms of studied indicators, the rates of the electrical conductivity ranged between 1.20-12.05 dSm-1 and the values of the degree of reaction in general was tend towards equality (6.9-7.3). The reason of spatial and temporal variation in this chemical water indicators refer to the geological rocks from which these ground waters pass through. As for salinity is concerned, the water of all wells was within the sever category, which indicated the magnitude of the use of this water in agriculture, because its proportion exceeds the limits of this chemical characteristic, while the surface resources water was within light to moderate category. In terms of the degree of reaction do not exceed the recommended index in the manual. As for its content of calcium, sodium, chloride and sulfate, all wells water was outside the usual range category, magnesium concentrations was within the permissible limit, while bicarbonate was within the slight to moderate category. The permeability index showed no objection to the use of this water for agriculture. Classified, all waters was in terms of salinity within class C4, as for the sodium hazards, the sources of water used for irrigation in sites W1, W2, W3, W4, and W5 were of low class S1, while wells W6, W7, W8 and W9 were within class. S2. According to geochemical properties and on basis of Cations, it became clear that there is water sovereignty Na+ and Ca+2, while according to anions, it was chloride-sulfur water.
The Effect of Salicylic Acid on the Growth Features of Sunflower Crops in Iraqi Middle-area Conditions
Authors: Rawi Abdulnaser T AL , Abdel Ghani Emad T 
Published: August 2023

Abstract
In order to determine the role of adding salicylic acid in reducing the impact of drought on the sunflower crop and increasing its tolerance to water stress, a field experiment was conducted during the spring of 2020 AD in one of the private agricultural fields in Latifiya district, Baghdad. Two agents were used in the experiment; the first was salicylic acid, which contained four Concentrations are (0, 100, 200, and 300 mg. L−1), and their corresponding symbols are S0, S1, S2, and S3, respectively. The second element is irrigation, which has three intervals (7, 14, and 21 days) between irrigations, and corresponding symbols I1, I2, and I3, respectively. The results indicated that, the highest plant height (PLH) was at 300 mg. L−1 treatment which was 189.98 cm. there are significant differences in the average number of leaves in the plant (NOL) when increasing the concentration of the spray solution of salicylic acid on the sun flower plant, as the highest average trait was 29.98 leaves. Plant−1 at the treatment 300 mg. L−1. The highest average LA was at the treatment 300 mg.-1 which amounted to 1931.9 cm2.Plant-1.the treatment 300 mg. L−1 recorded the highest average for leaf area index (LAI) was 4.95. The irrigation intervals have shown a clear significant effect on all growth characters, the irrigation interval at 7 days gave highest rate of plant height (189.05 cm), number of leaves in the plant (NOL) (29.05leaf. Plant−1), Leaf area of the plant (LA) (1711. 2cm2.plant−1), Leaf area index (LAI) (4.83).
Effect of Super Absorbent Polymer and Ceratophyllum Powder Application on Some Soil Physical Properties
Authors: Salih Salih M , Al abaied Abdalwhhab I 
Published: August 2023

Abstract
A two factorial laboratory experiment was conducted according to randomized complete block design with three replications, to investigate the effect of super absorbent polymer (SAP) and ceratophyllum powder application on some physical characteristics of loamy sand soil. The first factor included three levels of super absorbent polymer, namely 0,0.2, and 0.4 %. While the second factor consists of three levels of ceratophyllum powder i.e., 0,2, and 4 %. The treated soil (treated with super absorbent polymer and ceratophyllum powder) was exposed to 14 cycles of wetting and drying. Effect of experiments factors on coefficient of linear extensibility, soil bulk density and total porosity were measured. The obtained results show that the super absorbent polymer and ceratophyllum powder application led to increase the dry soil bulk density, total porosity, and the coefficient of linear extensibility values for all application levels. Regarding the soil aggregate stability, a significant increase was observed under effect of super absorbent polymer and ceratophyllum powder application. Where the highest value of soil aggregate stability was recorded at 0.4% level of SAP reached 54.2%. Likewise, the highest value of soil aggregate stability under effect of ceratophyllum powder application reached 30.7% at 4% level of application, compare to the control treatment that gave 11.1 % with increasing rate reached 76.5%. In same direction, all moisture content had increased under effect of study factors. However, the super absorbent polymer was superior to ceratophyllum powder application.
Vertical and Lateral Variation of Ecological Risk Index of Heavy Metals in the Euphrates River Sediments between Heet and Fallujah, Iraq.
Authors: Saber Mohammed , Saod Wahran M , Al-Heety Emad A 
Published: August 2023

Abstract
The heavy metals (HMs) contamination of river sediments and their ecological risks is a global environmental problem that has attracted the attention of researchers and those interested in environmental protection. The study aims to investigate the ecological hazards of some HMs in sediments of Euphrates River between the cities of Heet and Fallujah, Iraq and their lateral and vertical variations. At three depths—0-30, 30-60, and 60-90 cm—samples of sediment were collected from five sites. Atomic Absorption Flame Emission Spectrophotometer (ASC.7000) was used to measure concentration of Cd, Cr, Cu, Ni, Pb, and Zn. The ecological risk index (ErI) values of metals in Euphrates River sediment in the study area take the following descending order: Cd > Ni > Cu > Cr > Pb > Zn. The ErI levels were low for Cr, Cu, Ni, Pb and Zn and considerable ecological risk for Cd. The obtained results did not show a common lateral variation pattern of the ecological risk of the measured metals. There is a high level of risk for the measured metals at the downstream sampling sites except for the risk from Cd on the contrary. The potential ecological risk of Cd, Cr, Pb and Zn showed a similar vertical variation pattern which in turn reflects a common source or origin for these metals, while copper and nickel showed a different common distribution pattern.
Hydrogeochemical Evaluation of Surface and Groundwater in Haditha Area, Al-Anbar Governorate, Western Iraq
Authors: Al-Hadithy Israa B , Al-Mallah Aahed Y 
Published: August 2023

AbstractThis research deals with the study of the hydrochemical characteristics of surface water and groundwater to assess the quality of water and its suitability for different uses in the Haditha region. Thirty –Two samples were collected in July 2022,6 samples were taken from the Euphrates River and 17 samples from wells were analyzed. In this study, main cations ( Ca2+, Mg2+, Na+, and K+) and anions (Cl-, SO4, HCO3),Total dissolved Solids(TDS), pH, Electrical conductivity(EC), and Temperature(T) were studied. The results show that the water types are mainly earth-alkaline water with an increased portion of alkalis with prevailing SO4 and Cl according to Piper and Stiff diagram. The results of the water quality index (WQI) show that surface water are suitable for drinking while the groundwater is not suitable except for W1, W13, W15, W16 and W17. The classification of water for irrigation purposes according to the Sodium Adsorption Ratio and Residual sodium carbonate showed that the ground and surface water in this region is excellent and good quality according to Permeability Index. Irrigation water quality based on sodium ion percentage indicates that all samples belong to the permissible category for groundwater except for W1, W11, and W16, while Surface water is good quality for irrigation. Finally, the absence of management and low discharge, are the primary reasons for the continuous deterioration of water quality.
Numerical studies on tugboat performance during pushing operations
Authors: Abdelghafor Z , Taimuri G , Kujala P , Wang Y , Hirdaris S 
Published: August 2023

Abstract
This paper introduces a RANS CFD methodology for the evaluation of tugboat dynamics during pushing operations. Two- and three- dimensional methods that respectively utilize “Dynamic Fluid Body Interactions - (DFBI)” and “Tug Force Equilibrium kinematics-(TFE)” are assessed and compared with the aim to better understand the influence of fluid modelling on ship dynamics. For the DFBI method, an unsteady RANS solver comprising of a dynamic fluid body interaction module and a contact mechanics coupling algorithm are used to predict the forces between a tugboat and an assisted ship. For the TFE method, a steady RANS method is applied and contact actions are calculated as a sum of the hydrodynamic forces on the hull and the propeller. Whereas DFBI accounts for the time variation of the contact forces, the TFE is more rapid and could be used to derive operational decision support criteria. To demonstrate the latter the TFE method is used to derive the pushing forces based on a set of 16 numerical simulations. It is concluded that irrespective of the model used the tugboat speed and orientation may amplify the pushing forces. This effect could be prominent, especially at slow speeds for which the sway force acts in opposite direction to the tug.
A deep learning method for the prediction of focused waves in a wave flume
Authors: Zhang Mingyang , Tavakoli Sasan , Hirdaris Spyros 
Published: August 2023

Abstract
Rogue waves pose a significant risk to marine safety, emphasizing the need to accurately predict their occurrence in the open ocean. However, the complexity of their evolution, which may involve nonlinear physical phenomena such as wave-wave interaction and modulation instability, makes this task challenging. Currently the reconstruction of rogue waves involves generating focused waves through the superposition of different spectral components of irregular waves that are in phase at the focusing point. Despite its effectiveness, this approach is limited. The paper introduces a deep learning method based on Long short-term memory (LSTM) to predict focused waves generated in a Computational Fluid Dynamics (CFD) flume in the time domain. The model is trained on 60% of the generated wave time series, with the remaining 40% used for both validation and testing. The results demonstrate that the proposed method can assist with the prediction of focused waves at various observation points, indicating its potential as a promising approach for predicting rogue wave behaviour in the ocean.
A two-way coupled FSI ship hard grounding dynamics model
Authors: Taimuri G , Mikkola T , Kujala P , Hirdaris S 
Published: August 2023

Abstract
In the maritime sector, ship grounding incidents continue to be a serious problem that may lead to oil spills, capsizing, severe property damage, and even fatalities. Grounding accidents are currently understood utilizing inadequate statistical datasets, probabilistic grounding scenarios, and deterministic computational crashworthiness methodologies due to a lack of practical tools and techniques. The implementation of multiphysics assessment techniques is essential for the development of improved ship safety standards. This involves the use of rapid models for structural integrity rules and damage stability regulations. Taimuri et al., (2022) [1] introduced a rapid two-way coupled fluid-structure interaction (FSI) model that seeks to efficiently examine accidental loads following a ship hard grounding event to fulfil such a requirement. The current study offers an overview of the algorithm and its limitations.
Asymmetry in sagging and hogging responses of a ship hull
Authors: Matusiak J , Karola A , Niemelä A , Mikkola T , Hirdaris S 
Published: August 2023

Abstract
In this paper asymmetry in sagging and hogging of a hull progressing in regular waves is investigated by applying a weakly nonlinear potential flow theory. At first instance ship motions in waves are evaluated using a linear strip-theory yielding transfer functions of ship motions and sectional loads. Then, by assuming time-histories of ship motions the nonlinear part of the Froude-Krylov and restoring forces and moments are evaluated using a panel representation. Linear and weakly nonlinear predictions are compared against available model tests for a roll-on/off (Ro-Pax) ship hull. The results confirm that importance of nonlinearities of restoring and Froude-Krylov part of wave loading on asymmetry of sagging and hogging.
Comparative summary of approaches used with the impulse response method
Authors: Wermbter M. , Altenbach L. , Detlefsen O. , Abdel-Maksoud M. 
Published: August 2023

Abstract
This paper presents a comparison of various methodologies to calculate the seakeeping behaviour of ships using the impulse response method. Developments of several authors incorporate non-linearities regarding the radiation, diffraction and wave forces. In contrast to frequency domain methods, advantages are expected if ship motions become non-linear, for example in waves with high steepness ratios. The comparison is structured into analysis for each force component with and without motions in waves. The main contribution is the quantitative analysis for several ships, forward speeds and methodologies. Multiple frequency domain methods are incorporated in the analysis. The focus of the analysis lies on the evaluation of applicability as well as the limits of the method for all states investigated. The results of the impulse response method show the following: The method is applicable to several forward speeds. In long waves, the choice of the parameters calculated in the frequency domain for the computation of the radiation and diffraction forces has a strong influence on the computed motion amplitudes. In short waves, the computation of the added resistance is a considerable challenge. Especially at high forward speeds, the consideration of the stationary wave system is essential for obtaining accurate results with three-dimensional panel codes.
Numerical study on the influence of nozzle divergence half angle on thrust oscillation characteristic of underwater jet power
Authors: Si Pengfei , Wang Ningfei , Xia Shitong , Shi Lin , Li Shipeng , Tang Jianing 
Published: August 2023

Abstract
Underwater rocket propulsion is increasingly used in advanced marine vehicles that may be subject to supersonic gaseous jets while submerged. This work investigates the influence of supersonic nozzle divergence on the multi-flow field evolution process and the thrust oscillation characteristics by multiple numerical simulations using a VOF multiphase flow model. Four nozzle divergence half angles are taken into consideration. The analysis indicates that the thrust rises sharply at nozzle closure opens, then rapidly decreases and follows another rise. The thrust oscillates at high frequencies. As a result, increase of the nozzle divergence half angle leads to the size decrease of flow bubbles but does not affect the changing trends of the thrust. Increase of the nozzle divergence half angle leads to a reduction of the frequency of the thrust oscillations.
Numerical study of second-order wave forces using a Rankine panel method
Authors: Dong Guohua , Huang Jianghao , Yao Chaobang , Feng Dakui , Meng Fanliang 
Published: August 2023

Abstract
Numerical analysis of the wave forces acting on ships can be complex primarily because of the interactions between incident waves and structures. In this paper, the three-dimensional frequency domain Rankine panel method is used to study the seakeeping and second-order wave drift forces of a ship in waves. The model considers second-order wave forces acting on the ship hull and therefore accounts for slow drift ship motions and the added resistance. The second-order wave forces are evaluated using the pressure integral method, also known as the near-field approach. The unsteady velocity potential is divided into three parts namely (a) incident, (b) diffraction and (c) radiation to satisfy the Laplace equation. To avoid wave reflection the Rayleigh’s artificial friction is used in way of the free surface boundary. This method is equivalent to introducing a numerical damping beach for energy dissipation. The numerical results are compared with those of experiments for Wigley-III hull in head waves and the SCb-84 hull in oblique waves. Good agreement is obtained.
Hydrodynamic performance of manta rays under different motion parameter
Authors: Gao Pengcheng , Huang Qiaogao , Pan Guang , Liu Jing , Shi Yao , He Xing , Tian Xushun 
Published: August 2023

Abstract
This paper presents a numerical simulation of the steady propulsion state of manta rays and investigates the influence of single motion parameters and the addition of perturbation signals on the hydrodynamic characteristics and vortex evolution of manta rays. A numerical model and the motion equations of the manta ray were established by observing the living organisms, and then a computational method combining the immersed boundary method (IBM) and the Sphere function-based Gas Kinetic Scheme (SGKS) was used to simulate the active propulsion state of the manta ray. The results show that in a single motion parameter, as the motion frequency increases, the thrust force increases subsequently, but the propulsion efficiency decreases; with the increase of motion amplitude, the thrust also increases, and the propulsion efficiency reaches the maximum at the dimensionless amplitude of 0.35; as the wavenumber increases, the thrust reaches its maximum at wavenumber of 0.4, and the propulsion efficiency increases subsequently. When the same amplitude low-frequency sinusoidal perturbation is added, both thrust and efficiency decrease when the perturbation frequency is less than or equal to 0.4, and increase when the perturbation frequency is greater than 0.6. This work provides a new perspective to study the influence of manta ray motion parameters and perturbation parameters on its hydrodynamic characteristics.
Numerical Investigation on Drag and Vortex Induced Vibration Characteristics of Multiple Cylinders
Authors: Araki M 
Published: August 2023

Abstract
The drag and vortex induced vibration (VIV) characteristics of a multiple cylinder are investigated using the detached eddy simulations. The multiple cylinders consist of a single main cylinder and twin auxiliary cylinders for a deep sea mining riser. Tandem and side-by-side arrangements are tested and compared with the single cylinder. The drag characteristics are investigated with the stationary case in the range of 0.5∼2.0 × 105 in Reynolds number (Re). The drag of the tandem arrangement shows smaller drag than those of the single cylinder while it’s consisted with the three cylinders. The stationary vortexes are observed at the clearance between the main and auxiliary cylinder which make the tandem arrangement become airfoil-like section as a total which induce the smallest drag than the other cases. The VIV characteristics are studied with the cases of forced oscillation in the cross-flow direction. The damping and added mass coefficients in cross-flow direction are estimated from the time series of the lift forces. Flow field analysis reveal the difference in VIV characteristics due to the variety of the arrangements and the single pipe.