bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mooring Force Estimation for Floating Offshore Wind Turbines With Augmented Kalman Filter: a Step Towards Digital Twin
Authors: Yung Kobe Hoi-Yin , Xiao Qing , Incecik Atilla , Thompson Peter 
Published: January 2024

Abstract
During the recent research studies Digital Twin (DT) simulation models for Structural Health Monitoring (SHM) based on data-driven mode have been developed, which can provide accurate simulation and prediction of mooring forces of Floating Offshore Wind Turbines (FOWTs). However, the performance of this kind modelling is highly affected by the quantity of real data training set and it is limited to some specific configuration and the recorded environmental conditions. More importantly, the data-driven DT cannot interpret the physical meaning of structural dynamic interactions.
Therefore, a new Physics-Based estimator is proposed in this work. The fully coupled FOWT simulations are carried out in QBlade Ocean and the simulation results are used to prepare the Reduced-Order Model by system identification for different sea states. The proposed estimator is based on the Augmented Kalman Filter in which the unknown mooring force is augmented as a state. The prediction of state is adjusted with the measurable platform motion data. It demonstrates the ability of filtering the noise in measurements and capturing the dynamic behaviour of FOWT with acceptable low computational cost. This real-time state estimator also provides the foundation of developing the DT modelling framework of FOWT and enables us to scale-up FOWTs in the next stage.
Comparison of Fatigue Characteristics of Polyester and Nylon Mooring Lines for Shallow Water Floating Offshore Wind Turbines
Authors: Saleh Samer , Akers Richard , Koo Bonjun , Yau Henry , Lopez Tomas , Thiagarajan Krish 
Published: January 2024

Abstract
The offshore wind industry is growing, and turbines with power production of 10 MW or greater are likely to become the norm in the future for both shallow and deep waters. For up to 50 m water depth, bottom fixed structures like monopiles and jackets are considered technically and economically feasible. Beyond this water depth, floating sub-structures offer the promise of cost reduction. Synthetic fiber ropes like nylon and polyester are good candidates for mooring system designs not only for their low cost, corrosion resistance, and fatigue life compared to steel wires and chains but also for their low stiffness which can reduce the wave frequency loads on the floater, especially in shallow water. In an IOWTC 2022 paper, the present authors discussed the strength characteristics of a shallow water mooring system comprising of chain-heavy chain-polyester-chain combination. This combination was specially chosen to work in shallow water conditions (60–100 m). Using simulations, the most probable maximum values of the mooring line were presented and discussed. In this paper, fatigue analysis has been performed on a similar mooring configuration wherein we consider two synthetic material options: polyester and nylon. The IEA 10 MW reference wind turbine and a semi-submersible floating platform were used in our simulation in Nantucket, MA (Water Depth (WD) = 60m). Three different design load cases DLC 1.2, DLC 6.1, and SLC I.1 were conducted in our simulations and the mooring line fatigue damages converted to represent 25-year service life. The analysis of mooring line tension-tension fatigue damage is calculated using the T-N curves. The fatigue damage is estimated using the built-in fatigue analysis toolbox in OrcaFlex after performing a set of OrcaFlex simulation files based on different mooring line configurations and design load cases. In this work, the behavior of nylon vs. polyester in shallow water hybrid mooring applications is investigated and discussed.
Comparison of O&M Cost of Different Scenarios for a 1GW Floating Offshore Wind Farm
Authors: Zhao Chenyu , Johanning Lars 
Published: January 2024

Abstract
Operation and Maintenance (O&M) costs in an offshore wind project can constitute up to 30% of its total cost, a figure that can increase with the distance of the project offshore. The University of Exeter’s Renewable Energy Group developed a study utilising the O&M module of Ec simulator, which can furnish a user with critical performance indicators, to examine O&M costs under various scenarios for 1 GW floating offshore wind (FLOW) farm sites in the Celtic Sea. The simulator conducts a range of Monte Carlo simulations over the entire lifespan of the FLOW farm, considering user-specified variables and limitations such as fleet size and the vessel’s weather resilience. In this study, three different O&M cases are used to demonstrate the flexibility and functionality of the O&M module. Each case represents different wind farm selections under the exactly farm configuration, such as the capacity and numbers of the wind turbine. Results of these simulations offer a multitude of key performance indicators (KPIs), including energy production, downtime, energy-based availability and comprehensive O&M costs. It also gives more granular data, such as the number of component failures and vessel operating hours, aiding in the critical decision-making process for successful project management. The main objective of this study is to demonstrate how manipulating specific parameters can impact the viability of FLOW farms in the Celtic Sea.
Comparative Study of TLP and Semisubmersible for a 15 MW Horizontal Axis Wind Turbine (HAWT)
Authors: Huang Edward , Tang Zhaoxiang , Periyaiah Rathinam 
Published: January 2024

Abstract
This paper presents a conceptual design comparison between a 3-Column Tension Leg Platform (TLP) and a Semisubmersible (Semi) floating offshore wind turbine (FOWT) platform for the US west coast at a water depth of 1,100 m. The International Energy Agency (IEA) 15 MW horizontal-axis wind turbine (HAWT) is utilized to compare the floating platform design options.
TLP demonstrates exceptional dynamic behavior with very low displacements and almost no vertical/rotational motions. Its lightweight structure weight and simple geometry lend themselves to simplifying fabrication/integration processes and competitive LCOE levels.
This paper contains a quantitative comparison of TLP and Semisubmersible FOWT platforms in the following aspects:
• Applicable Design Codes
• Design environment load cases
• Platform configurations
• Hull weight and CG
• Global performance
• Tendon and mooring loads
• TLP with a slanted tendon as a sensitivity case
Additionally, it provides a qualitative comparison between the TLP and Semisubmersible FOWT platform from various perspectives, including platform configuration design, structure weight, center of gravity, fabrication, transportation, and installation (T&I) of floating substructure, station keeping, and the wind turbine installation.
Initial Global Design for Three-Column Semi-Submersible Hulls of a 15-MW Floating Wind Turbine
Authors: Wang Shuaishuai , Moan Torgeir 
Published: January 2024

Abstract
Support structure design of floating wind turbines (FWTs) is an iterative process, which can be accomplished into three phases, named 1) selecting of floater type (barge, semi, spar, TLP, etc.); 2) determining global dimensions for a given floater type; 3) determining scantlings of the floater based on detailed design. This study deals with the design phase 2), namely initial global design, for a three-column semi-submersible hull for a 15-MW FWT. An efficient and effective methodology, which was developed by authors in a previous study and successfully used for the global design of a 10-MW semi-submersible floater, is used in this case study. The initial global design criteria include simplified serviceability criteria related to the power performance as well as safety criteria in terms of intact stability and indirect global strength criteria through requirements to natural frequencies of rigid-body motions. First, a sensitivity study will be conducted to various design variables of the floater, including draft, column centerline spacing, outer column radius, outer pontoon radius, pontoon width and pontoon height. Based on the sensitivity study, important global design parameters are recognized for the floater, which facilitates the determination of initial design options. Subsequently, the intact stability analysis is performed for the selected design options for different wind directions. Critical load directions of the floater will be identified. In addition, the influence of deck beam dimensions and freeboard on intact stability is investigated. Finally, the global layouts of the floater are assessed based on global design criteria. This study provides new insights into the quasi-static or/and dynamic behavior of the promising FWT concept, which is essential to achieve serviceability and safety. In addition, it provides a basis for carrying out the detailed design to determine the scantlings in the third design phase.
Impact of Viscous Damping Linearization on FOWT Control Design
Authors: Fabregas Flavia Francesc , Browne Ian , Alexandre Armando , Chatzopoulos Aristeidis 
Published: January 2024

Abstract
Control design is traditionally carried out based on simplified linear models and subsequently tested on more realistic non-linear time domain models of a system. Issues with control performance and robustness can be introduced if the linear model is not representative of the real system, requiring additional design and testing with the realistic non-linear time domain models. This can be time consuming, and, in some cases, a satisfactory control design solution may not be achieved. It is therefore paramount to capture, in the linear model, the key physical drivers of the different system responses, which are generally referred to as states in the context of control design.
Floating Offshore Wind Turbine (FOWT) numerical models present several non-linearities, which are associated with the different sub-systems they are composed of, including the turbine, the platform and the moorings. In the context of the platform, and to some extent the mooring system, viscous nonlinear hydrodynamic damping effects have a significant impact on the response of the FOWT when subject to different environmental conditions. However, these viscous damping effects are generally not easily captured in the linear FOWT models generated by several aero-hydro-servo-elastic tools, including but not limited to BLADED and OpenFAST.
The focus of this paper is to investigate several methodologies to linearize viscous damping forces and to incorporate them in simplified linear models of FOWTs, with a strong emphasis on the initial control design phase in linear space. Two FOWT systems based on the semi-submersible DeepCWind (OC4), and VolturnUS-S platforms are investigated, with 5MW and 15MW ratings respectively. Results show that the impact of linearized viscous damping may depend on system size, and that some degrees of freedom may be more sensitive than others to the methodology used to linearize viscous damping.
Wake Effects on Multiline Anchor Loads for Floating Offshore Wind Turbines
Authors: Balakrishnan Krishnaveni , Arwade Sanjay , DeGroot Don 
Published: January 2024

Abstract
This paper studies the influence of wake effects on multiline anchor mooring line forces for floating offshore wind turbines for different environmental scenarios. Multiline anchoring is a concept in which seabed anchors are shared among three adjacent turbines through their mooring lines. In this scenario, one or more adjacent turbines could be in the downstream wind direction. In an offshore wind farm, the turbines in the downstream position experience lower wind speed and higher turbulence intensity because of the wake disturbances caused by the upstream turbines. Therefore, the multiline anchor system must be evaluated for each location for a given wind farm configuration. This paper studies five NREL 5MW turbines supported by OC3 Hywind spar buoys in the Hywind Scotland wind farm layout. Wind wake effects are predominant when the turbines are operating. Therefore, the operational design load case DLC1.6 is chosen for the analysis with three different environmental loading directions. NREL open-source tool FAST is used to perform the simulations. Jensen’s wake model and Frandsen’s Turbulence intensity (TI) model are employed to calculate the waked downstream turbine parameters such as reduced wind velocity and turbulence intensity. For each of the wind wave current directions, a case with wake and without wake has been studied. The result from each study is observed as peak multiline anchor force, which is the average of the maxima from six one-hour simulations. In the case of 30° and 120° load directions, one of the downstream turbines in the multiline system is experiencing wake effects, whereas in the case of 90°, two of the turbines are experiencing wake effects. Results show that the multiline system exhibited less tension with waked wind, resulting in decreased mooring line forces compared to cases without wake.
Streamlined Loads Analysis of Floating Wind Turbines With Fiber Rope Mooring Lines
Authors: Hall Matthew , Duong Brian , Lozon Ericka 
Published: January 2024

Abstract
This paper presents an approach for more accurate yet relatively streamlined accounting for the nonlinear characteristics of synthetic fiber rope mooring lines for floating wind turbines. First, we select a minimal set of parameters that can efficiently approximate a mooring line material’s quasi-static and dynamic stiffness characteristics. We also develop a set of baseline coefficients for different rope materials based on published product information and research papers. We then expand a quasi-static mooring model to include dynamic mooring line stiffness terms in a way that allows the nonlinear stiffness behavior of fiber ropes to be considered even in quasi-static analyses. For dynamic analysis, we have updated the model MoorDyn, coupled with OpenFAST, to work with the new dynamic mooring line stiffness terms. This includes the implementation of a new viscoelastic approach that allows the tension-strain relation of each mooring line segment to vary between two stiffness values, depending on the strain rate. After presenting the formulation of the approaches for modeling synthetic ropes, they are demonstrated on a floating wind turbine mooring system with taut polyester rope mooring lines. The results are compared with those of other approaches of similar fidelity, including the static-dynamic method and separate simulations with static and dynamic stiffness values. Comparing the results shows the ability of the new method to match the results of the previous methods in a more streamlined manner.
Effect of Training Model on the Physical Condition of Young Female Football Players
Authors: Pérez-Muñoz Salvador , Alonso García Gema , Benito García Laura , Rodríguez-Cayetano Alberto 
Published: January 2024

The aim of the study was to analyze the impact of two training models—the traditional methodology and an alternative or nonlinear mixed methodology—on coordination, speed, and changes of direction (COD) in U-12 football players. The subjects were divided into two groups: a traditional group of 11 female players and a second group of 14 female players, which followed a mixed methodology. Ten training sessions of 30 min were carried out focusing on motor coordination and COD. The variables analyzed were motor coordination with the SportComp test, COD with the Modified Agility test, and the Suttle Sprint and Dribbling test, with and without the ball, and speed over 30 m, with and without the ball. Overall, improvements were obtained in the mixed training program, leading to significant improvements (p < .05) in the variables of motor coordination, speed, and COD, with a large effect size. Therefore, coaches and physical trainers, taking into account that it causes greater benefits in the physical condition of female football players in training, than the traditional training program, can use the mixed training program.
Synthesis and Properties of (+)-Ketopinic and (–)-Camphanic Acids Esters Bearing a Nitrogen-Containing Heterocycle
Authors: Sokolova A. S. , Yarovaya O. I. , Kuzminykh L. V. , Ilyina M. G. , Borisevich S. S. , Esaulkova Ya. L. , Zarubaev V. V. , Salakhutdinov N. F. 
Published: January 2024

Abstract
A three-stage method was proposed for the synthesis of (1S)-(+)-camphor-10-sulfonic acid, (+)-ketopinic and (–)-camphanic acids esters containing a saturated nitrogen-containing heterocycle. It was found that (1S)-(+)-camphor-10-sulfonic acid esters undergo destruction with elimination of the sulfonic acid group in substitution reactions involving nitrogen-containing heterocycles. Esters of (+)-ketopinic and (–)-camphanic acids were formed during the proposed synthetic route, but undergo transesterification under column chromatography conditions. Quantum chemical calculations showed that the destruction of the ester bond in the case of (+)-ketopinic and (–)-camphanic acids requires less energy than the breaking of a similar bond in (–)-borneol esters. It was revealed that the internal bond strength index (IBSI) for the alkyl C–O bond in (–)-borneol esters is higher than in (+)-ketopinic and (–)-camphanic acid esters. Antiviral properties against the H1N1 influenza virus were studied for derivatives of (+)-ketopinic and (–)-camphanic acids.
Prospects for $$B_c^+$$ and $$B^+\rightarrow \tau ^+ \nu _\tau $$ at FCC-ee
Authors: Zuo Xunwu , Fedele Marco , Helsens Clément , Hill Donal , Iguro Syuhei , Klute Markus 
Published: January 2024

AbstractThe prospects are presented for precise measurements of the branching ratios of the purely leptonic $$B_c^+ \rightarrow \tau ^+ \nu _\tau $$

B
c
+

→

τ
+

ν
τ

and $$B^+ \rightarrow \tau ^+ \nu _\tau $$

B
+

→

τ
+

ν
τ

decays at the Future Circular Collider (FCC). This work is focused on the hadronic $$\tau ^{+} \rightarrow \pi ^+ \pi ^+ \pi ^- {\bar{\nu }}_\tau $$

τ
+

→

π
+

π
+

π
-

ν

¯

τ

decay in both $$B_c^+ \rightarrow \tau ^+ \nu _\tau $$

B
c
+

→

τ
+

ν
τ

and $$B^+ \rightarrow \tau ^+ \nu _\tau $$

B
+

→

τ
+

ν
τ

processes. Events are selected with two Boosted Decision Tree algorithms to optimise the separation between the two signal processes as well as the generic hadronic Z decay backgrounds. The range of the expected precision for both signals are evaluated in different scenarios of non-ideal background modelling. This paper demonstrates, for the first time, that the $$B^+ \rightarrow \tau ^+ \nu _\tau $$

B
+

→

τ
+

ν
τ

decay can be well separated from both $$B_c^+ \rightarrow \tau ^+ \nu _\tau $$

B
c
+

→

τ
+

ν
τ

and generic $$Z\rightarrow b{\bar{b}}$$

Z
→
b

b

¯

processes in the FCC-ee collision environment and proposes the corresponding branching ratio measurement as a novel way to determine the CKM matrix element $$|V_{ub}|$$

|

V

ub

|

. The theoretical impacts of both $$B^+ \rightarrow \tau ^+ \nu _\tau $$

B
+

→

τ
+

ν
τ

and $$B_c^+ \rightarrow \tau ^+ \nu _\tau $$

B
c
+

→

τ
+

ν
τ

measurements on New Physics cases are discussed for interpretations in the generic Two-Higgs-doublet model and leptoquark models.
Trends and Outcomes Associated With Bariatric Surgery and Pharmacotherapies With Weight Loss Effects Among Patients With Heart Failure and Obesity
Authors: Mentias Amgad , Desai Milind Y. , Aminian Ali , Patel Kershaw V. , Keshvani Neil , Verma Subodh , Cho Leslie , Jacob Miriam , Alvarez Paulino , Lincoff A. Michael , Van Spall Harriette G.C. , Lam Carolyn S.P. , Butler Javed , Nissen Steven E. , Pandey Ambarish 
Published: January 2024

BACKGROUND:
Utilization patterns of bariatric surgery among older patients with heart failure (HF), and the associations with cardiovascular outcomes, are not well known.

METHODS:
Medicare beneficiaries with HF and at least class II obesity from 2013 to 2020 were identified with Medicare Provider Analysis and Review 100% inpatient files and Medicare 5% outpatient files. Patients who underwent bariatric surgery were matched to controls in a 1:2 ratio (matched on exact age, sex, race, body mass index, HF encounter year, and HF hospitalization rate pre-surgery/matched period). In an exploratory analysis, patients prescribed pharmacotherapies with weight loss effects (semaglutide, liraglutide, naltrexone-bupropion, or orlistat) were identified and matched to controls with a similar strategy in addition to HF medical therapy data. Cox models evaluated associations between weight loss therapies (as a time-varying covariate) and mortality risk and HF hospitalization rate (calculated as the rate of HF hospitalizations following index HF encounter per 100 person-months) during follow-up.

RESULTS:

Of 298 101 patients with HF and body mass index ≥35 kg/m
2
, 2594 (0.9%) underwent bariatric surgery (45% men; mean age, 56.2 years; mean body mass index, 51.5 kg/m
2
). In propensity-matched analyses over a median follow-up of 4.7 years, bariatric surgery was associated with lower risk of all-cause mortality (HR, 0.55 [95% CI, 0.49–0.63];
P
<0.001), greater reduction in HF hospitalization rate (rate ratio, 0.72 [95% CI, 0.67–0.77];
P
<0.001), and lower atrial fibrillation risk (HR, 0.78 [95% CI, 0.65–0.93];
P
=0.006). Use of pharmacotherapies with weight loss effects was low (4.8%), with 96.3% prescribed GLP-1 (glucagon-like peptide-1) agonists (semaglutide, 23.6%; liraglutide, 72.7%). In propensity-matched analysis over a median follow-up of 2.8 years, patients receiving pharmacotherapies with weight loss effects (versus matched controls) had a lower risk of all-cause mortality (HR, 0.82 [95% CI, 0.71–0.95];
P
=0.007) and HF hospitalization rate (rate ratio, 0.87 [95% CI, 0.77–0.99];
P
=0.04).

CONCLUSIONS:
Bariatric surgery and pharmacotherapies with weight loss effects are associated with a lower risk of adverse outcomes among older patients with HF and obesity; however, overall utilization remains low.
Changing Forms of Maximalism in the Decision-Making of the Czech Constitutional Court
Authors: Ondřejek Pavel 
Published: January 2024

Abstract
The article analyses how wide and general conclusions are formulated in case law, using a sample of decisions of the Czech Constitutional Court from 1998 and 2018. The article shows tendencies towards institutionalisation of maximalist decision-making in the form of formulating general principles as starting points for decisions made in individual cases. Another important observation is connected with the changing form of maximalist judicial decisions, shifting from maximalism characterised by depth of the reasoning towards maximalism manifested in the width of impacts of an individual case, whereby the Czech Constitutional Court has been strengthening its position vis-à-vis other branches of government. In the conclusion of the article, it is emphasised that maximalism, in terms of separation of powers, rather represents an anti-systemic element in the laws of countries with civil-law legal system, such as the Czech Republic.