bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two combinatorial patterns of telomere histone marks in plants with canonical and non‐canonical telomere repeats
Authors: Adamusová Kateřina , Khosravi Solmaz , Fujimoto Satoru , Houben Andreas , Matsunaga Sachihiro , Fajkus Jiří , Fojtová Miloslava 
Published: December 2019

SummaryTelomeres, nucleoprotein structures at the ends of linear eukaryotic chromosomes, are crucial for the maintenance of genome integrity. In most plants, telomeres consist of conserved tandem repeat units comprising the TTTAGGG motif. Recently, non‐canonical telomeres were described in several plants and plant taxons, including the carnivorous plant Genlisea hispidula (TTCAGG/TTTCAGG), the genus Cestrum (Solanaceae; TTTTTTAGGG), and plants from the Asparagales order with either a vertebrate‐type telomere repeat TTAGGG or Allium genus‐specific CTCGGTTATGGG repeat. We analyzed epigenetic modifications of telomeric histones in plants with canonical and non‐canonical telomeres, and further in telomeric chromatin captured from leaves of Nicotiana benthamiana transiently transformed by telomere CRISPR‐dCas9‐eGFP, and of Arabidopsis thaliana stably transformed with TALE_telo C‐3×GFP. Two combinatorial patterns of telomeric histone modifications were identified: (i) an Arabidopsis‐like pattern (A. thaliana, G. hispidula, Genlisea nigrocaulis, Allium cepa, Narcissus pseudonarcissus, Petunia hybrida, Solanum tuberosum, Solanum lycopersicum) with telomeric histones decorated predominantly by H3K9me2; (ii) a tobacco‐like pattern (Nicotiana tabacum, N. benthamiana, C. elegans) with a strong H3K27me3 signal. Our data suggest that epigenetic modifications of plant telomere‐associated histones are related neither to the sequence of the telomere motif nor to the lengths of the telomeres. Nor the phylogenetic position of the species plays the role; representatives of the Solanaceae family are included in both groups. As both patterns of histone marks are compatible with fully functional telomeres in respective plants, we conclude that the described specific differences in histone marks are not critical for telomere functions.
Power Generation Using Kites in a GroundGen Airborne Wind Energy System: A Numerical Study
Authors: Nejad Alireza Mahdavi , Tryggvason Gretar 
Published: December 2019

Abstract
A computational model of a massless kite that produces power in an airborne wind energy (AWE) system is presented. AWE systems use tethered kites at high altitudes to extract energy from the wind and are being considered as an alternative to wind turbines since the kites can move in high-speed cross-wind motions over large swept areas to increase power production. In our model, the kite completes successive power-retraction cycles where the kite angle of attack is altered as required to vary the resultant aerodynamic forces on the kite. The flow field is found in a two-dimensional domain near the flexible kite by solving the full Navier–Stokes equations using an Eulerian grid together with a Lagrangian representation of the kite. The flow solver is a finite volume projection method using a non-uniform mesh on a staggered grid and corrector–predictor technique to ensure a second-order accuracy in time. The two-dimensional kite shape is modeled as a slightly cambered immersed boundary that moves with the flow. The flexible kite is modeled with a set of linear springs following Hooke’s law. The unstretched length of each elastic tether at a given time step is controlled using periodic triangular wave shapes to achieve the required power-retraction phases. A study was conducted in which the wave shape amplitude, frequency, and phase (between two tethers) were adjusted to achieve a suitably high net power output. The results are in good agreement with predictions for Loyd’s simple kite in two-dimensional motion. Aerodynamic coefficients for the kite, tether tensions, tether reel-out and reel-in speeds, and the vorticity fields in the kite wake are also determined.
Design and Analysis of a Valveless Impedance Pump for a Direct Sodium Borohydride–Hydrogen Peroxide Fuel Cell
Authors: Yang A. S. , Tseng J. W. , Wen C. Y. , Zhang H. 
Published: December 2019

Abstract
A valveless impedance pump is designed and applied for the first time to supply the liquid fuels for a direct sodium borohydride–hydrogen peroxide fuel cell (DBHPFC). This valveless pump consists of an amber latex rubber tube, which is connected at both ends to rigid stainless-steel tubes of different acoustic impedance, and a simple actuation mechanism with a small direct control (DC) motor and a cam combined. The cam is activated by the motor and periodically compresses the elastic tube at a position asymmetrical from the tube ends. The traveling waves emitted from the compression combine with the reflected waves at the impedance-mismatched rubber tube/stainless-steel tube interfaces. The resulting wave interference creates a pressure gradient and generates a net flow. When connected to a DBHPFC with an active area of 25 cm2, the pump can deliver the fuel at a maximum pumping rate of 30 ml/min, resulting in corresponding DBHPFC maximum power and a current of 13.0 W and 25.5 A, respectively. The specific power, volumetric power density, and back work ratio of the DBHPFC with this pumping method have been proven superior to those of the other pumping configuration with peristaltic pumps. This valveless impedance pump is mechanically simply and less susceptible to corrosion, and it can reduce the volume and weight of fuel cell systems to a measurable extent. The experimental results demonstrate the feasibility of the device for practical DBHPFC applications.
Experimental Study on Flow-Induced Motions (FIM) of a Floating Offshore Wind Turbine Semi-Submersible Type (OC4 Phase II Floater)
Authors: Gonçalves Rodolfo T. , Chame Maria E. F. , Silva Leandro S. P. , Koop Arjen , Hirabayashi Shinichiro , Suzuki Hideyuki 
Published: December 2019

Abstract
Flow-Induced Motions (FIM) is an issue for multi-column platforms, and the phenomenon can decrease the fatigue life of the mooring, riser, and cable systems. In the past, FIM was studied mainly for platforms installed in deep waters. The new concepts of Floating Offshore Wind Turbines (FOWT) have multi-column design and may therefore observe FIM. However, FOWTs have been installed in shallow water and, in this case, the FIM remains insufficiently investigated. To address this issue, FIM model tests were performed for the – Semisubmersible (SS) Floating System design developed for the DeepCwind project (OC4 Phase II). The goal of this paper is to investigate the presence of FIM for this type of system to show the importance of FIM in the design of FOWT. Three different incidence angles of the current were tested, namely 0, 90 and 180 degrees. For each heading, thirty reduced velocities were tested. The results showed amplitudes in the transverse direction of around 70% of the diameter of the platform column, which is similar to the ones observed for the deep-draft (DD) SS with circular columns and larger than for the platforms with square columns. The results showed that FIM was present for this specific FOWT SS investigated and that it may thus be essential to consider when designing the mooring system, as an increment in the total cost of the platform may make the system economically unfeasible. When extrapolating the results for the full-scale configuration, the FIM synchronization occurred for current velocities from 0.5m/s up to 1.2m/s, and the maximum nondimensional nominal amplitudes for the motions in the transverse direction reached 70% of the external column diameter.
Large Aeroelastic Model of a Floating Offshore Wind Turbine: Mechanical and Mechatronics Design
Authors: Muggiasca Sara , Fontanella Alessandro , Taruffi Federico , Giberti Hermes , Facchinetti Alan , Belloli Marco , Bollati Marco 
Published: December 2019

Abstract
This paper deals with the mechatronic design of a large-scale wind turbine model (outdoor scaled prototype) based on the DTU 10MW. This is going to be integrated in the model of a multi-purpose floating structure to be deployed at the Natural Ocean Engineering Laboratory (NOEL) in Reggio Calabria (Italy). The floating wind turbine model is the downscaling of the full-scale structure designed within the EU H2020 Blue Growth Farm project. The structural design of the scaled wind turbine is presented, starting from the aeroelastic and aerodynamic design carried out in a previous work.
A Consistent Structural Damping Model for Integrated and Superelement Modelling of Offshore Wind Turbine Support Structures in Wind Turbine Design Software Bladed
Authors: Collier William 
Published: December 2019

Abstract
In aero-elastic simulation of offshore wind turbines, the support structure can be modelled using an “integrated” approach, where the jacket and tower and modelled explicitly as one structural body, or a “superelement” approach, where the jacket part of the support structure is included as a superelement. For integrated modelling, vibration mode shapes are calculated for the whole support structure. For a superelement approach, separate mode shapes are defined for superelement and the tower. The different modal basis makes it difficult to align the structural damping definition for the two approaches, meaning that manual tuning of the modal damping ratios has previously been necessary to achieve equivalent damping on the whole support structure for the two approaches. To provide a consistent damping approach, it is proposed to specify modal damping ratios or Rayleigh damping on a modal basis which is common to the two approaches: the support structure natural mode shapes. When damping is specified on the natural modes of the support structure, equivalent support structure damping is observed for superelement and integrated modelling approaches. This allows the target support structure damping ratios to be achieved easily and also facilitates studies to compare the superelement and integrated modelling approaches.
Effects of Variations on the Experimental Set-Up on the Motion Response of a Floating Wind Semisubmersible (OC4 Type)
Authors: Gueydon Sebastien 
Published: December 2019

Abstract
With their light weights, small components like braces and heave plates and steady trim angle caused by the wind loads acting on the rotor, semisubmersible foundations used as support platform for wind turbines exhibit a complex behaviour where viscous loading play an important role. The work done by the Offshore Code Comparison Collaboration Continued with Correlation (OC5) project has shown that standard engineering tools were not always able to predict accurately the motions of the DeepCwind semisubmersible that were measured in a basin. The correct amplitude of the motions at the natural periods of this system appeared to be difficult to obtain with simulations (especially the low frequency surge, and the pitch resonant motion). In view of the complexity of the system, it was not possible to clearly identify the causes of the differences between the simulations and the model-test results. A follow-on validation campaign was therefore performed at the Maritime Research Institute Netherlands (MARIN) under the MARINET2 project with the same floating substructure, with a focus on better understanding the hydrodynamic loads and reducing uncertainty in the tests by minimizing the system complexity.
The wind turbine was replaced by a stiff tower with resembling inertia properties. The mooring system was simplified by using taut-spring lines with equivalent linear stiffness in surge. This paper reviews the new tests done with the simplified set-up and examines the differences with previous tests done with more complex test set-ups. The main motivation of this work is to study how variations of an experimental set-up can affect the outcome of tests in a wave basin. To start with, the main parameters of the systems (inertia, hydrostatics, and mooring stiffness) for all set-ups are characterized to check how similar they are. Then the level of damping in all systems is compared. Finally, the paper looks at how well the motion responses of this semisubmersible in waves correlate between all these campaigns.
Effects of Wind Farm Down-Regulation in the Offshore Wind Farm Alpha Ventus
Authors: Kretschmer Matthias , Pettas Vasilis , Cheng Po Wen 
Published: December 2019

Abstract
In recent years wind turbine down-regulation has been used or investigated for a variety of applications such as wind farm power optimisation, energy production curtailment and lifetime management. This study presents results from measurement data of tower loads and power obtained from two turbines located in the German offshore wind farm alpha ventus. The free streaming turbine, located closely to a fully equipped meteorological mast, was down-regulated to 50% for a period of 8 months, while the downwind turbine was operating normally. The results are compared to periods where both turbines were operated in normal conditions. Changes in loads and power are analysed according to incoming wind direction and magnitude. Results show a high reduction in the loads of the down regulated turbine, up to a level of 40%. For the turbine in wake the effects in loads are more prominent, showing a maximum reduction of 30%, compared to the effects in power and are seen in a wider sector of about 20° for loads and 10° for power.
Concept Design and Analysis of Wind-Tracing Floating Offshore Wind Turbines
Authors: Li Shuijin , Lamei Azin , Hayatdavoodi Masoud , Wong Carlos 
Published: December 2019

Abstract
Most of the existing floating offshore wind turbines (FOWT), whether in concept or built, host a single turbine. Structures that can host multiple turbines have received attention in recent years, mainly with the aim of reducing the overall cost of energy production and maintenance. A concept challenge of placing multiple wind turbines on a single floating platform is that under variable wind directions, the leading turbines may block the wind against the trailing turbines. In this work, concept design of a wind-tracing floating structure accommodating three wind turbines is presented. The triangular-shapefloating platform is made of pre-stressed concrete, and the turbines are located on the corners. The floating structure uses a single-point mooring system which allows for the entire structure to rotate in response to the change of wind direction. Due to the particular configuration of the floating structure, it is essential to consider the wind, wave and current loads, along with the response of the structure, simultaneously. Response of the FOWT to simultaneous environmental loads from different directions is studied by use of the constant panel approach of the Green function method, subject to constant wind loads on the turbines and linear mooring loads. We also consider the elasticity of the structure by use of finite element analysis, coupled with the hydro- and aero-dynamic loads and responses.
A Low Specific Mass, Free Floating Wind Energy Concept up to 40 MW
Authors: Alexander William 
Published: December 2019

Abstract
Presented here is a low specific mass, free-floating, open ocean, wind energy concept with nominal power capacity to 40 MW, on-board liquid fuels generation, and with operational and survival wave heights to 12 and 40 meters respectively. The estimated specific structural mass of 42 kG/kWp is about 1/3 of the specific mass of much smaller land-based turbines, and less than 6% of the specific structural mass of existing off-shore floating wind turbines. The turbine platform may be operated un-tethered in the open ocean using about 8% of the generated power, on average, for active station keeping. The generated energy may be stored on board via hydrogen electrolysis and liquification for periodic tanker unloading. Reduction of moment loads in the blades and nacelle support structure as well as the unique deep-water foundation result in the low specific mass and high stability.
Structure Design and Assessment of a Floating Foundation for Offshore Wind Turbines
Authors: Ye Qi , Cheng Shanshan , Kim Boksun , Collins Keri , Iglesias Gregorio 
Published: December 2019

Abstract
This paper summarizes the assessment of the structural analysis and design of a floating foundation for offshore floating wind turbine (FWT) based on DNVGL standard and Eurocode in terms of economy and reliability. The wind loads are calculated using empirical equations. The wave loads are obtained and verified using various methods including hand calculation, AQWA and Flow-3D. It is found that the shell thickness could be reduced significantly by introducing the stiffeners (stringer or ring), which can decrease the weight of the hull and lower the cost. While DNVGL and Eurocode yield similar design solutions if using plane shell structures, Eurocode significantly underestimates the buckling resistance of stiffened cylindrical shells.
Damping Identification of the TetraSpar Floater in Two Configurations With Operational Modal Analysis
Authors: Pegalajar-Jurado Antonio , Madsen Freddy J. , Bredmose Henrik 
Published: December 2019

Abstract
Second-order hydrodynamic loads can induce motions at the natural frequencies of a floating wind turbine. These resonant responses are highly dependent on the hydrodynamic damping, which is mostly introduced by viscous effects. Numerically, these viscous effects are often represented by a Morison drag term with relative velocity, which introduces forcing, sea state-dependent linear damping and amplitude-dependent quadratic damping. Recent literature shows that calibration of the Morison drag coefficients to decay tests is not sufficient to achieve an accurate response in the numerical models. In addition, calibration of the drag coefficient alone changes both forcing and damping. Hence, following common practice, additional damping terms are needed, which require calibration against operating conditions. In this study, we apply Operational Modal Analysis (OMA) to wave basin results for the TetraSpar floater of Stiesdal Offshore Technologies. The floater was tested at scale 1:60 with the DTU 10MW reference wind turbine, both in the semi and spar configurations. We identify the linearized damping ratio in surge and pitch for different environmental conditions and investigate its dependency on the sea state and the motion amplitude. Our preliminary results show that the damping of the pitch mode follows increasing trends with significant wave height and motion amplitude, whereas the damping in surge presents a less clear tendency. This is linked to the larger damping level, smaller natural frequency and larger OMA uncertainty for surge. The paper concludes with a discussion of the dependency of OMA estimates on the amount of data and its processing.
Deprescribing psychotropic medications in children: results of a national qualitative study
Authors: Barnett Erin R , Trepman Alissa Z , Fuson Hannah A , Acquilano Stephanie C , McLaren Jennifer L , Woloshin Steven , Leyenaar Joanna K 
Published: December 2019

Background and ObjectivePrescriptions for psychotropic medications to children have risen dramatically in recent years despite few regulatory approvals and growing concerns about side effects. Government policy and numerous programmes are attempting to curb this problem. However, the perspectives of practising clinicians have not been explored. To characterise the perspectives and experiences of paediatric primary care clinicians and mental health specialists regarding overprescribing and deprescribing psychotropic medications in children.MethodsWe conducted 24 semistructured interviews with clinicians representing diverse geographic regions and practice settings in the USA. Interview questions focused on clinician perspectives surrounding overprescribing and experiences with deprescribing. We transcribed audio files verbatim and verified them for accuracy. We analysed transcripts using a grounded theory approach, identifying emergent themes and developing a conceptual model using axial coding.ResultsAnalysis yielded themes within four domains: social and clinical contextual factors contributing to overprescribing, opportunities for deprescribing, and facilitators and barriers to deprescribing in paediatric outpatient settings. Most participants recognised the problem of overprescribing, and they described complex clinical and social contextual factors, as well as internal and external pressures, that contribute to overprescribing. Opportunities for deprescribing included identification of high-risk medications, routine reassessment of medication needs and recognition of the broader social needs of vulnerable children. Facilitators and barriers to deprescribing were both internal (eg, providing psychoeducation to families) and external (eg, parent and child preferences) to clinicians.ConclusionOur findings highlight a discrepancy between clinicians’ concerns about overprescribing and a lack of resources to support deprescribing in outpatient paediatric settings. To successfully initiate deprescribing, clinicians will need practical tools and organisational supports, as well as social resources for vulnerable families.
Auricular acupressure for cancer-related fatigue during lung cancer chemotherapy: a randomised trial
Authors: Lin Lu , Zhang Yan , Qian Hong Ying , Xu Jia Li , Xie Cong Yan , Dong Bei , Tian Li 
Published: December 2019

PurposeTo evaluate the effect of auricular acupressure (AA) on cancer-related fatigue (CRF), sleep disturbance and anxiety in lung cancer patients undergoing chemotherapy.Materials and methodsPatients were recruited from the respiratory department of a general hospital and were randomised into three groups. A 9-week course of AA using Semen Vaccariae (SV) (Group A)/AA using magnetic beads (Group B)/routine care (Group C) was implemented. CRF scores were used as the primary outcome while the sleep and anxiety scores were the secondary outcomes. Analysis of variance and least significant difference t-test were used to determine the intergroup differences and paired-sample t-test was used for the intragroup comparison.Results100 lung cancer patients undergoing chemotherapy were included. Compared with Group C, AA could significantly alleviate CRF (F:24.63, p<0.01), especially for physical and affective fatigue and Group A was more effective for managing physical fatigue than Group B in per-protocol (PP) (−1.75 (−2.69 to –0.82), p<0.01)/Intention to Treat analysis (ITT) (−1.41 (−2.39 to –0.41), p=0.01) analysis. However, AA had no effect on cognitive fatigue. Compared with Group C, only Group A produced significant improvements in sleep quality in PP analysis (−1.17 (−2.23 to –0.10), p=0.03) while it yielded negative results in ITT analysis (−0.82 (−1.74 to 0.10), p=0.08). Compared with Group C, AA could significantly reduce anxiety in PP analysis (F:9.35, p<0.01) while there was no statistical difference between Group B and Group C (−0.95 (−2.81 to 0.90), p=0.31), Group A and Group B (−1.26 (−3.12 to 0.59), p=0.18) in ITT analysis.ConclusionAA can alleviate CRF of lung cancer patients undergoing chemotherapy, especially for physical and affective fatigue. AA using SV is more effective for physical fatigue while AA using magnetic beads works better for anxiety. However, AA cannot improve the sleep quality.Trial registration numberISRCTNregistry (ISRCTN16408424).