bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Experimental Investigation of a Flexible Trailing Edge for Wind Energy Turbine Blades
Authors: Pohl Martin , Riemenschneider Johannes , Monner Hans Peter 
Published: November 2020

Abstract
The demand of affordable, renewable electric energy is still increasing. Wind energy is seen as one of the most promising resources for future electric energy supply. To reduce the cost of wind energy the dimensions of wind energy turbines are still increasing. This leads to higher power output due to the larger rotor diameters, but also due to the higher wind speeds above the boundary layer. This increase in rotor diameter is achieved at the expense of much higher structural loads especially in the rotor blade root. These loads consist of bending moments, that are mainly caused by gravity, wind shear, gusts and the tower influence to the blade.
A reduction of these root bending moments would allow a further increase of the rotor diameter, a longer lifetime or a lighter design and therefore be advantageous for the turbine. Load reduction can be achieved by using a trailing edge flap at the outer region of the blade, comparable to control surfaces of aircraft. This trailing edge is capable of moving several times per blade revolution and allows the manipulation of the flow to alleviate changes in the aerodynamic loading. In contrast to aircraft, sealing against environmental media, such as rain, dust, insects and so on is much more important to allow a high lifetime and low maintenance effort. Therefore, a flexible and gapless morphing trailing edge has been designed within the SmartBlades projects at the German Aerospace Center (DLR) for the mentioned purpose. Based on this design, a demonstrator was built, which was tested in a wind tunnel and on a rotational test site for its performance.
The paper will present the approach beginning with some design and modeling considerations of the flexible trailing edge and the demonstrator, which was used for testing. Main focus of the paper is the presentation of results obtained from a wind tunnel experiment at Oldenburg University and the rotational experiment at the field research site of the Technical University in Denmark (DTU). In these experiments, the effectiveness of the trailing edge flap could be demonstrated in the wind tunnel as well as in free field. Based on pressure taps and force sensors, the change in the lift of the airfoil due to the deflection of the flexible trailing edge was measured and the resulting polars are shown in this paper. Furthermore, the result of different simple control strategies for the trailing edge in terms of load reduction at the rotating test rig will be presented.
System Simulation of an Elastocaloric Heating and Cooling Device Based on SMA
Authors: Welsch Felix , Kirsch Susanne-Marie , Michaelis Nicolas , Mandolino Michele , Schütze Andreas , Seelecke Stefan , Motzki Paul , Rizzello Gianluca 
Published: November 2020

Abstract
Elastocaloric (EC) cooling uses solid-state NiTi-based shape memory alloy (SMA) as a non-volatile cooling medium and enables a novel environment-friendly cooling technology. Due to the high specific latent heats activated by mechanical loading/unloading, substantial temperature changes are generated in the material. Accompanied by a small required work input, a high coefficient of performance is achievable.
Recently, a fully functional and illustrative continuous operating elastocaloric air cooling system based on SMA was developed and realized. To assist the design process of an optimized device with given performance and efficiency requirements, a fully coupled thermo-mechanical system-level model of the multi-wire cooling unit was developed and implemented in MATLAB. The resulting compact simulation tool is qualified for massively parallel computation, which allows fast and comprehensive parameter studies.
In this work, the influence of different SMA diameters, rotation frequencies, and airflow rates is investigated. The results are analyzed to find the suited parameter for high efficiency (COP) and temperature span.
Terfenol-D Carbon Fiber Reinforced Polymer (CFRP): Embedded Sensing for Early Localized Damage Detection
Authors: Williams Brandon , Hall Asha , Myers Oliver 
Published: November 2020

Abstract
Carbon Fiber Reinforced Polymers (CFRPs) have become an essential part of designing and engineering lightweight rigid bodies, predominantly in the aerospace and automotive industries. Typical epoxy based CFRPs exhibit virtually no plasticity with minimal strain to failure. Although CFRPs have high specific strengths and elastic moduli, the brittle fracture mechanism presents unique challenges in failure detection for the US Army’s vertical lift vehicle components since failure can occur catastrophically. The Army currently uses a “safe-life” interval-based service methodology where components are replaced with regards to a usage spectrum rather than the component’s actual state of structural health. This paper explores a method for solving this problem by investigating the possibility of embedding Terfenol-D particles (∼100 microns in diameter), a magnetostrictive material, into the CFRP’s ply interphase for embedded non-contact, real-time, structural health monitoring. For baseline results, the change in localized (32 mm2 field of view) magnetic flux was only 0.02% for an applied load of 0–100% of the material’s ultimate tensile strength (UTS). For quasi-static testing procedure on specimen 5714 (15 wt.% Terfenol-D embedded CFRP) on a 0–40% loading interval of the material’s UTS, there was an observed localized (32 mm2 field of view) magnetic flux gradient of more than 5 mT (4%) with a reversible flux of 100%. For quasi-static testing procedure on specimen 5714 (15 wt.% Terfenol-D embedded CFRP) on a 0–70% loading interval of the material’s UTS, there was an observed localized (32 mm2 field of view) magnetic flux gradient of more than 3 mT (2%) with a reversible flux of only 25%. Terfenol-D embedded CRFPs have shown promising results for detecting instantaneous strain and degradation levels. Acoustic emission (AE) and X-ray computed tomography (CT) scanning were used to validate the observed results.
Noncontact/Remote Material Characterization Using Ultrasonic Guided Wave Methods
Authors: Ma Zhaoyun , Yu Lingyu 
Published: November 2020

Abstract
Noncontact and remote NDE systems and methods are highly desired in a broad range of engineering applications such as material property characterization. This paper aims to develop such a noncontact/remote NDE system based on laser ultrasonic guided waves and establish its fundamental capability for material thickness evaluation. The noncontact system employs pulsed laser (PL) for guided wave actuation and scanning laser Doppler vibrometer (SLDV) for guided wave wavefield sensing. A cylindrical planoconvex lens is adopted to focus the pulsed laser beam to a line source in order to excite broad band signals in the target plate. Aluminum plates with different thicknesses are evaluated through SLDV line scans and 2D time-space wavefields are acquired. Frequency-wavenumber (f-k) spectra are obtained through 2D Fourier transform, and the A0 dispersion curve for each plate is extracted. Through Comparing the extracted A0 curve with the theoretical A0 dispersion curves, the thicknesses of the tested plates are identified. Reflective tape effect on the plates are also studied: the reflective tape attached for SLDV enhancement affects the guided waves in the target plate significantly when the plate is relatively thin.
Designing a Morphable Parabolic Reflector Antenna Using Origami-Inspired Discretization and Efficient Global Optimization
Authors: Wilson Gregory , Lagoudas Dimitris , Hartl Darren 
Published: November 2020

Abstract
This research explores a segmented parabolic antenna that can change its physical shape via shape memory alloy actuators, thereby altering its radiation pattern when transmitting a signal. The parabolic dish has been discretized into an origami pattern to make use of the naturally compliant fold regions, about which shape memory alloy wires create moments. Modeling of antenna deformation is accomplished via Abaqus considering SMA wires contracting due to temperature change as a manifestation of the shape memory effect. An electromagnetic analysis of the deformed antenna follows in ANSYS-HFSS to determine the antenna gain in all directions around the structure. The computed radiation pattern is projected onto a goal shape (e.g. the contiguous United States) to determine the degree to which the shaped broadcast pattern matches that of a desired broadcast area. Finally, the design is iterated using an efficient global optimization algorithm to ascertain an actuation schedule that generates the most conformal broadcast pattern. Traditional optimization algorithms such as genetic or particle swarm may require thousands of designs, particularly when many design variables are considered. The efficient global optimization algorithm employs far fewer designs by fitting surrogate models to the data and only testing points where large improvement is expected, thus reducing design optimization time. The evolution and improvement to an antenna will be discussed for an antenna making use of eight, 16, and 24 SMA linear actuators to most optimally broadcast to only the United States while avoiding signal spill-over into other regions, and the lessons learned can then applied to match broadcast pattern based on other countries as well.
Numerical Optimization of Liner Impedance in Acoustic Duct
Authors: Billon Kévin , de Bono Emanuele , Perez Matthias , Collet Manuel , Salze Edouard , Matten Gaël , Ouisse Morvan , Volery Maxime , Lissek Hervé , Mardjono Jacky 
Published: November 2020

Abstract
The SALUTE project aims at evaluating performance of metacomposites for acoustic smart lining in grazing turbulent flow. Theoretical and numerical investigations are carried out for designing innovative specimen. A specific focus is placed in the realization of prototypes for evaluating the metacomposite liner performances in 2D and 3D liners, its process complexity and robustness. The insight gain in this project is new tools for obtaining innovative samples; the acoustical experimental tests demonstrate efficiency and robustness of such technology for controlling UHBR noise emission. This paper is focused on parametric study based on the maximization of the absorption coefficient in a duct by optimizing the impedance of a treated area.
Design and Optimization of Piezoelectric Actuators for Aeroacoustic Noises Control in a Turbofan
Authors: Perez M. , Ezzine M. , Billon K. , Clair V. , Mardjono J. , Collet M. 
Published: November 2020

Abstract
This paper reports on the design and optimization of different types of piezoelectric actuators for aeroacoustic control applications. This study was carried out within the context of the European project CleanSky 2/InnoSTAT. The aim of our work is to reduce the aeroacoustic noises that appear in an airplane turbofan by adding an area of piezoelectric actuators on the Outlet Guide Vanes (OGV). These piezoelectric structures will subsequently be controlled with an active approach and tested in the open-jet anechoic wind tunnel at LMFE. The noise source which has to be reduce/control comes from vortices located in the turbulent flow (which can for example be created by the fan module) interacting with the stator blades. The predominant frequencies and the pressure fluctuations levels related to these vortices rely on the airflow speed and are fixed between 1000Hz and 2000Hz in our case. To reach the target, we plan to manufacture an area of piezoelectric actuators on the intrados and the extrados of the stator blades in order to control the response of the blade to the turbulence of the airflow responsible for the aeroacoustic noise. Several adjacent blades will be equipped with this type of transducers. This study outline the design and the optimization of each piezoelectric cell in order to achieve good results in the frequency range previously defined as well as an acceptable mechanical strength of the blade. A most detailed study on the active shunt will be investigate later on.
Hooked on salt: Rethinking Alpine tectonics in Hallstatt (Eastern Alps, Austria)
Authors: Fernández Oscar , Habermüller Mario , Grasemann Bernhard 
Published: November 2020

AbstractPermian salt in the Hallstatt and neighboring salt structures of the Eastern Alps (Austria) crops out along with Triassic deep-water deposits that are at odds with the surrounding Triassic platform carbonates. The traditional interpretation of this juxtaposition is that the salt bodies were emplaced in the Late Jurassic as gravity nappes onto the carbonate platforms, in what has been considered to be the earliest orogenic event in the Eastern Alps. Here we describe for the first time a world-class outcrop of halokinetic sequences in Triassic platform carbonates flanking the Hallstatt diapir. Combining this with other outcrop evidence, we prove that the Hallstatt diapir grew passively during the Triassic, surrounded by carbonate platforms, and extruded to the seabed during the Jurassic. The development of the Hallstatt diapir in a platform setting disproves its emplacement as a gravity-driven nappe, proves the relevance of salt tectonics in the Mesozoic development of the Eastern Alps, and challenges the existence of a Late Jurassic Alpine orogenic event.
Seismicity trends and detachment fault structure at 13°N, Mid-Atlantic Ridge
Authors: Parnell-Turner R. , Sohn R.A. , Peirce C. , Reston T.J. , MacLeod C.J. , Searle R.C. , Simão N.M. 
Published: November 2020

AbstractAt slow-spreading ridges, plate separation is commonly partly accommodated by slip on long-lived detachment faults, exposing upper mantle and lower crustal rocks on the seafloor. However, the mechanics of this process, the subsurface structure, and the interaction of these faults remain largely unknown. We report the results of a network of 56 ocean-bottom seismographs (OBSs), deployed in 2016 at the Mid-Atlantic Ridge near 13°N, that provided dense spatial coverage of two adjacent detachment faults and the intervening ridge axis. Although both detachments exhibited high levels of seismicity, they are separated by an ∼8-km-wide aseismic zone, indicating that they are mechanically decoupled. A linear band of seismic activity, possibly indicating magmatism, crosscuts the 13°30′N domed detachment surface, confirming previous evidence for fault abandonment. Farther south, where the 2016 OBS network spatially overlapped with a similar survey done in 2014, significant changes in the patterns of seismicity between these surveys are observed. These changes suggest that oceanic detachments undergo previously unobserved cycles of stress accumulation and release as plate spreading is accommodated.
Association between P wave polarity in atrial premature complexes and cardiovascular events in a community-dwelling population
Authors: Kabutoya Tomoyuki , Imai Yasushi , Ishikawa Shizukiyo , Kario Kazuomi 
Published: November 2020

ObjectiveTo examine the association between polarity of atrial premature complexes (APCs) and stroke.DesignA prospective study.Setting and participantsA total of 11 092 participants in the Jichi Medical School cohort study were included after excluding patients with atrial fibrillation. We analysed stroke events in patients with (n=136) and without (n=10 956) APCs. With regard to polarity of APCs, patients were subcategorised into having (1) negative (n=39) or non-negative (n=97) P waves in augmented vector right (aVR), and (2) positive (n=28) or non-positive (n=108) P waves in augmented vector left (aVL).Outcome measuresThe primary endpoint was stroke.ResultsPatients with APCs were significantly older than those without APCs (64.1±9.2 vs 55.1±11.6 years, p<0.001). The mean follow-up period was 11.8±2.4 years. Stroke events were observed in patients with (n=13 events) and without (n=411 events) APCs. This difference was significant (log-rank 12.9, p<0.001); however, APCs were not an independent predictor of stroke after adjusting for age, sex, height, body mass index, current drinking, diabetes, systolic blood pressure, prior myocardial infarction, prior stroke and high-density lipoprotein-cholesterol (p=0.15). The incidence of stroke in patients with APCs and non-negative P wave in aVR was significantly higher than in patients without APCs (log-rank 20.1, p<0.001), and non-negative P wave in aVR was revealed to be an independent predictor of stroke (HR 1.84, 95% CI 1.02 to 3.30). The incidence of stroke in patients with APC with non-positive P wave in aVL was also significantly higher than in patients without APC (log-rank 15.3, p<0.001), and non-positive P wave in aVL was an independent predictor of stroke (HR 1.92, 95% CI 1.05 to 3.54).ConclusionsThe presence of APCs with non-negative P wave in aVR or non-positive P wave in aVL on 12-lead ECG was associated with a higher risk of incident stroke.
Falls in people living with HIV: a scoping review
Authors: Charumbira Maria Yvonne , Berner Karina , Louw Quinette Abegail 
Published: November 2020

ObjectivesRecent research has indicated seemingly increased propensity for falls and accelerated bone demineralisation in people living with HIV (PLWH). We aim to map out the extent and nature of existing research relating to falls in PLWH and describe the relationship between bone demineralisation and falls in PLWH.MethodsA scoping review was done following Arksey & O’Malley’s methodological framework and recommendations from Joanna Briggs Institute. Four databases were searched until October 2019 for peer-reviewed studies available in English reporting on the definition, prevalence, assessment, risk factors and interventions for falls in PLWH as well as information on bone demineralisation linked to falls in PLWH. Narrative reviews were excluded. Two reviewers independently performed the extraction using a predesigned Excel sheet. A descriptive analysis of extracted information was done.ResultsFourteen studies on falls in older PLWH were identified, with all but one study conducted in high-income countries. Prevalence of falls in PLWH ranged from 12% to 41%. Variable assessment tools/tests were used to assess potential risk factors, but it remains to be determined which are more predictive and appropriate for use among PLWH. Considerable agreement existed for risk factors regarding use of medications while evidence regarding functional and cognitive impairments were variable. Few studies compared risk factors for falls in PLWH with those in age-matched and sex-matched seronegative population. There is currently no evidence for interventions to prevent or reduce falls risk in PLWH.ConclusionMore research is needed on falls in younger cohorts of PLWH and in sub-Saharan Africa where HIV is most prevalent and more robust clades exist. More studies need to report on data in seronegative controls to determine risk factors unique to PLWH. More intervention studies targeted at falls prevention and promotion of bone health are required. Quality clinical practice guidelines highlighting validated assessment tools and outcome measures need to be developed.
Rationale and study protocol of the Physical Activity and Dietary intervention in women with OVArian cancer (PADOVA) study: a randomised controlled trial to evaluate effectiveness of a tailored exercise and dietary intervention on body composition, physical function and fatigue in women with ovarian cancer undergoing chemotherapy
Authors: Stelten Stephanie , Hoedjes Meeke , Kenter Gemma G , Kampman Ellen , Huijsmans Rosalie J , van Lonkhuijzen Luc RCW , Buffart LM 
Published: November 2020

IntroductionAs a consequence of ovarian cancer and its treatment, many women with ovarian cancer have to deal with reduced physical function, fatigue, and loss of weight and/or muscle mass, compromising quality of life. Exercise and dietary interventions can positively influence body composition, physical fitness and function, and fatigue in patients with cancer. However, there are no data from randomised controlled trials on the effectiveness of exercise and dietary interventions in patients with ovarian cancer. Due to a complex disease trajectory, a relatively poor survival and distinct disease-induced and treatment-induced side effects, it is unclear whether exercise and dietary interventions that were shown to be feasible and effective in other types of cancer produce comparable results in patients with ovarian cancer. The aim of this article is to present the design of the multicentre randomised controlled Physical Activity and Dietary intervention in OVArian cancer trial and to describe how the exercise and dietary intervention is tailored to specific comorbidities and disease-induced and treatment-induced adverse effects in patients with ovarian cancer.Methods and analysisAdult women with primary epithelial ovarian cancer who are scheduled to undergo first-line (neo)adjuvant chemotherapy (n=122) are randomly allocated to a combined exercise and dietary intervention or a usual care control group during chemotherapy. Primary outcomes are body composition, physical function and fatigue. Outcome measures will be assessed before the start of chemotherapy, 3 weeks after completion of chemotherapy and 12 weeks later. The exercise and dietary intervention was tailored to ovarian cancer-specific comorbidities and adverse effects of ovarian cancer and its treatment following the i3-S strategy.Ethics and disseminationThis study has been approved by the medical ethical committee of the Amsterdam UMC (reference: 018). Results of the study will be published in international peer-reviewed journals.Trial registration numberNetherlands Trial Registry (NTR6300).
Parental experiences of a diagnosis of neonatal diabetes and perceptions of newborn screening for glucose: a qualitative study
Authors: Shepherd Maggie , Knight Bridget A , Laskey Katherine , McDonald Timothy James 
Published: November 2020

Neonatal diabetes presents <6 months of life but delays in recognition result in presentation with life-threatening hyperglycaemia/diabetic ketoacidosis. Early identification and rapid genetic diagnosis is crucial and ensures correct treatment/management. Adding ‘glucose’ to newborn bloodspot screening (NBS) could aid prompt detection but requires evidence of parental acceptance.ObjectivesIncrease understanding of parental experience of presentation/recognition of neonatal diabetes and perceptions of glucose testing within NBS.SettingUK families confirmed with a genetic diagnosis of neonatal diabetes, November 2014–2018, were invited to participate.ParticipantsIn-depth qualitative interviews were conducted with 10 parents of 14 children. 8 had transient neonatal diabetes: KCNJ11 (n=5), ABCC8 (n=1), 6q24 (n=2), 6 had permanent neonatal diabetes: KCNJ11 (n=4), INS (n=1), homozygous GCK (n=1).Primary and secondary outcome measuresInterviews audio recorded, transcribed and subjected to thematic content analysis.Results3 key themes emerged:Babies were extremely ill at hospital admission, with extended stays in intensive care required.Identification of diabetes was not ‘standardised’ and perceived a ‘chance’ finding.Adding glucose to NBS was universally considered extremely positive.ConclusionsDiagnosis of neonatal diabetes is frequently delayed, resulting in critically ill presentation with prolonged intensive care support, additional healthcare costs and familial distress. Potential to detect hyperglycaemia earlier was universally endorsed by parents with no negative consequences identified. Although further study including a larger number of individuals is needed to confirm our findings this study provides the first evidence of acceptability of glucose testing fulfilling Wilson-Jungner criteria for implementation within the NBS programme.