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Tower fatigue and strength are crucial operational concerns of floating offshore wind turbines (FOWTs) due to the escalation of the vibration phenomena observed on these structures as compared to land-based ones. FOWT towers are excited by wave and wind polyperiodic disturbances yielding continual transient states of structural vibration that are challenging for vibration mitigation systems. Thus, the paper investigates a novel implementation of nonlinear optimal-based vibration control solutions for the full-scale, tension leg platform (TLP)-based, NREL 5MW wind turbine tower-nacelle model with a 10-ton tuned vibration absorber (TVA), equipped with a magnetorheological (MR) damper, located at the nacelle. The structure is subjected to excessive wave and wind excitations, considering floating platform motions derived from model experiments in a wave tank. The MR damper operates simultaneously with an electromagnetic force actuator (forming a hybrid TVA) or independently (a semiactive TVA). The study includes both actuators’ nonlinearities and dynamics, whereby the former are embedded in the Hamilton-principle-based nonlinear control solutions. The TVA is tuned either to the NREL 5MW tower-nacelle 1st bending mode frequency (TVA-TN) or to the TLP surge frequency (TVA-TLP). The optimal control task was redeveloped concerning the TVA stroke and transient vibration minimisation, including the implementation of the protected structure’s acceleration and relative displacement terms, as well as the nonzero velocity term in the quality index. The regarded model is embedded in a MATLAB/Simulink environment. On the basis of the obtained results, the TVA-TN solution is by far superior to the TVA-TLP one. All the regarded TVA-TN solutions provide a tower deflection safety factor of ca. 2, while reference systems without any vibration reduction solutions or with a passive TVA-TLP are at risk of tower structural failure as well as the hybrid TVA-TLP system. The obtained TVA stroke reductions of 25.7%/22.0% coincide with 3.6%/10.3% maximum tower deflection reductions for the semiactive/hybrid TVA-TN case (respectively) with regard to the previously developed approaches. Moreover, these reductions are obtained due to the sole control algorithm enhancement; thus, no additional resources are necessary, while this attainment is accompanied by a reduction in the required MR damper force. The lowest obtained TVA stroke amplitude of 1.66 m is guaranteed by the newly introduced semiactive control. Its hybrid equivalent ensures 8% lower primary structure deflection amplitude and reduced nacelle acceleration levels thanks to the utilisation of the force actuator of the relatively low power (ca. 6 kW); the trade-off is an increased TVA stroke amplitude of 2.19 m, which, however, is the lowest among all the tested hybrid solutions. The analysed reference passive TVA systems, along with a modified ground-hook hybrid solution, can hardly be implemented in the nacelle (especially along the demanding side–side direction). The latter, being the well-proven hybrid solution for steady-state tower deflection minimisation, yielded unsatisfactory results. The achievements of the study may be used for an effective design of a full-scale vibration reduction system for the TLP-based floating wind turbine structure.

Front-line bevacizumab (BEV) in combination with taxanes offers benefit in progression-free survival (PFS) in metastatic breast cancer (mBC). The medical records of mBC patients, treated with front-line BEV-based chemotherapy, were retrospectively reviewed in order to generate real life safety and efficacy data. Patients with human epidermal growth factor receptor 2 (HER2)-negative mBC treated with front-line BEV in combination with chemotherapy were eligible. Maintenance therapy with BEV and/or hormonal agents was at the physicians’ discretion. Among the 387 included patients, the most common adverse events were anemia (61.9%, mainly grade 1), grade 3/4 neutropenia (16.5%), grade 1/2 fatigue (22.3%), and grade 1/2 neuropathy (19.6%). Dose reductions were required in 164 cycles (7.1%) and toxicity led to treatment discontinuation in 21 patients (5.4%). The median PFS and the median overall survival (OS) were 13.3 (95% CI: 11.7–14.8) and 32.3 months (95% CI: 27.7–36.9), respectively. Maintenance therapy, with hormonal agents (ET) and/or BEV, was associated with longer OS versus no maintenance therapy (47.2 versus 23.6 months; p < 0.001) in patients with hormone receptor (HR)-positive disease and BEV maintenance offered longer OS versus no maintenance in patients with HR-negative disease (52.8 versus 23.3; p = 0.023). These real-life data show that front-line BEV-based chemotherapy in HER2-negative mBC patients is an effective treatment with an acceptable toxicity profile. The potential benefit of maintenance treatment, especially ET, is important and warrants further research.

This paper aims to identify the weaknesses of didactic praxis in the field of teaching foreign languages for specific purposes (LSP) and propose more effective approaches that take into consideration both the learner profile and the conditions in which learners acquire a language as a tool in their job, training or education. Based on the example of the teaching of German for medical purposes in the target country to highly qualified healthcare staff that have immigrated for professional reasons, we recapitulate the didactic/methodological principles of the Berlin Didactics, draw upon a critique of the CEFR and, on this basis, we theoretically demonstrate specific implementation strategies for a usage-based model of the teaching of languages for specific purposes that can realistically be incorporated in the curricula of LSP courses, independent of the target language. The first strategy concerns a data-driven approach to the teaching of languages for specific purposes by making use of (parallel) language corpora in the classroom. The second is the design of a dual teaching model, based on Vygotsky’s Zone of Proximal Development and promotes peer learning, while combining traditional LSP lessons and practical technical language training. The third proposed strategy concerns the role of mediation in the teaching of LSP. The paper concludes with a discussion of the benefits and limitations of the three didactic strategies that serves as a starting point for the design of relevant LSP policies, curricula and resources.

The hydrogenation of CO2 is a reaction of key technological and environmental importance, as it contributes to the sustainable production of fuels while assisting in the reduction of a major greenhouse gas. The reaction has received substantial attention over the years within the catalysis and electrocatalysis communities. In this respect, the electrochemical promotion of catalysis (EPOC) has been applied successfully to the CO2 hydrogenation reaction to improve the catalytic activity and selectivity of conductive films supported on solid electrolytes. However, designing an effective electrocatalytic reactor remains a challenge due to the connections required between the electrodes and the external potentiostat/galvanostat. This drawback could be alleviated if the catalytic reaction occurs in a reactor that simultaneously operates as a power generator. In this work, the Electrochemical Promotion of the CO2 hydrogenation reaction in a low-temperature solid oxide electrolyte fuel cell (SOFC) reactor is studied using yttria-stabilized zirconia (YSZ) and a platinum (Pt) electrode catalyst. The system has been studied in two distinct operation modes: (i) when the necessary energy for the electrochemical promotion is produced through the parallel reaction of H2 oxidation (galvanic operation) and (ii) when a galvanostat/potentiostat is used to impose the necessary potential (electrolytic operation). The performance of the fuel cell declines less than 15% in the presence of the reactant mixture (CO2 and H2) while producing enough current to conduct EPOC experiments. During the electrolytic operation of the electrochemical cell, the CO production rate is significantly increased by up to 50%.

Electrochemical promotion was used to modify the activity and selectivity of a Rh catalyst electrode in the CO2 hydrogenation reaction. The experiments were carried out in a temperature range of 350–430 °C at ambient pressure and at different CO2 to H2 gas feeding ratios (1:2 to 4:1). The only reaction products observed were CO and CH4, both under open- and closed-circuit conditions. The CH4 formation rate was found to increase with both positive and negative potential or current application. The CO formation rate followed the opposite trend. The selectivity to CH4 increased under high values of hydrogen partial pressure and decreased at high pressures of CO2. The results demonstrate how electrochemical promotion can be used to finely tune activity and selectivity for a reaction of high technical and environmental importance.

This paper aims to provide an insight into the way native speakers of different first languages (L1) who live in the same country and are therefore influenced to the same degree by the current Covid-19 pandemic (e.g. share the same everyday experiences and are confronted with the same linguistic input in the same context) frame Covid-19 related events. More specifically, a comparison between the framework of L1 speakers of German and L1 speakers of Greek, all residing in Greece during the pandemic. Our goal is to unveil commonalities and differences in the structuring of concepts using a frame-semantic approach. In order to investigate the frames that are indexed when talking about experiences, topics, and concepts newly introduced by the Covid-19 pandemic, we chose to build a small bilingual corpus based on participants’ answers in surveys in the respective languages. We use preliminary data to evaluate the feasibility of the theoretical as well as the methodological approach. This paper presents the pilot phase of a broader project whose final conclusions will be available in 2021.

Anastasios Papanastasiou,1 Konstantinos Sapalidis,1 Stylianos Mantalobas,1 Stefanos Atmatzidis,1 Nikolaos Michalopoulos,1 Valeriu Surlin,1 Athanasios Katsaounis,1 Aikaterini Amaniti,1 Paul Zarogoulidis,1 Ioannis Passos,1 Charilaos Koulouris,1 Efstathios Pavlidis,1 Dimitrios Giannakidis,1 Stelian Mogoanta,2 Christoforos Kosmidis,1 Isaak Kesisoglou113rd Department of Surgery, “AHEPA” University Hospital, Aristotle University of Thessaloniki, Medical School, Thessaloniki, Greece; 2Department of Surgery, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, Craiova, RomaniaBackground: Temporary hypocalcemia is the most common complication in patients after total thyroidectomy. To date, according to the literature, various predictors of the above complication have been proposed, but none of them seems to be effective enough.Objectives: The aim of this study was to develop a reliable predictive tool for biochemical hypocalcemia in the first 48 hrs after total thyroidectomy without central dissection by analyzing several parameters relevant to this operation and to suggest a new score.Methods: A retrospective study was performed on patients who had undergone total thyroidectomy without central neck dissection from October 2017 until January 2018. Data were collected from 36 patients and studied if there was a statistically significant relationship between the risk of hypocalcemia and 10 preselected prognostic factors.Results: The prognostic score was formed, which included the 6 factors that showed a statistically significant relationship. Moreover, an extensive check of the predictive value of the above score was performed. It was found, therefore, that at a value of 3 and above the sensitivity was 100%, the specificity 79.16%, the positive prognostic value (PPV) 70.58% and the negative predictive value (NPV) 100%.Conclusions: High sensitivity of CaReBe’S TiP score makes it feasible to predict patients with postoperative hypocalcemia. High NPV would allow surgeons to exclude patients with a score less than 3 from supplementary calcium medication and achieve a shorter hospitalization for them.Keywords: design, thyroidectomy, hypocalcemia, prognostic factors

Research infrastructures have been established throughout Europe in order to create robust organizations that will facilitate and enhance research and innovation processes and will advance society with innovative products and services. The Hellenic Integrated Marine Observing, Forecasting and Technology System (component of HIMIOFoTS RI) has been implemented in the framework of the National Roadmap for Research Infrastructures to form a large-scale infrastructure for the marine environment in Greece. It links together ocean observing and forecasting systems, coastal zone monitoring and management practices, as well as ocean engineering testing facilities. The overarching framework of the system supports the coordination of five organizations with expertise in the field of marine science and technology, the central management of research activities, and the common development of services and products. It comprises facilities and resources while it provides open access to research communities (academia, industry) to support the scientific advancements and innovation in their fields. The Hellenic Marine Observing, Forecasting and Technology System was further enhanced during its implementation through significant upgrades and developments in order to extend its observing capacity and the forecasting and technological abilities, while advancing the provided services and products.

In the present study, an inexpensive and practical way to detect phenolic compounds in wastewater was investigated. By using a simple one compartment three-electrode cell and performing cyclic voltammetry measurements, it was possible to quantitatively determine the presence of gallic and vanillic acid in acidic aqueous solutions due to their electrooxidation upon potential scanning. In the case of gallic acid, two oxidation peaks were observed whereas the vanillic acid cyclic voltammograms consisted of two oxidation and one reduction peaks. Correlation of the observed electrooxidation current density value with the concentration of each phenolic compound led to a linear relationship. Following the above methodology for a 1:1 mixture of these phenols, it was found that only a qualitative analysis was possible rather than a quantitative one.

Konstantinos Sapalidis,1 Christoforos Kosmidis,1 Nikos Michalopoulos,1 Stylianni Laskou,1 Efstathios Pavlidis,1 Stelios Mantalovas,1 Dimitrios Giannakidis,1 Aikaterini Amaniti,1 Charilaos Koulouris,1 Athanasios Katsaounis,1 Alexandru C Munteanu,1 Valeriou Surlin,1 Paul Zarogoulidis,2 Isaak Kesisoglou1 1Third Department of Surgery, AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 2Pulmonary-Oncology Department, “Theageneio” Cancer Hospital, Thessaloniki, Greece Background: In recent years, mini-laparoscopic procedures are gaining the preference of most surgeons due to their potentially better surgical outcomes. The Mini Lap Percutaneous Surgical System with MiniGrip® Handle is currently the less invasive instrument and can be applied to a wide range of operations. The current paper presents its application on percutaneous laparoscopic cholecystectomy. Materials and methods: From January 2017 to June 2017, 32 patients underwent percutaneous laparoscopic cholecystectomy with the MiniLap® system. All operations were performed by the same surgical team. Results: No conversions and no overall complications were reported. Drainage were not necessary. Mean surgical time was 35 minutes, while patients were released in

Esophageal lyomyoma are rare benign tumors of the esophagus and they remain usually undiagnosed until local compression symptoms occur in the esophagus. Gastroscopy or esophageal ultrasonography (EUS) are usually the methods of choice for diagnosis. Moreover; surgery is the solution for this entity. In our case we present diagnosis of esophageal lyomyoma using convex probe endobronchial ultrasound (EBUS) with a fine needle aspiration of 22G. Keywords: Esophagus, EBUS, FNA, Lyomyoma, Biopsy

Colonic lipomas are the second most common benign tumor of the colon. During a systematic literature search, a lack of review is observed. This study reports two cases of colonic lipomas and also tries to review the clinical and pathologic features of the reported symptomatic lipomas.

Background: Meckel’s diverticulum is a common congenital abnormality of the gastrointestinal tract encountered in about 1–3% of the general population. Although most patients remain asymptomatic, a minority will experience serious complications such as acute abdomen, haemorrhage or obstructive ileus. Of all patients presenting with symptoms of obstruction due to Meckel’s diverticulum 7–18% is due to volvulus. Case Report: A 39-year-old male with multiple previous episodes of obstructive ileus presented with an acute abdomen. An exploratory laparotomy was performed in order to reveal the cause of the obstruction. An internal hernia with ileal volvulus and a Meckel’s diverticulum was found, which was later confirmed by histopathological examination. Conclusion: Meckel’s diverticulum is a rare cause of acute abdomen and obstructive ileus which should be considered when the symptoms date back to childhood. The difficulty of preoperative diagnosis dictates the need for exploratory laparoscopy or laparotomy as diagnostic tools.

The present paper deals with the development of a multi-purpose floating tension leg platform (TLP) concept suitable for the combined offshore wind and wave energy resources exploitation, taking into account the prevailing environmental conditions at selected locations along the European coastline. The examined Renewable Energy Multi-Purpose Floating Offshore System (REFOS) platform encompasses an array of hydrodynamically interacting oscillating water column (OWC) devices, moored through tensioned tethers as a TLP platform supporting a 10 MW wind turbine (WT). The system consists of a triangular platform supported by cylindrical floaters, with the WT mounted at the deck’s center and the cylindrical OWC devices at its corners. Details of the modelling of the system are discussed and hydro-aero-elastic coupling between the floater; the mooring system; and the WT is presented. The analysis incorporates the solutions of the diffraction; the motion- and the pressure-dependent radiation problems around the moored structure, along with the aerodynamics of the WT into an integrated design approach validated through extensive experimental hydrodynamic scaled-down model tests. The verified theoretical results attest to the importance of the WT loading and the OWC characteristics on the dynamics of the system.