cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sonnenfleckenzeichnung Nr. 27665.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 30.12.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Eterocronia e marginalizzazione di un gruppo di operai siciliani
Creators: name: India, Tommaso
Publisher: name: Cambio. Rivista sulle Trasformazioni Sociali
Year: 2018

description: Through an ethnographic research conducted with a group of Sicilian workers employed in logistics, this paper analyzes the progressive social marginalization of these workers. Such marginalization was imposed through the creation of company time-maps that found their initial act in transferring the group analyzed from Palermo to Catania and the total coincidence between leisure time and work time. The creation of these time-maps and their affirmation and acceptance by the group of workers, due to their disgruntled strength and their ability to interfere with the lives of the workers covered by this paper, form an act of economic reasons and an act that also has a political value as it directly affects the social and existential organization of workers.
description: Cambio. Rivista sulle Trasformazioni Sociali, Vol. 7 No. 14 (2017)
On Families of Full Trios Containing Counter Machine Languages
Creators: name: Ibarra, Oscar H.
name: McQuillan, Ian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Computer and information sciences
subject: F.4.3

description: We look at nondeterministic finite automata augmented with multiple reversal-bounded counters where, during an accepting computation, the behavior of the counters is specified by some fixed pattern. These patterns can serve as a useful "bridge" to other important automata and grammar models in the theoretical computer science literature, thereby helping in their study. Various pattern behaviors are considered, together with characterizations and comparisons. For example, one such pattern defines exactly the smallest full trio containing all the bounded semilinear languages. Another pattern defines the smallest full trio containing all the bounded context-free languages. The "bridging" to other families is then applied, e.g. to certain Turing machine restrictions, as well as other families. Certain general decidability properties are also studied using this framework.
description: 28 pages, 1 figure
Sonnenfleckenzeichnung Nr. 27658.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 16.12.1987, erstellt von Hans Ulrich Keller.
Zusätzlich ist vermerkt: Beobachtung unvollständig (nicht abgeschlossen)
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen
Development of a dual-position oxidizer main valve
Creators: name:  MOONGEUN HONG
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: MAIN OXIDIZER VALVE
DUAL-POSITION
PARTIAL OPENING

description: The supply of liquid oxygen to a rocket combustor is usually controlled using oxidizer shut-off valve with \'on\' and \'off\' positions. However, the partial opened position of a dual-position valve can control and optimize the engine start transients by regulating the liquid oxygen mass flow during the startup of the engine. In this paper, the design and performances of a dual-position pneumatic poppet valve, which is intended to be employed in liquid rocket engines, have been presented. Numerical analysis investigates the effects of key parameters, such as orifice size, stopper size, and valve inlet pressure, on the dynamic characteristics of valve opening and it is shown that the dual-position valve meets the expected requirements.
Sonnenfleckenzeichnung Nr. 27601.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 27.08.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Stochastic Rising Bandits
Creators: name: Metelli, Alberto Maria
name: Trovò, Francesco
name: Pirola, Matteo
name: Restelli, Marcello
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: This paper is in the field of stochastic Multi-Armed Bandits (MABs), i.e., those sequential selection techniques able to learn online using only the feedback given by the chosen option (a.k.a. arm). We study a particular case of the rested and restless bandits in which the arms' expected payoff is monotonically non-decreasing. This characteristic allows designing specifically crafted algorithms that exploit the regularity of the payoffs to provide tight regret bounds. We design an algorithm for the rested case (R-ed-UCB) and one for the restless case (R-less-UCB), providing a regret bound depending on the properties of the instance and, under certain circumstances, of $\widetilde{\mathcal{O}}(T^{\frac{2}{3}})$. We empirically compare our algorithms with state-of-the-art methods for non-stationary MABs over several synthetically generated tasks and an online model selection problem for a real-world dataset. Finally, using synthetic and real-world data, we illustrate the effectiveness of the proposed approaches compared with state-of-the-art algorithms for the non-stationary bandits.
description: Corrected definition of "cumulative increment" (Equation 2) and efficient update (Appendix D)
Wiggly tails: a gravitational wave signature of massive fields around black holes
Creators: name: Degollado, Juan Carlos
name: Herdeiro, Carlos A. R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Massive fields can exist in long-lived configurations around black holes. We examine how the gravitational wave signal of a perturbed black hole is affected by such `dirtiness' within linear theory. As a concrete example, we consider the gravitational radiation emitted by the infall of a massive scalar field into a Schwarzschild black hole. Whereas part of the scalar field is absorbed/scattered by the black hole and triggers gravitational wave emission, another part lingers in long-lived quasi-bound states. Solving numerically the Teukolsky master equation for gravitational perturbations coupled to the massive Klein-Gordon equation, we find a characteristic gravitational wave signal, composed by a quasi-normal ringing followed by a late time tail. In contrast to `clean' black holes, however, the late time tail contains small amplitude wiggles with the frequency of the dominating quasi-bound state. Additionally, an observer dependent beating pattern may also be seen. These features were already observed in fully non-linear studies; our analysis shows they are present at linear level, and, since it reduces to a 1+1 dimensional numerical problem, allows for cleaner numerical data. Moreover, we discuss the power law of the tail and that it only becomes universal sufficiently far away from the `dirty' black hole. The wiggly tails, by constrast, are a generic feature that may be used as a smoking gun for the presence of massive fields around black holes, either as a linear cloud or as fully non-linear hair.
description: 6 pages, 4 figures
Next steps in aerostructural design of ultra-high aspect ratio wings
Creators: name:  YIYUAN MA
name:   ALI ELHAM
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: HIGH ASPECT-RATIO WINGS
CONCEPTUAL DESIGN
AEROSTRUCTURAL OPTIMIZATION

description: This paper presents the authors\' research work on the aerostructural design of Ultra-High Aspect-ratio Wings (UHARW). Firstly, aircraft configurations suitable for UHARW, especially unconventional configurations, are introduced and discussed. Then the aircraft conceptual design and analysis framework developed for the unconventional UHARW aircraft is described. The UHARW of the conceptually designed Strut-Braced Wing (SBW) and twin-fuselage aircraft are further investigated by employing a series of nonlinear aerostructural optimization methods, including the influences of aileron design and flutter constraint on the ultra-high aspect-ratio SBW design.
Sonnenfleckenzeichnung Nr. 27629.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 08.10.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
title: Ανίχνευση σαλμονέλας σε εντόσθια κοτόπουλων
titleType: AlternativeTitle
Creators: name: Μαχαίρας, Κωνσταντίνος
Publisher: name: University of Thessaly
Year: 2013
Subjects: subject: ΣΑΛΜΟΝΕΛΛΩΣΗ
subject: ΤΡΟΦΗ -- ΜΟΛΥΝΣΗ
subject: ΚΡΕΑΣ -- ΠΟΙΟΤΙΚΟΣ ΕΛΕΓΧΟΣ

description: Σημείωση: διατίθεται συμπληρωματικό υλικό σε ξεχωριστό αρχείο.
Sonnenfleckenzeichnung Nr. 27566.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 08.07.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
An Overview of Indian Spoken Language Recognition from Machine Learning Perspective
Creators: name: Dey, Spandan
name: Sahidullah, Md
name: Saha, Goutam
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Automatic spoken language identification (LID) is a very important research field in the era of multilingual voice-command-based human-computer interaction (HCI). A front-end LID module helps to improve the performance of many speech-based applications in the multilingual scenario. India is a populous country with diverse cultures and languages. The majority of the Indian population needs to use their respective native languages for verbal interaction with machines. Therefore, the development of efficient Indian spoken language recognition systems is useful for adapting smart technologies in every section of Indian society. The field of Indian LID has started gaining momentum in the last two decades, mainly due to the development of several standard multilingual speech corpora for the Indian languages. Even though significant research progress has already been made in this field, to the best of our knowledge, there are not many attempts to analytically review them collectively. In this work, we have conducted one of the very first attempts to present a comprehensive review of the Indian spoken language recognition research field. In-depth analysis has been presented to emphasize the unique challenges of low-resource and mutual influences for developing LID systems in the Indian contexts. Several essential aspects of the Indian LID research, such as the detailed description of the available speech corpora, the major research contributions, including the earlier attempts based on statistical modeling to the recent approaches based on different neural network architectures, and the future research trends are discussed. This review work will help assess the state of the present Indian LID research by any active researcher or any research enthusiasts from related fields.
description: Accepted for publication in ACM Transactions on Asian and Low-Resource Language Information Processing
Faster than light motion does not imply time travel
Creators: name: Andréka, H.
name: Madarász, J. X.
name: Németi, I.
name: Stannett, M.
name: Székely, G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Logic (math.LO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Seeing the many examples in the literature of causality violations based on faster-than- light (FTL) signals one naturally thinks that FTL motion leads inevitably to the possibility of time travel. We show that this logical inference is invalid by demonstrating a model, based on (3+1)-dimensional Minkowski spacetime, in which FTL motion is permitted (in every direction without any limitation on speed) yet which does not admit time travel. Moreover, the Principle of Relativity is true in this model in the sense that all observers are equivalent. In short, FTL motion does not imply time travel after all.
description: 11 pages, 5 figures
Sonnenfleckenzeichnung Nr. 27618.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 17.09.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Design and Testing of a small Water Electrothermal Thruster
Creators: name:  FABIANO PERINI
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: RESISTOJET
WATER
ELECTROTHERMAL
THRUSTER

description: With the rapidly increasing number of satellites in orbit, the growing complexity of their missions and the risk of collisions, there is a clear need to develop low-cost, low volume, reliable and high-thrust onboard propulsion systems. Traditionally, cold gas nitrogen systems have been used as they provide a simple solution, combining high reliability with low cost. However cold gas thrusters exhibit a fairly low specific impulse and poor storage densities. One possible way to enhance their performance is to heat the propellant in order to increase the specific impulse thus extending the mission life. When this is performed electrically with resistance heaters the thruster is known as resistojet. Resistojets are the simplest type of electrothermal thrusters. A standard propellant is hydrazine because it represents the best trade-off in terms of specific impulse, storage and distribution. Other propellants such as krypton and xenon, commonly used for Hall thrusters and ion engines, can be employed for resistojets. However, they must be stored at high pressure in specific tanks, moreover the increase in price observed in the recent years makes them commercially unattractive. Therefore, find cheap and easy-to-handle propellants is crucial for space agencies and private entities worldwide. Another propellant that seems interesting for its particular properties is pure water. Water is inexpensive, non-toxic and can be stored in liquid form. It is also an abundant resource in the solar system. Its small molecular mass makes it possible to achieve a high level of specific impulse. Although it presents some disadvantages: it has to be very pure, it must be kept from freezing and additional power is required for vaporization. Low power and low mass electrothermal water-fueled propulsion thruster and a torsional thrust balance are currently being developed at the !CARE laboratory in France. The thruster consists of a spherical tank for liquid water, a tank for the pressurizing gas (N2), a printed electronic control circuit based on the raspberry Pi microcontroller, a vaporization chamber, and a convergent-divergent nozzle for expanding the vapor. The input power remains below 50 W with a scalable thrust in the mN range and a specific impulse around 100 s. The prototype will be tested in zero-G flight, in the parabolic flight campaign next March 2024. In this contribution, we shall present the architecture of the water-fueled resistojet and the associated torsional thrust balance for measuring the thrust. We will focus especially on the vaporization chamber as it is a critical component of the propulsion system. Indeed, in the absence of gravity, vaporization must be effective to avoid droplet formation during the expansion process, therefore ensuring high performance.
Closing the loop: using course and teaching evaluation feedback to improve teaching
Creators: name: Williams, Lawrence
name: Forester, Amy
name: Peterson, Tawnya
Publisher: name: Oregon Health and Science University
Year: 2023
Subjects: subject: Educational Measurement
subject: Classroom/didactic teaching
subject: Educational research findings
subject: Educational research methods and models
subject: SOTL/Education scholarship

description: There are many methods for encouraging students to complete their course and teaching evaluations, including offering incentives, offering more time in class to complete evaluations, and offering students to participate in focus groups. But what happens after the evaluation period has ended? How can an instructor incorporate the feedback to improve their teaching practice? How can administrators work with instructors to incorporate feedback to improve courses and/or programs? Can instructors use mid-term (formative) evaluations to improve their courses? This session will cover what to do when evaluation data are ready and you're ready to implement changes based on the feedback. We'll review best practices from the literature and review how members of the School of Public Health use student feedback to improve their teaching.
Sonnenfleckenzeichnung Nr. 27539.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 01.06.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Sonnenfleckenzeichnung Nr. 27533.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 18.05.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g)
Reinforcement Learning for UAV control with Policy and Reward Shaping
Creators: name: Millán-Arias, Cristian
name: Contreras, Ruben
name: Cruz, Francisco
name: Fernandes, Bruno
Publisher: name: arXiv
Year: 2022
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: In recent years, unmanned aerial vehicle (UAV) related technology has expanded knowledge in the area, bringing to light new problems and challenges that require solutions. Furthermore, because the technology allows processes usually carried out by people to be automated, it is in great demand in industrial sectors. The automation of these vehicles has been addressed in the literature, applying different machine learning strategies. Reinforcement learning (RL) is an automation framework that is frequently used to train autonomous agents. RL is a machine learning paradigm wherein an agent interacts with an environment to solve a given task. However, learning autonomously can be time consuming, computationally expensive, and may not be practical in highly-complex scenarios. Interactive reinforcement learning allows an external trainer to provide advice to an agent while it is learning a task. In this study, we set out to teach an RL agent to control a drone using reward-shaping and policy-shaping techniques simultaneously. Two simulated scenarios were proposed for the training; one without obstacles and one with obstacles. We also studied the influence of each technique. The results show that an agent trained simultaneously with both techniques obtains a lower reward than an agent trained using only a policy-based approach. Nevertheless, the agent achieves lower execution times and less dispersion during training.
description: 9 pages, 9 figures, Preprint accepted at the 41st International Conference of the Chilean Computer Science Society, SCCC 2022, Santiago, Chile, 2022
Evolution of aluminum droplets in solid-propellant combustion by image analysis using deep learning
Creators: name:  MAGDELEINE AIRIAU
name:   ROBIN DEVILLERS
name:   ADRIEN CHAN HON TONG
name:   LE BESNERAIS GUY
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: DEEP LEARNING
ALUMINIUM COMBUSTION
SOLID-PROPELLANT
COMPUTER VISION

description: The shadowgraphy technique enables visualising burning aluminium droplets during combustion in combustion gases generated by a solid-propellant sample. To analyze these images, deep learning has already proven its efficiency but requires refined detection. A new method of instance segmentation has been tested with the Mask R-CNN network, which has been adapted to be more efficient. Diameter probability densities and velocity profiles for two pressures for a research composition were estimated from the detections obtained by the network and compared. This study stands out in the existing literature as it provides a substantial amount of data, enabling a rigorous and comprehensive investigation.
The Branch-cut Cosmology: A topological canonical quantum approach
Creators: name: Hess, Peter O.
name: Vasconcellos, César A. Zen
name: Pacheco, José de Freitas
name: Hadjimichef, Dimiter
name: Bodmann, Benno
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this contribution we sketch a branch-cut quantum formulation of the Wheeler-DeWitt equation analytically continued to the complex plane. As a starting point, we base our approach on the Hořava-Lifshitz formulation of gravity, which employs higher spatial-derivative terms of the spacetime curvature for renormalisation reasons. Following standard procedures, the quantization of the Lagrangian density is achieved by raising the Hamiltonian, the dynamical variable which represents the branch-cut complex scale factor and the conjugate momentum to the category of operators. We arrive at an Schrödinger-type equation with a non-linear potential. Solutions are then obtained and discussed for different potential parameterizations. The results reinforce the conception of a quantum leap between the contraction and expansion phases of the branch-cut universe, in good agreement with the Bekenstein criterion.
Performance Analysis of a Hybrid Thermal-Electric Turboprop Engine
Creators: name:  ROBERTO ANDRIANI
name:   ANTONELLA INGENITO
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: HYBRID
THERMAL
ELECTRIC
TURBOPROP

description: The reduction of fuel consumption and pollutant emission have guided the aeronautic engineers in their work for decades to design always more efficient aircraft engines. Along with this, the reduction and, in the next future, the overcoming of fossil fuels has become one of the most important challenges in the engine development. Aircraft engines are responsible of about 12% of the total carbon dioxide produced by transportation, moreover, the aeronautical authorities impose for the next years stringent limits in the production of CO2 and NOx. These limits are quite narrow, and it is difficult to respect them using only thermal engines. The introduction of electric engines in the aircraft power system is therefore unavoidable. The possibility of the introduction of hybrid thermal-electric engine for aircraft propulsion, the architecture of the system and its consequent effects on pollution reduction, have been evaluated.
Recensione di Memorie del futuro. Un percorso tra sociologia e studi culturali, di Paolo Jedlowsy
Creators: name: Grande, Teresa
Publisher: name: Cambio. Rivista sulle Trasformazioni Sociali
Year: 2018

description: Cambio. Rivista sulle Trasformazioni Sociali, Vol. 7 No. 14 (2017)
title: Η επίδραση της πλειομετρικής άσκησης σε βιοχημικές παραμέτρους που σχετίζονται με την καταστροφή του μυϊκού και συνδετικού ιστού
titleType: AlternativeTitle
Creators: name: Τόφας, Τρύφωνας
Publisher: name: University of Thessaly
Year: 2004
Subjects: subject: ΜΥΕΣ -- ΦΥΣΙΟΛΟΓΙΑ
subject: ΠΡΟΠΟΝΗΣΗ, ΠΛΕΙΟΜΕΤΡΙΚΗ

description: Όπως έχει υποστηριχθεί η πλειομετρική προπόνηση είναι ένα είδος άσκησης που βελτιώνει την ικανότητα απόδοσης του αθλητή. Εντούτοις πρόσφατες έρευνες έχουν δείξει ότι οι πλειομετρικές ασκήσεις μπορεί να προκαλέσουν καταστροφή του μυϊκού ιστού. Σκοπός της συγκεκριμένης έρευνας ήταν να εξετάσει εάν μια οξεία πλειομετρική προπόνηση μπορεί να οδηγήσει σε καταστροφή μυϊκού ή και συνδετικού ιστού. Μεθοδολογία: Στη συγκεκριμένη έρευνα έλαβαν μέρος 9 φοιτητές του Τμήματος Επιστήμης Φυσική Αγωγής και Αθλητισμού του Πανεπιστημίου Θεσσαλίας, ηλικίας 22.3±2.2 χρονών, βάρους 77.5±8.8 kg, ύψους 176.1±7.3 cm. Όλοι οι συμμετέχοντες εκτέλεσαν μια οξεία πλειομετρική προπόνηση, η οποία περιλάμβανε 2 σειρές των 96 αλμάτων: α)πολλαπλά άλματα πάνω από εμπόδια 50cm (8 σετ x 12 επαναλήψεις) και β) πολλαπλές αναπηδήσεις πάνω σε κύβο 50cm (8 σετ χ 12 επαναλήψεις). Μεταξύ των σετ υπήρχε διάλειμμα 90 δευτερολέπτων, ενώ μεταξύ των σειρών διάλειμμα 3 λεπτών. Για τον προσδιορισμό της έντασης της άσκησης, 3 λεπτά μετά το τέλος της προπόνησης μετρήθηκε η συγκέντρωση του γαλακτικού οξέως στο ολικό αίμα. Για το προσδιορισμό της καταστροφής μυϊκού και συνδετικού ιστού, αξιολογήθηκαν τόσο πριν όσο και 24, 48 και 72 ώρες μετά από την προπόνηση, δείκτες μυϊκής απόδοσης [εύρος κίνησης (ΕΚ), υποκειμενική αίσθηση του καθυστερημένου μυϊκού πόνου (ΚΜΠ), μέγιστη ομόκεντρη (ΜΟΔ) και έκκεντρη δύναμη (ΜΕΔ) των εκτεινόντων και καμπτήρων της άρθρωσης του γόνατος] και βιοχημικοί δείκτες [κρεατινική κινάση (ΚΚ), γαλακτική αφυδρογονάση (ΓΑ), μυοσφαιρίνη (ΜΣ) και υδροξυπρολίνη (ΥΠΡ)]. Αποτελέσματα: Τα αποτελέσματα έδειξαν ότι η οξεία πλειομετρική προπόνηση δεν μετάβαλε σημαντικά τους δείκτες μυϊκή καταστροφής (ΕΚ, ΚΠΜ, ΜΟΔ, ΜΕΔ, ΚΚ, ΓΑ και ΜΣ). Αντίθετα παρουσιάστηκαν σημαντικές μεταβολές στα επίπεδα υδροξυπρολίνης (δείκτης καταστροφής συνδετικού ιστού). Συμπεράσματα: Τα αποτελέσματα αυτά οδηγούν στο συμπέρασμα ότι μια οξεία πλειομετρική προπόνηση μπορεί να προκαλέσει καταστροφή συνδετικού ιστού χωρίς να επηρεάσει το μυϊκό ιστό.
The effect of interior heat flux on the atmospheric circulation of hot and ultra-hot Jupiters
Creators: name: Komacek, Thaddeus D.
name: Gao, Peter
name: Thorngren, Daniel P.
name: May, Erin M.
name: Tan, Xianyu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Many hot and ultra-hot Jupiters have inflated radii, implying that their interiors retain significant entropy from formation. These hot interiors lead to an enhanced internal heat flux that impinges upon the atmosphere from below. In this work, we study the effect of this hot interior on the atmospheric circulation and thermal structure of hot and ultra-hot Jupiters. To do so, we incorporate the population-level predictions from evolutionary models of hot and ultra-hot Jupiters as input for a suite of General Circulation Models (GCMs) of their atmospheric circulation with varying semi-major axis and surface gravity. We conduct simulations with and without a hot interior, and find that there are significant local differences in temperature of up to hundreds of Kelvin and in wind speeds of hundreds of m s$^{-1}$ or more across the observable atmosphere. These differences persist throughout the parameter regime studied, and are dependent on surface gravity through the impact on photosphere pressure. These results imply that the internal evolution and atmospheric thermal structure and dynamics of hot and ultra-hot Jupiters are coupled. As a result, a joint approach including both evolutionary models and GCMs may be required to make robust predictions for the atmospheric circulation of hot and ultra-hot Jupiters.
description: Accepted at ApJL, 17 pages, 8 figures
Growth Dynamics and Gas Transport Mechanism of Nanobubbles in Graphene Liquid Cells
Creators: name: Shin, Dongha
name: Park, Jong Bo
name: Kim, Yong-Jin
name: Kim, Sang Jin
name: Kang, Jin Hyoun
name: Lee, Bora
name: Cho, Sung-Pyo
name: Hong, Byung Hee
name: Novoselov, Konstantin S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Formation, evolution, and vanishing of bubbles are common phenomena in our nature, which can be easily observed in boiling or falling waters, carbonated drinks, gas-forming electrochemical reactions, etc. However, the morphology and the growth dynamics of the bubbles at nanoscale have not been fully investigated owing to the lack of proper imaging tools that can visualize nanoscale objects in liquid phase. Here we demonstrate, for the first time, that the nanobubbles in water encapsulated by graphene membrane can be visualized by in situ ultrahigh vacuum transmission electron microscopy (UHV-TEM), showing the critical radius of nanobubbles determining its unusual long-term stability as well as two distinct growth mechanisms of merging nanobubbles (Ostwald ripening and coalescing) depending on their relative sizes. Interestingly, the gas transport through ultrathin water membranes at nanobubble interface is free from dissolution, which is clearly different from conventional gas transport that includes condensation, transmission and evaporation. Our finding is expected to provide a deeper insight to understand unusual chemical, biological and environmental phenomena where nanoscale gas-state is involved.
description: 10 text pages, 4 figure pages, and 4 page Supplementary Information. Supplementary movies will be provided on request
Stall Development Control of a Blended-Wing_Body UAV Using a Bioinspired Leading-Edge Design
Creators: name:  CARLOS NEVES
name:   CATERINA GENNARI
name:   RAFFAELLO MARIANI
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: AERODYNAMICS
STALL DEVELOPMENT
BIOINSPIRED

description: This paper presents a numerical aerodynamic study of the stall characteristics and flow separation mechanisms of a blended wing body unmanned aerial vehicle being developed at KTH Royal Institute of Technology and proposes a bio-inspired leading-edge modification to control the separation mechanism and improve the aerodynamic performance of the aircraft at high angles of attack. A numerical study of the aircraft was performed at cruise speed, corresponding to Reynold\'s number of 1.3x106 , employing an Unsteady Reynolds Averaged Navier-Stokes solver with the Spalart-Allmaras turbulence model. Numerical results indicated that the aircraft is characterized by the presence of an unstable longitudinal vortex -visible at the stall angle of 9 deg -which breaks up at an angle of attack of 10 deg, resulting in an unsteady, full-chord stall cell in the mid-span region of the wing section. To mitigate this phenomenon, a modification to the leading edge between 0.4 m and 1.8 m wing spans was implemented inspired by the geometry of the nose of a porpoise whale, effectively generating a porpoise (hump) leading-edge inboard section. Preliminary numerical results indicate an increase in stall angle of attack to ~ 13 deg and an in maximum lift coefficient to ~ 1.0. Furthermore, the porpoise hump allowed controlling the stall behavior of the aircraft by enforcing a wing tip, trailing-edge separation stall achieved by the generation of an extended flow acceleration region at the leading edge.
Surfing in the phase space of spin-orbit coupling in binary asteroid systems
Creators: name: Nadoushan, Mahdi Jafari
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: For a satellite with an irregular shape, which is the common shape among asteroids, the well-known spin-orbit resonance problem could be changed to a spin-orbit coupling problem since a decoupled model does not accurately capture the dynamics of the system. In this paper, having provided a definition for close binary asteroid systems, we explore the structure of the phase space in a classical Hamiltonian model for spin-orbit coupling in a binary system. To map out the geography of resonances analytically and the cartography of resonances numerically, we reformulate a fourth-order gravitational potential function, in Poincare variables, via Stokes coefficients. For a binary system with a near-circular orbit, isolating the Hamiltonian near each resonance yields the pendulum model. Analysis of the results shows the geographical information, including the location and width of resonances, is modified due to the prominent role of the semi-major axis in the spin-orbit coupling model but not structurally altered. However, this resulted in modified Chirikov criterion to predict onset of large-scale chaos. For a binary system with arbitrary closed orbit, we thoroughly surf in the phase space via cartography of resonances created by fast Lyapunov indicator (FLI) maps. The numerical study confirms the analytical results, provides insight into the spin-orbit coupling, and shows some bifurcations in the secondary resonances which can occur due to material transfer. Also, we take the (65803) Didymos binary asteroid as a case to show analytical and numerical results.
description: 16 pages, 16 figures, accepted for publication in MNRAS
Sonnenfleckenzeichnung Nr. 27644.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 14.11.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Sonnenfleckenzeichnung Nr. 27509.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 14.04.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Literature Search and Application: Interventions for Children with Insulin-dependent Diabetes Mellitus
Creators: name: Colacchio, Bridget M.
Publisher: name: Unknown
Year: 2005

description: This article presents the results of a literature search designed to demonstrate the guidelines for conducting an evidence-based investigation as outlined by Leonard Gibbs (2003) and to identify interventions used in the psychosocial treatment of children with insulin-dependent diabetes mellitus (IDDM). The article will also propose strategies to apply and implement those interventions in a treatment plan for patients and families at Children’s Memorial Hospital in Chicago. Application and implementation strategies focus on a community-based, family support intervention adapted to fit the needs of the hospital’s patient and family population, as well as the parameters of the hospital setting.
ReFEx: Reusability Flight Experiment A Demonstration Experiment for Technologies for Aerodynamically Controlled RLV Stages
Creators: name:  RICKMERS
name:   KOTTMEIER
name:   WUBBELS
name:   BAUER
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: RLV
FLIGHT EXPERIMENT
HYPERSONICS
AERODYNAMIC

description: The Reusability Flight Experiment (ReFEx) is a technology demonstration flight experiment to gain developmental and operational experience with a fully aerodynamically controlled reusable launch vehicle stage. It is slated to launch from Koonibba test range in South Australia in 2024 using a VSB30 sounding rocket to inject it into a trajectory typical of returning stages. Key factor is to demonstrate the capability to autonomously initiate return flight trajectory to the launch site using only aerodynamic means and reach designated waypoints. The project is currently in the final stages of AIV and organisational activities such as applying for a launch license. This paper gives an overview of the main systems and focuses on a system level FtvlECA approach used to identify failure response modes for the flight safety analysis.
Non-Divergence of Unipotent Flows on Quotients of Rank One Semisimple Groups
Creators: name: Buenger, C. Davis
name: Zheng, Cheng
Publisher: name: arXiv
Year: 2014
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: Let $G$ be a semisimple Lie group of rank $1$ and $Γ$ be a torsion free discrete subgroup of $G$. We show that in $G/Γ$, given $ε>0$, any trajectory of a unipotent flow remains in the set of points with injectivity radius larger than $ δ$ for $1-ε$ proportion of the time for some $δ>0$. The result also holds for any finitely generated discrete subgroup $Γ$ and this generalizes Dani's quantitative nondivergence theorem \cite{D} for lattices of rank one semisimple groups. Furthermore, for a fixed $ε>0$ there exists an injectivity radius $δ$ such that for any unipotent trajectory $\{u_tx\}_{t\in [0,T]}$, either it spends at least $1-ε$ proportion of the time in the set with injectivity radius larger than $δ$ for all large $T>0$ or there exists a $\{u_t\}_{t\in\mathbb{R}}$-normalized abelian subgroup $L$ of $G$ which intersects $gΓg^{-1}$ in a small covolume lattice. We also extend these results when $G$ is the product of rank-$1$ semisimple groups and $Γ$ a discrete subgroup of $G$ whose projection onto each nontrivial factor is torsion free.
description: 23 pages
Sonnenfleckenzeichnung Nr. 27643.
Zeichnung von Flecken und Fackelflächen zur Ermittlung der Sonnenaktivität am 06.11.1987, erstellt von Hans Ulrich Keller
Creators: name: Eidgenössische Sternwarte in Zürich (ETH Zürich bzw. vor 1911 Polytechnikum)
Publisher: name: [s.n.]
Year: 1987

description: Bleistiftzeichnung mit Tinte und Farbstift überschrieben, erstellt als Projektionsbildzeichnung in der Eidgenössischen Sternwarte Zürich. Instrument: Zeiss Coudé-Refraktor (150/2250 mm).
Die Beobachtungen zu Einzelflecken und zu Sonnenfleckengruppen wurden mit Bleistift auf einem Vordruck eingetragen. Zusätzlich notiert: Tabelle mit den statistischen Angaben, für die Werte g, f sowie Gr (Anzahl g) und darüber hinaus einer Spalte für A: mit Hilfe eines korrekt-reduzierenden optischen Filters von blossem Auge sichtbare Flecken
Radio Communication Blackout Mitigation: Ray Tracing Analysis and Signal Characterization including Experimental Validation for Non-magnetized Plasmas
Creators: name:  JOHANNES SEBASTIAN LAUR
name:   DIANA LUIS
name:   ALAN VILADEGUT
name:   VINCENT FRITZGERALD GIANGASPERO
name:   ANDREA LANI
name:   JORGE LUIS GONZALES RIOS
name:   JORGE QUEROL
name:   JUAN VASQUEZ PERALVO
name:   JUAN CARLOS MERLANO DUNCAN
name:   ANDREAS HEIN
name:   JAN THOEMEL
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: RAYTRACING
SIGNAL CHARACTERIZATION
ATMOSPHERIC ENTRY PLASMA
PLASMA WIND TUNNEL VALIDATION

description: Atmospheric entries are a crucial part of space missions involving the possible loss of goods, data, and life in case of malfunctions. The cut-off of communication, also known as a radio communication blackout, is caused by the plasma surrounding the hypersonic (entry) vehicle in case the critical electron number density exceeds the radio frequency of the antenna. Mitigating radio communication blackouts during hypersonic flights and atmospheric entries is in the interest of the European Union\'s Horizon 2020 project MEESS T (Magnetohydrodynamic Enhanced Entry Systems for Space Transportation), alongside heat flux reduction and radiation mitigation using a high-temperature superconducting magnet. The BlackOut RAy Tracer (BORAT), a ray tracing method to predict the signal propagation in the plasma domain surrounding a hypersonic (entry) vehicle, was further developed. As characterizing the electromagnetic signal emerging from a radiation source like an antenna is essential for a better understanding of the nature behind the cutoff of communication, this feature was added to the latest version of BORAT. Two methods are analyzed and compared. One method called the Ray Density Refinement method, subsequently refines the ray density at the receiving antenna positions, which is used to increase the accuracy by marginally increasing the computational resources. The second method is called the Ray method. After propagating through the plasma area, the latter distributes the ray information discretely on the ray aperture. The method is validated using on-ground plasma wind tunnel experiments conducted at the von Karman Institute for Fluid Dynamics (VKI). The experimental setup contains one transmitting and one receiving antenna connected via a Vector Network Analyzer (VNA) measuring the scattering parameters, the magnitude and phase of the ratio of the received and transmitted signal. A new model is implemented to account for the realistic transmitting and receiving radiation patterns, respectively, for better agreement between the numerical fluid simulations in combination with the added ray tracing and signal characterization analysis and the experiment. The results from the numerical tools show a good agreement with the experimental measurements conducted at VKI. Possible errors like plasma fluctuations, numerical errors, and signal losses are considered.
A multi-wavelength view on the dusty Wolf-Rayet star WR 48a
Creators: name: Zhekov, Svetozar A.
name: Tomov, Toma
name: Gawronski, Marcin P.
name: Georgiev, Leonid N.
name: Borissova, Jura
name: Kurtev, Radostin
name: Gagne, Marc
name: Hajduk, Marcin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present results from the first attempts to derive various physical characteristics of the dusty Wolf-Rayet star WR 48a based on a multi-wavelength view of its observational properties. This is done on the basis of new optical and near-infrared spectral observations and on data from various archives in the optical, radio and X-rays. The optical spectrum of WR 48a is acceptably well represented by a sum of two spectra: of a WR star of the WC8 type and of a WR star of the WN8h type. The strength of the interstellar absorption features in the optical spectra of WR 48a and the near-by stars D2-3 and D2-7 (both members of the open cluster Danks 2) indicates that WR 48a is located at a distance of ~4 kpc from us. WR 48a is very likely a thermal radio source and for such a case and smooth (no clumps) wind its radio emission suggests a relatively high mass-loss rate of this dusty WR star (dM/dt = a few x 10^(-4) solar masses per year). Long timescale (years) variability of WR 48a is established in the optical, radio and X-rays. Colliding stellar winds likely play a very important role in the physics of this object. However, some LBV-like (luminous blue variable) activity could not be excluded as well.
description: Accepted for publication in MNRAS; 16 pages, 16 figures, 6 tables