cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers
Creators: name: Govindarajan, A.
name: Malomed, Boris A.
name: Mahalingam, A.
name: Uthayakumar, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate modulational instability (MI) in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD). In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores. Following the analytical consideration of the MI, numerical simulations are carried out to explore nonlinear development of the MI, revealing the generation of periodic chains of localized peaks with growing amplitudes, which may transform into arrays of solitons.
description: 20 pages, 23 figures, Applied Sciences - a special issue on Guided-Wave Optics, in press
Scoping and narrative review protocol: Influence of emulsion structure on physiology and health
Creators: name: Dassoff, Erik
name: Shireen, Arshia
name: Wright, Amanda
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Physiology
subject: FOS: Biological sciences
subject: Dietetics and Clinical Nutrition
subject: Nutrition
subject: Medicine and Health Sciences
subject: Life Sciences
subject: Food Science
subject: Digestion
subject: Emulsion
subject: Emulsion Structure
subject: Food Matrix
subject: Food Structure
subject: Health
subject: Lipids
subject: Nutrition
subject: Physiology

description: This protocol describes reproducible procedures for conducting a scoping review on the influence of emulsion structure on physiology and health. In addition, it considers the potential for a narrative structure to discuss novel mechanisms which may not be covered within the scope of existing food science literature.
Supplementary document for Near- and far-field study of polarization-dependent surface plasmon coupling in bowtie nano-aperture arrays - 6523548.pdf
Creators: name: Choi, Sungho
name: Park, Jongkyoon
name: Chew, Soo Hoon
name: Khurelbaatar, Tsendsuren
name: Gliserin, Alexander
name: Kim, Seungchul
name: Kim, Dong-Eon
Publisher: name: Optica Publishing Group
Year: 2023
Subjects: Uncategorized

description: Additional data considering the reviewer's comments
Vibronic exciton theory of singlet fission. I. Linear absorption and the anatomy of the correlated triplet pair state
Creators: name: Tempelaar, Roel
name: Reichman, David R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Recent time-resolved spectroscopic experiments have indicated that vibronic coupling plays a vital role in facilitating the process of singlet fission. In this work, which forms the first article of a series, we set out to unravel the mechanisms underlying singlet fission through a vibronic exciton theory. We formulate a model in which both electronic and vibrational degrees of freedom are treated microscopically and non-perturbatively. Using pentacene as a prototypical material for singlet fission, we subject our theory to comparison with measurements on polarization-resolved absorption of single crystals, and employ our model to characterize the excited states underlying the absorption band. Special attention is given to convergence of photophysical observables with respect to the basis size employed, through which we determine the optimal basis for more expensive calculations to be presented in subsequent work. We furthermore evaluate the energetic separation between the optically prepared singlet excited state and the correlated triplet pair state, as well as provide a real-space characterization of the latter, both of which are of key importance in the discussion of fission dynamics. We discuss our results in the context of recent experimental studies.
Mechanics of disordered auxetic metamaterials
Creators: name: Hanifpour, Maryam
name: Petersen, Charlotte F.
name: Alava, Mikko J.
name: Zapperi, Stefano
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Auxetic materials are of great engineering interest not only because of their fascinating negative Poisson's ratio, but also due to their increased toughness and indentation resistance. These materials are typically synthesized polyester foams with a very heterogeneous structure, but the role of disorder in auxetic behavior is not fully understood. Here, we provide a systematic theoretical and experimental investigation in to the effect of disorder on the mechanical properties of a paradigmatic auxetic lattice with a re-entrant hexagonal geometry. We show that disorder has a marginal effect on the Poisson's ratio unless the lattice topology is altered, and in all cases examined the disorder preserves the auxetic characteristics. Depending on the direction of loading applied to these disordered auxetic lattices, either brittle or ductile failure is observed. It is found that brittle failure is associated with a disorder-dependent tensile strength, whereas in ductile failure disorder does not affect strength. Our work thus provides general guidelines to optimize elasticity and strength of disordered auxetic metamaterials.
description: 5 pages, 5 figures
"USABILITY APPROACH TO THE DEVELOPMENT OF AN ORAL HYGIENE INSTRUCTION AND MOTIVATION MOBILE APPLICATION FOR ORTHODONTIC PATIENTS."
Creators: name: ADESUNLOYE, A. M
name: OTUYEMI, O. D
name: KOLAWOLE, K. A
name: NWHATOR, S. O
name: OLUWATOPE, A. O
name: IKONO, R. N
Publisher: name: SADI Journal
Year: 2024
Subjects: Dental health, Oral hygiene, Mobile application, Technology adoption, Usability, Orthodontic patients.

description: Introduction: Several interventions to improve oral hygiene compliance, such as verbal instructions, written instructions, illustrations using catalogues, videos, telephone calls, text messages, chat groups, and oral hygiene mobile applications, have been reported in patients undergoing fixed orthodontic treatment. This study aimed to develop and validate a mobile application based on a usability engineering framework from an end user perspective. Methods: The app design has a user end for patients. The description/screens of the graphic user interface (GUI) for users include registration, sign-in, home screen, setting screen, timer screen, and user profile. The approach involves the collection of data from 25 participants who underwent fixed orthodontic appliances and were recruited to interact with the mobile application to validate its usability. The methodology was considered in the context of the mobile app using a post study system usability questionnaire, which was applied to the users after 12 weeks of interaction. Results: A mobile application called the IFEORTHOCARE mobile app was developed with a user-end that illustrates oral hygiene instruction using a validated video, reminds patients about their oral health compliance with the aid of a push button alert, and empowers patients and clinicians to monitor oral hygiene compliance using feedback support in the form of a graphical display of the daily duration of toothbrushing. The mean PSSUQ score for all participants was 2.68 out of a maximum of 7.00, indicating a high degree of performance and satisfaction. Conclusion: The IFEORTHOCARE app was developed, and its usability has received strong overall satisfaction. In addition, there was a greater reduction in biofilm accumulation with the aid of this application
Lattice Boltzmann modeling and simulation of liquid jet breakup
Creators: name: Saito, Shimpei
name: Abe, Yutaka
name: Koyama, Kazuya
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: A three-dimensional color-fluid lattice Boltzmann model for immiscible two-phase flows is developed in the framework of a three-dimensional 27-velocity (D3Q27) lattice. The collision operator comprises the D3Q27 versions of three sub-operators: a multiple-relaxation-time (MRT) collision operator, a generalized Liu--Valocchi--Kang perturbation operator, and a Latva-Kokko--Rothman recoloring operator. A D3Q27 version of an enhanced equilibrium distribution function is also incorporated into this model to improve the Galilean invariance. Three types of numerical tests, namely, a static droplet, an oscillating droplet, and the Rayleigh--Taylor instability, show a good agreement with analytical solutions and numerical simulations. Following these numerical tests, this model is applied to liquid-jet-breakup simulations. The simulation conditions are matched to the conditions of the previous experiments. In this case, numerical stability is maintained throughout the simulation, although the kinematic viscosity for the continuous phase is set as low as $1.8\times10^{-4}$, in which case the corresponding Reynolds number is $3.4\times10^{3}$; the developed lattice Boltzmann model based on the D3Q27 lattice enables us to perform the simulation with parameters directly matched to the experiments. The jet's liquid column transitions from an asymmetrical to an axisymmetrical shape, and entrainment occurs from the side of the jet. The measured time history of the jet's leading-edge position shows a good agreement with the experiments. Finally, the reproducibility of the regime map for liquid-liquid systems is assessed. The present lattice Boltzmann simulations well reproduce the characteristics of predicted regimes, including varicose breakup, sinuous breakup, and atomization.
description: 20 pages, 17 figures
Thermal modelling of Advanced LIGO test masses
Creators: name: Wang, Haoyu
name: Blair, Carl
name: Álvarez, Miguel Dovale
name: Brooks, Aidan
name: Kasprzack, Marie F.
name: Ramette, Joshua
name: Meyers, Patrick M.
name: Kaufer, Steffen
name: O'Reilly, Brian
name: Mow-Lowry, Conor M.
name: Freise, Andreas
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: High-reflectivity fused silica mirrors are at the epicentre of current advanced gravitational wave detectors. In these detectors, the mirrors interact with high power laser beams. As a result of finite absorption in the high reflectivity coatings the mirrors suffer from a variety of thermal effects that impact on the detectors performance. We propose a model of the Advanced LIGO mirrors that introduces an empirical term to account for the radiative heat transfer between the mirror and its surroundings. The mechanical mode frequency is used as a probe for the overall temperature of the mirror. The thermal transient after power build-up in the optical cavities is used to refine and test the model. The model provides a coating absorption estimate of 1.5 to 2.0 ppm and estimates that 0.3 to 1.3 ppm of the circulating light is scattered on to the ring heater.
description: 14 pages, 9 figures
Vibronic exciton theory of singlet fission. II. Two-dimensional spectroscopic detection of the correlated triplet pair state
Creators: name: Tempelaar, Roel
name: Reichman, David R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Singlet fission, the molecular process through which photons are effectively converted into pairs of lower energy triplet excitons, holds promise as a means of boosting photovoltaic device efficiencies. In the preceding article of this series, we formulated a vibronic theory of singlet fission, inspired by previous experimental and theoretical studies suggesting that vibronic coupling plays an important role in fission dynamics. Here, we extend our model in order to simulate two-dimensional electronic spectra, through which the theory is further validated based on a comparison to recent measurements on pentacene crystals. Moreover, by means of such spectral simulations, we provide new insights into the nature of the correlated triplet pair state, the first product intermediate in the fission process. In particular, we address a disagreement in the literature regarding the identification, energies, and transition dipole moments of its optical transitions towards higher-lying triplet states.
Personalized instructor responses to guided student reflections: Analysis of two instructors' perspectives and practices
Creators: name: Reinholz, Daniel L.
name: Dounas-Frazer, Dimitri R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: One way to foster a supportive culture in physics departments is for instructors to provide students with personal attention regarding their academic difficulties. To this end, we have developed the Guided Reflection Form (GRF), an online tool that facilitates student reflections and personalized instructor responses. In the present work, we report on the experiences and practices of two instructors who used the GRF in an introductory physics lab course. Our analysis draws on two sources of data: (i) post-semester interviews with both instructors and (ii) the instructors' written responses to 134 student reflections. Interviews focused on the instructors' perceptions about the goals and framing of the GRF activity, and characteristics of good or bad feedback. Their GRF responses were analyzed for the presence of up to six types of statement: encouraging statements, normalizing statements, empathizing statements, strategy suggestions, resource suggestions, and feedback to the student on the structure of their reflection. We find that both instructors used all six response types, in alignment with their perceptions of what counts as good feedback. This exploratory qualitative investigation demonstrates that the GRF can serve as a mechanism for instructors to pay personal attention to their students. In addition, it opens the door to future work about the impact of the GRF on student-teacher interactions.
description: 12 pages, 2 tables
Constant-roll Inflation in $F(R)$ Gravity
Creators: name: Nojiri, S.
name: Odintsov, S. D.
name: Oikonomou, V. K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose the study of constant-roll inflation in $F(R)$ gravity. We use two different approaches, one that relates an $F(R)$ gravity to well known scalar models of constant-roll and a second that examines directly the constant-roll condition in $F(R)$ gravity. With regards to the first approach, by using well known techniques, we find the $F(R)$ gravity which realizes a given constant-roll evolution in the scalar-tensor theory. We also perform a conformal transformation in the resulting $F(R)$ gravity and we find the Einstein frame counterpart theory. As we demonstrate, the resulting scalar potential is different in comparison to the original scalar constant-roll case, and the same applies for the corresponding observational indices. Moreover, we discuss how cosmological evolutions that can realize constant-roll to constant-roll eras transitions in the scalar-tensor description, can be realized by vacuum $F(R)$ gravity. With regards to the second approach, we examine directly the effects of the constant-roll condition on the inflationary dynamics of vacuum $F(R)$ gravity. We present in detail the formalism of constant-roll $F(R)$ gravity inflationary dynamics and we discuss how the inflationary indices become in this case. We use two well known $F(R)$ gravities in order to illustrate our findings, the $R^2$ model and a power-law $F(R)$ gravity in vacuum. As we demonstrate, in both cases the parameter space is enlarged in comparison to the slow-roll counterparts of the models, and in effect, the models can also be compatible with the observational data. Finally, we briefly address the graceful exit issue.
description: CQG accepted
Ο ρόλος της επιχειρηματικότητας - Μελέτη περίπτωσης Airbnb
Creators: name: Δάβαρη, Ελένη
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Επιχειρηματικότητα
subject: Νεοφυείς επιχειρήσεις
subject: Startup companies
subject: Airbnb
subject: Επιχειρήσεις
subject: Βιωσιμότητα

description: Στην παρούσα διπλωματική εργασία μελετάται ο τρόπος που οι νεοσύστατες επιχειρήσεις έχουν γίνει μια κινητήρια δύναμη για τις νέες θέσεις εργασίας και συγκεκριμένα από τα μέσα της δεκαετίας του 2000 αποτελούν μία σημαντική δύναμη ανάπτυξης για τις προηγμένες χώρες, αφού τα αναδυόμενα έθνη προσπαθούν να ενεργοποιήσουν και να υποστηρίξουν τις νεοσύστατες επιχειρήσεις μέσω ενεργών κυβερνητικών πολιτικών για τις μεθόδους ανάπτυξής τους. Επίσης η δημοτικότητα της παγκοσμιοποιημένης οικονομίας έχει αυξηθεί δραματικά τα τελευταία χρόνια. Ωστόσο, περίπου το 30% των νεοσύστατων επιχειρήσεων έκλεισαν εντός δύο ετών από την ίδρυσή τους. Στόχος είναι η ανάδειξη των χαρακτηριστικών εσωτερικής τους ανάπτυξης μέσω της ανάλυσης των βασικών χαρακτηριστικών τους που προσδιορίζουν τις αξίες και τη νοοτροπία που δημιούργησαν μια νέα τάση κοινής διαμονής, η οποία άνοιξε τις πόρτες για ανθρώπους που δεν ειχαν σκεφτει ποτέ να συνδέσουν τη ζωή τους με τη βιομηχανία φιλοξενίας και που τους επέτρεψαν να κερδίσουν χρήματα, να μάθουν νέους πολιτισμούς, να βρουν νέους φίλους και για μερικούς από αυτούς τους επέτρεψαν ακόμη και να γίνουν επιχειρηματίες. Μία από τις πιο εξέχουσες πλατφόρμες που προσφέρει διαμονή απευθείας από οικοδεσπότες σε επισκέπτες είναι η Airbnb. Επειδή η Airbnb είναι μια αρκετά νέα θα λέγαμε εταιρία, η πολύ περιορισμένη έρευνα επικεντρώνεται στο σημαντικό ερώτημα πώς η Airbnb άλλαξε τη ζωή των οικοδεσποτών. Στην παρούσα εργασία γίνεται κατ’ αρχήν λόγος για τις νεοφυείς επιχειρήσεις, την νομοθεσία και την εν γένει εικόνα που υπάρχει στην Ελλάδα στον τομέα αυτό και στο δεύτερο μέρος της θεωρητικής έρευνας γίνεται προσπάθεια ανάλυσης της πλατφόρμας φιλοξενίας Airbnb, καθώς και του ως τώρα νομοθετικού πλαισίου που τη διέπει στην Ελλάδα. Από την ανάλυση της παρούσας εργασίας συμπεραίνεται πως η νέα σύσταση, η οργάνωση, η πρασινη επιχειρηματικότητα και η καινοτομία της νεοφυούς επιχείρησης μπορούν να θεωρηθούν τα σημαντικότερα βήματα για το start up της, ενώ η ταχεία ανάπτυξη είναι αυτή που διαχωρίζει τις νεοσύστατες επιχειρήσεις από τις μακροβιώτερες.
Effect of Lorentz Symmetry Breaking on the Deflection of Light in a Cosmic String Spacetime
Creators: name: Jusufi, Kimet
name: Sakallı, İzzet
name: Övgün, Ali
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the Lorentz symmetry breaking effects (LSBE) on the deflection of light by a rotating cosmic string spacetime in the weak limit approximation. We first calculate the deflection angle by a static cosmic string for a fixed spacelike 4-vector case (FSL) with the corresponding effective-string optical metric using the Gauss-Bonnet theorem (GBT). Then, we focus on a more general scenario, namely we calculate the deflection angle by a rotating cosmic string applying the GBT to Randers effective-string metric. We obtain a significant modification in the deflection angle because of the LSBE parameter. We find a first and second order correction terms due to the global effective topology which are proportional to the cosmic string and LSBE parameter, respectively. Finally, for a fixed time-like 4-vector (FTL) case, we show that the deflection angle is not affetced by LSBE parameter.
description: 9 pages; Accepted for publication in Physical Review D
MPEC 2024-Q71 : 2024 QE1
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 QE1

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
How to improve the sustainable strategy by lean management and a set of innovative methodologies?
Creators: name: Riva, Angelo
name: Pilotti, Luciano
Publisher: name: Economia Aziendale Online -
Year: 2023
Subjects: lean management, strategy, service, lean transformation

description: The study analyses how an integrated set of methodologies and a strategic control system permits the improvement the performance. This study uses both primary and secondary data. The finding shows how a set of methodologies (ACE methodology, customer and value satisfaction strategy, a set of problem-solving tools and projects for improvement, process management) and the system of control (use of a set of KPIs). are successfully applied and identify the reasons.
description: Economia Aziendale Online -, Vol 14, No 2 (2023): ISSUE 2/2023
Impact of next-to-leading order contributions to CMB lensing
Creators: name: Marozzi, Giovanni
name: Fanizza, Giuseppe
name: Di Dio, Enea
name: Durrer, Ruth
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this Letter we study the impact on cosmological parameter estimation, from present and future surveys, due to lensing corrections on CMB temperature and polarization anisotropies beyond leading order. In particular, we show how post-Born corrections, LSS effects and the correction due to the change in the polarization direction between the emission at the source and the detection at the observer, are non-negligible in the determination of the polarization spectra. They have to be taken into account for an accurate estimation of cosmological parameters sensitive to or even based on these spectra. We study in detail the impact of higher order lensing on the determination of the tensor-to-scalar ratio $r$ and on the estimation of the effective number of relativistic species $N_\text{eff}$. We find that neglecting higher order lensing terms can lead to misinterpreting these corrections as a primordial tensor-to-scalar ratio of about $\mathcal{O}(10^{-3})$. Furthermore, it leads to a shift of the parameter $N_\text{eff}$ by nearly two sigma considering the level of accuracy aimed by future S4 surveys.
description: 5 pages, 3 figures. Version accepted for publication in Physics Review Letters. Some references and comments added. Some modifications made to satisfy the PRL length constraint
$\mathcal{PT}$-symmetric wave guide system with evidence of a third-order exceptional point
Creators: name: Schnabel, Jan
name: Cartarius, Holger
name: Main, Jörg
name: Wunner, Günter
name: Heiss, Walter Dieter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An experimental setup of three coupled $\mathcal{PT}$-symmetric wave guides showing the characteristics of a third-order exceptional point (EP3) has been investigated in an idealized model of three delta-functions wave guides in W.~D. Heiss and G.~Wunner, J. Phys. A 49, 495303 (2016). Here we extend these investigations to realistic, extended wave guide systems. We place major focus on the strong parameter sensitivity rendering the discovery of an EP3 a challenging task. We also investigate the vicinity of the EP3 for further branch points of either cubic or square root type behavior.
description: 8 pages, 8 figures, minor changes in the text, additional references
Genesis of Karl Popper's EPR-Like Experiment and its Resonance amongst the Physics Community in the 1980s
Creators: name: Del Santo, Flavio
Publisher: name: arXiv
Year: 2017
Subjects: subject: History and Philosophy of Physics (physics.hist-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: I present the reconstruction of the involvement of Karl Popper in the community of physicists concerned with foundations of quantum mechanics, in the 1980s. At that time Popper gave active contribution to the research in physics, of which the most significant is a new version of the EPR thought experiment, alleged to test different interpretations of quantum mechanics. The genesis of such an experiment is reconstructed in detail, and an unpublished letter by Popper is reproduced in the present paper to show that he formulated his thought experiment already two years before its first publication in 1982. The debate stimulated by the proposed experiment as well as Popper's role in the physics community throughout 1980s is here analysed in detail by means of personal correspondence and publications.
description: 27 pages, 2 figures. Accepted for publication in 'Studies in History and Philosophy of Modern Physics'
Particle-based and Meshless Methods with Aboria
Creators: name: Robinson, Martin
name: Bruna, Maria
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Software (cs.MS)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Aboria is a powerful and flexible C++ library for the implementation of particle-based numerical methods. The particles in such methods can represent actual particles (e.g. Molecular Dynamics) or abstract particles used to discretise a continuous function over a domain (e.g. Radial Basis Functions). Aboria provides a particle container, compatible with the Standard Template Library, spatial search data structures, and a Domain Specific Language to specify non-linear operators on the particle set. This paper gives an overview of Aboria's design, an example of use, and a performance benchmark.
3D Relativistic MHD numerical simulations of X-shaped radio sources
Creators: name: Rossi, P.
name: Bodo, G.
name: Capetti, A.
name: Massaglia, S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A significant fraction of extended radio sources presents a peculiar X-shaped radio morphology: in addition to the classical double lobed structure, radio emission is also observed along a second axis of simmetry in the form of diffuse wings or tails. In a previous investigation we showed the existence of a connection between the radio morphology and the properties of the host galaxies. Motivated by this connection we performed two-dimensional numerical simulations showing that X-shaped radio sources may naturally form as a jet propagates along the major axis a highly elliptical density distribution, because of the fast expansion of the cocoon along the minor axis of the distribution. We intend to extend our analysis by performing three-dimensional numerical simulations and investigating the role of different parameters is determining the formation of the X-shaped morphology. The problem is addressed by numerical means, carrying out three-dimensional relativistic magnetohydrodynamic simulations of bidirectional jets propagating in a triaxial density distribution. We show that only jets with power $\lesssim 10^{44}$ erg s$^{-1}$ can give origin to an X-shaped morphology and that a misalignment of $30^o$ between the jet axis and the major axis of the density distribution is still favourable to the formation of this kind of morphology. In addition we compute synthetic radio emission maps and polarization maps. In our scenario for the formation of X-shaped radio sources only low power FRII can give origin to such kind of morphology. Our synthetic emission maps show that the different observed morphologies of X-shaped sources can be the result of similar structures viewed under different perspectives.
description: 13 pages, 16 figures, Astronomy and Astrophysics accepted
Suppressed dissipation of a quantum emitter coupled to surface plasmon polaritons
Creators: name: Yang, Chun-Jie
name: An, Jun-Hong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Enabling the confinement of light to a scale far below the one of conventional optics, surface plasmon polaritons (SPPs) induced by an electromagnetic field in a metal-dielectric interface supply an ideal system to explore strong quantized light-matter coupling. The fast matter-SPP population exchange reported in previous works makes it a candidate for spin manipulation, but such reversible dynamics asymptotically vanishes accompanying the quantum matter relaxing completely to its ground state. Here, we study the exact dissipative dynamics of a quantum emitter (QE) coupled to SPPs. It is interesting to find that, qualitatively different from conventional findings, the QE can be partially stabilized in its excited state even in the presence of the lossy metal. Our analysis reveals that it is the formation of a QE-SPP bound state which results in such suppressed dissipation. Enriching the decoherence dynamics of the QE in the lossy medium, our result is helpful to understand QE-SPP interactions and apply plasmonic nanostructures in quantum devices.
description: 6 pages, 3 figures
Ποια επενδυτική στρατηγική ασφάλισης λειτουργεί καλύτερα ;
Creators: name: Φέρτης, Νικόλαος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Στρατηγικές ασφάλισης χαρτοφυλακίου
subject: Επενδυτικές στρατηγικές ασφάλισης

description: Στην παρούσα εργασία θα αναφέρουμε την έννοια και την χρησιμότητα πίσω από την ασφάλιση ενός χαρτοφυλακίου, όπως και τα πιθανά πλεονεκτήματα αλλά και τους περιορισμούς από την εφαρμογή ενός τέτοιου είδους στρατηγικής. Θα εξετάσουμε κάποιες από τις πλέον γνωστές στρατηγικές ασφάλισης και τον ορθό τρόπο εφαρμογής τους, όπως επίσης και κάποια βασικά στοιχεία τα οποία ένας επενδυτής πρέπει να γνωρίζει ώστε να είναι σε θέση να κατανοήσει το πως λειτουργεί και που βασίζεται η κάθε στρατηγική. Θα κατασκευαστεί ένα βέλτιστο χαρτοφυλάκιο σύμφωνα με την θεωρία χαρτοφυλακίου του Markowitz, στο οποίο θα εφαρμόσουμε ξεχωριστά τις προηγουμένως εξεταζόμενες στρατηγικές ασφάλισης. Αυτό θα πραγματοποιηθεί με πραγματικά δεδομένα από την 01/01/2022 – 16/12/2022, μία περίοδο όπου η χρηματιστηριακή αγορά σημείωσε μεγάλη πτωτική πορεία. Στην συνέχεια θα γίνει αξιολόγηση των αποτελεσμάτων/αποδόσεων από την εφαρμογή της κάθε στρατηγικής. Σύμφωνα με αυτά θα εξαχθούν συμπεράσματα ως προς το ποια στρατηγική ασφαλίζει την αξία του χαρτοφυλακίου αποτελεσματικότερα κάτω από παρόμοιες συνθήκες με αυτές της αγοράς του 2022 και θα αναφέρουμε κάποιους παράγοντες, οι οποίοι μπορούν να επηρεάσουν την αποτελεσματικότητα αυτών των στρατηγικών.
Farmers' Marketing and Purchasing Associations
Creators: name: Research, Cooperative
name: Research, Cooperative
Publisher: name: Unknown
Year: 1943
Subjects: subject: Agribusiness
subject: Crop Production/Industries
subject: Livestock Production/Industries
subject: Marketing
subject: FOS: Economics and business

description: Excerpt from the Foreword: This list of farmers marketing and purchasing cooperatives includes independent local associations, federations of associations, large-scale centralized associations, sales agencies, independent service-rendering associations, subsidiaries whose businesses are distinct from those of the parent organizations, and those locals of federations which prepare independent reports.
description: Sections: Cotton and cotton products; Dairy products; Fruits and vegetables; Grain and dry beans; Livestock; Nuts; Poultry and eggs; Wool and mohair; Miscellaneous products; Special crops; Purchasing; and Service associations. Includes: Key to Selling Activities, Key to Buying Activities, and Key to Dollar Value.
Chirality, extended MHD statistics and solar wind turbulence
Creators: name: Zhu, Jian-Zhou
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We unite the one-flow-dominated-state (OFDS) argument of \citet{MeyrandGaltierPRL12} with the one-chiral-sector-dominated-state (OCSCS) one \citep[][]{hydrochirality} to form a nonlinear extended-magnetohydrodynamics (XMHD) theory for the solar wind turbulence (SWT), \textbf{ranging from the MHD- to subproton-, and even to subelectron-scale regimes} \citep[modifying the theory of][]{AbdelhamidLingamMahajanAPJ16}. Degenerate chiral states in \citet{MiloshevichLingamMorrisonNJP17}'s XMHD absolute equilibria are exposed with helical representation, to offer the basis of replacing the linear wave (of infinitesimal or arbitrarily finite amplitudes) arguments of previous theories with OCSDS. Possible connection of the OFDS-plus-OCSDS theory with the local minimal-energy/stability principle is also discussed.
description: uncorrected version
Finding Strong Gravitational Lenses in the Kilo Degree Survey with Convolutional Neural Networks
Creators: name: Petrillo, C. E.
name: Tortora, C.
name: Chatterjee, S.
name: Vernardos, G.
name: Koopmans, L. V. E.
name: Kleijn, G. Verdoes
name: Napolitano, N. R.
name: Covone, G.
name: Schneider, P.
name: Grado, A.
name: McFarland, J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The volume of data that will be produced by new-generation surveys requires automatic classification methods to select and analyze sources. Indeed, this is the case for the search for strong gravitational lenses, where the population of the detectable lensed sources is only a very small fraction of the full source population. We apply for the first time a morphological classification method based on a Convolutional Neural Network (CNN) for recognizing strong gravitational lenses in $255$ square degrees of the Kilo Degree Survey (KiDS), one of the current-generation optical wide surveys. The CNN is currently optimized to recognize lenses with Einstein radii $\gtrsim 1.4$ arcsec, about twice the $r$-band seeing in KiDS. In a sample of $21789$ colour-magnitude selected Luminous Red Galaxies (LRG), of which three are known lenses, the CNN retrieves 761 strong-lens candidates and correctly classifies two out of three of the known lenses. The misclassified lens has an Einstein radius below the range on which the algorithm is trained. We down-select the most reliable 56 candidates by a joint visual inspection. This final sample is presented and discussed. A conservative estimate based on our results shows that with our proposed method it should be possible to find $\sim100$ massive LRG-galaxy lenses at $z\lsim 0.4$ in KiDS when completed. In the most optimistic scenario this number can grow considerably (to maximally $\sim$2400 lenses), when widening the colour-magnitude selection and training the CNN to recognize smaller image-separation lens systems.
description: 24 pages, 17 figures. Published in MNRAS
Asymptotic Expansions and Conformal Covariance of the Mass of Conformal Differential Operators
Creators: name: Ludewig, Matthias
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We give an explicit description of the full asymptotic expansion of the Schwartz kernel of the complex powers of $m$-Laplace type operators $L$ on compact Riemannian manifolds in terms of Riesz distributions. The constant term in this asymptotic expansion turns turns out to be given by the local zeta function of $L$. In particular, the constant term in the asymptotic expansion of the Green's function $L^{-1}$ is often called the mass of $L$, which (in case that $L$ is the Yamabe operator) is an important invariant, namely a positive multiple of the ADM mass of a certain asymptotically flat manifold constructed out of the given data. We show that for general conformally invariant $m$-Laplace operators $L$ (including the GJMS operators), this mass is a conformal invariant in the case that the dimension of $M$ is odd and that $\ker L = 0$, and we give a precise description of the failure of the conformal invariance in the case that these conditions are not satisfied.
description: 38 pages, fixed a mistake in proof of Lemma 7.6
Volkov-Pankratov states in topological heterojunctions
Creators: name: Tchoumakov, S.
name: Jouffrey, V.
name: Inhofer, A.
name: Bocquillon, E.
name: Plaçais, B.
name: Carpentier, D.
name: Goerbig, M. O.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We show that a smooth interface between two insulators of opposite topological Z2 indices possesses multiple surface states, both massless and massive. While the massless surface state is non-degenerate, chiral and insensitive to the interface potential, the massive surface states only appear for a sufficiently smooth heterojunction. The surface states are particle-hole symmetric and a voltage drop reveals their intrinsic relativistic nature, similarly to Landau bands of Dirac electrons in a magnetic field. We discuss the relevance of the massive Dirac surface states in recent ARPES and transport experiments.
description: 5 pages, 3 figures; 6 pages of supplementary material incorporated; accepted for publication in Physical Review B as a Rapid Communication
Soliton Microcomb Range Measurement
Creators: name: Suh, Myoung-Gyun
name: Vahala, Kerry
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Laser-based range measurement systems (LIDAR) are important in many application areas including autonomous vehicles, robotics, manufacturing, formation-flying of satellites, and basic science. Coherent laser ranging systems using dual frequency combs provide an unprecedented combination of long range, high precision and fast update rate. Here, dual-comb distance measurement using chip-based soliton microcombs is demonstrated. Moreover, the dual frequency combs are generated within a single microresonator as counter-propating solitons using a single pump laser. Time-of-flight measurement with 200 nm precision at 500 ms averaging time is demonstrated. Also, the dual comb method extends the ambiguity distance to 26 km despite a soliton spatial period of only 16 mm. This chip-based source is an important step towards miniature dual-comb laser ranging systems that are suitable for photonic integration.
Recombination coefficients for O II lines in nebular conditions
Creators: name: Storey, P. J.
name: Sochi, Taha
name: Bastin, Robert
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Computational Physics (physics.comp-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We present the results of a calculation of recombination coefficients for O^{2+} + e^- using an intermediate coupling treatment that fully accounts for the dependence of the distribution of population among the ground levels of O^{2+} on electron density and temperature. The calculation is extended down to low electron temperatures where dielectronic recombination arising from Rydberg states converging on the O^{2+} ground levels is an important process. The data, which consist of emission coefficients for 8889 recombination lines and recombination coefficients for the ground and metastable states of O^+ are in Cases A, B and C, and are organised as a function of the electron temperature and number density, as well as wavelength. An interactive fortran 77 data server is also provided as an accessory for mining the line emission coefficients and obtaining Lagrange interpolated values for any choice of the two variables between the explicitly provided values for any set of wavelengths. Some illustrations of the application of the new data to nebular observations are also provided.
description: 15 pages, 7 figures, 6 tables
Imprenditorialità, innovazione e impatto sociale: un’analisi esplorativa sulle startup innovative a vocazione sociale in Italia
Creators: name: Del Bosco, Barbara
Publisher: name: ----
Year: 2023
Subjects: Imprenditorialità, startup innovative, nuove imprese, impatto sociale, vocazione sociale

description: Questo lavoro presenta un’analisi di tipo esplorativo sulle startup innovative a vocazione sociale presenti in Italia, finalizzato sia ad identificarne alcuni tratti caratterizzanti rispetto alle altre startup innovative, sia ad indagarne l’eterogeneità. Con riguardo a quest’ultimo aspetto è stata condotta una cluster analysis che ha permesso di identificare cinque cluster di startup innovative a vocazione sociale ed ha messo in luce come diverse tipologie di team imprenditoriali tendano a costituire startup con differenti caratteristiche in termini di dotazione di risorse intangibili. I risultati ottenuti permettono di avere un primo quadro del fenomeno ed offrono spunti per la ricerca futura su questa particolare tipologia di imprese che abbinano il perseguimento di un obiettivo di impatto sociale allo sviluppo, produzione e commercializzazione di un prodotto o servizio ad alto valore tecnologico.
description: ----, Vol 14, No 2 (2023): ISSUE 2/2023
Skyrmion-induced anomalous Hall conductivity on topological insulator surfaces
Creators: name: Araki, Yasufumi
name: Nomura, Kentaro
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Electron spin-momentum locking together with background magnetic textures can significantly alter the electron transport properties. We theoretically investigate the electron transport at the interface between a topological insulator and a magnetic insulator with magnetic skyrmions on the top. In contrast to the conventional topological Hall effect in normal metals, the skyrmions yield an additional contribution to the anomalous Hall conductivity even in the absence of in-plane magnetic texture, arising from the phase factor characteristic to Dirac electrons acquired at skyrmion boundary.
description: 10 pages, 4 figures; published version
Dynamical tides in coalescing superfluid neutron star binaries with hyperon cores and their detectability with third generation gravitational-wave detectors
Creators: name: Yu, Hang
name: Weinberg, Nevin N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The dynamical tide in a coalescing neutron star binary induces phase shifts in the gravitational waveform as the orbit sweeps through resonances with individual g-modes. Unlike the phase shift due to the equilibrium tide, the phase shifts due to the dynamical tide are sensitive to the stratification, composition, and superfluid state of the core. We extend our previous study of the dynamical tide in superfluid neutron stars by allowing for hyperons in the core. Hyperon gradients give rise to a new type of composition g-mode. Compared to g-modes due to muon-to-electron gradients, those due to hyperon gradients are concentrated much deeper in the core and therefore probe higher density regions. We find that the phase shifts due to resonantly excited hyperonic modes are ~ 10^{-3} rad, an order of magnitude smaller than those due to muonic modes. We show that by stacking events, third generation gravitational-wave detectors should be able to detect the phase shifts due to muonic modes. Those due to hyperonic modes will, however, be difficult to detect due to their smaller magnitude.
description: 11 pages, 4 figures, 4 tables. Accepted for publication in MNRAS
title: Ενεργειακά υβριδικά συστήματα πρόωσης πλοίου και έξυπνα πλοία
title: Hybrid propulsion systems in ships and smart ships
titleType: AlternativeTitle
Creators: name: Μπιμπλι, Άντζελα
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Συστήματα πρόωσης
Υβριδική τεχνολογία
Έξυπνα πλοία

description: Ο τομέας της ναυτιλίας είναι ένας από τους μεγαλύτερους κλάδους απασχόλησης από πλευράς οικονομικών μεγεθών. Εκατοντάδες δις δολάρια σε αξία αγαθών διακινούνται σε ετήσια βάση μέσω της ναυτιλίας, φροντίζοντας πως κάθε γωνιά του πλανήτη θα έχει πρόσβαση σε αγαθά όπως το πετρέλαιο, τα αυτοκίνητα, τα σιτηρά, τα ρούχα κ.λπ. Για να επιτευχθεί αυτό, ωστόσο απαιτείται ένας τεράστιος παγκόσμιος στόλος, χιλιάδων μεγάλων πλοίων, την υποστήριξη των οποίων καλούνται να αναλάβουν ακόμα περισσότερα μικρότερα πλοία. Επίσης, οι περισσότερες χώρες του κόσμου διαθέτουν πολεμικά πλοία, κάτι που επίσης συνεισφέρει στο τελικό αριθμό των πλοίων. Ο μεγάλος αυτός αριθμός πλοίων, τόσο επιβατηγών, όσο και εμπορικών και πολεμικών, οδηγεί στην ένταση ενός γνώριμου φαινομένου στην παγκόσμια κοινωνία τα τελευταία χρόνια: της κλιματικής αλλαγής. Με τις εκπομπές ρύπων των πλοίων να συνεισφέρουν στην παγκόσμια υπερθέρμανση, δεν είναι καθόλου παράλογη η έκκληση για περιορισμό των ρύπων και κατασκευή περισσότερων πράσινων, φιλικών προς το περιβάλλον, πλοίων. Έτσι, τα τελευταία χρόνια γίνονται προσπάθειες στο μέτωπο της αντιμετώπισης των εκπομπών ρύπων των πλοίων, είτε με την εφαρμογή μεθόδων για πρόωση με λιγότερες εκπομπές ή για φιλτράρισμα των εκπομπών σε ήδη υπάρχοντα συστήματα. Στην πρώτη λογική, την απάντηση έρχεται να δώσει η ηλεκτρική και υβριδική τεχνολογία, η οποία έχει εισαχθεί για τα καλά στην αυτοκίνηση, δίνοντας υποσχέσεις για πιθανή ενσωμάτωση και στα πλοία. Πλοία που τροφοδοτούνται και με ηλεκτρικό ρεύμα από ΑΠΕ και μπαταρίες, μπορούν να οδηγήσουν σε μικρότερη κατανάλωση καυσίμου για την κίνησή τους και όλες τις επιπλέον ανάγκες που υπάρχουν πάνω σε αυτά (κλιματισμός, εξαερισμός, φωτισμός, ηλεκτρικές συσκευές, κτλ). Η χαμηλότερη κατανάλωση από τα πλοία μεταφράζεται σε λιγότερες εκπομπές ρύπων διοξειδίου του άνθρακα, αλλά και σε μικρότερη διαρκή ζήτηση για πετρέλαιο, το οποίο πλέον χρησιμοποιείται για μια πληθώρα εφαρμογών (θέρμανση, παραγωγή ενέργειας, πλαστικά, χημική βιομηχανία) , οδηγώντας σε συνεχή εκμετάλλευση των κοιτασμάτων και καταστροφή φυσικού περιβάλλοντος. 7 Ωστόσο, οι υβριδικές/ηλεκτρικές τεχνολογίες δεν δύνανται να εφαρμοστούν μόνο και μόνο προς χάριν της «πράσινης» κίνησης των πλοίων. Θα πρέπει να εντοπίζονται τα οφέλη τους και σε ποιο βαθμό αυτά επιτυγχάνονται, δεδομένων των συνθηκών υπό των οποίων κάθε τύπος πλοίου λειτουργεί σήμερα. Δεν έχουν όλα τα πλοία τις ίδιες απαιτήσεις σε διαθεσιμότητα, εφεδρεία και ταχύτητα, κάτι που σημαίνει ότι δεν είναι βέβαιο πως ένα υβριδικό σύστημα μπορεί να ανταπεξέλθει σε αυτές. Έτσι, σκοπός της παρούσας διπλωματικής εργασίας είναι να διερευνηθεί το κατά πόσο είναι βιώσιμη η υβριδική και ηλεκτρική τεχνολογία σε συγκεκριμένα πλοία και πόσο μπορεί να συνεισφέρει στην εξοικονόμηση καυσίμου, άρα και στη μείωση των εκπομπών ρύπων (διοξείδιο του άνθρακα) .