cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Understanding High-Field Electron Transport Properties of Monolayer Transition Metal Dichalcogenides and Strain Effects
Creators: name: Zhang, Chenmu
name: Cheng, Long
name: Liu, Yuanyue
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Monolayer transition metal dichalcogenides (MX2) are promising candidates for future electronics. Although the transport properties (e.g. mobility) at low electric field have been widely studied, there are limited studies on high-field properties, which are important for many applications. Particularly, there is lack of understanding of the physical origins underlying the property differences across different MX2. Here by combining first-principles calculations with Monte Carlo simulations, we study the high-field electron transport in defects-free unstrained and tensilely strained MX2 (M=Mo, W and X=S, Se). We find that WS2 has the highest peak velocity (due to its smallest effective mass) that can be reached at the lowest electric field (owing to its highest mobility). Strain can increase the peak velocity by increasing the scattering energy. After reaching the peak velocity, most MX2 demonstrates negative differential mobility (NDM). WS2 shows the largest NDM among unstrained MX2 due to the strongest effect of electron transfer from the low-energy small-mass valley to the high-energy large-mass valley. The tensile strain increases the valley separation, which on one hand suppresses the electron transfer in WS2, on the other hand allows the electrons to access the non-parabolic band region of the low-energy valley. The latter effect leads to an NDM for electrons in the low-energy valley, which can significantly increase the overall NDM at moderate strain. The valley-separation induced NDM in the low-energy valley is found to be a general phenomenon. Our work unveils the physical factors underlying the differences in high-field transport properties of different MX2, and also identifies the most promising candidate as well as effective approach for further improvement.
Space-Charge Limited Current from a Finite Emitter in Nano- and Microdiodes
Creators: name: Gunnarsson, Johannes Bergur
name: Torfason, Kristinn
name: Manolescu, Andrei
name: Valfells, Agust
Publisher: name: arXiv
Year: 2020
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We simulate numerically the classical charge dynamics in a microscopic, planar, vacuum diode with a finite emitter area and a finite number of electrons in the gap. We assume electrons are emitted under space-charge limited conditions with a fixed potential applied to the diode. The Coulomb interaction between all electrons is included using the method of molecular dynamics. We compare our results to the conventional two-dimensional Child-Langmuir and explain how it is limited in applicability for sub-micron diameter emitters. Finally, we offer some simple relations for understanding space-charge limited flow from very small emitters.
description: 5 pages, 5 figures
pT-fluctuations and multiparticle clusters in heavy-ion collisions
Creators: name: Broniowski, Wojciech
name: Bozek, Piotr
name: Florkowski, Wojciech
name: Hiller, Brigitte
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the centrality dependence of the pT-correlations in the event-by-event analysis of relativistic heavy-ion collisions at RHIC made recently by the PHENIX and STAR Collaborations. We notice that sigma^2 dynamical scales to a very good accuracy with the inverse number of the produced particles, n. This scaling can be naturally explained by formation of clusters. We discuss the nature of clusters and provide numerical estimates of correlations coming from resonance decays, which are tiny, and a model where particle are emitted from local thermalized sources moving at the same collective velocity. This "lumped cluster" model can explain the data when on the average 6-15 particles are contained in a cluster. We also point out simple relations of the popular correlation measures to the covariance, which arise under the assumptions (well holding at RHIC) that the distributions are sharply peaked in n and that the dynamical compared to statistical fluctuations are small.
description: 14 pages, 4 figures, talk and discussion presented at "Correlations and Fluctuations in Relativistic Nuclear Collisions", 7-9 July 2006, Florence
Εφαρμογές Τυχαίων Περίπατων στην Κατηγοριοποίηση και στην Μείωση Διάστασης Δεδομένων.
Creators: name: Γαβριηλίδης, Βασίλειος Φαιδωνα
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: Μηχανές Διανυσμάτων Υποστήριξης
Τυχαίοι περίπατοι
Μείωση Διάστασης
Support Vector Machines
Random Walks
Dimensionality Reduction

description: Στην παρούσα εργασία, ο κύριος στόχος ήταν η ενασχόληση με νέους πυρήνες και χρησιμοποίησή τους για κατηγοριοποίηση δεδομένων. Οι προτεινόμενοι πίνακες πυρήνα δημιουργούνται χρησιμοποιώντας δυνάμεις ήδη γνωστών πινάκων πυρήνα. Τέτοιες μέθοδοι παραγωγής πινάκων πυρήνα έχουν χρησιμοποιηθεί και στο παρελθόν αλλά δεν έχουν δημοσιευτεί ποτέ αποτελέσματα κατηγοριοποίησης. Διεξήχθησαν πειράματα σε διάφορα σύνολα δεδομένων και χρησιμοποιήθηκαν στατιστικά τεστ για την σύγκριση του προτεινόμενου τρόπου χρήσης πινάκων πυρήνα έναντι του κλασικού τρόπου χρήσης που μπορούν να χρησιμοποιηθούν στις μηχανές διανυσμάτων υποστήριξης (Support Vector Machines - SVM). Επίσης, παρουσιάζονται αποτελέσματα κατηγοριοποίησης σε πραγματικές βάσεις δεδομένων όπως είναι η αναγνώριση δραστηριότητας ανθρώπων (activity recognition). Ακόμη προτείνουμε μια μέθοδο για μείωση διάστασης δεδομένων η οποία μπορεί να ενσωματωθεί σε ένα ενιαίο πλαίσιο μείωσης διάστασης, και παρουσιάζουμε κάποιες αξιοσημείωτες προβολές δεδομένων.
description: Novel Kernel Matrices that reflect on the general structure of data are proposed for classification. The proposed Matrices are generated using powers of already known Kernel Matrices. This technique has already been mentioned but no application to classification has ever been shown. Experiments on various datasets are conducted and statistical test are performed comparing our proposed approach against current Kernel Matrices used on support vector machines. We show classification results to real database problems such as activity recognition. Lastly we show some noteworthy projections using our kernel matrix when it is embedded in a famous dimensionality reduction framework.
Putting our money where our mouth is: Open Hydrology Done Right in the eWaterCycle II project
Creators: name: Hut, Rolf
name: Drost, Niels
name: Giesen, Nick Van De
name: Werkhoven, Ben Van
name: Aerts, Jerom
name: Inti Pelupessy
name: Weel, Berend
name: Dzigan, Yifat
name: Vos, Martine De
name: Verhoeven, Stefan
name: Oord, Gijs Van Den
name: Haren, Ronald Van
name: Zwaan, Janneke Van Der
name: Meersbergen, Maarten Van
Publisher: name: Zenodo
Year: 2019

description: In the eWaterCycle II project we took up the challenge to “do Open Hydrology right”. This is a presentation from and EGU session on Open Science (https://meetingorganizer.copernicus.org/EGU2019/EGU2019-9276-2.pdf)
Two-Dimensional Electron Gas as a Basis for Low-Loss Hyperbolic Metamaterials
Creators: name: Mastro, Michael A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The implementation of hyperbolic metamaterials as component in optical waveguides, semiconductor light emitters and solar cells has been limited by the inherent loss in the metallic layers. The features of a hyperbolic metamaterial arise by the presence of alternating metal and a dielectric layers. This work proposes that the deleterious loss characteristic of metal-based hyperbolic metamaterials can be minimized by employing a III-nitride superlattice wherein a two-dimensional electron gas (2DEG) functions as the metallic layer.
Promotion of cooperation induced by nonlinear attractive effect in spatial Prisoner's Dilemma game
Creators: name: Guan, Jian-Yue
name: Wu, Zhi-Xi
name: Huang, Zi-Gang
name: Xu, Xin-Jian
name: Wang, Ying-Hai
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We introduce nonlinear attractive effects into a spatial Prisoner's Dilemma game where the players located on a square lattice can either cooperate with their nearest neighbors or defect. In every generation, each player updates its strategy by firstly choosing one of the neighbors with a probability proportional to $\mathcal{A}^α$ denoting the attractiveness of the neighbor, where $\mathcal{A}$ is the payoff collected by it and $α$ ($\geq$0) is a free parameter characterizing the extent of the nonlinear effect; and then adopting its strategy with a probability dependent on their payoff difference. Using Monte Carlo simulations, we investigate the density $ρ_C$ of cooperators in the stationary state for different values of $α$. It is shown that the introduction of such attractive effect remarkably promotes the emergence and persistence of cooperation over a wide range of the temptation to defect. In particular, for large values of $α$, i.e., strong nonlinear attractive effects, the system exhibits two absorbing states (all cooperators or all defectors) separated by an active state (coexistence of cooperators and defectors) when varying the temptation to defect. In the critical region where $ρ_C$ goes to zero, the extinction behavior is power law-like $ρ_C$ $\sim$ $(b_c-b)^β$, where the exponent $β$ accords approximatively with the critical exponent ($β\approx0.584$) of the two-dimensional directed percolation and depends weakly on the value of $α$.
description: 7 pages, 4 figures
Factors influencing the sensitivity of the alkaline comet assay for detection of DNA damage after low doses of radiation
Creators: name: Fjell, Christopher David
Publisher: name: University of British Columbia
Year: 2009

description: The alkaline comet assay is a sensitive technique for measuring single-strand breaks in DNA of individual mammalian cells. The method uses fluorescent microscopy to examine DNA patterns resulting from alkaline agarose gel electrophoresis of individual cells after staining with propidium iodide. Factors influencing the sensitivity of the assay to low doses of radiation were investigated in three parts. 1) A model was developed for the digital image supplied by the camera; and improvements in image quality were achieved by subtracting the dark-field image. 2) The conditions for staining of comets with propidium iodide were optimized for image quality by minimizing the background fluorescence through inclusion of 0.02 M NaCl, increasing in the staining time to several hours, and mimmizing the dye concentration. The dependence of comet fluorescence on dye concentration required a model of two binding modes with equilibrium constants, 3.7±0.6 x 10⁵ M⁻¹ and 3.6±0.2 x 10⁷ M⁻¹. These values are in general agreement with reported values for DNA in solution (3.0±0.2 x 10⁵ M⁻¹) and bound by nucleoprotein (1.1±0.4 x 10⁷ M⁻¹). A decline in the number of binding sites with increasing radiation damage explained the loss of comet fluorescence with increasing DNA damage. 3) Limitations in sensitivity due to background damage were investigated. A portion of background damage was found to be induced during cell suspension and preparation of agarose gels. The measurement of damage was not significantly influenced by alkaline lysis duration but was strongly affected by extended alkaline rinse duration. Enhanced sensitivity and minimum background damage were found using a cell suspension including culture medium, higher temperature agarose stock solution and a three hour rinse protocol. The sensitivity of the assay was found to be limited by additional background variations at an average level equivalent to 0.05 Gy. Sensitivity below this level would require averaging measurements from multiple, replicate samples.
Centre of pressure estimation during walking using only inertial-measurement units and end-to-end statistical modelling
Creators: name: Podobnik, Janez
name: Kraljic, David
name: Zadravec, Matjaz
name: Munih, Marko
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Estimation of the centre of pressure (COP) is an important part of the gait analysis, for example, when evaluating the functional capacity of individuals affected by motor impairment. Inertial measurement units (IMUs) and force sensors are commonly used to measure gait characteristic of healthy and impaired subjects. We present a methodology for estimating the COP solely from raw gyroscope, accelerometer, and magnetometer data from IMUs using statistical modelling. We demonstrate the viability of the method using an example of two models: a linear model and a non-linear Long-Short-Term Memory (LSTM) neural network model. Models were trained on the COP ground truth data measured using an instrumented treadmill and achieved the average intra-subject root mean square (RMS) error between estimated and ground truth COP of 12.3mm and the average inter-subject RMS error of 23.7mm which is comparable or better than similar studies so far. We show that the calibration procedure in the instrumented treadmill can be as short as a couple of minutes without the decrease in our model performance. We also show that the magnetic component of the recorded IMU signal, which is most sensitive to environmental changes, can be safely dropped without a significant decrease in model performance. Finally, we show that the number of IMUs can be reduced to five without deterioration in the model performance.
description: 21 pages
Pairing Symmetry and Upward Curvature of Upper Critical Field in Superconducting $Na_{0.35} Co O_2 \cdot y H_2 O$
Creators: name: Kao, Jun-Ting
name: Lin, Jiunn-Yuan
name: Mou, Chung-Yu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The origin for the upward curvature of the upper critical field ($H_{c2}$) observed in hydrate cobaltate Na$_{0.35}$CoO$_{2} \cdot y$H$_{2}$O is investigated based on the microscopic gap equation. It is shown that the observed upward curvature results from the transition between two different pairing symmetries that occur on different energy bands. Furthermore, different pairing symmetries involved in the transition results in different upward curvatures. By considering transitions among all lowest possible pairing symmetries, it is found that the transition of the pairing symmetry from s-wave at low fields to $d_{x^2-y^2}+ id_{xy}$ at high fields is the best fit to the experimental data. Our results provide an important clue to the understanding of the superconductivity in hydrate cobaltate.
description: 4 pages, 1 figures
Laser-processing of grinded and mechanically abraded Nb-surfaces
Creators: name: Porshyn, V.
name: Rothweiler, P.
name: Lützenkirchen-Hecht, D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The effect of pulsed laser polishing on rough niobium surfaces was investigated. We created different well-defined roughness profiles with standard emery papers and subsequently remelted random surface areas with a size of about 2x2 mm^2 with nanosecond laser pulses (wavelength of 1064 nm, pulse length of 10 ns). Pristine as well as laser-treated surfaces were investigated using optical profilometry and atomic force microscopy, and the surface topography was described by means of correlation functions. Uniformly rough and highly smooth surface geometries were achieved for fractals above and below 7 μm, respectively. Moreover, the behavior of foreign particles during the laser processing was investigated in detail. The polishing procedure was also monitored point by point by detecting electrical signals, i.e., sample charging, which resulted from the intense laser illumination. The measured electrical charges were found to be correlated with the local surface texture. Thus, regions with initially high roughness profiles and regions with extensive laser-induced defects could be directly identified from the detected electrical signals.
description: 24 pages, 8 figures
The Neutral Higgs Effects on Rare Decays $B \to X_s l^+ l^-$ in T2HDM
Creators: name: Lü, Lin-xia
name: Xiao, Zhen-jun
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the new physics contributions to the branching ratios of the rare decays $B \to X_s l^+ l^-$ $(l=e, μ)$ induced by neutral Higgs bosons loop diagrams in the top quark two-Higgs-doublet model (T2HDM). From the numerical calculations, we find that (a) the neutral Higgs boson's correction to $B \to X_s l^+ l^-$ decays interferes constructively with its standard model counterpart, but small in magnitude; (b) the neutral Higgs contributions to the branching ratio of $B \to X_s l^+ l^-$ decay can be neglected safely if their masses are larger than 100 GeV and $\tanβ\leq 40$.
description: RevTex file,12 pages, 3 eps figues
Η επιθετικότητα, ο εκφοβισμός και η κοινωνική επάρκεια στα πλαίσια των αλληλεπιδράσεων με τους συνομηλίκους: Οι απόψεις παιδιών προεφηβικής ηλικίας
Creators: name: Κουκουτσης, Νικόλαος Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: Επιθετικότητα
Εκφοβισμός
Κοινωνική επάρκεια
Aggression
Bullying
Social competence

description: Ο στόχος της παρούσας έρευνας ήταν η διερεύνηση των αντιλήψεων παιδιών προεφηβικής ηλικίας αναφορικά με τη σχέση μεταξύ επιθετικότητας/εκφοβισμού και κοινωνικής επάρκειας, στα πλαίσια των κοινωνικών τους αλληλεπιδράσεων. Το δείγμα της έρευνας αποτέλεσαν 232 αγόρια και 217 κορίτσια, ηλικίας 10 έως 13 ετών, που φοιτούσαν στην Ε’ και ΣΤ’ Δημοτικού. Ειδικότερα, διερευνήθηκαν οι διαφυλικές διαφορές σε επίπεδο συμπεριφορών, οι συσχετίσεις των υπό μελέτη μεταβλητών, η συμπεριφορά των παιδιών στα περιστατικά εκφοβισμού, οι επιδράσεις των επιθετικών και των θετικών κοινωνικών συμπεριφορών στην κοινωνική επάρκεια και το δίκτυο σχέσεων των υπό μελέτη μεταβλητών.
description: The purpose of the present study was to investigate the preadolescents’ perceptions on the relationship between aggression/bullying and social competence, as part of their social interactions. The sample consisted of 232 boys and 217 girls, aged 10-13 years, who were attending the fifth and sixth grade. In particular, investigated the gender differences in behavior, the correlations of the study variables, the children's behavior in bullying, the effects of aggressive and prosocial behaviors in social competence and the network of relationships of the studied variables.
SLOCC invariant and semi-invariants for SLOCC classification of four-qubits
Creators: name: Li, D.
name: Li, X.
name: Huang, H.
name: Li, X.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show there are at least 28 distinct true SLOCC entanglement classes for four-qubits by means of SLOCC invariant and semi-invariants and derive the number of the degenerated SLOCC classes for n-qubits.
description: 22 pages, no figures, 9 tables, submit the paper to a journal
Information transfer between turbulent boundary layer and porous media
Creators: name: Wang, Wenkang
name: Chu, Xu
name: Lozano-Durán, Adrián
name: Helmig, Rainer
name: Weigand, Bernhard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The interaction between the flow above and below a permeable wall is a central topic in the study of porous media. While previous investigations have provided compelling evidence of the strong coupling between the two regions, few studies have quantitatively measured the directionality, i.e., causal-and-effect relations, of this interaction. To shed light on the problem, we use transfer entropy as a marker to evaluate the causal interaction between the free turbulent flow and the porous media using interface-resolved direct numerical simulation. Our results show that the porosity of the porous medium has a profound impact on the intensity, time scale and spatial extent of surface-subsurface interactions. For values of porosity equal to 0.5, top-down and bottom-up interactions strongly are asymmetric, the former being mostly influenced by small near-wall eddies. As the porosity increases, both top-down and bottom-up interactions are dominated by shear-flow instabilities.
การประยุกต์ใช้ระบบ HACCP ในการควบคุมความสะอาดปลอดภัย ในกระบวนการผลิตแซนวิชของครัวสวนดุสิต
Creators: name: จันทร์จนา ศิริพัรธ์วัฒนา
name: มนัสวี แย้มฉ่ำไพร
name: กรรณิการ์ บัวแย้ม
Publisher: name: วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
Year: 2549
Subjects: อาหารปลอดภัย,แซนวิช,ครัวสวนดุสิต,HACCP

description: 1, 2, วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
ปัจจัยส่วนบุคคล เชาวน์อารมณ์ และภาวะความสุขของผู้ปกครอง ที่ส่งผลต่อการดูแลเด็กที่มีความบกพร่องทางสถิติปัญญา
Creators: name: ทิพย์วัลย์ สีจันทร์
Publisher: name: วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
Year: 2549
Subjects: ความบกพร่องทางสถิติปัญญา,ปัจจัยส่วนบุคคล,เชาวน์อารมณ์,ภาวะความสุขของผู้ปกครอง

description: 1, 2, วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
วิเคราะห์ผลงานจิตรกรรมภาพคน ของ อเมดีโอ โมดิกลิ อานี (Amedeo Modigliani)
Creators: name: วรรณา พิเชฐพฤทธ์
Publisher: name: วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
Year: 2549
Subjects: จิตกรรม,ประติมากรรม,ภาพเหมือน

description: 1, 2, วารสารวิจัย มสด สาขามนุษยศาสตร์และสังคมศาสตร์
Multiband Weighting of X-ray Polarization Data
Creators: name: Marshall, Herman L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: An optimal estimate for Stokes parameters is derived for the situation in X-ray astronomy where the instrument has a modulation factor that varies significantly with energy but the signals are very weak or mildly polarized. For such sources, the band of analysis may be broadened in order to obtain a significant polarization measurement. Optimal estimators are provided for the cases of binned and unbinned data and applied to data such as might be obtained for faint or weakly polarized sources observed using the Imaging X-ray Polarimetry Explorer (IXPE). For a sample situation, the improvement in the minimum detectable polarization is 6-7% using a count weighted root-mean-square of the modulation factor, when compared to a count weighted average. Improving the modulation factor, such as when using a neural network approach to IXPE event tracks, can provide additional improvement up to 10-15%. The actual improvement depends on the spectral shape and the details of the instrument response functions.
description: 12 pages, 1 figure, accepted for publication in the Astrophysical Journal
Photodissociation feedback of Population III stars \\on their neighbor prestellar cores
Creators: name: Susa, Hajime
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the star formation process in primordial environment in the presence of radiative feedback by other population III stars formed earlier. In this paper, we focus our attention on the effects by photodissociative radiation toward the full understanding of the radiative feedback effects. We perform three dimensional radiation hydrodynamics simulations on this issue as well as analytic estimates, paying special attention on the self-shielding effect and dynamics of the star-forming cloud. As a result, we find that the ignition timing of the source star is crucial. If the ignition is later than the epoch when the central density of the collapsing cloud exceeds $\sim 10^3-10^4{\rm cm^{-3}}$, the collapse cannot be reverted, even if the source star is located at $\la$ 100pc. The uncertainty of the critical density comes from the variety of initial conditions of the collapsing cloud. We also find the analytic criteria for a cloud to collapse with given central density, temperature and the Lyman-Werner(LW) band flux which irradiates the cloud. Although we focus on the radiation from neighbor stars, this result can also be applied to the effects of diffuse LW radiation field, that is expected to be built up prior to the reionization of the universe. We find that self-gravitating clouds can easily self-shield from diffuse LW radiation and continue their collapse for densities larger than $\sim 10^3 {\rm cm^{-3}}$.
description: 14pages, 11figures, ApJ accepted
Size and doping effects on the coercive field of ferroelectric nanoparticles
Creators: name: Michael, Th.
name: Trimper, S.
name: Wesselinowa, J. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A microscopic model for describing ferroelectric nanoparticles is proposed which allows us to calculate the polarization as a function of an external electric field, the temperature, the defect concentration and the particle size. The interaction of the constituents of the material, arranged in layers, depends on both the coupling strength at the surface and that of defect shells in addition to the bulk values. The analysis is based on an Ising model in a transverse field, modified in such a manner to study the influence of size and doping effects on the hysteresis loop of the nanoparticles. Using a Green function technique in real space we find the coercive field, the remanent polarization and the critical temperature which differ significantly from the bulk behavior. Depending on the varying coupling strength due to the kind of doping ions and the surface configuration, the coercive field and the remanent polarization can either increase or decrease in comparison to the bulk behavior. The theoretical results are compared with a variety of different experimental data.
description: 16 pages, 7 figures
Astrofotografia na escola: Um guia rápido de astrofotografia para professores e estudantes
Creators: name: FERREIRA, LUCAS
Publisher: name: Zenodo
Year: 2022
Subjects: Astrofotografia
Recurso didático
Oficina
Baixo custo
Educação em astronomia
Ensino de astronomia

description:           O guia "Astrofotografia na escola" é um recurso didático direcionado à prática da astrofotografia. Disponível para ser impresso em A4, ou acessado digitalmente. Esse recurso didático destina-se a professores, profissionais da educação e da astronomia, estudantes e entusiastas que possuam interesse na prática da astrofotografia, para ser aplicado em diversos contextos e ambientes formais e não formais de aprendizagem em ciências e astronomia.

          O recurso didático contém: conteúdos de astronomia e astrofotografia; planos de atividades, projetos e oficinas multi e interdisciplinares; moldes e astrofotografias para impressão; imagens de referência; recursos para ensinar astronomia, astrofotografia e ciências.

Capa - Pág. 1

História da Astronomia - Pág. 2

Astrofotografia - Pág. 3

Passo a passo “Como capturar uma Astrofotografia” - Págs. 4 e 5

Plano de Atividade I: Astrofotografia na escola - Pág. 6

Plano de Atividade II: Astrofotografia como projeto interdisciplinar - Pág. 7

Oficina “Mapa Celeste Astrofotográfico” - Págs. 8 e 9

Moldes para impressão das regiões de Órion, Escorpião e Cruzeiro do Sul - Págs. 10, 11 e 12

Plano de Atividade III: Constelações e mitologia - Pág. 13

Plano de Atividade IV: Astrofísica e curiosidades - Pág. 21

Plano de Atividade V: Nebulosas e meio interestelar - Pág. 24

Oficina “Brincando com as Nebulosas” - Pág. 24

Molde das nebulosas na região de Órion - Pág. 28

Autoria: Lucas Ferreira (UnB/IF/MNPEF).

A discussão sobre a aplicação desse material e demais detalhes está publicada em: - 33ª edição da Revista Latino-Americana de Educação em Astronomia (RELEA), disponível em: https://www.relea.ufscar.br/index.php/relea/article/view/602.- VI Simpósio Nacional de Educação em Astronomia (VI SNEA 2022), disponível em: https://sab-astro.org.br/wp-content/uploads/2023/12/SNEA2022_CO-41.pdf.

 

Citação:

FERREIRA, L. Astrofotografia na escola: Um guia rápido de astrofotografia para professores e estudantes. Recurso didático. Zenodo, 29 jun. 2022. Disponível em: https://doi.org/10.5281/zenodo.6777193. Acesso em 29 jun. 2022.
Transmon in a semi-infinite high-impedance transmission line -- appearance of cavity modes and Rabi oscillations
Creators: name: Wiegand, Emely
name: Rousseaux, Benjamin
name: Johansson, Göran
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this letter, we investigate the dynamics of a single superconducting artificial atom capacitively coupled to a transmission line with a characteristic impedance comparable or larger than the quantum resistance. In this regime, microwaves are reflected from the atom also at frequencies far from the atom's transition frequency. Adding a single mirror in the transmission line then creates cavity modes between the atom and the mirror. Investigating the spontaneous emission from the atom, we then find Rabi oscillations, where the energy oscillates between the atom and one of the cavity modes.
Oscillations observed in Umbra, Plage, Quiet-Sun and the Polarity Inversion Line of Active Region 11158 using HMI/SDO Data
Creators: name: Norton, A. A.
name: Stutz, R. B.
name: Welsch, B. T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Using data from the Helioseismic Magnetic Imager, we report on the amplitudes and phase relations of oscillations in quiet-Sun, plage, umbra and the polarity inversion line (PIL) of an active region NOAA$\#$11158. We employ Fourier, wavelet and cross correlation spectra analysis. Waves with 5-minute periods are observed in umbra, PIL and plage with common phase values of $ϕ(v,I)=\fracπ{2}$, $ϕ(v,B_{los})=-\fracπ{2}$. In addition, $ϕ(I,B_{los})=π$ in plage are observed. These phase values are consistent with slow standing or fast standing surface sausage wave modes. The line width variations, and their phase relations with intensity and magnetic oscillations, show different values within the plage and PIL regions, which may offer a way to further differentiate wave mode mechanics. Significant Doppler velocity oscillations are present along the PIL, meaning that plasma motion is perpendicular to the magnetic field lines, a signature of Alvènic waves. A time-distance diagram along a section of the PIL shows Eastward propagating Doppler oscillations converting into magnetic oscillations; the propagation speeds range between 2$-$6 km s$^{-1}$. Lastly, a 3-minute wave is observed in select regions of the umbra in the magnetogram data.
description: 20 pages, 12 figures
NMR-ON studies of europium vanadate and hcp cobalt
Creators: name: Willetts, Martin
Publisher: name: University of British Columbia
Year: 2009

description: The quadrupole interaction on Eu³⁺ in EuVO₄ was investigated using low temperature nuclear orientation. The interaction strength, P, on the ¹⁵²Eu nuclei was measured as 1±4 MHz, with a total cooling time of 24 hours. This low value is attributed to either the high symmetry of the europium lattice postion, or a very long (greater than one day) spin lattice relaxation time. The NMR frequency of ⁵⁹Co was measured at low temperature, using the first observation of thermometric NMR in a conductor. The motive was to measure the frequency pulling in cobalt metal, and the resonance was observed to be 218.4(4) MHz at 70mK, which is 1.5 MHz below the 1 K value. The frequency pulling effect on the nuclear resonance is due to the Suhl-Nakamura interaction between the nuclear spins.
Ζητήματα από την εφαρμογή της Σύμβασης της Βιέννης για τις διεθνείς πωλήσεις κινητών πραγμάτων (CISG): Πεδίο εφαρμογής - Μη ανταπόκριση των πραγμάτων στη σύμβαση πώλησης (Έννοια - Έννομες συνέπειες)
Creators: name: Kanter-BAx, Myron Alexandros (Κάντερ-Μπαξ, Μύρων Αλέξανδρου)
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: διεθνής πώληση
Σύμβαση της Βιέννης
μη ανταπόκριση
international sale
CISG
non conformity

description: Η παρούσα μελέτη αφορά στο νομικό ρυθμιστικό πλαίσιο που διέπει τις διεθνείς πωλήσεις κινητών πραγμάτων και ειδικότερα εστιάζει στο διεθνές ομοιόμορφο δίκαιο που εισάγει η Σύμβαση των Ηνωμένων Εθνών για τις διεθνείς πωλήσεις κινητών πραγμάτων («Σύμβαση της Βιέννης»). Στο πρώτο μέρος της μελέτης αναπτύσσονται ζητήματα που αφορούν στις προϋποθέσεις εφαρμογής της Σύμβασης της Βιέννης, και συγκεκριμένα επιχειρείται η οριοθέτηση τόσο του υποκειμενικού, αντικειμενικού, τοπικού και χρονικού πεδίου εφαρμογής της Σύμβασης όσο και του ρυθμιστικού πεδίου εφαρμογής της. Στο δεύτερο μέρος της μελέτης επιχειρείται ο εννοιολογικός προσδιορισμός της υποχρέωσης του πωλητή για παράδοση στον αγοραστή πραγμάτων που ανταποκρίνονται στις απαιτήσεις της σύμβασης διεθνούς πώλησης, ο σαφής διαχωρισμός και οριοθέτηση του περιεχομένου της υποχρέωσης αυτής έναντι των λοιπών υποχρεώσεων του πωλητή καθώς επίσης και η ένταξη της μη ανταπόκρισης των πραγμάτων στις απαιτήσεις της σύμβασης πώλησης, στο σύστημα συμβατικών παραβάσεων που οικοδομείται αυτόνομα στο πλαίσιο της Σύμβασης.
description: The present thesis deals with the regulatory framework around the international sales of goods in particular with a focus on the international uniform law which is introduced by the United Nations Convention on contracts for the International Sale of Goods («Vienna Convention»). The first part of the present thesis covers issues regarding the requirements for the application of the Vienna Convention, and more specifically an attempt is made to draw the boundaries for the subjective, objective, territiorial and temporal field of application of the Convention as well as the regulative field of its application. In the second part of the present thesis an attempt is made to determine the concept of the obligation of the seller to deliver to the buyer goods which conform with the requirements of the international sale’s contract, to draw the boundaries and make a clear distinction between this obligation’s content and other obligations of the seller and to also include the non-conformity within the system of contractual infringments which is constructed autonomously in the context of the Convention.
String tension and string susceptibility in two-dimensional generalized Weingarten model
Creators: name: Hanada, Masanori
name: Kubo, Fukuichiro
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the two-dimensional generalized Weingarten model reduced to a point, which interpolates reduced Weingarten model and the large-N gauge theory. We calculate the expectation value of the Wilson loop using Monte-Carlo method and determine the string tension and string susceptibility. The numerical result suggests that the string susceptibility approaches to -2 in a certain parametric region, which implies that the branched-polymer configurations are suppressed.
description: 13 pages; typos corrected
$κ-$Minkowski spacetime and a uniformly accelerating observer
Creators: name: Kim, Hyeong-Chan
name: Yee, Jae Hyung
name: Rim, Chaiho
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We analyze the response of a detector with a uniform acceleration $α$ in $κ-$Minkowski spacetime using the first order perturbation theory. The monopole detector is coupled to a massless complex scalar field in such a way that it is sensitive to the Lorentz violation due to the noncommutativity of spacetime present in the $κ-$deformation. The response function deviates from the thermal distribution of Unruh temperature at the order of $1/κ$ and vanishes exponentially as the proper time of the detector exceeds a certain critical time, a logarithmic function of $κ$. This suggests that the Unruh temperature becomes not only fuzzy but also eventually decreases to zero in this model.
description: 13 pages, 2 figures
Superfast Line Profile Variations in the Spectra of OBA Stars III: A0 Star $α^2\,$CVn, New Results
Creators: name: Kholtygin, A. F.
name: Moiseeva, A. V.
name: Yakunin, I A.
name: Hubrig, S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: This work is a continuation of the studies of the ultrafast variability of line profiles in the spectra of early-type stars. Line profile variations (LPVs) in the spectrum a chemically peculiar A0Vp star $α^2\,$CVn are investigated using the January 6, 2020 observations carried out with the 6-meter BTA telescope at Special Astrophysical observatory (SAO) of the Russian Academy of Sciences (RAS) equipped with the MSS spectrograph. Regular short-term periodic variations of the H$_β$, Fe\,II, and Cr\,II lines were detected with periods ranging from $\sim\!$4 to $\sim\!$140 minutes. The magnetic field of the star was determined for all observations. The average measured longitudinal magnetic field component over the entire duration of observations is about $\approx$600\,G, which is close to the value expected from the well-known magnetic field phase curve.
description: 11 pages, 8 figures
Συγκριτική και Περιγραφική Ανάλυση των Μεταφραστικών Επιλογών σε τραγούδια της ταινίας «Μαλλιά Κουβάρια» (Tangled) της Disney.
Creators: name: Γρίβα, Κυριακή Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Μετάφραση τραγουδιών
Μιούζικαλ
Song translation
Disney
Musical

description: Η παρούσα εργασία αποτελεί μια μελέτη περίπτωσης. Σκοπός της είναι να αναλύσει συγκριτικά και περιγραφικά τις μεταφραστικές επιλογές που έκανε η στιχουργός Μυρτώ Κοντοβά κατά τη διασκευή στα ελληνικά των τραγουδιών του μιούζικαλ κινουμένων σχεδίων της Disney «Μαλλιά Κουβάρια» (Tangled). Πρώτα ανιχνεύονται ποσοτικά δέκα στρατηγικές μετάφρασης τραγουδιών μιούζικαλ, όπως αυτές ορίστηκαν από τον Johan Franzon. Τα ποσοτικά στοιχεία συνδυάζονται με τα δεδομένα της συνέντευξης, που παραχώρησε η Μυρτώ Κοντοβά και τις μέχρι τώρα θεωρίες που διέπουν το συγκεκριμένο ζήτημα. Από την ανάλυση όλων των παραπάνω προκύπτουν συμπεράσματα που αφορούν τη διαδικασία μετάφρασης τραγουδιών, τις επικρατέστερες στρατηγικές και τους παράγοντες που επιβάλλουν συγκεκριμένες μεταφραστικές επιλογές.
description: Τhe aim of the present case study is to analyze in a comparative and descriptive way the lyricist’s Myrto Kontova song translating choices in Disney’s cartoon musical "Tangled» . First, ten musical song translation strategies, as identified by Johan Franzon, were detected quantitatively. Quantitative data were combined with the data deriving from the interview given by Myrto Kontova, who adapted the songs of the film in Greek. By the analysis of all the above emerged the results of the study regarding song translation process, the dominant strategies and the factors that impose specific translating choices.
End-to-End Training of CNN Ensembles for Person Re-Identification
Creators: name: Serbetci, Ayse
name: Akgul, Yusuf Sinan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We propose an end-to-end ensemble method for person re-identification (ReID) to address the problem of overfitting in discriminative models. These models are known to converge easily, but they are biased to the training data in general and may produce a high model variance, which is known as overfitting. The ReID task is more prone to this problem due to the large discrepancy between training and test distributions. To address this problem, our proposed ensemble learning framework produces several diverse and accurate base learners in a single DenseNet. Since most of the costly dense blocks are shared, our method is computationally efficient, which makes it favorable compared to the conventional ensemble models. Experiments on several benchmark datasets demonstrate that our method achieves state-of-the-art results. Noticeable performance improvements, especially on relatively small datasets, indicate that the proposed method deals with the overfitting problem effectively.
A Computational Approach to Measuring the Semantic Divergence of Cognates
Creators: name: Uban, Ana-Sabina
name: Ciobanu, Alina-Maria
name: Dinu, Liviu P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Meaning is the foundation stone of intercultural communication. Languages are continuously changing, and words shift their meanings for various reasons. Semantic divergence in related languages is a key concern of historical linguistics. In this paper we investigate semantic divergence across languages by measuring the semantic similarity of cognate sets in multiple languages. The method that we propose is based on cross-lingual word embeddings. In this paper we implement and evaluate our method on English and five Romance languages, but it can be extended easily to any language pair, requiring only large monolingual corpora for the involved languages and a small bilingual dictionary for the pair. This language-agnostic method facilitates a quantitative analysis of cognates divergence -- by computing degrees of semantic similarity between cognate pairs -- and provides insights for identifying false friends. As a second contribution, we formulate a straightforward method for detecting false friends, and introduce the notion of "soft false friend" and "hard false friend", as well as a measure of the degree of "falseness" of a false friends pair. Additionally, we propose an algorithm that can output suggestions for correcting false friends, which could result in a very helpful tool for language learning or translation.
On the Thermodynamic Geometry of BTZ Black Holes
Creators: name: Sarkar, Tapobrata
name: Sengupta, Gautam
name: Tiwari, Bhupendra Nath
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the Ruppeiner geometry of the thermodynamic state space of a general class of BTZ black holes. It is shown that the thermodynamic geometry is flat for both the rotating BTZ and the BTZ Chern Simons black holes in the canonical ensemble. We further investigate the inclusion of thermal fluctuations to the canonical entropy of the BTZ Chern Simons black holes and show that the leading logartithmic correction due to Carlip is reproduced. We establish that the inclusion of thermal fluctuations induces a non zero scalar curvature to the thermodynamic geometry.
description: 1+17 pages, LaTeX, 4 eps figures
Simulation of non-radiative energy transfer in photosynthetic systems using a quantum computer
Creators: name: Guimarães, José Diogo
name: Tavares, Carlos
name: Barbosa, Luís Soares
name: Vasilevskiy, Mikhail I.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Biological Physics (physics.bio-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Photosynthesis is an important and complex physical process in nature, whose comprehensive understanding would have many relevant industrial applications, for instance in the field of energy production. In this paper we propose a quantum algorithm for the simulation of the excitonic transport of energy, occurring in the first stage of the process of photosynthesis. The algorithm takes in account the quantum and environmental effects (pure-dephasing), influencing the quantum transport. We performed quantum simulations of such phenomena, for a proof of concept scenario, in an actual quantum computer the IBM Q, of 5 qubits. We validate the results with the Haken-Ströbl model and discuss the influence of environmental parameters on the efficiency of the energy transport.
Δομική και Πολιτισμική Βία στο έργο του J. Galtung: Διερεύνηση της ερμηνείας των όρων από την Ελληνική εκπαιδευτική κοινότητα
Creators: name: Καπετανίδου, Μαριάνα Νικολάου
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: βία
παιδαγωγική της Ειρήνης
μετάφραση κειμένων κοινωνικών επιστημών
violence
pedagogy of Peace
social sciences texts translation

description: Η παρούσα διπλωματική εργασία έχει διεπιστημονικό χαρακτήρα. Μέσω της μετάφρασης στοχεύεται να παρουσιαστούν και να διευκρινιστούν οι όροι της «δομικής» και «πολιτισμικής» βίας, σύμφωνα με την τυπολογία της βίας του J. Galtung, οι οποίοι αποτελούν βασικούς όρους της Έρευνας για την Ειρήνη και της Παιδαγωγικής της Ειρήνης. Παράλληλα διερευνάται κατά πόσο οι όροι αυτοί είναι γνωστοί σε δείγμα 119 ελλήνων/ίδων εκπαιδευτικών, 91 μαθητών/ριών γυμνασίου και 110 μαθητών/ριών λυκείου και πώς ερμηνεύονται. Στο πρώτο μέρος αφού παρουσιάζεται η έννοια της ειρήνης και οι μορφές της βίας, γίνεται εκτενή αναφορά στην Έρευνα για την Ειρήνη, την Παιδαγωγική της Ειρήνης και τη μεταφραστική διαδικασία. Το δεύτερο μέρος είναι αφιερωμένο στη μεθοδολογία, τα αποτελέσματα και τα συμπεράσματα της έρευνας για την αναγνώριση και ερμηνεία των όρων από την ελληνική εκπαιδευτική κοινότητα. Στο τρίτο μέρος παρατίθεται σε δίστηλο η μετάφραση, από την αγγλική στην ελληνική γλώσσα, των δύο άρθρων του J. Galtung «Βία, Ειρήνη, και Έρευνα της Ειρήνης» (1969) και «Πολιτισμική βία» (1990).
description: The present thesis has an interdisciplinary character. Through translation is aimed to be presented and clarified the terms of "structural" and "cultural" violence, according to J. Galtung’s typology of violence, which are key terms of the Peace Research and Peace Education. At the same time it is researched whether these terms are known to a sample of 119 Greek educators, 91 pupils of middle school and 110 pupils of high school and how they are interpreted. In the first part are presented the concept of peace and the types of violence, followed by an extensive reference to the Peace Research, the Pedagogy of Peace and the translation process. The second part is dedicated to the methodology, the results and the conclusions of the research on the terms “structural” and “cultural” violence in the Greek educational community. In the third part we meet in a two columns presentation the translation, from English to Greek language, of J. Galtung’s two articles “Violence, Peace and Peace Research" (1969) and "Cultural Violence" (1990).
u-Deformed WZW Model and Its Gauging
Creators: name: Klimcik, Ctirad
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 81T40

description: We review the description of a particular deformation of the WZW model. The resulting theory exhibits a Poisson-Lie symmetry with a non-Abelian cosymmetry group and can be vectorially gauged.
description: This is a contribution to the Proc. of the O'Raifeartaigh Symposium on Non-Perturbative and Symmetry Methods in Field Theory (June 2006, Budapest, Hungary), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/