cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fast simulations of extragalactic microlensing
Creators: name: Shalyapin, V. N.
name: Gil-Merino, R.
name: Goicoechea, L. J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We present a new and very fast method for producing microlensing magnification maps at high optical depths. It is based on the combination of two approaches: (a) the two-dimensional Poisson solver for a deflection potential and (b) inverse polygon mapping. With our method we extremely reduce the computing time for the generation of magnification patterns and avoid the use of highly demanding computer resources. For example, the generation of a magnification map of size 2000 x 2000 pixels, covering a region of 20 Einstein radii, takes a few seconds on a state-of-the-art laptop. The method presented here will facilitate the massive production of magnification maps for extragalactic microlensing studies within the forthcoming surveys without the need for large computer clusters. The modest demand of computer power and a fast execution time allow the code developed here to be placed on a standard server and thus provide the public online access through a web-based interface.
description: A&A in press (7 pages, 3 figures)
title: Putting the Quantum to Work: Otto Sackur’s Pioneering Exploits in the Quantum Theory of Gases
Creators: name: Badino, Massimiliano
name: Friedrich, Bretislav
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 3.1 Biographical Overview
3.2 The Problem of Chemical Equilibrium
3.3 The Beginnings of the Quantum Theory of Gases
3.4 Sackur’s “Elementary Regions”
3.5 The Generalization of Sackur’s Statistical Theory
3.6 Conclusion
References
Footnotes
Note on operadic harmonic oscillator
Creators: name: Paal, Eugen
name: Virkepu, Jyri
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 18D50, 70G60

description: It is explained how the time evolution of the operadic variables may be introduced. As an example, an operadic Lax representation of the harmonic oscillator is considered.
description: LaTeX2e, 6 pages, no figures
Driving Around Los Santos: Space, Place, and Place-making in Grand Theft Auto V
Creators: name: Neuner, Alyssa Marie
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: American studies
subject: games studies
subject: mapping
subject: place
subject: placemaking
subject: space

description: With the emergence of videogames came an exodus to the digital worlds created within them. To understand this shift is to understand the human needs they have come to fulfill. One of these basic human necessities is having a sense of place. Here Grand Theft Auto V becomes one game in a slew of game titles to foster this need.
A new method incorporating deep learning with shape priors for left ventricular segmentation in myocardial perfusion SPECT images
Creators: name: Zhu, Fubao
name: Zhao, Jinyu
name: Zhao, Chen
name: Tang, Shaojie
name: Nan, Jiaofen
name: Li, Yanting
name: Zhao, Zhongqiang
name: Shi, Jianzhou
name: Chen, Zenghong
name: Jiang, Zhixin
name: Zhou, Weihua
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Background: The assessment of left ventricular (LV) function by myocardial perfusion SPECT (MPS) relies on accurate myocardial segmentation. The purpose of this paper is to develop and validate a new method incorporating deep learning with shape priors to accurately extract the LV myocardium for automatic measurement of LV functional parameters. Methods: A segmentation architecture that integrates a three-dimensional (3D) V-Net with a shape deformation module was developed. Using the shape priors generated by a dynamic programming (DP) algorithm, the model output was then constrained and guided during the model training for quick convergence and improved performance. A stratified 5-fold cross-validation was used to train and validate our models. Results: Results of our proposed method agree well with those from the ground truth. Our proposed model achieved a Dice similarity coefficient (DSC) of 0.9573(0.0244), 0.9821(0.0137), and 0.9903(0.0041), a Hausdorff distances (HD) of 6.7529(2.7334) mm, 7.2507(3.1952) mm, and 7.6121(3.0134) mm in extracting the endocardium, myocardium, and epicardium, respectively. Conclusion: Our proposed method achieved a high accuracy in extracting LV myocardial contours and assessing LV function.
description: 21 pages, 14 figures
Vegetation-Hydrodynamic Interactions and the Stability of Channel Inlets of Tidal Freshwater Wetlands, Chesapeake Bay System
Creators: name: Statkiewicz, Anna
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Geomorphology
subject: Environmental geology
subject: Water resources management
subject: Aquatic Vegetation
subject: Chesapeake Bay
subject: Geomorphology
subject: Marsh
subject: Shear Stress
subject: Tidal Freshwater Wetlands

description: To maintain elevation, deposition of mineral and organic sediment in tidal freshwater wetlands (TFWs) must outweigh losses due to sea-level rise, erosion, decomposition, and compaction. Sediment loads into tidal marshes are controlled by inlet size and sediment supply, but interactions among vegetation, hydraulics, and geomorphology affect sediment retention. This study focused on these interactions in TFW inlets partially covered by aquatic vegetation (N.luteum, Z.aquatica, and H.verticullata). Measurements of hydraulic parameters and geomorphic change were correlated with observations of spatial and morphological characteristics for each vegetation type. The aquatic plants grew in significantly different water depths and well-defined platforms formed in areas occupied by emergent vegetation where effective shear stress is lowest. Net annual accretion data indicate an inverse relationship between maximum inlet depth and accretion rate. These results suggest that initial vegetation colonization modifies channel inlet morphology; both vegetation and morphology generate the shear stress distributions, which maintain channel form.
title: The Concepts of Light Atoms and Light Molecules and Their Final Interpretation
Creators: name: Fick, Dieter
name: Kant, Horst
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 4.1 First Corpuscular Concepts of Light
4.2 Light Molecules, Static Concepts
4.3 Dynamical Treatments of Light Multiples
4.4 Obituary
Appendix
Abbreviations and Archives
Acknowledgements
References
Footnotes
title: Early Interactions of Quantum Statistics and Quantum Mechanics
Creators: name: Monaldi, Daniela
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 5.1 The Birth of Quantum Statistics
5.2 Heisenberg’s Many-body Problem and Quantum Resonance
5.3 Dirac’s “On the Theory of Quantum Mechanics”
5.4 Conclusion
Abbreviations and Archives
References
Footnotes
title: Pourparlers for Amalgamation: Some Early Sources of Quantum Gravity Research
Creators: name: Rickles, Dean
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 6.1 The Torch of Unification: Mie, Hilbert, Weyl and Haas
6.2 Einstein on the Relationship between Gravity and Quantum
6.3 Quantum Meets Gravity in the Pages of Nature
6.4 On the Way to Quantum Geometry
6.5 Conclusion
Abbreviations and Archives
Acknowledgements
References
Footnotes
title: Superposing Dynamos and Electrons: Electrical Engineering and Quantum Physics in the Case of Nishina Yoshio
Creators: name: Ito, Kenji
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 7.1 Engineering in Japan
7.2 Nishina Yoshio as an Engineering Student
7.3 The Klein-Nishina Formula
7.4 Superposition of States in the Klein-Nishina Paper
7.5 Conclusion
Acknowledgements
References
Footnotes
Measurement of the complete nuclide production and kinetic energies of the system 136Xe + hydrogen at 1 GeV per nucleon
Creators: name: Napolitani, P.
name: Schmidt, K. -H.
name: Tassan-Got, L.
name: Armbruster, P.
name: Enqvist, T.
name: Heinz, A.
name: Henzl, V.
name: Henzlova, D.
name: Kelic, A.
name: Pleskac, R.
name: Ricciardi, M. V.
name: Schmitt, C.
name: Yordanov, O.
name: Audouin, L.
name: Bernas, M.
name: Lafriaskh, A.
name: Rejmund, F.
name: Stephan, C.
name: Benlliure, J.
name: Casarejos, E.
name: Ordonez, M. Fernandez
name: Pereira, J.
name: Boudard, A.
name: Fernandez, B.
name: Leray, S.
name: Villagrasa, C.
name: Volant, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present an extensive overview of production cross sections and kinetic energies for the complete set of nuclides formed in the spallation of 136Xe by protons at the incident energy of 1 GeV per nucleon. The measurement was performed in inverse kinematics at the FRagment Separator (GSI, Darmstadt). Slightly below the Businaro-Gallone point, 136Xe is the stable nuclide with the largest neutron excess. The kinematic data and cross sections collected in this work for the full nuclide production are a general benchmark for modelling the spallation process in a neutron-rich nuclear system, where fission is characterised by predominantly mass-asymmetric splits.
description: 18 pages, 14 figures
title: The Origins of Maria Göppert’s Dissertation on Two-Photon Quantum Transitions at Göttingen’s Institutes of Physics 1920-1933
Creators: name: Masters, Barry R.
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 8.1 Physics in Germany at the Beginning of the Twentieth Century and the Development of the Institutes of Physics at the University of Göttingen
8.2 Göppert as a University and Doctoral Student
8.3 What Was the Role of Paul Dirac in Göppert’s Dissertation Research?
8.4 Reconstruction of Göppert’s Göttingen Dissertation
8.5 What Was Known and What Did Göppert Contribute in Her Dissertation Research?
8.6 Conclusion
Acknowledgements
References
Footnotes
title: An Act of Creation: The Meitner-Frisch Interpretation of Nuclear Fission
Creators: name: Stuewer, Roger H.
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 9.1 The Birth of the Liquid-Drop Model
9.2 The Extension of the Liquid-Drop Model: Heisenberg and von Weizsäcker
9.3 Bohr’s Theory of the Compound Nucleus
9.4 The Interpretation of Fission
9.5 Aftermath
9.6 Conclusion
Abbreviations and Archives
References
Footnotes
ИДЕНТИФИКАЦИОННЫЕ ХАРАКТЕРИСТИКИ АРХИТЕКТУРЫ КРОНШТАДТА
Creators: name: СЛЕПЧЕНКО А.Л.
Publisher: name: Международный журнал гуманитарных и естественных наук
Year: 2020
Subjects: КОНСТРУКТИВИЗМ
КОНСТРУКТИВИСТЫ
СОВРЕМЕННАЯ АРХИТЕКТУРА
ЖИЛАЯ АРХИТЕКТУРА
ПЕРЕОСМЫСЛЕНИЕ НАСЛЕДИЯ
CONSTRUCTIVISM
CONSTRUCTIVISTS
MODERN ARCHITECTURE
RESIDENTIAL ARCHITECTURE
RETHINKING HERITAGE

description: Данная статья посвящена изучению характерных особенностей городской среды города Кронштадта. Определены факторы, повлиявшие на формирование городской среды Кронштадта и предопределившие путь города на много лет вперёд. Проанализированы факторы, повлиявшие на архитектуру Кронштадта и его типологию. Выявлены идентификационные характеристики застройки и архитектуры города, проведен анализ городской среды и определены характерные особенности, создающие уникальную архитектуру Кронштадта.
COAST: COntrollable Arbitrary-Sampling NeTwork for Compressive Sensing
Creators: name: You, Di
name: Zhang, Jian
name: Xie, Jingfen
name: Chen, Bin
name: Ma, Siwei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Recent deep network-based compressive sensing (CS) methods have achieved great success. However, most of them regard different sampling matrices as different independent tasks and need to train a specific model for each target sampling matrix. Such practices give rise to inefficiency in computing and suffer from poor generalization ability. In this paper, we propose a novel COntrollable Arbitrary-Sampling neTwork, dubbed COAST, to solve CS problems of arbitrary-sampling matrices (including unseen sampling matrices) with one single model. Under the optimization-inspired deep unfolding framework, our COAST exhibits good interpretability. In COAST, a random projection augmentation (RPA) strategy is proposed to promote the training diversity in the sampling space to enable arbitrary sampling, and a controllable proximal mapping module (CPMM) and a plug-and-play deblocking (PnP-D) strategy are further developed to dynamically modulate the network features and effectively eliminate the blocking artifacts, respectively. Extensive experiments on widely used benchmark datasets demonstrate that our proposed COAST is not only able to handle arbitrary sampling matrices with one single model but also to achieve state-of-the-art performance with fast speed. The source code is available on https://github.com/jianzhangcs/COAST.
description: Published in IEEE Transactions on Image Processing, 2021
title: Tsung-Sui Chang’s Contribution to the Quantization of Constrained Hamiltonian Systems
Creators: name: Yin, Xiaodong
name: Zhu, Zhongyuan
name: Salisbury, Donald C.
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 10.1 Biographical Overview
10.2 Studies on Constrained Hamiltonian Systems before Chang’s Work
10.3 Chang’s Contributions to Hamiltonian Systems
10.4 Conclusion
Abbreviations and Archives
Acknowledgements
List of Chang’s Publications
References
Footnotes
Proton Radiography in Background Magnetic Fields
Creators: name: Arran, Christopher
name: Ridgers, Christopher P.
name: Woolsey, Nigel C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Proton radiography has proved increasingly successful as a diagnostic for electric and magnetic fields in high energy density physics experiments. Most experiments use target-normal-sheath-acceleration sources with a wide energy range in the proton beam, as the velocity spread can help differentiate between electric and magnetic fields and provide time histories in a single shot. However, in magnetised plasma experiments with strong background fields, the broadband proton spectrum leads to velocity-spread-dependent displacement of the beam and significant blurring of the radiograph. We describe the origins of this blurring and show how it can be removed from the experimental measurement, and we outline the conditions under which such deconvolutions are successful. As an example, we apply this method to a magnetised plasma experiment that used a background magnetic field of 3 T. The strong displacement and energy spread of the proton beam reduced the spatial resolution from tens of microns to a few millimetres. The deconvolution procedure is applied showing the accurate recovery of radiographs with resolutions better than 100 microns, enabling the recovery of more accurate estimates of the path integrated magnetic field. This work extends accurate proton radiography to a class of experiments with significant background magnetic fields, particularly those experiments with an applied external magnetic field.
ХУДОЖЕСТВЕННО-КОМПОЗИЦИОННЫЕ АСПЕКТЫ ЕСТЕСТВЕННОГО ОСВЕЩЕНИЯ В АРХИТЕКТУРЕ
Creators: name: СЛЕПЧЕНКО А.Л.
Publisher: name: Международный журнал гуманитарных и естественных наук
Year: 2020
Subjects: ЕСТЕСТВЕННЫЙ СВЕТ
АРХИТЕКТУРА
ИСТОРИЯ
СВЕТОТЕНЬ
ПРОСТРАНСТВО
NATURAL LIGHT
ARCHITECTURE
HISTORY
CHIAROSCURO
SPACE

description: Данная статья посвящена изучению использования естественного света как архитектурного приёма. Изучено влияние света на архитектуру на протяжении всей истории, определена взаимосвязь философских аспектов, религии и мировоззренческих взглядов в определенные исторические периоды и архитектурных приёмов с использованием естественного освещения. Рассмотрена эволюция теоретических знаний в понимании роли естественного света в архитектуре, этапы ее формирования с точки зрения использования естественного света.
ПРОБЛЕМА СООТНОШЕНИЯ ВЕРЫ И РАЗУМА В СРЕДНЕВЕКОВОЙ ФИЛОСОФИИ
Creators: name: БОЙКО О.А.
Publisher: name: Международный журнал гуманитарных и естественных наук
Year: 2020
Subjects: СРЕДНЕВЕКОВАЯ ФИЛОСОФИЯ
ВЕРА
РАЗУМ
ФИЛОСОФИЯ ПАТРИСТИКИ
ФИЛОСОФИЯ СХОЛАСТИКИ
MEDIEVAL PHILOSOPHY
FAITH
REASON
PATRISTIC PHILOSOPHY
SCHOLASTIC PHILOSOPHY

description: В статье анализируется понимание средневековыми философами соотношения веры и разума. Автор рассматривает размышления таких представителей философии патристики, как Климент Александрийский, Ориген, Тертуллиан, Аврелий Августин. Также затрагивается содержание сочинений Ареопагитического корпуса. Обращаясь к философии схоластики, автор останавливается на идеях Абеляра, Фомы Аквинского, Дунса Скота и Уильяма Оккама. На примере учений этих ярких мыслителей выявляются основные варианты решения поставленной проблемы, определяется доминирующая установка в её решении.
On Strategic Measures and Optimality Properties in Discrete-Time Stochastic Control with Universally Measurable Policies
Creators: name: Yu, Huizhen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 90C40, 93E20, 60J05

description: This paper concerns discrete-time infinite-horizon stochastic control systems with Borel state and action spaces and universally measurable policies. We study optimization problems on strategic measures induced by the policies in these systems. The results are then applied to risk-neutral and risk-sensitive Markov decision processes, as well as their partially observable counterparts, to establish the measurability of the optimal value functions and the existence of universally measurable, randomized or nonrandomized, $ε$-optimal policies, for a variety of average cost criteria and risk criteria. We also extend our analysis to a class of minimax control problems and establish similar optimality results under the axiom of analytic determinacy.
description: 37 pages. This version corrects minor typos. Some of the results in this work are improvements of the author's earlier results given in Section 3.1 of arXiv:2104.00181v1. A shorter version of this paper is to be published in the journal Mathematics of Operations Research
Τουριστική Ανάπτυξη και Επισκεψιμότητα του Εθνικού Πάρκου Βόρειας Πίνδου Νομού Γρεβενών
Creators: name: Παρδάλης, Κωνσταντίνος Μιχαήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2025
Subjects: Εθνικό Πάρκο
Τουριστική Ανάπτυξη
Επισκεψιμότητα
National Park
Tourism Developmen
Visitation

description: Σκοπός της έρευνας είναι η ανάδειξη της επισκεψιμότητας και της τουριστικής ανάπτυξης του Εθνικού Πάρκου Βόρειας Πίνδου. Επιπλέον στόχος της είναι να αναδείξει προβλήματα και ελλείψεις της περιοχής, για να γνωστοποιηθούν στο ευρύ επιστημονικό αλλά και γενικότερα στο κοινό, προκειμένου να αντιμετωπιστούν από την πολιτεία και την επιστημονική κοινότητα οι παρούσες ελλείψεις , και να αναβαθμιστεί τουριστικά η περιοχή με σεβασμό πάντα προς το περιβάλλον.
description: The purpose of the research is to highlight the visitor numbers and tourism development of the Northern Pindos National Park. In addition, its goal is to highlight problems and shortcomings of the area, in order to make them known to the wider scientific community and the public in general, in order for the state and the scientific community to address the current shortcomings, and to upgrade the area in terms of tourism, always with respect for the environment.
title: Feynman’s Struggle and Dyson’s Surprise: The Development and Early Application of a New Means of Representation
Creators: name: Wüthrich, Adrian
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 11.1 Development, Modern Application and Interpretation of Feynman Diagrams
11.2 Feynman’s Struggle for a Physical Interpretation of the Dirac Equation
11.3 Zitterbewegung
11.4 Positrons and Interaction
11.5 Abandoning the Search for a Microscopic Analysis
11.6 Solution to the Problems through an Appropriate Representation of the Phenomena
11.7 Comparison to Other Developments of Concepts and Means of Representation
Abbreviations and Archives
Acknowledgements
References
Footnotes
title: Orthodoxies on the Interpretation of Quantum Theory: The Case of the Consistent History Approach
Creators: name: Freire, Olival
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 12.1 Orthodoxies and Heterodoxies in Quantum Physics
12.2 The Polysemic New Orthodoxy
12.3 The Consistent History Approach and Its Rhetorical Resources
12.4 The Reception of the Consistent History Approach
12.5 Conclusion
Abbreviations and Archives
Acknowledgements
References
Footnotes
Magnetic field induced singlet - triplet phase transition in quasi one-dimensional organic superconductors
Creators: name: Belmechri, N.
name: Abramovici, G.
name: Heritier, M.
name: Haddad, S.
name: Kaddour, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We propose a theoretical model of quasi-one-dimensional superconductors, with attractive electron-electron interactions dominant in the singlet d-wave channel and sub-dominant in the p-wave channel. We discuss, in the mean field approximation, the effect of a magnetic field applied perpendicularly to the direction of the lowest conductivity. The lowest free energy phase corresponds to a singlet d-wave symmetry in low fields, but to a triplet symmetry in high fields. A first order singlet-triplet phase transition is expected at moderate applied fields of a few teslas. We propose to ascribe the recent critical field and NMR experimental data, observed in superconducting (TMTSF)2ClO4 to such an effect.
description: 6 pages, 2 figures, accepted in EPL
GIRGENSOHNIA DIPTERA BUNGE O'SIMLIGI VA UNING KIMYOVIY TARKIBI
Creators: name: Akramova, Zuhraxon
name: Ismoilov, Muminjon
Publisher: name: Zenodo
Year: 2025

description: Ushbu ilmiy ishda Girgensohnia diptera Bunge o’simligining bilogik tafsifi va kimyoviy tarkibi haqida ma’lumot beriladi.
Semantic Detection of Potential Wind-borne Debris in Construction Jobsites: Digital Twining for Hurricane Preparedness and Jobsite Safety
Creators: name: Kamari, Mirsalar
name: Ham, Youngjib
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: In the United States, hurricanes are the most devastating natural disasters causing billions of dollars worth of damage every year. More importantly, construction jobsites are classified among the most vulnerable environments to severe wind events. During hurricanes, unsecured and incomplete elements of construction sites, such as scaffoldings, plywoods, and metal rods, will become the potential wind-borne debris, causing cascading damages to the construction projects and the neighboring communities. Thus, it is no wonder that construction firms implement jobsite emergency plans to enforce preparedness responses before extreme weather events. However, relying on checklist-based emergency action plans to carry out a thorough hurricane preparedness is challenging in large-scale and complex site environments. For enabling systematic responses for hurricane preparedness, we have proposed a vision-based technique to identify and analyze the potential wind-borne debris in construction jobsites. Building on this, this paper demonstrates the fidelity of a new machine vision-based method to support construction site hurricane preparedness and further discuss its implications. The outcomes indicate that the convenience of visual data collection and the advantages of the machine vision-based frameworks enable rapid scene understanding and thus, provide critical heads up for practitioners to recognize and localize the potential wind-borne derbies in construction jobsites and effectively implement hurricane preparedness.
description: This paper has been accepted in i3CE(2021) conference
Electron-electron interaction effects on the photophysics of metallic single-walled carbon nanotubes
Creators: name: Wang, Zhendong
name: Psiachos, Demetra
name: Badilla, Roberto F.
name: Mazumdar, Sumit
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Single-walled carbon nanotubes are strongly correlated systems with large Coulomb repulsion between two electrons occupying the same $p_z$ orbital. Within a molecular Hamiltonian appropriate for correlated $π$-electron systems, we show that optical excitations polarized parallel to the nanotube axes in the so-called metallic single-walled carbon nanotubes are to excitons. Our calculated absolute exciton energies in twelve different metallic single-walled carbon nanotubes, with diameters in the range 0.8 - 1.4 nm, are in nearly quantitative agreement with experimental results. We have also calculated the absorption spectrum for the (21,21) single-walled carbon nanotube in the E$_{22}$ region. Our calculated spectrum gives an excellent fit to the experimental absorption spectrum. In all cases our calculated exciton binding energies are only slightly smaller than those of semiconducting nanotubes with comparable diameters, in contradiction to results obtained within the {\it ab initio} approach, which predicts much smaller binding energies. We ascribe this difference to the difficulty of determining the behavior of systems with strong on-site Coulomb interactions within theories based on the density functional approach. As in the semiconducting nanotubes we predict in the metallic nanotubes a two-photon exciton above the lowest longitudinally polarized exciton that can be detected by ultrafast pump-probe spectroscopy. We also predict a subgap absorption polarized perpendicular to the nanotube axes below the lowest longitudinal exciton, blueshifted from the exact midgap by electron-electron interactions.
The potential for Earth-mass planet formation around brown dwarfs
Creators: name: Payne, Matthew J.
name: Lodato, Giuseppe
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent observations point to the presence of structured dust grains in the discs surrounding young brown dwarfs, thus implying that the first stages of planet formation take place also in the sub-stellar regime. Here, we investigate the potential for planet formation around brown dwarfs and very low mass stars according to the sequential core accretion model of planet formation. We find that, for a brown dwarfs of mass 0.05M_{\odot}, our models predict a maximum planetary mass of ~5M_{\oplus}, orbiting with semi-major axis ~1AU. However, we note that the predictions for the mass - semi-major axis distribution are strongly dependent upon the models chosen for the disc surface density profiles and the assumed distribution of disc masses. In particular, if brown dwarf disc masses are of the order of a few Jupiter masses, Earth-mass planets might be relatively frequent, while if typical disc masses are only a fraction of Jupiter mass, we predict that planet formation would be extremely rare in the sub-stellar regime. As the observational constraints on disc profiles, mass dependencies and their distributions are poor in the brown dwarf regime, we advise caution in validating theoretical models only on stars similar to the Sun and emphasise the need for observational data on planetary systems around a wide range of stellar masses. We also find that, unlike the situation around solar-like stars, Type-II migration is totally absent from the planet formation process around brown dwarfs, suggesting that any future observations of planets around brown dwarfs would provide a direct measure of the role of other types of migration.
description: 11 pages, accepted for publication in MNRAS
KitBit: A New AI Model for Solving Intelligence Tests and Numerical Series
Creators: name: Corsino, Víctor
name: Gilpérez, José Manuel
name: Herrera, Luis
Publisher: name: arXiv
Year: 2022
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The resolution of intelligence tests, in particular numerical sequences, has been of great interest in the evaluation of AI systems. We present a new computational model called KitBit that uses a reduced set of algorithms and their combinations to build a predictive model that finds the underlying pattern in numerical sequences, such as those included in IQ tests and others of much greater complexity. We present the fundamentals of the model and its application in different cases. First, the system is tested on a set of number series used in IQ tests collected from various sources. Next, our model is successfully applied on the sequences used to evaluate the models reported in the literature. In both cases, the system is capable of solving these types of problems in less than a second using standard computing power. Finally, KitBit's algorithms have been applied for the first time to the complete set of entire sequences of the well-known OEIS database. We find a pattern in the form of a list of algorithms and predict the following terms in the largest number of series to date. These results demonstrate the potential of KitBit to solve complex problems that could be represented numerically.
description: 11 pages
Rabi oscillations and photocurrent in quantum-dot tunnelling junctions
Creators: name: Fainberg, Boris
name: Nitzan, Abraham
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Motivated by the experiments by Zrenner et al. [Nature 418, 612 (2002)], we study the influence of relaxation processes on converting Rabi oscillations in a strongly biased single-quantum-dot photodiode into deterministic photocurrents. We show that the behavior of a quantum dot with different tunnel rates for electron and holes is qualitatively different from that with the equal tunnel rates: in the latter case the current shows attenuating oscillations with the Rabi frequency. In contrast, for different electrons and holes tunnelling rates, the frequency of these oscillations diminishes, and they disappear beyond a definite asymmetry threshold. We give an analytical solution of the problem and a numerical example showing a different behaviour of the transferred charge in the small attenuation limit for equal and different tunnel rates for electrons and holes.
description: 4 pages, two figures. Physica Status Solidi, in press
Thick GEM versus thin GEM in two-phase argon avalanche detectors
Creators: name: Bondar, A.
name: Buzulutskov, A.
name: Grebenuk, A.
name: Pavlyuchenko, D.
name: Tikhonov, Y.
name: Breskin, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The performance of thick GEMs (THGEMs) was compared to that of thin GEMs in two-phase Ar avalanche detectors, in view of their potential application in coherent neutrino-nucleus scattering, dark-matter search and in other rare-event experiments. The detectors comprised a 1 cm thick liquid-Ar layer followed by either a double-THGEM or a triple-GEM multiplier, operated in the saturated vapor above the liquid phase. Three types of THGEMs were studied: those made of G10 and Kevlar and that with resistive electrodes (RETHGEM). Only the G10-made THGEM showed a stable performance in two-phase Ar with gains reaching 3000. Successful operation of two-phase Ar avalanche detectors with either thin- or thick-GEM multipliers was demonstrated at low detection thresholds, of 4 and 20 primary electrons respectively. Compared to the triple-GEM the double-THGEM multiplier yielded slower anode signals; this allowed applying a pulse-shape analysis to effectively reject noise signals. Noise rates of both multipliers were evaluated in two-phase Ar; with detection thresholds of 20 electrons and applying pulse-shape analysis noise levels as low as 0.007 Hz per 1 cm2 of active area were reached.
description: 11 pages, 19 figures. Submitted to JINST
Spherically symmetric problem on the brane and galactic rotation curves
Creators: name: Viznyuk, Alexander
name: Shtanov, Yuri
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the braneworld model with induced gravity to clarify the role of the cross-over length scale \ell in the possible explanation of the dark-matter phenomenon in astrophysics and in cosmology. Observations of the 21 cm line from neutral hydrogen clouds in spiral galaxies reveal that the rotational velocities remain nearly constant at a value v_c ~ 10^{-3}--10^{-4} in the units of the speed of light in the region of the galactic halo. Using the smallness of v_c, we develop a perturbative scheme for reconstructing the metric in a galactic halo. In the leading order of expansion in v_c, at the distances r \gtrsim v_c \ell, our result reproduces that obtained in the Randall-Sundrum braneworld model. This inequality is satisfied in a real spiral galaxy such as our Milky Way for distances r ~ 3 kpc, at which the rotational velocity curve becomes flat, v_c ~ 7 \times 10^{-4}, if \ell \lesssim 2 Mpc. The gravitational situation in this case can be approximately described by the Einstein equations with the so-called Weyl fluid playing the role of dark matter. In the region near the gravitating body, we derive a closed system of equations for static spherically symmetric situation under the approximation of zero anisotropic stress of the Weyl fluid. We find the Schwarzschild metric to be an approximate vacuum solution of these equations at distances r \lesssim (r_g \ell^2)^{1/3}. The value \ell \lesssim 2 Mpc complies well with the solar-system tests. At the same time, in cosmology, a low-density braneworld with \ell of this order of magnitude can mimic the expansion properties of the high-density LCDM (lambda + cold dark matter) universe at late times. Combined observations of galactic rotation curves and gravitational lensing can possibly discriminate between the higher-dimensional effects and dark matter.
description: 29 pages, text slightly revised, references added, version to be published in PRD
A low energy neutrino factory with non-magnetic detectors
Creators: name: Huber, Patrick
name: Schwetz, Thomas
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We show that a very precise neutrino/anti-neutrino event separation is not mandatory to cover the physics program of a low energy neutrino factory and thus non-magnetized detectors like water Cerenkov or liquid Argon detectors can be used. We point out, that oscillation itself strongly enhances the signal to noise ratio of a wrong sign muon search, provided there is sufficiently accurate neutrino energy reconstruction. Further, we argue that apart from a magnetic field, other means to distinguish neutrino from anti-neutrino events (at least statistically) can be explored. Combined with the fact that non-magnetic detectors potentially can be made very big, we show that modest neutrino/anti-neutrino separations at the level of 50% to 90% are sufficient to obtain good sensitivity to CP violation and the neutrino mass hierarchy for $\sin^22θ_{13}>10^{-3}$. These non-magnetized detectors have a rich physics program outside the context of a neutrino factory, including topics like supernova neutrinos and proton decay. Hence, our observation opens the possibility to use a multi-purpose detector also in a neutrino factory beam.
description: 13 pages, 4 figures, discussion improved, new figure 4, version to appear in PLB
Constraints on Unparticle Physics from Solar and KamLAND Neutrinos
Creators: name: Anchordoqui, Luis
name: Goldberg, Haim
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Interest has been directed recently towards low energy implications of a non-trivial conformal sector of an effective field theory with an IR fixed point (Λ), manifest in terms of ``unparticles'' with bizarre properties. We re-examine the implications of the limits on decay lifetimes of solar neutrinos for unparticle interactions. We study in detail the fundamental parameter space (Λ, M) and derive bounds on the energy scale M characterizing the new physics. We work strictly within the framework where conformal invariance holds down to low energies. We first assume that couplings of the unparticle sector to the Higgs field are suppressed and derive bounds with Λin the TeV region from neutrino decay into scalar unparticles. These bounds are significant for values of the anomalous dimension of the unparticle operator 1.0 < d < 1.2. For a region of the parameter space, we show that the bounds are comparable to those arising from production rates at high energy colliders. We then relax our assumption, by considering a more natural framework which does not require a priori restrictions on couplings of Higgs-unparticle operators, and derive bounds with Λin meV region from neutrino decay into vector unparticles. Such low scales for the IR fixed point are relevant in gauge theories with many flavors.
description: To be published in Phys. Lett. B
Phase diagram of model anisotropic particles with octahedral symmetry
Creators: name: Noya, E. G.
name: Vega, C.
name: Doye, J. P. K.
name: Louis, A. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We computed the phase diagram for a system of model anisotropic particles with six attractive patches in an octahedral arrangement. We chose to study this model for a relatively narrow value of the patch width where the lowest-energy configuration of the system is a simple cubic crystal. At this value of the patch width, there is no stable vapour-liquid phase separation, and there are three other crystalline phases in addition to the simple cubic crystal that is most stable at low pressure. Firstly, at moderate pressures, it is more favourable to form a body-centred cubic crystal, which can be viewed as two interpenetrating, and almost non-interacting, simple cubic lattices.Secondly, at high pressures and low temperatures, an orientationally ordered face-centred cubic structure becomes favourable. Finally, at high temperatures a face-centred cubic plastic crystal is the most stable solid phase.
description: 12 pages,10 figures
Curvature and torsion in growing actin networks
Creators: name: Shaevitz, Joshua W.
name: Fletcher, Daniel A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Biomolecules (q-bio.BM)
subject: Biological Physics (physics.bio-ph)
subject: Cell Behavior (q-bio.CB)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Intracellular pathogens such as Listeria monocytogenes and Rickettsia rickettsii move within a host cell by polymerizing a comet-tail of actin fibers that ultimately pushes the cell forward. This dense network of cross-linked actin polymers typically exhibits a striking curvature that causes bacteria to move in gently looping paths. Theoretically, tail curvature has been linked to details of motility by considering force and torque balances from a finite number of polymerizing filaments. Here we track beads coated with a prokaryotic activator of actin polymerization in three dimensions to directly quantify the curvature and torsion of bead motility paths. We find that bead paths are more likely to have low rather than high curvature at any given time. Furthermore, path curvature changes very slowly in time, with an autocorrelation decay time of 200 seconds. Paths with a small radius of curvature, therefore, remain so for an extended period resulting in loops when confined to two dimensions. When allowed to explore a 3D space, path loops are less evident. Finally, we quantify the torsion in the bead paths and show that beads do not exhibit a significant left- or right-handed bias to their motion in 3D. These results suggest that paths of actin-propelled objects may be attributed to slow changes in curvature rather than a fixed torque.
The growth of a C_0-semigroup characterised by its cogenerator
Creators: name: Eisner, Tanja
name: Zwart, Hans
Publisher: name: arXiv
Year: 2008
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47D06, 47A30, 47A10

description: We characterise contractivity, boundedness and polynomial boundedness for a C_0-semigroup on a Banach space in terms of its cogenerator V (or the Cayley transform of the generator) or its resolvent. In particular, we extend results of Gomilko and Brenner, Thomee and show that polynomial boundedness of a semigroup implies polynomial boundedness of its cogenerator. As is shown by an example, the result is optimal. For analytic semigroups we show that the converse holds, i.e., polynomial boundedness of the cogenerators implies polynomial boundedness of the semigroup. In addition, we show by simple examples in (C^2,\|\cdot\|_p), p \neq 2, that our results on the characterisation of contractivity are sharp. These examples also show that the famous Foias-Sz.-Nagy theorem on cogenerators of contraction semigroups on Hilbert spaces fails in (C^2,\|\cdot\|_p) for p\neq 2.
description: 13 pages, to appear in J. Evol. Equ
Analysis and integration of soil parameters and vegetation of a Cariboo-Chilcotin wetland in British Columbia
Creators: name: Jones, Carol Elizabeth
Publisher: name: University of British Columbia
Year: 2010

description: The objective of this project was to investigate the relationships which exist between soil parameters and vegetation distribution in a wetland in the Chilcotin region of B.C. These relationships are presently poorly understood, yet pressure from agriculture and wildlife interests are increasing the need for the management of these wetlands. The project was designed as an intensive study of a single wetland, to reduce the influence of non-soil factors on the vegetation distribution. Sixty sites were sampled for both soil and vegetation. Soil samples were analyzed for parameters relating to nutrient levels, salt content, soil reaction, and organic matter content. The vegetation was classified using three computer assisted techniques; a tabular analysis, a cluster analysis, and a dissimilarity analysis. The resulting classifications were evaluated for ease of identification and utility in distinguishing significant variation in soil properties. The vegetation distribution appeared to be dominantly controlled by the water level, which is reflected in the high pH, high salt content of the drier regions, and the high levels of organic matter production and accumulation in the wetter regions. The extremes of the gradient are characterized by distinct vegetation communities and by soil types which can be statistically separated on the basis of these controlling factors. The intermediate region of the gradient can be separated into various community types, depending upon the method employed. A simplified pattern of four vegetation types occurring on soils which are significantly different in those parameters shown to control vegetation distribution can be developed for this wetland. The soils were classified into four groups, resulting from a cluster analysis based on those parameters indicated by factor analysis to be important. The distribution of single species and community types were found to be poor indicators of these soil groupings.
ASSESSMENT OF PREHARVEST MICROBIAL QUALITY OF CANTALOUPES AND PUBLIC HEALTH RISKS ASSOCIATED WITH CANTALOUPES CONTAMINATED WITH LISTERIA MONOCYTOGENES
Creators: name: Wang, Miao
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Food science
subject: Public health
subject: Microbiology
subject: FOS: Biological sciences

description: Cantaloupe has been recognized as a common vehicle for foodborne infections among fresh produce commodities. A severe multistate outbreak of Listeria monocytogenes associated with the consumption of whole cantaloupe resulted in 33 deaths in 2011. Quantitative microbial risk assessment (QMRA) modeling in food safety risk analysis has been acknowledged as an efficient tool to estimate and provide knowledge needed to manage potential public health risks associated with foodborne pathogens. The objectives of this study were to (i) conduct a microbiological survey of pre-harvest cantaloupes from farms in mid-Atlantic region, and (ii) develop a "farm to table" QMRA model for L. monocytogenes in cantaloupe. The results of the regional microbiological survey indicated a 5.3% (2/38) prevalence of generic Escherichia coli and negative for L. monocytogenes and Salmonella on cantaloupe during harvest season. A QMRA model was developed based on a thorough review of data from scientific publications and communications with fresh-cut processing industry. The model was simulated with Monte Carlo technique for 100,000 iterations in @Risk. The model estimated the public health risks associated with the consumption of both fresh-cut and whole cantaloupes in the U.S. The model demonstrated the risk associated with the consumption of a serving of fresh-cut cantaloupe is around 10 times higher than that for whole cantaloupe. Using the baseline model, the estimated median number of listeriosis cases per year associated with the consumption of fresh-cut cantaloupe among susceptible subpopulation and general healthy population are 0.0368 and 0.00134, respectively. Sensitivity analysis suggested temperature control during retail (correlation coefficient: 0.69) and home storage (correlation coefficient: 0.48) are two critical factors in mitigating the risk for fresh-cut cantaloupe consumption while home storage temperature (correlation coefficient: 0.79) after cutting is the most important factor for whole cantaloupe consumption. The QMRA model provided critical information for risk management and identified the critical data gaps including initial contamination and prevalence for future risk assessments of melon.
title: From Do-it-yourself Quantum Mechanics to Nanotechnology? The History of Experimental Semiconductor Physics, 1970–2000
Creators: name: Kehrt, Christian
Publisher: name: Max-Planck-Gesellschaft zur Förderung der Wissenschaften
Year: 2013

description: 13.1 New Research Technologies at the Quantum Level
13.2 The 1970s: A New Quantum Generation
13.3 Von Klitzing’s Nobel Prize: The Discovery of the Quantum Hall Effect
13.4 The 1980s: Founding the Walter Schottky Institute
13.5 Munich Nanoscience Networks
13.6 Nano-biotechnologies. New Forms of Interdisciplinary Cooperation?
13.7 Conclusion: The Reinvention of Semiconductor Physics
References
Footnotes