cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Stability and Control of Chaplygin Beanies Coupled to a Platform through Nonholonomic Constraints
Creators: name: Buchanan, Blake
name: Travers, Matthew
name: Choset, Howie
name: Kelly, Scott
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Multiagent Systems (cs.MA)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Many multi-agent systems in nature are comprised of agents that interact with, and respond to, the dynamics of their environment. In this paper, we approach the study of such agent-environment interactions through the study of passively compliant vehicles coupled to their environment via simple nonholonomic constraints. We first consider a single passively compliant Chaplygin beanie atop a platform having translational compliance, introduce the reduced equations for the system using the notion of nonholonomic momentum, and provide proof for its stability under arbitrary deformations of the elastic element modeling its compliance. We then direct our focus to results concerning the frequency response and control of passive Chaplygin beanies under actuation of the platform, discuss rich dynamical features arising from periodic actuation, and develop rules by which control can be exerted to collect and disperse multiple passive vehicles. We then discuss how the latter of these results clarifies the extent to which stable behavior can be excited in the system through exogenous control.
Some variants of the exponential formula, with application to the multivariate Tutte polynomial (alias Potts model)
Creators: name: Scott, Alexander D.
name: Sokal, Alan D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Combinatorics (math.CO)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 05A19 (Primary); 05A15, 05A18, 05C15, 05C30, 05C99, 06A07, 82B20 (Secondary)

description: We prove some variants of the exponential formula and apply them to the multivariate Tutte polynomials (also known as Potts-model partition functions) of graphs. We also prove some further identities for the multivariate Tutte polynomial, which generalize an identity for counting connected graphs found by Riordan, Nijenhuis, Wilf and Kreweras and in more general form by Leroux and Gessel, and an identity for the inversion enumerator of trees found by Mallows, Riordan and Kreweras. Finally, we prove a generalization of Mobius inversion on the partition lattice.
description: LaTeX2e, 39 pages. Dedicated to the memory of Pierre Leroux. Version 2 includes a new Appendix presenting a generalization of Mobius inversion on the partition lattice
Resonantly-paired fermionic superfluids
Creators: name: Gurarie, V.
name: Radzihovsky, L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a theory of a degenerate atomic Fermi gas, interacting through a narrow Feshbach resonance, whose position and therefore strength can be tuned experimentally, as demonstrated recently in ultracold trapped atomic gases. The distinguishing feature of the theory is that its accuracy is controlled by a dimensionless parameter proportional to the ratio of the width of the resonance to Fermi energy. The theory is therefore quantitatively accurate for a narrow Feshbach resonance. In the case of a narrow s-wave resonance, our analysis leads to a quantitative description of the crossover between a weakly-paired BCS superconductor of overlapping Cooper pairs and a strongly-paired molecular Bose-Einstein condensate of diatomic molecules. In the case of pairing via a p-wave resonance, that we show is always narrow for a sufficiently low density, we predict a detuning-temperature phase diagram, that in the course of a BCS-BEC crossover can exhibit a host of thermodynamically-distinct phases separated by quantum and classical phase transitions. For an intermediate strength of the dipolar anisotropy, the system exhibits a p_x + i p_y paired superfluidity that undergoes a topological phase transition between a weakly-coupled gapless ground state at large positive detuning and a strongly-paired fully-gapped molecular superfluid for a negative detuning. In two dimensions the former state is characterized by a Pfaffian ground state exhibiting topological order and non-Abelian vortex excitations familiar from fractional quantum Hall systems.
description: 71 pgs, 28 eps figures
Diffusion propagator metrics are biased when simultaneous multi-slice acceleration is used
Creators: name: Muftuler, L. Tugan
name: Nencka, Andrew S.
name: Koch, Kevin M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: Advanced diffusion MRI models are being explored to study the complex microstructure of the brain with higher accuracy. However, these techniques require long acquisition times. Simultaneous multi-slice (SMS) accelerates data acquisition by exciting multiple image slices simultaneously and separating the overlapping slices using a mathematical model. However, this slice separation is not exact and leads to crosstalk between simultaneously excited slices. Although this residual leakage is small, it affects quantitative MRI techniques such as diffusion imaging. In this study, the effects of SMS acceleration on the accuracy of propagator metrics obtained from the MAP-MRI technique was investigated. Ten healthy volunteers were scanned with SMS accelerated multi-shell diffusion MRI acquisitions. Group analyses were performed to study brain regions typically affected by SMS acceleration. In addition, diffusion metrics from atlas based fiber tracts of interest were analyzed to investigate how propagator metrics in major fiber tracts were biased by 2- and 3-band SMS acceleration. Both zero-displacement metrics and non-Gaussianity metrics were significantly altered when SMS acceleration was used. MAP-MRI metrics calculated from SMS-3 showed significant differences with respect to SMS-2. Furthermore, when shorter TR afforded by SMS acceleration was used, the characteristics of this bias have changed. This has implications for studies using diffusion MRI with SMS acceleration to investigate the effects of a disease or injury on the brain tissues.
description: The MRI engineers noted that different methods were used for combining coil images with single-band and SMS. To avoid this confounding effect, single-band data were excluded from the main analyses. However, single-band to SMS-2 comparisons were not significantly different, suggesting coil image combination was not a main effect. Thus, single-band comparisons were shown in supplementary data
Qubit Teleportation and Transfer across Antiferromagnetic Spin Chains
Creators: name: Venuti, L. Campos
name: Boschi, C. Degli Esposti
name: Roncaglia, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We explore the capability of spin-1/2 chains to act as quantum channels for both teleportation and transfer of qubits. Exploiting the emergence of long-distance entanglement in low-dimensional systems [Phys. Rev. Lett. 96, 247206 (2006)], here we show how to obtain high communication fidelities between distant parties. An investigation of protocols of teleportation and state transfer is presented, in the realistic situation where temperature is included. Basing our setup on antiferromagnetic rotationally invariant systems, both protocols are represented by pure depolarizing channels. We propose a scheme where channel fidelity close to one can be achieved on very long chains at moderately small temperature.
description: 5 pages, 4 .eps figures
Measurement-based quantum computer in the gapped ground state of a two-body Hamiltonian
Creators: name: Brennen, Gavin K.
name: Miyake, Akimasa
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We propose a scheme for a ground-code measurement-based quantum computer, which enjoys two major advantages. First, every logical qubit is encoded in the gapped degenerate ground subspace of a spin-1 chain with nearest-neighbor two-body interactions, so that it equips built-in robustness against noise. Second, computation is processed by single-spin measurements along multiple chains dynamically coupled on demand, so as to keep teleporting only logical information into a gap-protected ground state of the residual chains after the interactions with spins to be measured are turned off. We describe implementations using trapped atoms or polar molecules in an optical lattice, where the gap is expected to be as large as 0.2 kHz or 4.8 kHz respectively.
description: 5 pages, 1 figure; v3 the extended final version
Motional squeezing for trapped ion transport and separation
Creators: name: Sutherland, R. T.
name: Burd, S. C.
name: Slichter, D. H.
name: Libby, S. B.
name: Leibfried, D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Transport, separation, and merging of trapped ion crystals are essential operations for most large-scale quantum computing architectures. In this work, we develop a theoretical framework that describes the dynamics of ions in time-varying potentials with a motional squeeze operator, followed by a motional displacement operator. Using this framework, we develop a new, general protocol for trapped ion transport, separation, and merging. We show that motional squeezing can prepare an ion wave packet to enable transfer from the ground state of one trapping potential to another. The framework and protocol are applicable if the potential is harmonic over the extent of the ion wave packets at all times. As illustrations, we discuss two specific operations: changing the strength of the confining potential for a single ion, and separating same-species ions with their mutual Coulomb force. Both of these operations are, ideally, free of residual motional excitation.
Microcomputer communications & planning
Creators: name: Harrington, Daniel James
Publisher: name: University of British Columbia
Year: 2008

description: Contemporary planning literature is comprised of many different sub-sections, including one that considers the application of computer technology. Within this sub-section, topics such as expert systems, geographic information systems and database management have all been covered. One subject yet to be addressed however, is microcomputer communications, an industry which is growing rapidly. The purpose of this thesis is to conduct an initial exploration and description of microcomputer communications within a planning context. Following a definition of the subject, a terminology review and a historical perspective, the paper addresses the basic considerations for using the technology. The paper then moves to a synopsis of products and services available in the online industry. A discussion on professional use follows with medicine, education, law and civil engineering highlighted. A review of MC's existing place in the planning profession is offered. The paper then ends by summarizing the research process and findings. The methodology for this paper evolved as a result of a lack of traditional planning sources. Therefore, the paper relies on collateral references and hands-on experimentation to introduce MC technology and to discuss it from a planning perspective. It is interesting to speculate how MC could most benefit planning, such as the establishment of a national online data service featuring a library for document storage, e-mail for communication and online conferences for current issues. Despite this speculation, the primary conclusion to be drawn from this paper is that to effectively incorporate MC into a planning application, planners must be familiar with the technology and its inherent strengths and weaknesses.
Morphogen Transport in Epithelia
Creators: name: Bollenbach, T.
name: Kruse, K.
name: Pantazis, P.
name: Gonzalez-Gaitan, M.
name: Julicher, F.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Quantitative Biology (q-bio.OT)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We present a general theoretical framework to discuss mechanisms of morphogen transport and gradient formation in a cell layer. Trafficking events on the cellular scale lead to transport on larger scales. We discuss in particular the case of transcytosis where morphogens undergo repeated rounds of internalization into cells and recycling. Based on a description on the cellular scale, we derive effective nonlinear transport equations in one and two dimensions which are valid on larger scales. We derive analytic expressions for the concentration dependence of the effective diffusion coefficient and the effective degradation rate. We discuss the effects of a directional bias on morphogen transport and those of the coupling of the morphogen and receptor kinetics. Furthermore, we discuss general properties of cellular transport processes such as the robustness of gradients and relate our results to recent experiments on the morphogen Decapentaplegic (Dpp) that acts in the fruit fly Drosophila.
MPEC 2024-T70 : 2024 TA1
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 TA1

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Materials of the Ditidaht Language Documentation Project
Creators: name: Edgar, Christine
name: Shepherd, Dorothy
name: Tate, Fran
name: Thompson, Michael
name: Sylak-Glassman, John
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021

description: Materials from field research geared toward phonetic and phonological research, including word lists, recordings, and metadata to increase usability of materials
Extreme Near-Field Heat Transfer Between Gold Surfaces
Creators: name: Tokunaga, Takuro
name: Jarzembski, Amun
name: Shiga, Takuma
name: Park, Keunhan
name: Francoeur, Mathieu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Extreme near-field heat transfer between metallic surfaces is a subject of debate as the state-of-the-art theory and experiments are in disagreement on the energy carriers driving heat transport. In an effort to elucidate the physics of extreme near-field heat transfer between metallic surfaces, this Letter presents a comprehensive model combining radiation, acoustic phonon and electron transport across sub-10-nm vacuum gaps. The results obtained for gold surfaces show that in the absence of bias voltage, acoustic phonon transport is dominant for vacuum gaps smaller than ~2 nm. The application of a bias voltage significantly affects the dominant energy carriers as it increases the phonon contribution mediated by the long-range Coulomb force and the electron contribution due to a lower potential barrier. For a bias voltage of 0.6 V, acoustic phonon transport becomes dominant at a vacuum gap of 5 nm, whereas electron tunneling dominates at sub-1-nm vacuum gaps. The comparison of the theory against experimental data from the literature suggests that well-controlled measurements between metallic surfaces are needed to quantify the contributions of acoustic phonon and electron as a function of the bias voltage.
description: 27 pages, 4 figures, 2 supplementary figures
Spin-Torque Ferromagnetic Resonance Measurements of Damping in Nanomagnets
Creators: name: Fuchs, G. D.
name: Sankey, J. C.
name: Pribiag, V. S.
name: Qian, L.
name: Braganca, P. M.
name: Garcia, A. G. F.
name: Ryan, E. M.
name: Li, Zhi-Pan
name: Ozatay, O.
name: Ralph, D. C.
name: Buhrman, R. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We measure the magnetic damping parameter a in thin film CoFeB and permalloy (Py) nanomagnets at room temperature using ferromagnetic resonance driven by microwave frequency spin-transfer torque. We obtain $α_{CoFeB} = 0.014 \pm 0.003$ and $α_{Py}=0.010 \pm 0.002$, values comparable to measurements for extended thin films, but significantly less than the effective damping determined previously for similar nanomagnets by fits to time-domain studies of large-angle magnetic excitations and magnetic reversal. The greater damping found for the large amplitude nanomagnet dynamics is attributed to the nonlinear excitation of non-uniform magnetic modes.
description: 13 pages, 2 figures
Παραγωγή ασβέστου υψηλής δραστικότητας κατάλληλης για αποκαταστάσεις μνημείων και ιστορικών κτιρίων
Creators: name: Ζαχαροπούλου, Γεωργία Π.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Ασβεστοκονιάματα
Lime mortars

description: Στόχος της διδακτορικής διατριβής είναι να συνεισφέρει στον προβληματισμό σχετικά με τα αίτια των ανεπιτυχών εφαρμογών ασβεστοκονιαμάτων στις αποκαστάσεις μνημείων και ιστορικών κτιρίων, καθώς και στην αποτίμηση των τεχνολογικών και μηχανικών χαρακτηριστικών των βασισμένων στην άσβεστο ιστορικών κονιαμάτων. Να συμβάλει επίσης στην ανάπτυξη καινοτόμου τεχνογνωσίας που θα διασφαλίσει την παραγωγή και διάθεση στο εμπόριο δομικής ασβέστου κατάλληλης για επεμβάσεις από εγχώριες πρώτες ύλες. Αντικείμενο της έρευνας αποτέλεσε η διερεύνηση της βελτιστοποίησης της παραγωγής δοκιμής ασβέστου υψηλής δραστικότητας. Μελετήθηκε πειραματικά η επίδραση της μεταβολής των κυρίων παραμέτρων όλων των επιμέρους φάσεων της διαδικασίας παραγωγής ασβέστου στα ποιοτικά χαρακτηριστικά της. Η καταλληλότητα της ασβέστου ελέχθηκε περαιτέρω με την παρασκευή κονιαμάτων. Η επιλογή της συγκεκριμένης μεθοδολογίας ελέγχου βασίστηκε στα τεχνολογικά δεδομένα που προέκυψαν από τη συγκριτική μελέτη της ελληνικής παραδοσιακής και σύγχρονης τεχνογνωσίας παραγωγής ασβέστου, σε σχέση με στοιχεία από τη διεθνή βιβλιογραφία και εμπειρία. Ως περιοχή ολιστικής προσέγγισης και έρευνας στον ελληνικό χώρο, επιλέχθηκε ο αντιπροσωπευτικός, με βάση διεθνή επιστημονικά και φιλοσοφικά κριτήρια, ιστορικός τόπος παραγωγής ασβέστου στο Ασβεστοχώρι ν. Θεσσαλονίκης. Με βάση τα εργαστηριακά αποτελέσματα αξιολογούνται τα επιμέρους - ΕΛΟΤ ΕΝ 459:2001 ή προτεινόμενα- κριτήρια ελέγχου και διατυπώνονται προτάσεις προδιαγραφών βέλτιστων ποιοτικών ελέγχου
description: The scope of the PhD research is to contribute to the understanding of the unsuccessful use of lime based mortars in monuments' and historical buildings' conservation, to the assessment of the technological and mechanical characteristics of the historical lime mortars and also to the development of innovative greek know-how that will help the production of suitable building lime from local raw materials. The objective was the investigation of the amelioration of the high reactivity building lime's production. The influence of main parameters' change-during all the intermediate productive phases to lime's quality was thoroughly studied. Lime's suitability for interventions was furthermore investigated through mortar's manufacture and study of their technological and mechanical characteristics. The selected methodology was based upon technological data derived from the comparative study of the tradition and modern greek know-how in lime production and the international experience and bibliography. The historical site of lime production in Asvestohori(Thessaloniki, Greece) has been selected-according to international scientific and philosophical criteria-for an holistic approach and study. The laboratory research-based on ΕΛΟΤ ΕΝ 459:2001 or suggested test methods and criteria-concluded to proposals of specifications of best production parameters and of specifications of quality control
Alternating sum formulae for the determinant and other link invariants
Creators: name: Dasbach, Oliver T.
name: Futer, David
name: Kalfagianni, Efstratia
name: Lin, Xiao-Song
name: Stoltzfus, Neal W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Geometric Topology (math.GT)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 57M25, 57M27

description: A classical result states that the determinant of an alternating link is equal to the number of spanning trees in a checkerboard graph of an alternating connected projection of the link. We generalize this result to show that the determinant is the alternating sum of the number of quasi-trees of genus j of the dessin of a non-alternating link. Furthermore, we obtain formulas for other link invariants by counting quantities on dessins. In particular we will show that the $j$-th coefficient of the Jones polynomial is given by sub-dessins of genus less or equal to $j$.
description: 18 pages, 8 figures; extended version
Instabilities in numerical loop quantum cosmology
Creators: name: Rosen, Jessica
name: Jung, Jae-Hun
name: Khanna, Gaurav
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this article we perform von Neumann analysis of the difference equations that arise as a result of loop quantum gravity being applied to models of cosmology and black holes. In particular, we study the numerical stability of Bianchi I LRS (symmetric and non-symmetric constraint) and Schwarzschild interior (symmetric constraint) models, and find that there exist domains over which there are instabilities, generically. We also present explicit evolutions of wave-packets in these models and clearly demonstrate the presence of these instabilities.
description: 6 pages, 8 figures
Σύνθεση πυρρολυλοβενζοθειαζολίων και φαρμακοχημική μελέτη τους σε in vitro πρότυπα που σχετίζονται κυρίως με τις χρόνιες επιπλοκές του σακχαρώδους διαβήτη: μελέτη βασισμένη σε βιοϊσοστερή σχεδιασμό
Creators: name: Najlaa, Zaher S.
Publisher: name: Aristotle University of Thessaloniki
Year: 2003
Subjects: Ελεύθερες ρίζες
Λιποφιλικότητα
Free radicals
Lipophilicity

description: Στην εργασία αυτή πραγματοποιούνται η σύνθεση και η φαρμακοχημική μελέτη παραγώγων του 2-(1Η-πυρρολ-3-υλο)βενζοθειαζολίου με πιθανή χρησιμότητα στην αντιμετώπιση των χρόνιων επιπλοκών του σακχαρώδους διαβήτ. Συντίθεται συνολικά σαράντα ενώσεις. Είκοσιτρείς ενώσεις ταυτοποιήθηκαν πλήρως. Εξετάζεται η ικανότητα έξι πρωτότυπων ενώσεων να αναστέλλουν in vitro ρίζες υδροξυλίου και να αλληλεπιδρούν με τη σταθερή ελεύθερη ρίζα του (Dpph). Οι τιμές που προκύπτουν υποδεικνύουν ότι πιθανά, οι αντιοξειδωτικές ιδιότητες αυτών των μορίων θα μπορούσαν να εκδηλωθούν και in vivo. Εξετάζεται η ικανότητα μιας από τις πρωτότυπες ενώσεις, που διαθέτει συγκριτικά καλύτερο συνδυασμό φαρμακοχημικών ιδιοτήτων, ένωση 21, να αναστέλλει in vitro τη γλυκοξυλίωση των πρωτεϊνών από φρουκτόζη. Βρίσκεται ότι η ένωση αυτή παρουσιάζει ισχυρή δραστικότητα. Εκτιμάται η λιποφιλικότητα των ενώσεων με δύο διαφορετικές υπολογιστικές μεθόδους(Clogp and LogPec) οι οποίες βρίσκεται ότι σχετίζονται. Τέλος, κατανάλλεται προσπάθεια συσχετισμών επιλεγμένων υπολογισμένων φυσικοχημικών ιδιοτήτων των τελικών ενώσεων με τη δραστικότητά τους ως αναστολέων της αναγωγάσης της αλδόζης. Βρίσκεται ότι υπάρχει τάση συσχέτισης με τη διπολική ροπή των μορίων
description: The aim of this thesis was the synthesis of appropriaty substituded derivatives of [3-1,3-benzothiazol-2-y1)-2-benzoyl1-1H-pyrrol-1-y1]acetic acid that will combine aldose reductase inhibitory activity, antioxidant potential and ability to prevent the irreversible glyco(fructo)-oxidative modification of proteins, a combination of biological profile that is desirable for the pharmacotherapy of the chronic complications of diabetes mellitus. Six out of 23 synthesized and fully characterized compounds, which include the substructure of pyrrol-1-yl-acetic acid(i.e. final products), were studied for their ability to inhibit the enzyme aldose reductase, and it was found that their IC50 values were in the range of 8,7-1010nM. The reductive-antioxidant profile of final products was investigated based on their ability to interact with DPPH and to scavenge hydroxyl radicals(OH). Although none of the compounds interacted with DPPH two of them (21 and 25) are strong. OH scavengers. Finally, based on its physicochemical as well as biological profile, compound 21 of series A was tested for its ability to inhibit the glycation of albumin under fructation conditions, and it was found to be more potent than reference compound trolox. The above results, taken together, are considered encouraging as(3-benzothiale-1-yl-pyrrol-1-yl)acetic acid (21) combines positively three biological activity directly connected to a number of pathological conditions. Notable examples are the long term complications of diabetes mellitus
Bayesian Poroelastic Aquifer Characterization from InSAR Surface Deformation Data Part II: Quantifying the Uncertainty
Creators: name: Alghamdi, Amal
name: Hesse, Marc
name: Chen, Jingyi
name: Villa, Umberto
name: Ghattas, Omar
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geophysics (physics.geo-ph)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Uncertainty quantification of groundwater (GW) aquifer parameters is critical for efficient management and sustainable extraction of GW resources. These uncertainties are introduced by the data, model, and prior information on the parameters. Here we develop a Bayesian inversion framework that uses Interferometric Synthetic Aperture Radar (InSAR) surface deformation data to infer the laterally heterogeneous permeability of a transient linear poroelastic model of a confined GW aquifer. The Bayesian solution of this inverse problem takes the form of a posterior probability density of the permeability. Exploring this posterior using classical Markov chain Monte Carlo (MCMC) methods is computationally prohibitive due to the large dimension of the discretized permeability field and the expense of solving the poroelastic forward problem. However, in many partial differential equation (PDE)-based Bayesian inversion problems, the data are only informative in a few directions in parameter space. For the poroelasticity problem, we prove this property theoretically for a one-dimensional problem and demonstrate it numerically for a three-dimensional aquifer model. We design a generalized preconditioned Crank--Nicolson (gpCN) MCMC method that exploits this intrinsic low dimensionality by using a low-rank based Laplace approximation of the posterior as a proposal, which we build scalably. The feasibility of our approach is demonstrated through a real GW aquifer test in Nevada. The inherently two dimensional nature of InSAR surface deformation data informs a sufficient number of modes of the permeability field to allow detection of major structures within the aquifer, significantly reducing the uncertainty in the pressure and the displacement quantities of interest.
Local Asymmetry and the Inner Radius of Nodal Domains
Creators: name: Mangoubi, Dan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Spectral Theory (math.SP)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35P20; 58J50

description: Let M be a closed Riemannian manifold of dimension n. Let f be an eigenfunction of the Laplace-Beltrami operator corresponding to an eigenvalue λ. We show that the volume of {f>0} inside any ball B whose center lies on {f=0} is > C|B|/λ^n. We apply this result to prove that each nodal domain contains a ball of radius > C/λ^n.
description: 12 pages, 1 figure; minor corrections; to appear in Comm. PDEs
FSEI-GPU: GPU accelerated simulations of the fluid-structure-electrophysiology interaction in the left heart
Creators: name: Viola, Francesco
name: Spandan, Vamsi
name: Meschini, Valentina
name: Romero, Joshua
name: Fatica, Massimiliano
name: de Tullio, Marco D.
name: Verzicco, Roberto
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The reliability of cardiovascular computational models depends on the accurate solution of the hemodynamics, the realistic characterization of the hyperelastic and electric properties of the tissues along with the correct description of their interaction. The resulting fluid-structure-electrophysiology interaction (FSEI) thus requires an immense computational power, usually available in large supercomputing centers, and requires long time to obtain results even if multi-CPU processors are used (MPI acceleration). In recent years, graphics processing units (GPUs) have emerged as a convenient platform for high performance computing, as they allow for considerable reductions of the time-to-solution. This approach is particularly appealing if the tool has to support medical decisions that require solutions within reduced times and possibly obtained by local computational resources. Accordingly, our multi-physics solver has been ported to GPU architectures using CUDA Fortran to tackle fast and accurate hemodynamics simulations of the human heart without resorting to large-scale supercomputers. This work describes the use of CUDA to accelerate the FSEI on heterogeneous clusters, where both the CPUs and GPUs are used in synergistically with minor modifications of the original source code. The resulting GPU accelerated code solves a single heartbeat within a few hours (from three to ten depending on the grid resolution) running on premises computing facility made of few GPU cards, which can be easily installed in a medical laboratory or in a hospital, thus opening towards a systematic computational fluid dynamics (CFD) aided diagnostic.
Adiabatic cavity QED with pairs of atoms: Atomic entanglement and Quantum teleportation
Creators: name: Lazarou, C.
name: Garraway, B. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the dynamics of a pair of atoms, resonantly interacting with a single mode cavity, in the situation where the atoms enter the cavity with a time delay between them. Using time dependent coupling functions to represent the spatial profile of the mode, we considered the adiabatic limit of the system. Although the time evolution is mostly adiabatic, energy crossings play an important role in the system dynamics. Following from this, entanglement, and a procedure for cavity state teleportation are considered. We examine the behaviour of the system when we introduce decoherence, a finite detuning, and potential asymmetries in the coupling profiles of the atoms.
description: 12 pages, 7 figures, To appear in European Physical Journal Special Topics
Solvation Effects on Free Energy Surface of Polyalanine
Creators: name: Gokoglu, G.
name: Arkin, H.
name: Akturk, E.
name: Celik, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We have simulated 10-residue polyalanine chain by multicanonical method to visualize the 3D topographic picture of the free energy landscape over the whole range of temperatures, hence to show the funnel along the folding pathway exhaustively. We have simulated and compared the system in vacuo and in solvent, and examined the changes in the free energy landscape due to the solvent effects, which are taken into account by commonly used model Accessible Surface Area.
description: 12pages, 3figures
Relationship between three-dimensional velocity of filament eruptions and CME association
Creators: name: Seki, Daikichi
name: Otsuji, Kenichi
name: Ishii, Takako T.
name: Asai, Ayumi
name: Ichimoto, Kiyoshi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: It is widely recognised that filament disappearances or eruptions are frequently associated with Coronal Mass Ejections (CMEs). Since CMEs are a major source of disturbances of the space environment surrounding the Earth, it is important to investigate these associations in detail for the better prediction of CME occurrence. However, the proportion of filament disappearances associated with CMEs is under debate. The estimates range from $\sim$10% to $\sim$90% and could be affected by the manners to select the events. In this study, we aim to reveal what parameters control the association between filament eruptions and CMEs. We analysed the relationships between CME associations and the physical parameters of filaments including their length, maximum ascending velocity, and direction of eruptions using 28 events of filament eruptions observed in H$α$. We found that the product of the maximum radial velocity and the filament length is well correlated with the CME occurrence. If the product is larger than 8.0$\times$10$^{6}$ km$^{2}$ s$^{-1}$, the filament will become a CME with a probability of 93%, and if the product is smaller than this value, it will not become a CME with a probability of 100%. We suggest a kinetic-energy threshold above which filament eruptions are associated with CMEs. Our findings also suggest the importance of measuring the velocity vector of filament eruption in three-dimensional space for the better prediction of CME occurrence.
description: accepted for publication in Earth, Planets and Space
Systematic gripper arrangement for a handling device in lightweight production processes
Creators: name: Ballier, Fabian Johannes
Publisher: name: Karlsruhe
Year: 2019
Subjects: Handling
Textile
Algorithm

description: Handhabungsgeräte sind ein integraler Bestandteil automatisierter Produktionsprozesse. Dennoch werden sie in der Regel als nicht wertschöpfend angesehen, weshalb ihre Planung und Projektierung mit geringem Zeit- und Personalaufwand so effektiv wie möglich sein sollte. Gleichzeitig bleiben sie ein wichtiger Teil der Prozesskette und müssen in diesem Zusammenhang bestimmte Bedingungen erfüllen. Um ihre Funktionalität zu gewährleisten und wenig Zeit in die Projektierung zu investieren, sind Handhabungsgeräte oft überdimensioniert. Insbesondere bei flachen Teilen führt dies zu schweren Handhabungslösungen, bei denen das Gewicht des Handhabungsobjekts und des Handhabungsgerätes in einem Missverhältnis zueinander stehen. Ziel der vorliegenden Arbeit ist es, die Projektierung von Handhabungsgeräten so weit wie möglich zu automatisieren. Dieser Prozess wird am Beispiel der Prozesskette zur Herstellung von Leichtbauteilen mit den Verfahren „sheet molding compound“ (SMC) und „resin transfer molding“ (RTM) dargestellt. In einem ersten Schritt wird ein modulares Handhabungsgerät entwickelt und aufgebaut, das eine große Anzahl von Greiferanordnung ermöglicht. Mit diesem Handhabungsgerät kann dann die resultierende Durchbiegung von flachen Bauteilen mit verschiedenen Greiferanordnungen gemessen werden. Um sicherzustellen, dass es nicht immer notwendig ist die Durchbiegungen zu messen, wird mit ABAQUS ein Modell aufgebaut, das eine Simulation der Durchbiegung ermöglicht. Anhand dieses Simulationsmodells wird eine Designlogik für die Anordnung der Greifer entwickelt. Diese Designlogik arbeitet in zwei Schritten und basiert auf dem Ansatz des „growing neural gas“ (GNG), das durch die Implementierung zusätzlicher Regeln an das Problem angepasst wird. Zuerst wird eine erste Greiferkonfiguration basierend auf der Geometrie des Objekts erstellt, die dann durch einen iterativen Prozess aus Simulation und Anpassung verbessert wird. Da die Herstellung von Leichtbauteilen oft mehr als nur einen Zuschnitt erfordert, werden am Ende systematisch verschiedene Lösungen für die verschiedenen Zuschnitte zu einer Greiferanordnung zusammengefasst und ein Verfahren gezeigt, wie dies ,mit dem zuvor entwickelten modularen Handhabungsgerät realisiert, werden kann.
High p_T Hadron Correlation and No Correlation
Creators: name: Hwa, Rudolph C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: An overview of the correlation among high-p_T hadrons produced in heavy-ion collisions is presented. Emphasis is placed on the physical processes that can quantitatively account for the data on correlations in p_T, ηand ϕon the near and far sides. Predictions are made on processes that have no observable correlations for hadrons produced at intermediate and higher p_T at RHIC and LHC.
description: 8 pages including 14 figures. Talk given at Hard Probes 2006
Effect of lattice mismatch-induced strains on coupled diffusive and displacive phase transformations
Creators: name: Bouville, Mathieu
name: Ahluwalia, Rajeev
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Materials which can undergo slow diffusive transformations as well as fast displacive transformations are studied using the phase-field method. The model captures the essential features of the time-temperature-transformation (TTT) diagrams, continuous cooling transformation (CCT) diagrams, and microstructure formation of these alloys. In some materials systems there can exist an intrinsic volume change associated with these transformations. We show that these coherency strains can stabilize mixed microstructures (such as retained austenite-martensite and pearlite-martensite mixtures) by an interplay between diffusive and displacive mechanisms, which can alter TTT and CCT diagrams. Depending on the conditions there can be competitive or cooperative nucleation of the two kinds of phases. The model also shows that small differences in volume changes can have noticeable effects on the early stages of martensite formation and on the resulting microstructures. -- Long version of cond-mat/0605577 -- Keywords: Ginzburg-Landau, martensite, pearlite, spinodal decomposition, shape memory, microstructures, TTT diagram, CCT diagram, elastic compatibility
description: 10 pages, 13 figures, long version of cond-mat/0605577. Physical Review B, to appear in volume 75 (2007)
Συμβολή στη μελέτη της επιζωοτολογίας, τη διάγνωση και τη φαρμακευτική αντιμετώπιση της λεϊσμανίωσης του σκύλου
Creators: name: Αθανασίου, Λαμπρινή Β.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Φαρμακοκινητική
Επιζωοτιολογία
Aminosidine
Pharmacokinetics
Epidemiology

description: Αντικείμενο του πρώτου μέρους της παρούσας διατριβής ήταν η ανίχνευση αντισωμάτων κατά της leishmania σε κλινικά υγιείς σκύλους 7 περιοχών της Ελλάδας. Το υψηλότερο ποσοστό διαπιστώθηκε στην Αττική 30,11% και το χαμηλότερο και το χαμηλότερο στη Φλώρινα 2%. Το γένος, ο τύπος του τριχώματος και η απασχόληση των σκύλων σε αντίθεση με την ηλικία δε φαίνεται να επηρεάζουν το ποσοστό οροθετικότητας. Στο δεύτερο μέρος της διατριβής εκτιμήθηκε η ασφάλεια και αποτελεσματικότητα της αμινοσιδίνης στη φαρμακευτική αντιμετώπιση της λεϊσμανίωσης του σκύλου. Υστερα από υποδόρια χορήγηση για 21 ημέρες αμινοσιδίνης στη δόση των 15mg/kg σ.β. άπαξ ημερησίως παρατηρήθηκε υψηλή βιοδιαθεσιμότητα και ανεκτικότητα και υποχώρηση των κλινικών και των κλινικοπαθολογικών ανωμαλιών. Ωστόσο, παράσιτα ανιχνεύθηκαν με PCR στον από των λεμφογαγγλίων και το μυελό των οστών
description: The objective of the first part of the study was to assess the regimal exposure of dogs to Leishmania in Greece by determining its seroprevalence simutaneously in 7 geographical areas in clinically healthy dogs. The highest seroprevalence was observed in dogs living in Athens 30,11% and the lowest in Florina 2%. Seroprevalence was not correlated with utility, gender and length of hate coat while it was affected by age. The second part of the study was carried out in order to assess safety and efficacy of aminosidine in the treatment of canine leishmaniosis. After s.c. inspection of ciminosidine for 21 days at the dosage regimen of 15mg/kg b.w. SID, high biovailabity and good tolerance was observed as well as partial remission of clinical signs and clinicopathological abnormalities. However, parasites were still present in lymph nodes and bone marrow
A pure Skyrme instanton
Creators: name: Speight, J. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The nuclear Skyrme model is considered in the extreme limit where the nucleon radius tends to infinity. In this limit only the Skyrme term in the action is significant. The model is then conformally invariant in dimension 4, and supports an instanton solution which can be constructed explicitly. The construction uses the conformal invariance and a certain symmetry reduction to reduce the model to the static phi^4 model in one dimension. The phi^4 kink solution gives the radial profile of the instanton, the kink position zero-mode corresponding to the instanton width.
description: 7 pages, published version, includes explicit check that the instanton satisfies the field equations
Addiction among high school students: determination of nicotine, substance, game, and internet addiction levels
Creators: name: Aslan, Tuba Korkmaz
name: Batı, Serap
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy
subject: Mental Health

description: The aims of this study were to determine the levels of cigarette smoking, psychoactive substances, game, and internet addiction among high school students and to examine whether addictions show a significant difference according to some socio-demographic variables and the relationships between addiction types. A total of 530 high school students studying in Turkey, agreed to participate in the study. Data were collected through face-to-face interviews using the Sociodemographic Questionnaire (which contains DSM-V categories of addictive substances), Fagerström Test for Nicotine Dependence (FTND), Game Addiction Scale (GAS), and Internet Addiction Test (IAT). Approximately 1.9% of the respondents were smokers and 0.8% were inhalant users. Respondents scored 7.43 ± 2.88 on FTND, 13.92 ± 5.57 on the GAS, and 43.44 ± 18.80 on the IAT. Male respondents received a higher average score on the GAS than female respondents, and female respondents received a higher average score on the IAT than male respondents. As body mass index increased, a statistically significant, positive and moderate correlation was found between GAS scores and IAT scores. Addictions are becoming more and more widespread and measures, information, and research should be increased and young people should be educated about addictions.
Effective Theory of Inflationary Magnetogenesis and Constraints on Reheating
Creators: name: Maity, Debaprasad
name: Pal, Sourav
name: Paul, Tanmoy
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Effective theory framework based on symmetry has recently gained widespread interest in the field of cosmology. In this paper, we apply the same idea on the genesis of the primordial magnetic field and its evolution throughout the cosmological universe. Given the broken time-diffeomorphism symmetry by the cosmological background, we considered the most general Lagrangian of electromagnetic and metric fluctuation up to second order, which naturally breaks conformal symmetry in the electromagnetic (EM) sector. We also include parity violation in the electromagnetic sector with the motivation that has potential observational significance. In such a set-up, we explore the evolution of EM, scalar, and tensor perturbations considering different observational constraints. In our analysis we emphasize the role played by the intermediate reheating phase which has got limited interest in all the previous studies. Assuming the vanishing electrical conductivity during the entire period of reheating, the well-known Faraday electromagnetic induction has been shown to play a crucial role in enhancing the strength of the present-day magnetic field. We show how such physical effects combined with the PLANCK and the large scale magnetic field observation makes a large class of models viable and severely restricts the reheating equation of state parameter within a very narrow range of $0.01 < ω_\mathrm{eff} < 0.27$, which is nearly independent of reheating scenarios we have considered.
description: JCAP accepted
Flow diagram of the metal-insulator transition in two dimensions
Creators: name: Anissimova, S.
name: Kravchenko, S. V.
name: Punnoose, A.
name: Finkel'stein, A. M.
name: Klapwijk, T. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The discovery of the metal-insulator transition (MIT) in two-dimensional (2D) electron systems challenged the veracity of one of the most influential conjectures in the physics of disordered electrons, which states that `in two dimensions, there is no true metallic behaviour'; no matter how weak the disorder, electrons would be trapped and unable to conduct a current. However, that theory did not account for interactions between the electrons. Here we investigate the interplay between the electron-electron interactions and disorder near the MIT using simultaneous measurements of electrical resistivity and magnetoconductance. We show that both the resistance and interaction amplitude exhibit a fan-like spread as the MIT is crossed. From these data we construct a resistance-interaction flow diagram of the MIT that clearly reveals a quantum critical point, as predicted by the two-parameter scaling theory (Punnoose and Finkel'stein, Science 310, 289 (2005)). The metallic side of this diagram is accurately described by the renormalization group theory without any fitting parameters. In particular, the metallic temperature dependence of the resistance sets in when the interaction amplitude reaches gamma_2 = 0.45 - a value in remarkable agreement with the one predicted by the theory.
description: as published