cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
An evaluation of soil and water management practices on a lowland soil with poor natural drainage
Creators: name: Heinonen, John Stanley
Publisher: name: University of British Columbia
Year: 2008

description: Low-lying areas of the Lower Fraser Valley tend to have poor natural soil drainage. Excess moisture, because of a high water table and ponded surface water, restricts the range of crops that can be grown and influences farm management decisions regarding the nature and timing of field operations. When economic considerations lead farmers to commence field operations when the soil is too wet, the result can be structural degradation of the soil, leading to the formation of surface seals and crusts and a compact ploughpan. The aim of this study was to evaluate the effectiveness of various management practices in controlling the water table, to gain an understanding of the mechanisms governing excess water accumulation, persistence, and removal from lowland soils, and to make management recommendations from these. Monitoring was conducted on two adjacent farms on Westham Island. They differed in their management of excess water: one relied on surface ditching, subsoiling, mole drains, and cover crops, while the other used a system of perforated subsurface drainlines emptying into a ditch that was pumped to keep the water level low. Soil-water pressure potentials were measured automatically and manually with piezometers located in selected depressions and surrounding slightly higher ground from February to April 1981. Depth of ponded surface water and water level in the ditches draining each farm were monitored. Rainfall was recorded with four rain gauges. Bulk densities and saturated hydraulic conductivities of the surface crust, ploughpan, and subsoil were measured. Soil penetration resistances and aggregate stabilities (wet sieving) were measured as indices of compaction and structural stability. Earthworm numbers and biomasses were measured in both farm. Land drainage through a system of subsurface drainlines was found to lower the water table more rapidly after rainfall, and reducing the depth and duration of ponding compared to undrained land. Drainage resulted in more trafficable and opportunity days for field operations. Drainage dramatically increased earthworm populations which in turn improved the drainage via the pathways for water movement provided by burrows. Although there was a more severe ploughpan in the undrained farm there was no evidence that it impeded water movement. There were no differences in aggregate stabilities between farms. The presence of ponded water in depressions was found to be due mainly to a low permeability surface seal which was more severe in the undrained farm. The presence of the seal resulted in surface runoff to low areas and slowed water infiltration there. Subsoiling and moling may also aggravate excess water problems by directing water to low areas. Surface ditches were found to be ineffective in removing ponded water. Using a cover crop, which reduced the severity of crusting and ponding, was a more effective practice than subsoiling when the soil was undrained.
MPEC 2024-T71 : 2024 TB1
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 TB1

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.
Additional file 1 of The role of MORC3 in silencing transposable elements in mouse embryonic stem cells
Creators: name: Desai, Varsha P.
name: Chouaref, Jihed
name: Wu, Haoyu
name: Pastor, William A.
name: Kan, Ryan L.
name: Oey, Harald M.
name: Li, Zheng
name: Ho, Jamie
name: Vonk, Kelly K. D.
name: San Leon Granado, David
name: Christopher, Michael A.
name: Clark, Amander T.
name: Jacobsen, Steven E.
name: Daxinger, Lucia
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 1: Figures S1–S12. List of supplementary figures, titles and legends.
Baryon-Strangeness Correlations from Hadron/String- and Quark-Dynamics
Creators: name: Haussler, Stephane
name: Bleicher, Marcus
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Baryon-strangeness correlations ($C_{BS}$) are studied with a hadron/string transport approach (UrQMD) and a dynamical quark recombination model (quark molecular dynamics, qMD) for various energies from $E_{lab}=4A$ GeV to $\sqrt{s_{NN}}=200$ GeV. As expected, we find that the hadron/string dynamics shows correlations similar to a simple hadron gas. In case of the quark molecular dynamics, we find that initially the $C_{BS}$ correlation is that of a weakly interacting QGP but changes in the process of hadronization also to the value for a hadron gas. Therefore, we conclude that the hadronization process itself makes the initial baryon strangeness correlation unobservable. To make an experimental study of this observable more feasible, we also investigate how a restriction to only charged kaons and $Λ$'s (instead of all baryons and all strange particles) influences the theoretical result on $C_{BS}$. We find that a good approximation of the full result can be obtained in this limit in the present simulation.
description: Proceedings of the Conference on Quark Confinement and the Hadron Spectrum
Synchronous Inductor Switched Energy Extraction Circuits for Triboelectric Nanogenerator
Creators: name: Pathak, Madhav
name: Kumar, Ratnesh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Systems and Control (eess.SY)
subject: Signal Processing (eess.SP)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Triboelectric nanogenerator (TENG), a class of mechanical to electrical energy transducers, has emerged as a promising solution to self-power Internet of Things (IoT) sensors, wearable electronics, etc. The use of synchronous switched energy extraction circuits (EECs) as an interface between TENG and battery load can deliver multi-fold energy gain over simple minded Full Wave Rectification (FWR). This paper presents a detailed analysis of Parallel and Series Synchronous Switched Harvesting on Inductor (P-SSHI and S-SSHI) EECs to derive the energy delivered to the battery load and compare it with the standard FWR (a 3rd circuit) in a common analytical framework, under both realistic conditions, and also ideal conditions. Further, the optimal value of battery load to maximize output and upper bound beyond which charging is not feasible are derived for all the three considered circuits. These closed-form results derived with general TENG electrical parameters and first-order circuit non-idealities shed light on the physics of the modeling and guide the choice and design of EECs for any given TENG. The derived analytical results are verified against PSpice based simulation results as well as the experimentally measured values.
Apparent induction, kinetic and physical properties of the multiple species of ornithine decarboxylase, forms A and B, in the kidney and liver of hormone-treated rat
Creators: name: Janzen, Andrea K.
Publisher: name: University of British Columbia
Year: 2008

description: Ornithine decarboxylase occurs in the kidney and liver of control and hormone treated rats as two ionic forms, designated ODC A and B in order of elution by DEAE-Sepharose chromatography. These studies were designed to better characterize the multiple forms of ODC and to investigate the functions and possible origins of ODC A and B in growth hormone, prolactin and/or dexamethasone stimulated tissue. The two species of ODC existed in separate and distinct proportions in control rat kidney and liver. Within the kidney and liver of growth hormone, prolactin and dexamethasone stimulated rats, the proportions of ODC A and B were altered, reflecting the increased half-life of ODC B. In growth hormone-stimulated animals, form B had an increased half-life of 25 minutes in the kidney and 60 minutes in the liver. Hormone stimulated rats were also given either LiC1, actinomycin D orputrescine, which decreased total ODC activity. The ODC A:B ratio was altered in some instances, but only within the kidney. In these cases, the enhanced proportion and most likely the stability of the B form of ODC was inhibited or removed, as in the response of ODC to LiC1 in the stimulated kidney. Within the liver, there was no alteration of the A:B ratio. Possibly, the liver uses different signalling or regulatory mechanisms. ODC B did not have any kinetic advantage over A in either the kidney or liver of growthhormone-treated rats, as Km°rn and Vmax values did not differ significantly between forms A and B in either case. The charge separation of ODC A and B from the kidney and liver was shown to be dependent on the state of phosphorylation based on the evidence that prior treatment of supernatant containing ODC with alkaline phosphatase resulted in the elution of active ODC A only by DEAE chromatography. Finally, ODC A and B did not differ in molecular weight (-48kD) as seen on an SDS-PAGE gel. In growth hormone-treated rats, ODC showed complex responses in terms of activity orkinetics. Not only did the ratio of liver ODC A and B not respond to lithium, actinomycin or putrescine treatment, but there was evidence of multiple species of ODC within forms A and B having different kinetic and half-life properties.
Γνωστικές και γλωσσικές ιδιαιτερότητες παιδιών πρώτης παιδικής ηλικίας που βρίσκονται σε επικινδυνότητα να αναπτύξουν σχολικές δυσκολίες: ένα ψυχοπαιδαγωγικό πρόγραμμα πρώιμης εκπαίδευσης μέσω αναλυτικών μεθόδων
Creators: name: Αναγνωστοπούλου, Ελένη Σ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Σχολικές δυσκολίες
Πρώιμη παρέμβαση
Γνωστικό ύφος
Ολιστική-αναλυτική μέθοδος
Παιδιά με ήπια νοητικά προβλήματα
Learning difficulties
Early intervention
Gognitive style
Holistic-analytic method
Slow learners

description: Αντικείμενο της διατριβής ήταν ο εντοπισμός παιδιών προσχολικής ηλικίας που παρουσιάζουν πρώιμες ενδείξεις σχολικών δυσκολιών, η αξιολόγηση των μαθησιακών τους ικανοτήτων ώστε να διαπιστωθούν ανεπάρκειες και η εφαρμογή κατάλληλου παιδαγωγικού προγράμματος. Αρχικά εντοπίστηκαν 328 παιδιά προσχολικής ηλικίας, τα οποία σύμφωνα με τις νηπιαγωγούς τους παρουσίαζαν δυσκολίες στο νηπιαγωγείο. Τα παιδιά αυτά αξιολογήθηκαν με το ΙΤΡΑ και η ανάλυση των ευρυμάτων οδήγησε σε 4 διαφορετικά προφίλ(ομάδες) μαθησιακής-γνωστικής ικανότητας. Επιλέχθηκε η ομάδα με τη χαμηλή μαθησιακή ικανότητα. Στα 30 παιδιά της ομάδας αυτής διερευνήθηκαν οι μέθοδοι επεξεργασίας(ολιστική-αναλυτική) στην επίλυση έργων που κατασκευάστηκαν από την ερευνήτρια. Τα 30 παιδιά χωρίστηκαν σε πειραματική ομάδα και ομάδα ελέγχου. Τα παιδιά της πειραματικής ομάδας συμμετείχαν σε πρόγραμμα παρέμβασης με έμφαση στη διδασκαλία αναλυτικών μεθόδων. Τα παιδιά και των 2 ομάδων επαναξιολογήθηκαν με την ολοκλήρωση του προγράμματος. Συμπερασματικά, φαίνεται ότι τα παιδιά της πειραματικής ομάδας επωφελήθηκαν από το πρόγραμμα παρέμβασης και έγιναν πιο αποτελεσματικά στην επίλυση έργων αφού απέκτησαν αναλυτικές μεθόδους επεξεργασίας. Επίσης διαπιστώθηκε βελτίωση σε ικανότητες και διεργασίες που αξιολογεί το ΙΤΡΑ
description: The presenyt thesis dissertation had three main objectives : to detect preschool children who excibit early signs of school difficulties; to evaluate their learning abilities so as to find their deficits; to apply a suitable educational programe. First, 328 preschool children were detected, who according to their teachers had shown signs of school difficulties. These children were evaluated with the ITRA test data analysis led to the formulation of 4 different profiles(groups) of learning-cognitive abilities. The group with the lower learning ability consisting of 30 children was chosen to participate in the programme. The researcher investigated the holistic-analytic style these children used in problem-solving tasks. The children were separated in two groups : the experimental group and the control group. The children in the experimental group took part in an individualized intervention programme with emphasis mainly in the teaching of analytic methods. After the completion of the programme the children in both groups were post-evaluated. Conclusively the children in the experimental group seemed to have benefited from the intervention programme but also to have become more effective in problem solving tasks, after they had conquered analytic processing methods
Οι σχέσεις μεταξύ μεγέθους, αποδοτικότητας και κινδύνου στις βιομηχανικές επιχειρήσεις με πρόσθετη εφαρμογή στις ενώσεις αγροτικών συνεταιρισμών
Creators: name: Σεργάκη, Παναγιώτα Δ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Αποδοτικότητα
Χρηματοοικονομικός κίνδυνος
Επιχειρηματικός κίνδυνος
Αγροτικοί Συνεταιρισμοί
Profitability
Financial risk
Business risk
Unions of agricultural cooperatives

description: Η διατριβή εξετάζει τις σχέσεις που δημιουργούνται μεταξύ του μεγέθους, της αποδοτικότητας και του κινδύνου των επιχειρήσεων και τον τρόπο με τον οποίο επηρεάζουν την αποδοτικότητα των ιδιωτικών επιχειρήσεων και των ενώσεων αγροτικών συνεταιρισμών. Τα δεδομένα καλύπτουν μια περίοδο 5 ετών για τις ιδιωτικές βιομηχανικές επιχειρήσεις(1995-1999) και 6 ετών(1995-2000) για τις ενώσεις αγροτικών συνεταιρισμών. Αναπτύχθηκε ένα θεωρητικό μοντέλο με σύστημα τεσσάρων ταυτόχρονων εξισώσεων με εξαρτημένες μεταβλητές το μέγεθος, την αποδοτικότητα, τον χρηματοοικονομικό και τον επιχειρηματικό κίνδυνο. Τα εμπειρικά αποτελέσματα εξήχθηκαν με τη βοήθεια μικτών διαχρονικών και διαστρωματικών στοιχείων με τα υποδείγματα των σταθερών και των τυχαίων αποτελεσμάτων, με τη μέθοδο των φαινομενικά μη εξαρτημένων εξισώσεων(SUR) και με τη μέθοδο των ελάχιστων τετραγώνων τριών σταδίων(3SLS) με το υπόδειγμα των σταθερών αποτελεσμάτων
description: The dissertation examines the impact of financial parameters on invested own firm and agricultural cooperatives in Greece. Data has been collected over a period of 5 years for invested own firms(3.281) and 6 years for unions of agricultural cooperatives (93). It has been developed a theoretical model within a system of four simultaneous equations presenting size, profitability, financial and business risk as dependent variables. Financial analysis results were used with the help of panel data sur and 3SLS techniques to estimate those parameters which would determine the profit performance of the invested own firms and the cooperatives in Greece as well as to compare and contrast their financial structure and policies
Two-dimensional small-world networks: navigation with local information
Creators: name: Chen, Jian-Zhen
name: Liu, Wei
name: Zhu, Jian-Yang
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Navigation process is studied on a variant of the Watts-Strogatz small world network model embedded on a square lattice. With probability $p$, each vertex sends out a long range link, and the probability of the other end of this link falling on a vertex at lattice distance $r$ away decays as $ r^{-α}$. Vertices on the network have knowledge of only their nearest neighbors. In a navigation process, messages are forwarded to a designated target. For $α<3$ and $α\neq 2$, a scaling relation is found between the average actual path length and $pL$, where $L$ is the average length of the additional long range links. Given $pL>1$, dynamic small world effect is observed, and the behavior of the scaling function at large enough $pL$ is obtained. At $α=2$ and 3, this kind of scaling breaks down, and different functions of the average actual path length are obtained. For $α>3$, the average actual path length is nearly linear with network size.
description: Accepted for publication in Phys. Rev. E
Discovery of a Young, Energetic 70.5 ms Pulsar Associated with the TeV Gamma-ray Source HESS J1837-069
Creators: name: Gotthelf, E. V.
name: Halpern, J. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the discovery of 70.5 ms pulsations from the X-ray source AX J1838.0-0655 using the Rossi X-ray Timing Explorer (RXTE). PSR J1838-0655 is a rotation-powered pulsar with spin-down luminosity Edot = 5.5e36 ergs/s, characteristic age tau = P/2Pdot = 23 kyr, and surface dipole magnetic field strength Bs = 1.9e12 G. It coincides with an unresolved INTEGRAL source and the extended TeV source HESS J1837-069. At an assumed distance of 6.6 kpc by association with an adjacent massive star cluster, the efficiency of PSR J1838-0655 converting spin-down luminosity to radiation is 0.8% for the 2-10 keV ASCA flux, 9% for the 20-300 keV INTEGRAL flux and ~3% for the >200 GeV emission of HESS J1837-069, making it a plausible power source for the latter. A Chandra X-ray observation resolves AX J1838.0-0655 into a bright point source surrounded by a ~2' diameter, centrally peaked nebula. The spectra of the pulsar and nebula are each well fitted by power laws, with photon indices Gamma = 0.5(0.3-0.7) and Gamma = 1.6(1.1-2.0), respectively. The 2-10 keV X-ray luminosities of the pulsar and nebula are L(PSR) = 4.6e34 d(6.6)^2 ergs/s and L(PWN) = 5.2e33 d(6.6)^2 ergs/s. A second X-ray source adjacent to the TeV emission, AX J1837.3-0652, is resolved into an apparent pulsar/PWN; it may also contribute to HESS J1837-069. The star cluster RSGC1 may have given birth to one or both pulsars, while fueling TeV emission from the extended PWN with target photons for inverse Compton scattering.
description: Comments: 8 pages, 7 figure, Latex, emulateapj style. To appear in the Astrophysical Journal
MPEC 2024-T72 : 2024 TC1
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 TC1

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.
A High Order Godunov Scheme with Constrained Transport and Adaptive Mesh Refinement for Astrophysical MHD
Creators: name: Fromang, S.
name: Hennebelle, P.
name: Teyssier, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In this paper, we present a new method to perform numerical simulations of astrophysical MHD flows using the Adaptive Mesh Refinement framework and Constrained Transport. The algorithm is based on a previous work in which the MUSCL--Hancock scheme was used to evolve the induction equation. In this paper, we detail the extension of this scheme to the full MHD equations and discuss its properties. Through a series of test problems, we illustrate the performances of this new code using two different MHD Riemann solvers (Lax-Friedrich and Roe) and the need of the Adaptive Mesh Refinement capabilities in some cases. Finally, we show its versatility by applying it to two completely different astrophysical situations well studied in the past years: the growth of the magnetorotational instability in the shearing box and the collapse of magnetized cloud cores. We have implemented this new Godunov scheme to solve the ideal MHD equations in the AMR code RAMSES. It results in a powerful tool that can be applied to a great variety of astrophysical problems, ranging from galaxies formation in the early universe to high resolution studies of molecular cloud collapse in our galaxy.
description: 17 pages, 12 figures, accepted in Astronomy & Astrophysics. A version with high resolution figure is avalaible at http://www.damtp.cam.ac.uk/user/fromang/publi/ramses.pdf
XRP Network and Proposal of Flow Index
Creators: name: Aoyama, Hideaki
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Finance (q-fin.GN)
subject: FOS: Economics and business

description: XRP is a modern crypto-asset (crypto-currency) developed by Ripple Labs, which has been increasing its financial presence. We study its transaction history available as ledger data. An analysis of its basic statistics, correlations, and network properties are presented. Motivated by the behavior of some nodes with histories of large transactions, we propose a new index: the ``Flow Index.'' The Flow Index is a pair of indices suitable for characterizing transaction frequencies as a source and destination of a node. Using this Flow Index, we study the global structure of the XRP network and construct bow-tie/walnut structure.
description: 15 pages, 15 Figures, for "Blockchain Kyoto 2011" JPS Conference Proceedings
Can Existing Theory Predict the Response of Tropical Cyclone Intensity to Idealized Landfall?
Creators: name: Chen, Jie
name: Chavas, Daniel R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Tropical cyclones cause significant inland hazards, including wind damage and freshwater flooding, that depend strongly on how storm intensity evolves at and after landfall. Existing theoretical predictions for the time-dependent and equilibrium response of storm intensity have been tested over the open ocean but not yet to be applied to storms after landfall. Recent work examined the transient response of the tropical cyclone low-level wind field to instantaneous surface roughening or drying in idealized axisymmetric f-plane simulations. Here, experiments testing combined surface roughening and drying with varying magnitudes of each are used to test theoretical predictions for the intensity response. The transient response to combined surface forcings can be reproduced by the product of their individual responses, in line with traditional potential intensity theory. Existing intensification theory is generalized to weakening and found capable of reproducing the time-dependent inland intensity decay. The initial (0-10min) rapid decay of near-surface wind caused by surface roughening is not captured by existing theory but can be reproduced by a simple frictional spin-down model, where the decay rate is a function of surface roughness. Finally, the theory is shown to compare well with the prevailing empirical decay model for real-world storms. Overall, results indicate the potential for existing theory to predict how tropical cyclone intensity evolves after landfall.
Η αθλητική αρετή στον Πίνδαρο
Creators: name: Κοντού, Μαρία-Ζωή Ι.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Επινίκιες Ωδές
Αθλητική αρετή
Epinikian Oder
Athletic Arete

description: Η παρούσα διατριβή αποτελείται από 5 κεφάλαια. Το πρώτο κεφάλαιο, το οποίο είναι εισαγωγικλη, αποτελεί μια ιστορική αναδρομή στην εξέλιξη της ποιητικής παραγωγής μέχρι το χορικό λυρικό άσμα του 5ου π.Χ. αι. Το δεύτερο κεφάλαιο αναφέρεται στη διαχρονικότητα και σημαντικότητα του αθλητισμού στην αρχαία ελληνική σκέψη από τον Ομηρο μέχρι και την εποχή του ποιητή Πίνδαρου καθώς και στην ύπαρξη του αθλητικού συναγωνισμού με τη μορφή των Μεγάλων Αγώνων μέσα από τη δημιουργία της πόλης-κράτους. Στο τρίτο κεφάλαιο παρουσιάζεται η έννοια της αθλητικής αρετής στη συνείδηση του ποιητή καθώς και το στοιχείο της αρετής στον συναγωνισμό ποιητών-καλλιτεχνικών. Στο τέταρτο κεφάλαιο αναλύονται το εξής βασικά θέματα : 1. To στοιχείο της αρετής στη σχέση αθλητή-ποιητή 2. Ο έπαινος του νικητή και η αθλητική αρετή 3. Η πινδαρική θεώρηση της ήττας ως έλλειψη της αθλητικής αρετής 4. Ο ποιητής ως αθλητής στο αγώνισμα της διαπαιδαγώγησης και 5. Η έννοια της αρετής και οι οικονομικές απολαβές αθλητή και ποιητή
description: The present study consist of 5 chapters. The first one, which is introductory, constitudes a historical retrospect on the evolution of the poetical production up to the choric lyric ode of the 5th century B.C. The second chapter refer to the importance of athletic for the ancient greek mind from Homer up to Pindar's age, as well as to the existence of the athletic competition under the form of the great events through the creation of the city-state. In the third chapter, the consept of arete in the poet's consciousness is presented, as well as the element of arete in the competitiveness between poets and artists. In the fourth chapter, the following basic topics are analyzed : 1. The element of arete are to the relation between athlete and poet 2. The praise of the victor and athletic arete 3. The pindaric concept of defeat at lack of athletic arete 4. The poet ar an athlete in the educational contest 5. The aspect of arete and the financial rewords of athlete and poet
DKP oscillator in the presence of a spinning cosmic string
Creators: name: Yang, Yi
name: Hassanabadi, Hassan
name: Chen, Hao
name: Long, Zheng-Wen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the modification of gravitational fields generated by topological defects on a generalized Duffin-Kemmer-Petiau (DKP) oscillator for spin-0 particle under spinning cosmic string background. The generalized DKP oscillator equation under spinning cosmic string background is established, and the impact of the Cornell potential on the generalized DKP oscillator is presented. We give the influence of space-time and potential parameters on energy levels.
Nonthermal Hard X-ray Emission and Iron Kalpha Emission from a Superflare on II Pegasi
Creators: name: Osten, R. A.
name: Drake, S.
name: Tueller, J.
name: Cummings, J.
name: Perri, M.
name: Moretti, A.
name: Covino, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on an X-ray flare detected on the active binary system II~Pegasi with the Swift telescope. The trigger had a 10-200 keV luminosity of 2.2$\times10^{32}$ erg s$^{-1}$-- a superflare, by comparison with energies of typical stellar flares on active binary systems. The trigger spectrum indicates a hot thermal plasma with T$\sim$180 $\times10^{6}$K. X-ray spectral analysis from 0.8--200 keV with the X-Ray Telescope and BAT in the next two orbits reveals evidence for a thermal component (T$>$80 $\times10^{6}$K) and Fe K 6.4 keV emission. A tail of emission out to 200 keV can be fit with either an extremely high temperature thermal plasma (T$\sim3\times10^{8}$K) or power-law emission. Based on analogies with solar flares, we attribute the excess continuum emission to nonthermal thick-target bremsstrahlung emission from a population of accelerated electrons. We estimate the radiated energy from 0.01--200 keV to be $\sim6\times10^{36}$ erg, the total radiated energy over all wavelengths $\sim10^{38}$ erg, the energy in nonthermal electrons above 20 keV $\sim3\times10^{40}$ erg, and conducted energy $<5\times10^{43}$ erg. The nonthermal interpretation gives a reasonable value for the total energy in electrons $>$ 20 keV when compared to the upper and lower bounds on the thermal energy content of the flare. This marks the first occasion in which evidence exists for nonthermal hard X-ray emission from a stellar flare. We investigate the emission mechanism responsible for producing the 6.4 keV feature, and find that collisional ionization from nonthermal electrons appears to be more plausible than the photoionization mechanism usually invoked on the Sun and pre-main sequence stars.
description: 41 pages, 7 figures, accepted for publication in the Astrophysical Journal
Geometry of Invariant Tori of Certain Integrable Systems with Symmetry and an Application to a Nonholonomic System
Creators: name: Fassò, Francesco
name: Giacobbe, Andrea
Publisher: name: arXiv
Year: 2007
Subjects: subject: Symplectic Geometry (math.SG)
subject: Dynamical Systems (math.DS)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Bifibrations, in symplectic geometry called also dual pairs, play a relevant role in the theory of superintegrable Hamiltonian systems. We prove the existence of an analogous bifibrated geometry in dynamical systems with a symmetry group such that the reduced dynamics is periodic. The integrability of such systems has been proven by M. Field and J. Hermans with a reconstruction technique. We apply the result to the nonholonomic system of a ball rolling on a surface of revolution.
description: This is a contribution to the Proc. of workshop on Geometric Aspects of Integrable Systems (July 17-19, 2006; Coimbra, Portugal), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/
Growth, carcass composition, and plasma growth hormone levels in cyclically fed rainbow trout, Oncorhynchus mykiss microform
Creators: name: Inglis, Susan D.
Publisher: name: University of British Columbia
Year: 2008

description: The compensatory growth response (C.G.R.), a phase of rapid growth following a period of feeding restriction, is investigated in rainbow trout (Oncorhynchus mykiss). Underyearling rainbow trout were individually identified using coded tags and placed on either a cyclic feeding regime of 3 weeks of starvation followed by 3 weeks of refeeding (to elicit a G.C.R.) or a daily feeding regime. The effects of this feeding regime on growth, body composition, and plasma growth hormone levels were recorded weekly for 24 weeks to include 4 feeding cycles. Fish that were placed on a cyclic feeding regime exhibited higher specific growth rates, protein levels and lower fat content than fish that were fed daily. The condition factor, which is an index of the fatness or leanness of a fish, was slightly lower than that of the control groups at the end of the experiment as a leaner fish was produced. The response to the starvation phase of the feeding cycle (as far as weight and fat loss were concerned) decreased in intensity with subsequent feeding cycles, indicating that the fish were acclimating to the feeding regime. There was a significant increase in variability of both the weight and length data within the cyclically fed population as the experiment progressed and they showed increased sensitivity to water quality. No "inphase" cycling of plasma growth hormone levels was observed for the cyclically fed fish. The implications of these findings in the use of cyclic feeding regimes in fish culture are discussed.
Colour Dependence of the Distribution of IRAS Galaxies revealed by Multifractal Measures
Creators: name: Pan, Jun
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Multifractal measures are applied to three IRAS galaxy subsamples selected by colour from the PSCz catalogue. As shown by generalised dimension spectrum, hot IRAS galaxies are found less clustered than cold galaxies, but the difference is very weak. An alternative tool, the conditional multifractal dimension spectrum reveals apparent peculiarity of the distribution of hot galaxies, especially at high orders. The conditional multifractal measure is basically measuring the environment of selected galaxies. A detailed analysis of the distribution of galaxies with their number of neighbours turns out that cold galaxies are more likely living in over dense regions than hot galaxies. Further studies suggest that, since the colour of IRAS galaxies is a good trace of star formation rate, it is possible that we have statistical evidence here for enhanced star formation rate due to galaxy interactions
description: minor revision; accepted by A&A
Automated photometry of $γ$ Cassiopeiae:the last roundup
Creators: name: Smith, Myron A.
name: Henry, G. W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Gamma Cas (B0.5IVe) is the noted prototype of a subgroup of classical Be stars exhibiting hard thermal X-ray emission. This paper reports results from a 23-year optical campaign with an Automated Photometric Telescope (APT) on this star. A series of unstable long cycles of length 56--91 days has nearly ceased over the last decade. Herein, we revise the frequency of the dominant coherent signal at 0.82238 cy/d. This signal's amplitude has nearly disappeared in the last 15 years but has somewhat recovered its former strength. We confirm the presence of secondary nonradial pulsation signals found by other authors at frequencies 1.25, 2.48, and 5.03 cy/d. The APT data from intensively monitored nights reveal rapidly variable amplitudes among these frequencies. We show that peculiarities in the 0.82 cy/d waveform exist that can vary even over several days. Although the 0.82 cy/d frequency is near the star's presumed rotation frequency. However, because of its phase slippage with respect to a dip pattern in the star's far-UV light curve it is preferable to consider the latter pattern, not the 0.82 cy/d signal, that carries a rotation signature. We also find hints of the UV dip pattern in periodograms of early-season APT data.
description: 17 pages, 8 figures; Accepted by ApJ
Η συμβουλευτική διαδικασία: προς αναζήτηση ενός μοντέλου ψυχοκοινωνικής συμβουλευτικής παρέμβασης
Creators: name: Σαλπιστής, Σάββας Ν.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004

description: Στην παρούσα έρευνα παρουσιάζονται και αναπτύσσονται θεωρητικές και μεθοδολογικές απόψεις που αφορούν τη συμβουλευτική παρέμβαση στα πλαίσια της προσχολικής αγωγής. Το μοντέλο που χρησιμοποιήσαμε είναι επικεντρωμένο στο προσωπικό, γιατί θεωρούμε πως η αντιμετώπιση και επίλυση των περισσοτέρων προβλημάτων που εμφανίζονται στο χώρο της προσχολικής αγωγής είναι συχνότατα εφικτή διαμέσου του προσωπικού, εφόσον αυτό έχει την απαραίτητη υποστήριξη και γνώση. Ως εκ τούτου, η διατριβή αυτή στοχεύει στην περιγραφή της διαδικασίας της συμβουλευτικής παρέμβασης και των αποτελεσμάτων της, στην καλυτερη κατανόηση της αλληλεπίδρασης ανάμεσα στον σύμβουλο και την ομάδα προσωπικού και στην ανακάλυψη του τρόπου με τον οποίο αυτή η αλληλεπίδραση επηρεάζει το αποτέλεσμα της συμβουλευτικής παρέμβασης. Αυτό θα συνέβαλε στην εξέλιξη ενός μοντέλου που με αφετηρία το προσωπικό, θα στόχευε σε ευνοϊκά για το παιδί αποτελέσματα
description: This research presents and develops theoretical and methodological concepts related to consultation process as far as preschool education is concerned. This model, which was used, is focused on the staff because we consider that most of the problems that appear in the environment of preschool education can be faced and solved by the staff, provided they have the essential support and knowledge. Therefore, this thesis aims at the description of the consultation process and its effects, at better knowledge of the mutual influence between the consultant and the staff as well as the discovery of the way in which this mutual influences shapes the result of this consultation process. This would result in the development of a model which based on staff's help, would lead to favourable results for the child
The statistics of critical points of Gaussian fields on large-dimensional spaces
Creators: name: Bray, Alan J.
name: Dean, David S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We calculate the average number of critical points of a Gaussian field on a high-dimensional space as a function of their energy and their index. Our results give a complete picture of the organization of critical points and are of relevance to glassy and disordered systems, and to landscape scenarios coming from the anthropic approach to string theory.
description: 5 pages
Broadband RF Phased Array Design with MEEP: Comparisons to Array Theory in Two and Three Dimensions
Creators: name: Hanson, Jordan C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Phased array radar systems have a wide variety of applications in engineering and physics research. Phased array design usually requires numerical modeling with expensive commercial computational packages. Using the open-source MIT Electrogmagnetic Equation Propagation (MEEP) package, a set of phased array designs is presented. Specifically, one and two-dimensional arrays of Yagi-Uda and horn antennas were modeled in the bandwidth [0.1 - 5] GHz, and compared to theoretical expectations in the far-field. Precise matches between MEEP simulation and radiation pattern predictions at different frequencies and beam angles are demonstrated. Given that the computations match the theory, the effect of embedding a phased array within a medium of varying index of refraction is then computed. Understanding the effect of varying index on phased arrays is critical for proposed ultra-high energy neutrino observatories which rely on phased array detectors embedded in natural ice. Future work will develop the phased array concepts with parallel MEEP, in order to increase the detail, complexity, and speed of the computations.
Preparation of Entangled States by Quantum Markov Processes
Creators: name: Kraus, B.
name: Büchler, H. P.
name: Diehl, S.
name: Kantian, A.
name: Micheli, A.
name: Zoller, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We investigate the possibility of using a dissipative process to prepare a quantum system in a desired state. We derive for any multipartite pure state a dissipative process for which this state is the unique stationary state and solve the corresponding master equation analytically. For certain states, like the Cluster states, we use this process to show that the jump operators can be chosen quasi-locally, i.e. they act non-trivially only on a few, neighboring qubits. Furthermore, the relaxation time of this dissipative process is independent of the number of subsystems. We demonstrate the general formalism by considering arbitrary MPS-PEPS states. In particular, we show that the ground state of the AKLT-model can be prepared employing a quasi--local dissipative process.
description: minor changes, references added, appendix removed
An "All Possible Steps" Approach to the Accelerated Use of Gillespie's Algorithm
Creators: name: Lipshtat, Azi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Many physical and biological processes are stochastic in nature. Computational models and simulations of such processes are a mathematical and computational challenge. The basic stochastic simulation algorithm was published by D. Gillespie about three decades ago [D.T. Gillespie, J. Phys. Chem. {\bf 81}, 2340, (1977)]. Since then, intensive work has been done to make the algorithm more efficient in terms of running time. All accelerated versions of the algorithm are aimed at minimizing the running time required to produce a stochastic trajectory in state space. In these simulations, a necessary condition for reliable statistics is averaging over a large number of simulations. In this study I present a new accelerating approach which does not alter the stochastic algorithm, but reduces the number of required runs. By analysis of collected data I demonstrate high precision levels with fewer simulations. Moreover, the suggested approach provides a good estimation of statistical error, which may serve as a tool for determining the number of required runs.
description: Accepted for publication at the Journal of Chemical Physics. 19 pages, including 2 Tables and 4 Figures
Universal velocity distributions in an experimental granular fluid
Creators: name: Reis, Pedro M.
name: Ingale, Rohit A.
name: Shattuck, Mark D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present experimental results on the velocity statistics of a uniformly heated granular fluid, in a quasi-2D configuration. We find the base state, as measured by the single particle velocity distribution $f(c)$, to be universal over a wide range of filling fractions and only weakly dependent on all other system parameters. There is a consistent overpopulation in the distribution's tails, which scale as $f\propto\exp(\mathrm{const.}\times c^{-3/2})$. More importantly, the high probability central region of $f(c)$, at low velocities, deviates from a Maxwell-Boltzmann by a second order Sonine polynomial with a single adjustable parameter, in agreement with recent theoretical analysis of inelastic hard spheres driven by a stochastic thermostat. To our knowledge, this is the first time that Sonine deviations have been measured in an experimental system.
description: 13 pages, 15 figures, with minor corrections, submitted to Phys. Rev. E
Operation of Natural Gas Pipeline Networks With Storage Under Transient Flow Conditions
Creators: name: Hari, Sai Krishna Kanth
name: Sundar, Kaarthik
name: Srinivasan, Shriram
name: Zlotnik, Anatoly
name: Bent, Russell
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We formulate a nonlinear optimal control problem for intra-day operation of a natural gas pipeline network that includes storage reservoirs. The dynamics of compressible gas flow through pipes, compressors, reservoirs, and wells are considered. In particular, a reservoir is modeled as a rigid, hollow container that stores gas under isothermal conditions and uniform density, and a well is modeled as a vertical pipe. For each pipe, flow dynamics are described by a coupled partial differential equation (PDE) system in density and mass flux variables, with momentum dissipation modeled using the Darcy-Wiesbach friction approximation. Compressors are modeled as scaling up the pressure of gas between inlet and outlet. The governing equations for all network components are spatially discretized and assembled into a nonlinear differential-algebraic equation (DAE) system, which synthesizes above-ground pipeline and subsurface reservoir dynamics into a single reduced-order model. We seek to maximize an objective function that quantifies economic profit and network efficiency subject to the flow equations and inequalities that represent operating limitations. The problem is solved using a primal-dual interior point solver and the solutions are validated in computational experiments and simulations on several pipeline test networks to demonstrate the effectiveness of the proposed methodology.
description: 13 pages
Διαχείριση της ζήτησης του νερού στο βιομηχανικό τομέα στη Θεσσαλονίκη
Creators: name: Βαγιωνά, Δήμητρα Γ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Διαχείριση της ζήτησης του νερού
Βιομηχανική χρήση του νερού
Water demand management
industrial water use

description: Η σημερινή κρίση του νερού αφείλεται στην αποτυχία θεώρησης του ως αγαθού πρώτης ανάγκης που βρίσκεται σε ανεπάρκεια. Η αντιμετώπιση του προβλήματος αυτού μπορεί να πραγματοποιηθεί με την ορθολογικότερη χρήση των υπαρχόντων αποθεμάτων σε συνδυασμό με τη διαχείριση της ζήτησης του νερού. Με την παραδοχή των αρχών της βιώσιμης ανάπτυξης στην υδατική πολιτική, η διαχείριση της ζήτησης αποτελεί πρώτη προτεραιότητα. Η διαχείριση της ζήτησης προσανατολίζεται στη χρήση οικονομικών εργαλείων, τεχνολογιών εξοικονόμησης νερού και εκστρατειών ενημέρωσης και περιβαλλοντικής εκπαίδευσης των καταναλωτών. Η διδακτορική διατριβή ασχοελίται με τη διαχείριση της ζήτησης του νερού στον τομέα της ύδρευσης και πιο συγκεκριμένα στο βιομηχανικό τομέα. Σκοπός είναι η ανάλυση των παραγόντων που επηρεάζουν τη ζήτηση του νερού, η εύρεση της ελαστικότητας της ζήτησης του νερού και η πρόβλεψη της μελλοντικής ζήτησης ως αποτέλεσμα της εφαρμογής εναλλακτικών πολιτικών διαχείρισης της ζήτησης
description: Reliable water supply and the protection of a quatic resources through adequate water management are essential to support all aspects of human life. The old trend of designing the cheapest reliable supply with little or no attention to demand determinants, pricing structures and financing policies is no longer suitable. Nowdays, there is a wide recognision that there is a need for strategies for the sustainable development ensures an appropriate exploitation of water resources, which minimizes the adverse environmental imports. The thesis deals with water demand management strategies in the industrial sector in the city of Thessaloniki. The aim of the thesis is to analyze the parameters that affect industrial water demand, estimate elasticities of water demand and forecast water demand by applying alternative water demand management policies
Infrared non-perturbative QCD running coupling from Bogolubov approach
Creators: name: Arbuzov, Boris A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We apply Bogolubov approach to QCD to demonstrate a spontaneous generation of three-gluon gauge invariant effective interaction which contributes significantly at the infrared region. The contribution of this interaction to $α_s(p^2)$ leads to description of its behaviour in correspondence to phenomenology and lattice calculations without introduction of any additional parameter.
description: 8 pages, 3 figures, corrected types, precision of calculations improved, one figure added
Αυτόματη κατάστρωση και αριθμητική ολοκλήρωση εξισώσεων κίνησης μηχανικών συστημάτων με πολλαπλά παραμορφώσιμα μέλη
Creators: name: Γκούντας, Ηρακλής Ι.
Publisher: name: Aristotle University of Thessaloniki
Year: 2004
Subjects: Μηχανικά συστήματα
Αριθμητική επίλυση
Περιοδική απόκριση
Κινητήρες
Mechanical systems
Numerical solution
Periodic responce
Engines

description: Η ανάλυση για τη μελέτη της δυναμικής συμπεριφοράς πολύπλοκων μηχανικών συστημάτων, των οποίων κάποια μέλη είναι παραμορφώσιμα και εκτελούν μεγάλες κινήσεις στερεού σώματος, επιτάσσει την ανάπτυξη κατάλληλων μεθοδολογιών για την κατάστρωση και την επίλυση των εξισώσεων κίνησης με όσο το δυνατό πιο αυτόματο τρόπο, κυρίως με χρήση ηλεκτρονικών υπολογιστών. Μια σημαντική κατηγορία μηχανισμών που επωφελείται από τέτοιες μεθοδολογίες είναι αυτή των κινητήρων οχημάτων
description: The need for the study of the dynamic response of complex mechanical systems demands the development of proper methologies for the construction and resolution of the equations of motion, mainly with the use of computers. An important class of mechanisms that benefits from these methologies is the class of vehicle motor engines