cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Analysis of Shellfish Growing Areas of Alabama, Florida and Georgia, USA - Using the Pearl Shellfish Sanitation Model
Creators: name: Conte, Fred S.
name: Ahmadi, Abbas
Publisher: name: CentMA
Year: 2015
Subjects: modeling; shellfish sanitation; water quality; shellfish closure rules

description: According to the United States (U.S.), National Shellfish Sanitation Program (NSSP) standards, the shellfish growing areas in modeling, shellfish sanitation, water quality, shellfish closure rules the U.S. must be closed for harvest when the estimated 90th percentile of fecal coliform concentrations exceeds the NSSP limit of 14/43 Most Probable Number/100 mL (NSSP, 2009, NSSP, 2011). Pearl is a model that identifies harvest areas at risk for fecal coliform contamination (Conte and Ahmadi, 2012). Once the risk areas are identified, the Aquarius model can be used to adjust closure rules (Conte and Ahmadi, 2011). In multi-state analyses using the Pearl model, we have developed a hypothesis that state agencies are inadvertently applying the model's Pearl Limit of 8/26 MPN/100 mL in place of the NSSP limit of 14/43 MPN/100 mL for a 5-tube test to guard against shellfish-related illnesses (Conte and Ahmadi, 2012; 2013; 2014). The datasets used to develop the hypothesis were from Oakland Bay, Washington (Pacific Northwest), Arcata Bay, California (Pacific Northern California), and seven shellfish bays of the Texas Gulf Coast (Western Gulf of Mexico). The main purpose of this paper is to test this hypothesis using different datasets from shellfish growing areas in the states of Alabama (Eastern Gulf of Mexico), Florida (Eastern Gulf of Mexico and south Atlantic Coast) and Georgia (South Atlantic Coast), all located in the southeastern United States. An additional objective is to use the state’s datasets in Pearl analyses to detect the shellfish growing areas that pose a possible health risk to shellfish consumers during some periods
description: International Journal on Food System Dynamics, Vol 5, No 4 (2014): Special issue: Challenge of IT, Innovation and Knowledge
Classical Phase Space Density for the Relativistic Hydrogen Atom
Creators: name: Nieuwenhuizen, Th. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum mechanics is considered to arise from an underlying classical structure (``hidden variable theory'', ``sub-quantum mechanics''), where quantum fluctuations follow from a physical noise mechanism. The stability of the hydrogen ground state can then arise from a balance between Lorentz damping and energy absorption from the noise. Since the damping is weak, the ground state phase space density should predominantly be a function of the conserved quantities, energy and angular momentum. A candidate for this phase space density is constructed for ground state of the relativistic hydrogen problem of a spinless particle. The first excited states and their spherical harmonics are also considered in this framework. The analytic expression of the ground state energy can be reproduced, provided averages of certain products are replaced by products of averages. This analysis puts forward that quantum mechanics may arise from an underlying classical level as a slow variable theory, where each new quantum operator relates to a new, well separated time interval.
description: 15pages AIP tex with 1 Figure
The spin-double refraction in two-dimensional electron gas
Creators: name: Bercioux, D.
name: Ramaglia, V. Marigliano
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We briefly review the phenomenon of the spin-double refraction that originates at an interface separating a two-dimensional electron gas with Rashba spin-orbit coupling from a one without. We demonstrate how this phenomenon in semiconductor heterostructures can produce and control a spin-polarized current without ferromagnetic leads.
"YANGI O'ZBEKISTON TARAQQIYOTI" STRATEGIYASIDA RESPUBLIKANI KELGUSIDA RIVOJLANTIRISHNING MAQSAD VA VAZIFALARI
Creators: name: Qodirova, Laziza
Publisher: name: Zenodo
Year: 2024

description: Ushbu maqolada mamlakatimizda sodir bo’layotgan barcha o’zgarishlar, taraqqiyot va rivojlanishlar yo’lidagi barcha tamoyillarga asoslangan holda olib borilayotgan ustuvor yo’nalishlar haqida batafsil so’z yuriritiladi.
The Development of Automated Information Systems to reduce the Digital Divide in Agricultural Communities: The Case of the Agricultural Information Service in Tierra Blanca (SIT), Costa Rica
Creators: name: Thomas, Laura Solera
name: Alvarado, Daniela Muñoz
name: Araya, Carlos Angulo
name: Ramírez, José Joaquín Brenes
name: Ramírez, José Manuel Brenes
name: Víquez, Gabriel Brenes
name: Acuña, Sonia Gómez
name: Redondo, Fausto Víquez
Publisher: name: CentMA
Year: 2015
Subjects: Digital divide agricultural library; information systems; information access; digital literacy; Tierra Blanca; Costa Rica

description: This study aims to analyze the phenomena of the digital divide in the community of Tierra Blanca and presents the case of the Agricultural Information Service in Tierra Blanca as a solution to reduce the digital divide in this farming community. Based on the promise that Information and Communication Technologies (ICT) have a great importance in today´s society, the article analyzes the concept of digital divide composed by three components: access to information, connectivity and digital literacy, contextualized in farming communities. The paper studies the relationship between the digital divide and the productive, political, economic, social, cultural and commercial business development of small farmers. Based on the collaboration of a group of farmers in Tierra Blanca, the impact of the digital divide is considered specifically in this community. The case of the Agricultural Information Service in Tierra Blanca is presented as an automated information system that allows to combat lags generated by this phenomena. The study concludes that the case of the Agricultural Information Service in Tierra Blanca is an initiative that has reduced the digital divide in a comprehensive way for farmers, but the development of comprehensive policies and strategies at the community and national levels is necessary, seeking the involvement of various institutions and communities.
description: International Journal on Food System Dynamics, Vol 5, No 4 (2014): Special issue: Challenge of IT, Innovation and Knowledge
Urban Gardening Realities: The Example Case Study of Portsmouth, England
Creators: name: Hallsworth, Alan
name: Wong, Alfred
Publisher: name: CentMA
Year: 2015

description: This paper offers an empirical case study of the potential for urban gardening to contribute to individual food security. Food security generally encompasses both availability and accessibility. In Western Europe, availability per se has declined in importance with the development of national and international transportation networks. During the past decade, urban gardening has gained political currency as a strategy to provide greater food security at the local level. However, prevailing economic and social structures hamper the likelihood that urban gardening might offer much greater food security. Realistically, contemporary urban gardening most closely resembles a middle-class pursuit for personal enjoyment.
description: International Journal on Food System Dynamics, Vol 6, No 1 (2015)
Doped carrier formulation and mean-field theory of the tt't''J model
Creators: name: Ribeiro, Tiago C.
name: Wen, Xiao-Gang
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In the generalized-tJ model the effect of the large local Coulomb repulsion is accounted for by restricting the Hilbert space to states with at most one electron per site. In this case the electronic system can be viewed in terms of holes hopping in a lattice of correlated spins, where holes are the carriers doped into the half-filled Mott insulator. To explicitly capture the interplay between the hole dynamics and local spin correlations we derive a new formulation of the generalized-tJ model where doped carrier operators are used instead of the original electron operators. This ``doped carrier'' formulation provides a new starting point to address doped spin systems and we use it to develop a new, fully fermionic, mean-field description of doped Mott insulators This mean-field approach reveals a new mechanism for superconductivity, namely spinon-dopon mixing, and we apply it to the tt't''J model as of interest to high-temperature superconductors. In particular, we use model parameters borrowed from band calculations and from fitting ARPES data to obtain a mean-field phase diagram that reproduces semi-quantitatively that of hole and electron doped cuprates. The mean-field approach hereby presented accounts for the local antiferromagnetic and d-wave superconducting correlations which, we show, provide a rational for the role of t' and t'' in strengthening superconductivity as expected by experiments and other theoretical approaches. As we discuss how t, t' and t'' affect the phase diagram, we also comment on possible scenarios to understand the differences between as-grown and oxygen reduced electron doped samples.
description: 17 pages, 2 figures. Homepage http://dao.mit.edu/~wen/
The iron record of asteroidal processes in carbonaceous chondrites
Creators: name: Garenne, A.
name: Beck, P.
name: Montes-Hernandez, G.
name: Bonal, L.
name: Quirico, E.
name: Proux, O.
name: Hazemann, J. L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The valence of iron has been used in terrestrial studies to trace the hydrolysis of primary silicate rocks. Here, we use a similar approach to characterize the secondary processes, namely thermal metamorphism and aqueous alteration, that have affected carbonaceous chondrites. X-ray absorption near-edge structure spectroscopy at the Fe-K- edge was performed on a series of 36 CM, 9 CR, 10 CV, and 2 CI chondrites. Among the four carbonaceous chondrites groups studied, a correlation between the iron oxidation index (IOI = [2 ((Fe2+) + 3(Fe3+))/FeTOT) and the hydrogen content is observed. However, within the CM group, for which a progressive alteration sequence has been defined, a conversion of Fe3+ to Fe2+ is observed with increasing degree of aqueous alteration. This reduction of iron can be explained by an evolution in the mineralogy of the secondary phases. In the case of the few CM chondrites that experienced some thermal metamorphism, in addition to aqueous alteration, a redox memory of the aqueous alteration is present: a significant fraction of 3+ 2+ 0 Fe is present, together with Fe and sometimes Fe. From our data set, the CR chondrites show a wider range of IOI from 1.5 to 2.5. In all considered CR chondrites, the three oxidation states of iron coexist. Even in the least-altered CR chondrites, the fraction of Fe3+ can be high (30% for MET 00426). This observation confirms that oxidized iron has been integrated during formation of fine-grained amorphous material in the matrix. Last, the IOI of CV chondrites does not reflect the reduced/oxidized classification based on metal and magnetite proportions, but is strongly correlated with petrographic types. The valence of iron in CV chondrites therefore appears to be most closely related to thermal history, rather than aqueous alteration, even if these processes can occur together .
Short-term drought forecasting combining stochastic and geo-statistical approaches
Creators: name: C.A. Karavitis
name: C.G. Vasilakou
name: D.E. Tsesmelis
name: Oikonomou, Panagiotis D.
name: N.A. Skondras
name: D. Stamatakos
name: V. Fassouli
name: S. Alexandris
Publisher: name: figshare
Year: 2020
Subjects: subject: 90509 Water Resources Engineering
subject: FOS: Civil engineering

description: The current work presents the application of the seasonal Auto Regressive Integrated Moving Average Model (ARIMA) using the Standard Precipitation Index (SPI) as a drought indicator and then depicting the spatial distribution through geo-statistical methods. Greece is very often facing the hazardous impacts of droughts, hence presenting an almost ideal case for such an application. The applied methodology used precipitation data from 55 meteorological stations in two sets distributed throughout the country. To assess the drought, SPI was calculated for a variety of temporal steps. The statistical analyses of the examined temporal step parameters were performed and the Seasonal ARIMA model was employed. Then based on such link, forecasting attempts were derived and presented. The effort may lead to a further understanding of drought duration, magnitude and spatial extend in semi-arid areas. It is believed that such a methodology may provide some useful anticipatory information on the area’s vulnerability to drought and thus portraying the system’s susceptibility to change, damages and losses. In this context, drought contingency planning may be included in the decision making arsenal in order to also widen existing perceptions of the area’s inherent weaknesses and limited resilience to both anthropogenic and natural hazards, serving at the same time as an early warning mechanism.
The time distribution of quantum events
Creators: name: Jurman, Danijel
name: Nikolic, Hrvoje
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We develop a general theory of the time distribution of quantum events, applicable to a large class of problems such as arrival time, dwell time and tunneling time. A stopwatch ticks until an awaited event is detected, at which time the stopwatch stops. The awaited event is represented by a projection operator $π$, while the ideal stopwatch is modeled as a series of projective measurements at which the quantum state gets projected with either $\barπ=1-π$ (when the awaited event does not happen) or $π$ (when the awaited event eventually happens). In the approximation in which the time $δt$ between the subsequent measurements is sufficiently small (but not zero!), we find a fairly simple general formula for the time distribution ${\cal P}(t)$, representing the probability density that the awaited event will be detected at time $t$.
description: 18 pages, 3 figures, version accepted for publication in Phys. Lett. A
Analysis of function and survival in ALS patients with diaphragm pacing using virtual controls
Creators: name: Taylor, Albert
name: Miller, Robert
name: Onders, Raymond
name: Ennist, David
Publisher: name: F1000Research
Year: 2016

description: This poster used random forests and gradient boosting machine algorithms to develop individual patient-level disease progression predictions for ALS patients involved in a clinical trial of the NeuRx DPS® Diaphragm Pacing System (DPS). Virtual controls for ALSFRS-R and survival were generated from the predictions and compared to the observed outcomes.
On the Matching Equations of Kinetic Energy Shaping in IDA-PBC
Creators: name: Harandi, M. Reza J.
name: Taghirad, Hamid D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Interconnection and damping assignment passivity-based control scheme has been used to stabilize many physical systems such as underactuated mechanical systems through total energy shaping. In this method, some partial differential equations (PDEs) arisen by kinetic and potential energy shaping, shall be solved analytically. Finding a suitable desired inertia matrix as the solution of nonlinear PDEs related to kinetic energy shaping is a challenging problem. In this paper, a systematic approach to solve this matching equation for systems with one degree of underactuation is proposed. A special structure for desired inertia matrix is proposed to simplify the solution of the corresponding PDE. It is shown that the proposed method is more general than that of some reported methods in the literature. In order to derive a suitable desired inertia matrix, a necessary condition is also derived. The proposed method is applied to three examples, including VTOL aircraft, pendubot and 2D SpiderCrane system.
On divisibility of Narayana numbers by primes
Creators: name: Bona, Miklos
name: Sagan, Bruce
Publisher: name: arXiv
Year: 2005
Subjects: subject: Combinatorics (math.CO)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary 11B50; Secondary 05A10, 11A07, 11B64

description: Using Kummer's Theorem, we give a necessary and sufficient condition for a Narayana number to be divisible by a given prime. We use this to derive certain properties of the Narayana triangle.
description: 5 pages, see related papers at http://www.math.msu.edu/~sagan
Xenon1T excess from electron recoils of non-relativistic Dark Matter
Creators: name: Buttazzo, Dario
name: Panci, Paolo
name: Teresi, Daniele
name: Ziegler, Robert
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We show that electron recoils induced by non-relativistic Dark Matter interactions can fit well the recently reported Xenon1T excess, if they are mediated by a light pseudo-scalar in the MeV range. This is due to the favorable momentum-dependence of the resulting scattering rate, which partially compensates the unfavorable kinematics that tends to strongly suppress keV electron recoils. We study the phenomenology of the mediator and identify the allowed parameter space of the Xenon1T excess which is compatible with all experimental limits. We also find that the anomalous magnetic moments $(g-2)_{μ,e}$ of muons and electrons can be simultaneously explained in this scenario, at the prize of a fine-tuning in the couplings of the order of a few percent.
description: 5 pages, 4 figures; v2: updated experimental values for (g_2)_mu; some clarifications and references added; conclusions unchanged; version published in PLB
Self-Sustained Thought Processes in a Dense Associative Network
Creators: name: Gros, Claudius
Publisher: name: arXiv
Year: 2005
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Several guiding principles for thought processes are proposed and a neural-network-type model implementing these principles is presented and studied. We suggest to consider thinking within an associative network built-up of overlapping memory states. We consider a homogeneous associative network as biological considerations rule out distinct conjunction units between the information (the memories) stored in the brain. We therefore propose that memory states have a dual functionality: They represent on one side the stored information and serve, on the other side, as the associative links in between the different dynamical states of the network which consists of transient attractors. We implement these principles within a generalized winners-take-all neural network with sparse coding and an additional coupling to local reservoirs. We show that this network is capable to generate autonomously a self-sustained time-series of memory states which we identify with a thought process. Each memory state is associatively connected with its predecessor. This system shows several emerging features, it is able (a) to recognize external patterns in a noisy background, (b) to focus attention autonomously and (c) to represent hierarchical memory states with an internal structure.
description: 14 pages, 9 figures
A new method for studying the vibration of non-homogeneous membranes
Creators: name: Amore, Paolo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We present a method to solve the Helmholtz equation for a non-homogeneous membrane with Dirichlet boundary conditions at the border of arbitrary two-dimensional domains. The method uses a collocation approach based on a set of localized functions, called "little sinc functions", which are used to discretize two-dimensional regions. We have performed extensive numerical tests and we have compared the results obtained with the present method with the ones available from the literature. Our results show that the present method is very accurate and that its implementation for general problems is straightforward.
description: 16 pages, 7 figures, 6 tables
Landscapes, dynamic heterogeneity and kinetic facilitation in a simple off-lattice model
Creators: name: Bowles, R. K.
name: Saika-Voivod, I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present a simple off-lattice hard-disc model that exhibits glassy dynamics. The inherent structures are enumerated exactly, transitions between metabasins are well understood, and the particle configurations that act to facilitate dynamics are easily identified. The model readily maps to a coarse grained dynamic facilitation description.
description: 5 pages, 5 figures, submitted to PRE
Exact exchange optimized effective potential and self-compression of stabilized jellium clusters
Creators: name: Payami, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this work, we have used the exchange-only optimized effective potential in the self-consistent calculations of the density functional Kohn-Sham equations for simple metal clusters in stabilized jellium model with self-compression. The results for the closed-shell clusters of Al, Li, Na, K, and Cs with $N=$2, 8, 18, 20, 34, and 40 show that the clusters are 3% more compressed here than in the local spin density approximation. On the other hand, in the LSDA, neglecting the correlation results in a contraction by 1.4%.
description: 7 pages, RevTex, 5 eps figures, 2 tables
The Future of the Common Agricultural Policy
Creators: name: Sturgess, Ian M.
name: Sturgess, Ian M.
Publisher: name: Unknown
Year: 1991
Subjects: Agricultural and Food Policy

description: This article summarises the forces for change in the Common Agricultural Policy of the European Economic Community and the political limits upon it, together with some recent developments which contribute to their understanding. The emphasis in the paper, as in Community politics, is on budgetary and environmental pressures rather than on issues of efficiency or international trade. The institutions and shibboleths which encourage the conservation of a policy which is in most respects inefficient, inequitable and ineffective are explained, with particular attention to the processes of fixing prices and budgets and the profoundly different objectives of Community member countries.
Continuous-wave phase-sensitive parametric image amplification
Creators: name: Gigan, S.
name: Lopez, L.
name: Delaubert, V.
name: Treps, N.
name: Fabre, C.
name: Maitre, A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study experimentally parametric amplification in the continuous regime using a transverse-degenerate type-II Optical Parametric Oscillator operated below threshold. We demonstrate that this device is able to amplify either in the phase insensitive or phase sensitive way first a single mode beam, then a multimode image. Furthermore the total intensities of the amplified image projected on the signal and idler polarizations are shown to be correlated at the quantum level.
description: 14 pages, 7 figures, submitted to Journal of Modern Optics, Special Issue on Quantum Imaging
Superfluid-Insulator transitions of bosons on Kagome lattice at non-integer fillings
Creators: name: Sengupta, K.
name: Isakov, S. V.
name: Kim, Yong Baek
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the superfluid-insulator transitions of bosons on the Kagome lattice at incommensurate filling factors f=1/2 and 2/3 using a duality analysis. We find that at f=1/2 the bosons will always be in a superfluid phase and demonstrate that the T_3 symmetry of the dual (dice) lattice, which results in dynamic localization of vortices due to the Aharanov-Bohm caging effect, is at the heart of this phenomenon. In contrast, for f=2/3, we find that the bosons exhibit a quantum phase transition between superfluid and translational symmetry broken Mott insulating phases. We discuss the possible broken symmetries of the Mott phase and elaborate the theory of such a transition. Finally we map the boson system to a XXZ spin model in a magnetic field and discuss the properties of this spin model using the obtained results.
description: 10 pages, 8 figures, a few typos corrected
LINGVISTIK UNIVERSITETLARDA MADANIYATLARARO KOMPETENSIYANI RIVOJLANTIRISH
Creators: name: Jo'rayeva, Muhayyo
name: Shamsiddinov, Navruzbek
Publisher: name: Zenodo
Year: 2024

description: Ushbu maqola tilshunoslik universitetlarida madaniyatlararo kompetensiyani rivojlantirishning muhim vazifasini o‘rganadi. Global muloqot davrida tilshunos mutaxassislar til bilimidan ustun turishi va turli madaniy kontekstlarni chuqur tushunishi kerak. Maqolada madaniyatlararo kompetensiyaning ahamiyati ko‘rib chiqiladi, uni lingvistik ta’limda rivojlantirishning samarali strategiyalari taklif etiladi va tilshunoslik universitetlarining madaniy jihatdan xabardor va malakali muloqotchilarni shakllantirishdagi roli ta’kidlanadi.
Space-Time Structure and Electromagnetism
Creators: name: Wanas, M. I.
name: Ammar, Samah A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Two Lagrangian functions are used to construct geometric field theories. One of these Lagrangians depends on the curvature of space, while the other depends on curvature and torsion. It is shown that the theory constructed from the first Lagrangian gives rise to pure gravity, while the theory constructed using the second Lagrangian gives rise to both gravity and electromagnetism. The two theories are constructed in a version of absolute parallelism geometry in which both curvature and torsion are, simultaneously, non-vanishing. One single geometric object, {\it W-tensor}, reflecting the properties of curvature and torsion, is defined in this version and is used to construct the second theory. The main conclusion is that a necessary condition for geometric representation of electromagnetism is the presence of a non-vanishing torsion in the geometry used.
description: 17 pages, LaTeX file, revised version
Dipolar-stabilized first and second-order antiskyrmions in ferrimagnetic multilayers
Creators: name: Heigl, Michael
name: Koraltan, Sabri
name: Vaňatka, Marek
name: Kraft, Robert
name: Abert, Claas
name: Vogler, Christoph
name: Semisalova, Anna
name: Che, Ping
name: Ullrich, Aladin
name: Schmidt, Timo
name: Hintermayr, Julian
name: Grundler, Dirk
name: Farle, Michael
name: Urbánek, Michal
name: Suess, Dieter
name: Albrecht, Manfred
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Skyrmions and antiskyrmions are topologically protected spin structures with opposite topological charge. Particularly in coexisting phases, these two types of magnetic quasi-particles may show fascinating physics and potential for spintronic devices. While skyrmions are observed in a wide range of materials, until now antiskyrmions were exclusive to materials with D2d symmetry. In this work, we show first and second-order antiskyrmions stabilized by magnetic dipole-dipole interaction in Fe/Gd-based multilayers. We modify the magnetic properties of the multilayers by Ir insertion layers. Using Lorentz transmission electron microscopy imaging, we observe coexisting antiskyrmions, Bloch skyrmions, and type-2 bubbles and determine the range of material properties and magnetic fields where the different spin objects form and dissipate. We perform micromagnetic simulations to obtain more insight into the studied system and conclude that the reduction of saturation magnetization and uniaxial anisotropy leads to the existence of this zoo of different spin objects and that they are primarily stabilized by dipolar interaction.
Environnement, Ressources et Conflits au Burkina Faso
Creators: name: Hubert, Nicolas
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2021
Subjects: Burkina Faso
Environnement
Développement minier
Extractivisme
Gestion des ressources naturelles
Relations internationales
Développement et conflits
Environnement et conflits
Changements climatiques et conflits
Afrique de l'Ouest
Parcs nationaux et conflits
Sahel

description: Cette thèse s’interroge sur les relations existantes entre l’exploitation des ressources naturelles, les dégradations de l’environnement et la propagation des dynamiques conflictuelles au Burkina Faso. En adoptant une approche interdisciplinaire, cette recherche explique que l’altération des conditions socio-environnementales modifie non seulement les conditions de vie, mais également les représentations et structures sociales, politiques et environnementales des sociétés affectées. Tout en s’intégrant dans le débat abordant le nexus environnement et conflits armés, cette recherche se distancie volontairement des études portant exclusivement sur les changements climatiques et étudie directement les dégradations environnementales anthropiques issues de l’industrie extractive, ou des exclusions environnementales accompagnant les aires naturelles protégées, participant aux altérations globales du climat et constituant un catalyseur des impacts sociaux et politiques contemporains des changements climatiques. En effectuant une étude qualitative de 4 sites miniers industriels et de deux aires naturelles protégées, cette thèse montre alors que l’altération des conditions et structures socio-environnementales a été en même temps un facteur constitutif de l’érosion de la légitimité et de l’autorité de l’État central burkinabè et de l’accroissement des zones d’influence ainsi que des bassins de recrutement des groupes armés au Burkina Faso.
Evolution of progenitor stars of Type Ibc supernovae and long gamma-ray bursts
Creators: name: Yoon, S. -C.
name: Langer, N.
name: Cantiello, M.
name: Woosley, S. E.
name: Glatzmaier, G. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss how rotation and binary interactions may be related to the diversity of type Ibc supernovae and long gamma-ray bursts. After presenting recent evolutionary models of massive single and binary stars including rotation, the Tayler-Spruit dynamo and binary interactions, we argue that the nature of SNe Ibc progenitors from binary systems may not significantly differ from that of single star progenitors in terms of rotation, and that most long GRB progenitors may be produced via the quasi-chemically homogeneous evolution at sub-solar metallicity. We also briefly discuss the possible role of magnetic fields generated in the convective core of a massive star for the transport of angular momentum, which is potentially important for future stellar evolution models of supernova and GRB progenitors.
description: 6 pages, 4 figures, to appear in IAU Symp. 250, Massive Stars as Cosmic Engines, Kauai (HI), 12/2007, ed. F. Bresolin, P. Crowther, & J. Puls
Collective synchronization of undulatory movement through contact
Creators: name: Zhou, Wei
name: Hao, Zhuonan
name: Gravish, Nick
Publisher: name: arXiv
Year: 2020
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Many biological systems synchronize their movement through physical interactions. By far the most well studied examples concern physical interactions through a fluid: beating cilia, swimming sperm and worms, and flapping wings, all display synchronization behavior through fluid mechanical interactions. However, as the density of a collective increases individuals may also interact with each other through physical contact. In the field of "active matter" systems, it is well known that inelastic contact between individuals can produce long-range correlations in position, orientation, and velocity. In this work we demonstrate that contact interactions between undulating robots yield novel phase dynamics such as synchronized motions. We consider undulatory systems in which rhythmic motion emerges from time-independent oscillators that sense and respond to undulatory bending angle and speed. In pair experiments we demonstrate that robot joints will synchronize to in-phase and anti-phase oscillations through collisions and a phase-oscillator model describes the stability of these modes. To understand how contact interactions influence the phase dynamics of larger groups we perform simulations and experiments of simple three-link undulatory robots that interact only through contact. Collectives synchronize their movements through contact as predicted by the theory and when the robots can adjust their position in response to contact we no longer observe anti-phase synchronization. Lastly we demonstrate that synchronization dramatically reduces the interaction forces within confined groups of undulatory robots indicating significant energetic and safety benefits from group synchronization. The theory and experiments in this study illustrate how contact interactions in undulatory active matter can lead to novel collective motion and synchronization.
Connecting the dots: Making sense of sociograms
Creators: name: Wiley, Jennilyn M.
Publisher: name: ACRL (Association of College and Research Libraries, a division of the American Library Association)
Year: 2024
Subjects: social network analysis
SNA
visual literacy
sociograph
academic libraries

description: This chapter provides a practical approach to understanding the history, terminology, and methods used to create sociograms, which are graph-based visualizations that showcase social connections. Data collection processes, privacy implications, and ties to DEI initiatives are explored as they relate to responsibly interpreting, evaluating, and creating this type of visualization. Examples of data visualization in social network analysis (SNA) as it has been used by the fields of social psychology, human resources, and education are included to demonstrate the breadth and practicality of the approach.
Multiple Phases with the Same Quantized Hall Conductance in a Two-Subband System
Creators: name: Zhang, X. C.
name: Faulhaber, D. R.
name: Jiang, H. W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In a GaAs/AlGaAs two-dimensional electron system with two occupied subbands, the experimentally determined phase diagram in the density-magnetic field plane exhibits rich topological features. Ring-like structures are observed at even integer filling factors, in the phase diagram. Even with the identical quantized Hall resistance values as those given rise by the ordinary integer quantum Hall effect due to the Landau level quantization; the activation energies of these states within the rings are much smaller. These ring structures cannot account for by the simple single particle picture. We argue that ferromagnetic quantum Hall states, due to the interaction of two energy levels with opposite spin and different subband indices, are responsible for these unusual structures.
description: Physical Review letter in press
БИР ГУРУҲ ШАХСЛАРТОМОНИДАН СОДИР ЭТИЛАДИГАН БЕЗОРИЛИК ЖИНОЯТИНИНГ СУБЪЕКТИВ ТОМОНИ ТАҲЛИЛИ
Creators: name: Рахимов, Бобир
Publisher: name: Zenodo
Year: 2024

description: Мазкур мақолада бир гуруҳ шахслар томонидан содир этиладиган безорилик жиноятининг субъектив томони таҳлилига доир масалалар баён этилган.
Calculation of the one loop box integral at Finite Temperature and Density
Creators: name: Khvorostukhin, A. S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Calculation of hadronization, decay or scattering processes at non-zero temperatures and densities within the Nambu-Jona-Lasinio-like models requires some techniques for computation of Feynmann diagrams. Decomposition of Feynman diagrams at the one loop level leads to the appearance of elementary integrals with one, two, three, and four fermion lines. For example, evaluation of the $ππ$ scattering amplitude requires calculating a box diagram with four fermion lines. In this work, the real and imaginary parts of the box integral at the one loop level are provided in the form suitable for numerical evaluation. The obtained expressions are applicable to any value of temperature, particle mass, and chemical potential. We pay special attention to the conditions for the existence of the appearing improper integrals and correct the results \cite{Klevansky} for the three fermion lines. As a result, we have obtained constraints on possible values of particle momenta. Among the expressions for the box integral, the general formulas for the integral with an arbitrary number of lines are derived for the case with zero or collinear fermion momenta.
description: 22 pages, no figures. The second version of the paper is essentialy distinct from the first one. The puzzle with different values of the three line integral for different coordinate systems is solved
Self-Dual Fields Harbored by a Kerr-Taub-bolt Instanton
Creators: name: Aliev, A. N.
name: Saçlioğlu, Cihan
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a new exact solution for self-dual Abelian gauge fields living on the space of the Kerr-Taub-bolt instanton, which is a generalized example of asymptotically flat instantons with non-self-dual curvature, by constructing the corresponding square integrable harmonic form on this space.
description: 7 pages
Gluons in charmoniumlike states
Creators: name: Sun, Wei
name: Chen, Ying
name: Sun, Peng
name: Yang, Yi-Bo
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The mass components of charmoniumlike states are investigated through the decomposition of QCD energy-momentum tensor (EMT) on lattice. The quark mass contribution $\langle H_m\rangle$ and the momentum fraction $\langle x\rangle$ of valence charm quark and antiquark are calculated for conventional $1S,1P,1D$ charmonia and the exotic $1^{-+}$ charmoniumlike state, based on the $N_f=2+1$ gauge configurations generated by the RBC/UKQCD collaboration. It is found that $\langle H_m\rangle$ is close to each other and around 2.0 to 2.2 GeV for these states, which implies that the mass splittings among these states come almost from the gluon contribution of QCD trace anomaly. The $\langle x\rangle$ of the $1^{-+}$ state is only around 0.55, while that in conventional charmonia is around 0.7 to 0.8. This difference manifests that the proportion of light quarks and gluons in the $1^{-+}$ charmoniumlike state is significantly larger than conventional states.
description: 9 pages, 6 figures; v2: match the published version
Allocative vs. Technical Efficiency, and Related Matters in Linear Programming
Creators: name: Drynan, Ross G.
name: Drynan, Ross G.
Publisher: name: Unknown
Year: 1987
Subjects: Research Methods/ Statistical Methods

description: The relationship between technical and allocative efficiency is examined by drawing on concepts of activity dominance in linear programming. The conclusion is reached that there is no fundamental distinction between technical and allocative efficiency. Other topics addressed in the paper, all connected by the common thread of activity dominance, include activity specification and the nature of returns to scale.
Aspects of Agricultural Policy in the European Community 1986/87
Creators: name: Manegold, Dirk
name: Manegold, Dirk
Publisher: name: Unknown
Year: 1987
Subjects: Agricultural and Food Policy

description: The article reviews recent developments in and under the Common Agricultural Policy of the European Community. It shows the complicated systems of market regulations, points to the performance of markets and informs on the latest proposals and decisions (prior to 1 April, 1987). The main features and effects of the agri-monetary regime are explained as well as the new proposals for its modification. Finally, the budgetary constraints are considered. The main conclusions are that the CAP is going to change although a thorough reform is not in sight. At present, the most urgent task is to cut down useless intervention stocks and to prevent their immediate resurgence.
Revisiting the OZI-forbidden Radiative Decays of Orthoquarkonia
Creators: name: Li, Gang
name: Li, Tong
name: Li, Xue-Qian
name: Ma, Wen-Gan
name: Zhao, Shu-Min
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is interesting to investigate the OZI-forbidden radiative orthoquarkonium decays $J/ψ\to γπ^0, γη$ and $γη'$ in perturbative QCD. In this work without the approximations adopted in literature we carry out a full one-loop calculation which involves integrations of 4-point and 5-point loop functions. Our numerical results are in agreement with the present data. We also briefly discuss the decays of $J/ψ\to γ+ρ^0$, as well as $Υ\to π^0γ, ηγ, η'γ$.
description: 18pages,2figures;final version to appear in Nucl.Phys. B
Auf die Worte kommt es an: Die soziale Situation in der ethnosemantischen Annäherung an das Feld
Creators: name: Maeder, Christoph
Publisher: name: Zenodo
Year: 2020
Subjects: Ethnographie
Soziologie
Wissenssoziologie
Ethnographie der Situation
Semantik
Fuldaer Feldarbeitstage

description: Aus dem Manuskript «Die hier [...] an einem Beispiel vorgestellte, ethnosemantische Annäherung an das Feld möchte die Möglichkeiten der Beschreibung von sozialen Welten mittels der Anknüpfung an dem Wortwörtlichkeitsprinzip an einem
 materialen Datenfragment zeigen. Dafür wird vorgeführt, wie die Felderschließung zu verschiedenen sozialen Situationen über eine Registratur von Begriffen aus dem Feld angegangen und interpretiert werden kann. Auf den so registrierten und thematisierten Worten und Begriffen beruht auf der Ebene der fraglosen Alltäglichkeit im Sinne des Thomastheorems die Wirklichkeitskonstruktion
 in spezifischen Kontexten. Die Worte formen für die spezifischen und im Feld vorfindbaren Situationen ein kulturelles Register von Situationen, mit denen die Feldangehörigen fraglos operieren können. Der kompetente, d.h. situativ verständliche lokale Sprachgebrauch erzeugt so gesehen über reziproke Routinisierungen die kulturelle Zugehörigkeit als ein habituelles Merkmal der Handelnden. Und in einer solchen Sprache und Rede wird implizit immer auf einen Ausschnitt der institutionellen Ordnung verwiesen.» [103f.]
description: +repphzhbib2020F
Chile-EU Trade Agreement: What Can We Learn from Trade Statistics?
Creators: name: De Pablo Valenciano, Jaime
name: Angel Giacinti Battistuzzi, Miguel
name: Garcia Azcaráte, Tomás
Publisher: name: CentMA
Year: 2015
Subjects: Markets; Fruit fresh; Trade Structure; Business Development and Benchmarking

description: An Association Agreement concluded between the European Union and Chile in 2002 included a comprehensive Free Trade Agreement (FTA) that entered into force in February 2003. Our purpose is to analyse some of the economic consequences of the agricultural part of this agreement focusing in the fruit and vegetable market. Our finding is that market concentration has significantly decreased since the beginning of previous decade and has been reinforced in both markets. This has been an advantage for both Chilean producers and European consumers of fruits and vegetables.
description: International Journal on Food System Dynamics, Vol 6, No 1 (2015)
Phase-Space Methods for Simulating the Dissipative Many-Body Dynamics of Collective Spin Systems
Creators: name: Huber, Julian
name: Kirton, Peter
name: Rabl, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We describe an efficient numerical method for simulating the dynamics and steady states of collective spin systems in the presence of dephasing and decay. The method is based on the Schwinger boson representation of spin operators and uses an extension of the truncated Wigner approximation to map the exact open system dynamics onto stochastic differential equations for the corresponding phase space distribution. This approach is most effective in the limit of very large spin quantum numbers, where exact numerical simulations and other approximation methods are no longer applicable. We benchmark this numerical technique for known superradiant decay and spin-squeezing processes and illustrate its application for the simulation of non-equilibrium phase transitions in dissipative spin lattice models.
description: 21 pages, 7 figures
FAIR Facilities and Instruments: Enabling transparency, reproducibility, and equity through persistent identifiers
Creators: name: Mayernik, Matt
name: Johnson, Andrew
name: Julian, Renaine
name: Mundoma, Claudius
name: Murray, Matthew
name: Ranganath, Adi
Publisher: name: DataCite
Year: 2024
Subjects: Persistent Identifier
Metadata
Instruments
Life Sciences
Astronomy
Metadata Game Changers

description: DataCite, in partnership with Metadata Game Changers, is excited to announce two community dialogue sessions designed to engage the broader Life Sciences and Astronomy communities in co-developing metadata enhancements supporting the development and use of persistent identifiers (PIDs) for instruments and projects. We would like to invite both metadata creators and users to join us and take an active role in advancing infrastructure solutions to identify, describe, discover, and track the impact of instruments and projects across domain communities.

The Persistent Identifiers for Instruments Community Dialogue will build on the work of the Persistent Identification of Instruments (PIDInst) group and the FAIR Facilities and Instruments Research Coordination Network.

Topics will include:

Ownership & provenance

Series & versioning

Replicability & reuse

Discoverability

Impact measurement

These dialogues represent the first phase of a larger project recently launched by DataCite. Generously funded by the Richard Lounsbery Foundation, this project aims to address present challenges in data accessibility, transparency, and reproducibility across the Life Science and Astronomy communities by fostering collaboration and developing transformative solutions. Insights, feedback, and proposed metadata enhancements gathered during these dialogues will directly inform subsequent prototype developments designed by DataCite.

Speaker: Matt Mayernick (University Corporation for Atmospheric Research)

A recording of the presentation can be found here: https://www.youtube.com/watch?v=fjR5VaBMIqc&t=564s