cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Magnetic Pulse Welding of Sheets – Process Modelling
Creators: name: Shotri, R.
name: Racineux, G.
name: De, A.
Publisher: name: TU Dortmund
Year: 2021
Subjects: subject: magnetic pulse welding
subject: high strain rate plastic deformation
subject: high velocity impact investigation
subject: electromagnetic field - pressure
subject: finite element modelling
subject: dissimilar sheets joining
subject: 620
subject: 670

description: Magnetic pulse welding involves the application of a controlled electromagnetic impulse and consequent high velocity impact between two overlapped parts, which leads to plastic deformation and consolidation between the parts along the interface without melting. The key variables in magnetic pulse welding include a high magnitude discharge energy of damped sinusoidal nature, the coil type and geometry and the materials, thicknesses and geometry of the overlapped metallic sheets. A computer-based coupled electromagnetic and dynamic mechanical analysis of magnetic pulse welding of sheets is presented in this work to provide an insightful understanding of the evolution of joints, which is otherwise intractable for monitoring due to the high speed of the process and the presence of a high electromagnetic field. The computed results show that such a computational process model can serve as a robust design tool for a fundamental understanding as well as for the identification of suitable conditions for achieving a defect-free, reliable joint.
Hi-C 2.1 Observations of Reconnection Nanojets
Creators: name: Patel, Ritesh
name: Pant, Vaibhav
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: One of the possible mechanisms for heating the solar atmosphere is the magnetic reconnection occurring at different spatio-temporal scales. The discovery of fast bursty nanojets due to reconnection in the coronal loops has been linked to nanoflares and considered as possible mechanism for coronal heating. The occurrence of these jets mostly in the direction inwards to the loop were observed in the past. In this study, we report ten reconnection nanojets, four with directions inward while six moving outward to the loop, in observations from High-resolution Coronal Imager 2.1 (Hi-C 2.1) and Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). We determined the maximum length, spire width, speed, and lifetimes of these jets and studied their correlations. We found that outward moving jets with higher speeds are longer in length and duration while the inward moving jets show opposite behaviour. Average duration of the outward jets is $\approx$42 s and inwards jets is $\approx$24s. We identified jets with subsonic speeds below 100 km s$^{-1}$ to high-speed over 150 km s$^{-1}$. These jets can be identified in multiple passbands of AIA extending from upper transition region to the corona suggesting their multi-thermal nature.
description: Accepted for publication in The Astrophysical Journal
THE MEASUREMENT OF STRUCTURAL VARIATION OVER TIME: THE CASE FOR ADVERTISING AND FOOD DEMAND
Creators: name: Ward, R.W.
name: Myers, L.H.
name: Ward, R.W.
name: Myers, L.H.
Publisher: name: Unknown
Year: 1978
Subjects: subject: Demand and Price Analysis
subject: Marketing
subject: FOS: Economics and business

description: A distributed lagged advertising model with coefficients having random and systematic adjustments was estimated. The paths of parameter adjustments clearly identify structural changes in advertising effectiveness and price responsiveness. The model is used to show improvements over fixed models for forecasting.
Sustaining an Alaska Coastal Community: Integrating Place Based Well-Being Indicators and Fisheries Participation
Creators: name: Marysia Szymkowiak
name: Kasperski, Stephen
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: Marine Biology
subject: Science Policy

description: The incorporation of human dimensions into ecosystem-based fisheries management has largely focused on metrics of economic welfare. Yet researchers have demonstrated the variety of well-being that is derived from fisheries as well as the need for localized and collaborative scientific efforts that result in appropriately contextualized metrics. This article presents the results of a project intended to address these needs and inform the North Pacific fisheries management process with a set of indicators that are related to multiple dimensions of human well-being and links to fisheries participation. The article showcases a mechanism of applying a well-being framework and participatory methods to develop locally relevant quantitative indicators for one of the most highly engaged fishing communities in Alaska - Sitka. These indicators can be used to track how fishery shocks may reverberate through social systems and affect fishing communities. Furthermore, the discussion of the multifaceted well-being indicators presents information on local values and complex dynamics between community well-being and fisheries that are difficult to conceptualize and integrate into management decisions. Ultimately, this work can facilitate a more comprehensive incorporation of human dimensions into ecosystem-based frameworks in fisheries management, contextualizing that expansion within locally relevant narratives that engage stakeholders in resource management.
Quantum Fragmentation in the Extended Quantum Breakdown Model
Creators: name: Chen, Bo-Ting
name: Prem, Abhinav
name: Regnault, Nicolas
name: Lian, Biao
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a one-dimensional (1D) extended quantum breakdown model comprising a fermionic and a spin degree of freedom per site, and featuring a spatially asymmetric breakdown-type interaction between the fermions and spins. We analytically show that, in the absence of any magnetic field for the spins, the model exhibits Hilbert space fragmentation within each symmetry sector into exponentially many Krylov subspaces and hence displays non-thermal dynamics. Here, we demonstrate that the fragmentation naturally occurs in an entangled basis and thus provides an example of "quantum fragmentation." Besides establishing the nature of fragmentation analytically, we also study the long-time behavior of the entanglement entropy and its deviation from the expected Page value as a probe of ergodicity in the system. Upon introducing a non-trivial magnetic field for the spins, most of the Krylov subspaces merge and the model becomes chaotic. Finally, we study the effects of strong randomness on the system and observe behavior similar to that of many-body localized systems.
description: 30 pages, 13 figures
YANGI O'ZBEKISTONDA MA'NAVIY TARBIYANING TA'SIRCHANLIGINI OSHIRISHDA MILLIY AXBOROTDAGI MEDIANING O`RNI.
Creators: name: Jurakulov Jamol Komilovich, Xakimxonova Xamida Muhitdinovna
Publisher: name: Zenodo
Year: 2025

description: Annotasiya: ushbu maqolada ta’lim va tarbiya jarayoniga ma’naviy tarbiyaning ta’sirchanligi yangi O‘zbekistonda milliy axborot orqali ekanligi, ta’lim va tarbiya jarayonida kompyuter texnologiyalari va axborotni qayta ishlash, axborot almashinuvi ta’lim va tarbiya jarayonida ma’naviy tarbiyaning milliy axborotning tasirchanlik imkoniyatlari xaqida fikr muloxaza yuritiladi.
On Feedback Control in Kelly Betting: An Approximation Approach
Creators: name: Hsieh, Chung-Han
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optimization and Control (math.OC)
subject: Computational Finance (q-fin.CP)
subject: Mathematical Finance (q-fin.MF)
subject: FOS: Mathematics
subject: FOS: Economics and business

description: In this paper, we consider a simple discrete-time optimal betting problem using the celebrated Kelly criterion, which calls for maximization of the expected logarithmic growth of wealth. While the classical Kelly betting problem can be solved via standard concave programming technique, an alternative but attractive approach is to invoke a Taylor-based approximation, which recasts the problem into quadratic programming and obtain the closed-form approximate solution. The focal point of this paper is to fill some voids in the existing results by providing some interesting properties when such an approximate solution is used. Specifically, the best achievable betting performance, positivity of expected cumulative gain or loss and its associated variance, expected growth property, variance of logarithmic growth, and results related to the so-called survivability (no bankruptcy) are provided.
description: To appear in the proceedings of the 2020 IEEE Conference on Control Technology and Applications (CCTA)
Additional file 2 of Validation of the global lung initiative 2012 multi-ethnic spirometric reference equations in healthy urban Zimbabwean 7–13 year-old school children: a cross-sectional observational study
Creators: name: Tafadzwa Madanhire
name: Ferrand, Rashida
name: Engi Attia
name: Elopy Sibanda
name: Simba Rusakaniko
name: Rehman, Andrea
Publisher: name: figshare
Year: 2020
Subjects: subject: Space Science
subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics

description: Additional file 2. Visual plots. Histograms and Q-Q plots showing the distribution of anthropometric variables and spirometry z-scores.
Game Description Logic with Integers: A GDL Numerical Extension
Creators: name: Mittelmann, Munyque
name: Perrussel, Laurent
Publisher: name: arXiv
Year: 2019
Subjects: subject: Logic in Computer Science (cs.LO)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Many problems can be viewed as games, where one or more agents try to ensure that certain objectives hold no matter the behavior from the environment and other agents. In recent years, a number of logical formalisms have been proposed for specifying games among which the Game Description Language (GDL) was established as the official language for General Game Playing. Although numbers are recurring in games, the description of games with numerical features in GDL requires the enumeration from all possible numeric values and the relation among them. Thereby, in this paper, we introduce the Game Description Logic with Integers (GDLZ) to describe games with numerical variables, numerical parameters, as well as to perform numerical comparisons. We compare our approach with GDL and show that when describing the same game, GDLZ is more compact.
description: 23 pages, extended version of the paper published at the conference FoIKS 2020 (11th International Symposium on Foundations of Information and Knowledge Systems)
Climate, Shocks, Weather and Maize Intensification Decisions in Rural Kenya
Creators: name: Martina, Bozzola
name: Smale, Melinda
name: Di Falco, Salvatore
name: Martina, Bozzola
name: Smale, Melinda
name: Di Falco, Salvatore
Publisher: name: Unknown
Year: 2016
Subjects: subject: Environmental Economics and Policy
subject: International Development
subject: Climate Change
subject: Maize
subject: Smallholder farmer
subject: Vulnerability
subject: Kenya

description: We explore how climate, climate risk and weather affect maize intensification among smallholders in Kenya. We find that they all play an important role in maize intensification choice. The economic implications of this choice are also analyzed. We find that the share of maize area planted to hybrid seeds contributes positively to expected crop income, without increasing exposure to income variability or downside risk. The promotion of maize intensification is potentially a valuable adaptation strategy to support the well-being of smallholder farmers.
Additional file 1 of Validation of the global lung initiative 2012 multi-ethnic spirometric reference equations in healthy urban Zimbabwean 7–13 year-old school children: a cross-sectional observational study
Creators: name: Tafadzwa Madanhire
name: Ferrand, Rashida
name: Engi Attia
name: Elopy Sibanda
name: Simba Rusakaniko
name: Rehman, Andrea
Publisher: name: figshare
Year: 2020
Subjects: subject: Space Science
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: Additional file 1. Comparison between children included and excluded from the study. A table summarizing the demographic and anthropometry characteristics for children included and excluded from the study.
Supermassive black holes as possible sources of ultra high energy cosmic rays
Creators: name: Tursunov, Arman
name: Stuchlík, Zdeněk
name: Kološ, Martin
name: Dadhich, Naresh
name: Ahmedov, Bobomurat
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Production and acceleration mechanisms of ultra-high-energy cosmic rays (UHECRs) of energy $>10^{20}$eV, clearly beyond the GZK-cutoff limit remain unclear that points to exotic nature of the phenomena. Recent observations of extragalactic neutrino may indicate the source of UHECRs being an extragalactic supermassive black hole (SMBH). We demonstrate that ultra-efficient energy extraction from rotating SMBH driven by the magnetic Penrose process (MPP) could indeed foot the bill. We envision ionization of neutral particles, such as neutron beta-decay, skirting close to the black hole horizon that energizes protons to over $10^{20}$eV for SMBH of mass $10^9 M_{\odot}$ and magnetic field of strength $10^4$G. Applied to Galactic center SMBH we have proton energy of order $\approx 10^{15.6}$eV that coincides with the knee of the cosmic ray spectra. We show that large $γ_z$ factors of high-energy particles along the escaping directions occur only in the presence of induced charge of the black hole that is known as the Wald charge in the case of uniform magnetic field. It is remarkable that the process neither requires extended acceleration zone, nor fine-tuning of accreting matter parameters. Further, this leads to certain verifiable constraints on SMBH's mass and magnetic field strength as UHECRs sources. This clearly makes ultra-efficient regime of MPP one of the most promising mechanisms for fueling UHECRs powerhouse.
description: 14 pages, 6 figures
Model Predictive Wave Disturbance Rejection for Underwater Soft Robotic Manipulators
Creators: name: Walker, Kyle L.
name: Della Santina, Cosimo
name: Giorgio-Serchi, Francesco
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Inspired by the octopus and other animals living in water, soft robots should naturally lend themselves to underwater operations, as supported by encouraging validations in deep water scenarios. This work deals with equipping soft arms with the intelligence necessary to move precisely in wave-dominated environments, such as shallow waters where marine renewable devices are located. This scenario is substantially more challenging than calm deep water since, at low operational depths, hydrodynamic wave disturbances can represent a significant impediment. We propose a control strategy based on Nonlinear Model Predictive Control that can account for wave disturbances explicitly, optimising control actions by considering an estimate of oncoming hydrodynamic loads. The proposed strategy is validated through a set of tasks covering set-point regulation, trajectory tracking and mechanical failure compensation, all under a broad range of varying significant wave heights and peak spectral periods. The proposed control methodology displays positional error reductions as large as 84% with respect to a baseline controller, proving the effectiveness of the method. These initial findings present a first step in the development and deployment of soft manipulators for performing tasks in hazardous water environments.
description: To be presented at RoboSoft 2024, San Diego
Assessment of Effectiveness of Conflict Management Strategies Amongst Rural Households in Osun State, Nigeria
Creators: name: Adisa, B.O.
name: Adeloye, K.A.
name: Adisa, B.O.
name: Adeloye, K.A.
Publisher: name: Unknown
Year: 2017
Subjects: subject: Community/Rural/Urban Development
subject: Consumer/Household Economics
subject: Household conflict
subject: conflict management strategies
subject: effectiveness

description: The study was conducted with the purpose of assessing the effectiveness of conflict management strategies amongst rural households in Osun State, Nigeria. 153 household heads, selected through multistage sampling technique, were interviewed for the study through the administration of pre-tested interview schedule in the three purposively selected rural Local Government Areas (LGAs). The mean age of the respondents was 47±17.8 and 62.1% of them were male. In addition, the mean household size was 6.3±3.9 and majority (78.4%) were farmers. Causes of rural household conflicts identified were inadequate finance, wives’ insubordination and interference from third party, amongst others. The findings revealed that at p<0.01, occupation (χ2=33.483); sex (χ2=29.502); and religion affiliation (χ2=31.612) of the respondents had significant association with effectiveness of conflict management strategies. Furthermore, at p<0.01, respondents’ age (r= 0.512) and household size (r= -0.483) had significant relationship with conflict management strategies’ effectiveness. The study concludes that conflict management strategies amongst rural households were effective. It was recommended that policy makers, rural developers and extension agents should include effective conflict management strategies in programme packages.
Soft Fermi Surfaces and Breakdown of Fermi Liquid Behavior
Creators: name: Metzner, W.
name: Rohe, D.
name: Andergassen, S.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Electron-electron interactions can induce Fermi surface deformations which break the point-group symmetry of the lattice structure of the system. In the vicinity of such a "Pomeranchuk instability" the Fermi surface is easily deformed by anisotropic perturbations, and exhibits enhanced collective fluctuations. We show that critical Fermi surface fluctuations near a d-wave Pomeranchuk instability in two dimensions lead to large anisotropic decay rates for single-particle excitations, which destroy Fermi liquid behavior over the whole surface except at the Brillouin zone diagonal.
description: 12 pages, 2 figures, revised version as published
Constraints to information and communication technology utilisation by village extension agents in south-south Nigeria
Creators: name: Awhareno, U.S.
name: Nndai, F.N.
name: Awhareno, U.S.
name: Nndai, F.N.
Publisher: name: Unknown
Year: 2017
Subjects: subject: Research and Development/Tech Change/Emerging Technologies
subject: ICT
subject: Utilisation
subject: Village Extension Agents
subject: Agricultural Technologies
subject: Dissemination

description: The study assessed constraints to the use of information and communication technologies (ICT) by village extension agents in South-south Nigeria. The population of the study comprises all village extension agents (VEAs) in South-south Nigeria. A total sample of 300 VEAs was selected using a multistage sampling procedure. A set of questionnaire was used for primary data collection while frequency count, percentage, mean score and standard deviation were used for data analysis. The results show that majority (87.7%) of VEAs had tertiary education, working experience (20 years) and average monthly income of sixty thousand naira. The ICT tools used by VEAs included phone (M=3.77), radio (M=3.70), television (M=3.51), video (M=2.56), computer (M=2.53), personal e-mail (M=2.51) and internet (M=2.50). Constraints to ICT use were lack of internet access in the rural areas (M=3.61), lack of ICT infrastructure (M=3.53), high cost of internet subscription (M=3.47), lack of training on ICT (M=3.42), lack of power supply (M=3.23) and poor income (M=3.14). It was recommended that the identified constraints to ICT utilisation should be tackled by the appropriate stakeholders with adequate provision of ICT infrastructure and improved power supply in order to encourage massive utilisation of ICT by VEAs. Also, effort should be geared towards encouraging ICT usage by VEAs with adequate inclusion of ICT in the pre-service curriculum of prospective VEAs.
Magnetization switching in polycrystalline Mn3Sn thin film induced by self-generated spin-polarized current
Creators: name: Xie, Hang
name: Chen, Xin
name: Zhang, Qi
name: Mu, Zhiqiang
name: Zhang, Xinhai
name: Yan, Binghai
name: Wu, Yihong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Electrical manipulation of spins is essential to design state-of-the-art spintronic devices and commonly relies on the spin current injected from a second heavy-metal material. The fact that chiral antiferromagnets produce spin current inspires us to explore the magnetization switching of chiral spins using self-generated spin torque. Here, we demonstrate the electric switching of noncollinear antiferromagnetic state in Mn3Sn by observing a crossover from conventional spin-orbit torque to the self-generated spin torque when increasing the MgO thickness in Ta/MgO/Mn3Sn polycrystalline films. The spin current injection from the Ta layer can be controlled and even blocked by varying the MgO thickness, but the switching sustains even at a large MgO thickness. Furthermore, the switching polarity reverses when the MgO thickness exceeds around 3 nm, which cannot be explained by the spin-orbit torque scenario due to spin current injection from the Ta layer. Evident current-induced switching is also observed in MgO/Mn3Sn and Ti/Mn3Sn bilayers, where external injection of spin Hall current to Mn3Sn is negligible. The inter-grain spin-transfer torque induced by spin-polarized current explains the experimental observations. Our findings provide an alternative pathway for electrical manipulation of non-collinear antiferromagnetic state without resorting to the conventional bilayer structure.
description: 29 pages, 6 figures
Position and momentum observables on R and on R^3
Creators: name: Carmeli, C.
name: Heinonen, T.
name: Toigo, A.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We characterize all position and momentum observables on R and on R^3. We study some of their operational properties and discuss their covariant joint observables.
description: 18 pages
HPC Infrastructures Workshop: 2020 Online Event
Creators: name: Shoukourian, Hayk
name: Weinberg, Volker
name: Radosław Januszewski
name: Stoffers, Huub
name: Johansson, Andreas
name: Salminen, Susanna
name: Ezhilmathi Krishnasamy
name: Meyer, Norbert
name: Pleiter, Dirk
name: Robin, François
name: Souques, Frederic
name: Jean-Marc Ducos
name: Jean-Philippe Nomine
Publisher: name: Zenodo
Year: 2021
Subjects: HPC Infrastructures Workshop
High-Performance Computing
Proceedings
EWHPC
EuroHPC Joint Undertaking

description: The annually held series of European Workshops on HPC Infrastructures (EWHPC) aim to bring together worldwide specialists in HPC centre design and operation to discuss the latest trends in infrastructure and supporting technologies for supercomputing centres.
 Due to the COVID-19 pandemic, the 11th EWHPC was cancelled and a shorter online event was offered instead. It attracted more than 100 participants from 40 different HPC sites and provided a general overview on EuroHPC Joint Undertaking (JU) as well as updates on three EuroHPC JU pre-exascale consortia and their systems: Leonardo (hosted at CINECA), LUMI (hosted at CSC), and MareNostrum 5 (hosted at BSC).
 The EWHPC online event was held on 14th of October and virtually collocated with an online PRACE Topical Session on “Exascale for European Datacentres” held on 15 October 2020, then followed by the traditional PRACE session on HPC infrastructures with technical presentations from PRACE sites on 16 October 2020.
 This document summarises the presentations and discussions held at the online event and the PRACE session on HPC infrastructures.
Crop framers' adaptation strategies to mitigate conflicts with nomads in oyo state
Creators: name: Yekinni, O.T.
name: Adeniyi, R.T.
name: Adebisi, S.A.
name: Yekinni, O.T.
name: Adeniyi, R.T.
name: Adebisi, S.A.
Publisher: name: Unknown
Year: 2017
Subjects: subject: Crop Production/Industries
subject: Farm Management
subject: Crop farmers
subject: nomads
subject: adaptation strategy
subject: ecosystem
subject: ethnicity

description: Conflicts on the use of resources are not uncommon in human systems. However, when they degenerate to violence, threatening progress, peace and development of the society; it would be necessary to address the problem. This study focused on adaptation strategies employed by crop farmers to manage conflicts with nomads in Oyo state. A multistage sampling procedure was used to select 120 respondents for the study. Data were collected with the use of interview schedule on crop farmers’ socioeconomic characteristics, causes of conflicts, effect of conflicts and coping strategies. Data were analysed using descriptive and inferential (Chisquare and PPMC) statistics. Results show that most of the respondents were Yoruba (89.2%), male (86.7%), married (98.3%), had farming (87.5%) as their primary occupation with mean age of 55 years. Mostly identified causes of conflicts were crop damage (weighted mean=194.9), indiscriminate bush burning (188.3) and blockage of water (174.2). Effects of conflicts mostly experienced by farmers were reduction in output and income of farmers (197.4), destruction of crops (193.4), anger/anxiety/emotional exhaustion (180.0). Coping strategies mostly employed were prayer for peace (184.9), early harvesting (181.6) and appease of other party (166.6). More than half (55.8%) of the respondents used low level of coping strategies. Significant relationship existed between coping strategies employed and ethnicity (χ2=11.609), other forms of education (χ2=19.164; p=0.001) as well as effect of conflicts (r=0.400). Adaptation strategies employed by the respondents should be investigated, validated and adopted by appropriate authorities in order to mitigate the regular conflicts among farmers and nomads in Nigeria.
Measurement of the partial widths of the Z into up- and down-type quarks
Creators: name: The OPAL Collaboration
name: Abbiendi, G.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Using the entire OPAL LEP1 on-peak Z hadronic decay sample, Z -> qbarq gamma decays were selected by tagging hadronic final states with isolated photon candidates in the electromagnetic calorimeter. Combining the measured rates of Z -> qbarq gamma decays with the total rate of hadronic Z decays permits the simultaneous determination of the widths of the Z into up- and down-type quarks. The values obtained, with total errors, were Gamma u = 300 ^{+19}_{-18} MeV and Gamma d = 381 ^{+12}_{-12} MeV. The results are in good agreement with the Standard Model expectation.
description: 22 pages, 5 figures, Submitted to Phys. Letts. B
Atomic carbon, nitrogen, and oxygen forbidden emission lines in the water-poor comet C/2016 R2 (Pan-STARRS)
Creators: name: Raghuram, S.
name: Hutsemékers, D.
name: Opitom, C.
name: Jehin, E.
name: Bhardwaj, A.
name: Manfroid, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The N$_2$ and CO-rich and water-depleted comet C/2016 R2 (Pan-STARRS) (hereafter `C/2016 R2') is a unique comet for detailed spectroscopic analysis. We aim to explore the associated photochemistry of parent species, which produces different metastable states and forbidden emissions, in this cometary coma of peculiar composition. We re-analyzed the high-resolution spectra of comet C/2016 R2, which were obtained in February 2018, using the UVES spectrograph of the European Southern Observatory (ESO) Very Large Telescope (VLT). Various forbidden atomic emission lines of [CI], [NI], and [OI] were observed in the optical spectrum of this comet when it was at 2.8 au from the Sun. The observed forbidden emission intensity ratios are studied in the framework of a couple-chemistry emission model. The model calculations show that CO$_2$ is the major source of both atomic oxygen green and red-doublet emissions in the coma of C/2016 R2 (while for most comets it is generally H$_2$O), whereas, CO and N$_2$ govern the atomic carbon and nitrogen emissions, respectively. Our modelled oxygen green to red-doublet and carbon to nitrogen emission ratios are higher by a factor {of 3}, when compared to the observations. These discrepancies can be due to uncertainties associated with photon cross sections or unknown production/loss sources. Our modelled oxygen green to red-doublet emission ratio is close to the observations, when we consider an O$_2$ abundance with a production rate of 30\% relative to the CO production rate. The collisional quenching is not a significant loss process for N($^2$D) though its radiative lifetime is significant ($\sim$10 hrs). Hence, the observed [NI] doublet-emission ratio ([NI] 5198/5200) of 1.22, which is smaller than the terrestrial measurement by a factor {1.4}, is mainly due to the characteristic radiative decay of N($^2$D).
description: 15 pages,11 Figures, 7 Tables
Unitarity of Time-Like Noncommutative Gauge Theories: The Violation of Ward Identities in Time-Ordered Perturbation Theory
Creators: name: Ohl, Thorsten
name: Rückl, Reinhold
name: Zeiner, Jörg
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study Ward identities for simple processes with external gauge bosons in the time-ordered perturbation theory approach to time-like noncommutative gauge theories. We demonstrate that these Ward identities cannot be satisfied when all orders in the noncommutativity parameters theta_i0 are taken into account. We conclude that in time-ordered perturbation theory one cannot solve the unitarity problem of time-like noncommutative quantum field theories.
description: 16 pages LaTeX (feynmp.sty, elsart.cls and thophys.sty included). Clarified the comments on Seiberg-Witten Maps, updated references. This version has been accepted for publication in Nuclear Physics B
Multiple merging in the Abell cluster 1367
Creators: name: Cortese, L.
name: Gavazzi, G.
name: Boselli, A.
name: Iglesias-Paramo, J.
name: Carrasco, L.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a dynamical analysis of the central ~1.3 square degrees of the cluster of galaxies Abell 1367, based on 273 redshift measurements (of which 119 are news). From the analysis of the 146 confirmed cluster members we derive a significantly non-Gaussian velocity distribution, with a mean location C_{BI} = 6484+/-81 km/s and a scale S_{BI} = 891+/-58 km/s. The cluster appears elongated from the North-West to the South-East with two main density peaks associated with two substructures. The North-West subcluster is probably in the early phase of merging into the South-East substructure (~ 0.2 Gyr before core crossing). A dynamical study of the two subclouds points out the existence of a group of star-forming galaxies infalling into the core of the South-East subcloud and suggests that two other groups are infalling into the NW and SE subclusters respectively. These three subgroups contain a higher fraction of star-forming galaxies than the cluster core, as expected during merging events. Abell 1367 appears as a young cluster currently forming at the intersection of two filaments.
description: 15 pages, 13 figures, 7 tables. Accepted for publication on A&A. High resolution figures at http://goldmine.mib.infn.it/papers/a1367.html
From charge transfer type insulator to superconductor
Creators: name: Guo, Wei
name: Han, Rushan
Publisher: name: arXiv
Year: 2003
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We propose a microscopic model Hamiltonian to account for impurity doping induced insulator-superconductor transition and the coexistence of antiferromagnetism and superconductivity in the high-Tc cuprates. The crossover from non Fermi liquid to Fermi liquid regime characterized by delocalization of delocalization of d electrons at Cu sites is discussed.
Community participation and beneficiaries' perceived sustainability of community and social development projects in Ibadan, Oyo State, Nigeria
Creators: name: Obar, E.E.
name: Adekoya, A.E.
name: Nkwocha, C.A.
name: Obar, E.E.
name: Adekoya, A.E.
name: Nkwocha, C.A.
Publisher: name: Unknown
Year: 2017
Subjects: subject: Community/Rural/Urban Development
subject: Community participation
subject: Project sustainability
subject: CSDP

description: Development interventions are often targeted at alleviating community challenges and enhancing livelihood sustainability. However, most intervention efforts usually have short-lived impacts and the projects often degenerate into nothingness. However, community participation has been fingered as one major tool that can ensure the sustainability of community development projects. This study therefore examined the effects of community participation on the sustainability of Community and Social Development Project (CSDP) in Ibadan, Oyo State, Nigeria. Multistage sampling procedure was used to select respondents for the study. Three communities each from the urban, peri-urban and rural areas where CSDP had completed projects were purposively selected for the study. A total of 168 respondents were randomly selected in these communities. Quantitative data on respondents’ age, sex, marital status, household size, community and social characteristics were collected using interview schedule. Data were analysed using frequency counts, percentages and mean, as well as PPMC and Chi-square. The mean age of respondents was 52.8±14.0 years; most (69.6%) of the respondents were males..More than one third of the respondents had tertiary education (43.5%). More than half (53.0%) of the respondents spent 2-5 hours in community development, (56.6%) participated in the project, (52.4%) were indigenes and (55.4%) were community project management committee (CPMC) members. The mean number of years spent in the community was 17.7±15.2 years. The area in which respondents participated most was sharing of idea ( X =2.39). while (55.4%) had high level of participation and (66.1%) indicated that the projects had high sustainability. Significant (p<0.05) relationships exist between project sustainability (r=0.415), age (r=0.281), number of years of formal education (r=0.154, number of hours spent in community (r=0.469) and level of community participation in CSDP. Chi-square shows that significant (p<0.05) associations exist between sex (χ2=9.721), type of community participation (χ2=26.820), status in the community (χ2=41.985) and level of community participation. It was observed that males participated more in community development than females. Also, technical sustainability of projects was found to be low. Therefore efforts should be made to encourage youths to participate in community development.
Cultural and linguistic capital, standardized tests and the perpetuation of educational inequities
Creators: name: Ayre, Jessica
Publisher: name: The University of British Columbia
Year: 2012

description: Students who possess the socioeconomic, cultural and linguistic capital of the dominant class come to school with a “head start” and stand to benefit most from standardized tests. In my conceptual study examining the relationship between socioeconomic, cultural and linguistic capital, and educational attainment, I employ a critical review of the pertinent literature beginning with Bourdieu and Passeron’s seminal work. Although researchers have been operationalizing Bourdieu’s cultural capital theory for over thirty years, it is clear that there has been little agreement as to how cultural capital should be measured, or even if it can be measured. I argue that much of the empirical research critiquing the impact of Bourdieu’s notion of cultural and linguistic capital on educational attainment has been operationalized from a positivist perspective and based on narrow conceptions of Bourdieu’s theory, and consequently, has provided inconclusive and often contradictory results. Utilizing a definition of cultural capital more closely aligned with that intended by Bourdieu, I examine the connection between socioeconomic, cultural and linguistic capital, and standardized tests, and explore how educational inequities are perpetuated through the use of standardized forms of assessment, discussing the implications of my findings for educational practice throughout. I then suggest some first-and second-order changes that may at the very least make standardized tests accessible to all learners, and at best, make public education equitable for all members of the school community.
Quantifying transmission electron microscopy irradiation effects using two-dimensional materials
Creators: name: Susi, Toma
name: Meyer, Jannik C.
name: Kotakoski, Jani
Publisher: name: arXiv
Year: 2019
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Important recent advances in transmission electron microscopy instrumentation and capabilities have made it indispensable for atomic-scale materials characterization. At the same time, the availability of two-dimensional materials has provided ideal samples where each atom or vacancy can be resolved. Recent studies have also revealed new possibilities for a different application of focused electron irradiation: the controlled manipulation of structures and even individual atoms. Evaluating the full range of future possibilities for this method requires a precise physical understanding of the interactions of electrons with energies as low as 15 keV now used in (scanning) transmission electron microscopy, becoming feasible due to advances both in experimental techniques and in theoretical models. We summarize the state of current knowledge of the underlying physical processes based on the latest results on two-dimensional materials, with a focus on the physical principles of the electron-matter interaction, rather than the material-specific irradiation-induced defects it causes.
description: 18 pages, 2 boxes, 2 figures, 1 table
Involvement in non-farm activities and occurrence of domestic conflicts among rural farmers in Edo State, Nigeria
Creators: name: Edeoghan, C.O.
name: Koledoye, G.F.
name: Edeoghan, C.O.
name: Koledoye, G.F.
Publisher: name: Unknown
Year: 2017
Subjects: subject: Community/Rural/Urban Development
subject: Farm Management
subject: Non-farm activities
subject: domestic conflicts
subject: rural farmers

description: As part of effort to promote rural dwellers’ wellbeing, several studies had been conducted to examine the causes and resolution of domestic conflicts among farmers but less attention is paid to their involvement in non-farm activities as a strategy to mitigate domestic conflicts, particularly in Edo State, Nigeria. The study therefore assessed male and female rural farmers’ involvement in non-farm activities in Edo State with a view to unveiling the effects on occurrence of domestic conflicts. Specifically, it analysed the benefits derived in nonfarm activities as well as establishing relationship between their involvement in non-farm activities and frequency of occurrence of domestic conflicts among male and female farmers. Multi-stage sampling procedure was used to select 130 respondents (65 males and 65 females) in the same household using interview schedule. Data on socioeconomic characteristics, non-farm activities performed and frequency of occurrence of domestic conflicts were described with the use of mean, standard deviation, frequency and percentages while Pearsons’ Product Moment Correlation was used to determine the relationship that exists between benefits derived due to their involvement in non-farm activities and frequency of occurrence of domestic conflicts. Results show that 63.1% and 66.2% of male and female were between the ages of 20 and 40 years while only 9.2% of male and 38.5% of female having no formal education. Non farm activities such as wood carving (Χ=2.94±0.57), building/construction ( Χ=2.92±0.48) and Carpentry/ furniture works ( Χ=2.83±0.83) were the major non-farm activities with high involvement among male while petty trading (Χ=2.99±0.83), hairdressing (Χ=3.24±0.94) and tailoring ( Χ=2.73±0.88) recorded high involvement level among their female counterparts. Income generation (Χ=3.29±0.64) and creation of self employment (Χ=3.24±0.27) were among the benefits derived for their involvement. A negative and significant correlation existed between farmers’ involvement in non-farm activities and frequency of occurrence of domestic conflicts (r= -0.51; p≤0.01).It was concluded that involvement in non farm activities among rural farmers is central to resolving domestic conflicts. It is therefore, recommended that farmers in the rural areas should be encouraged to involve in non-farm activities by social and development workers as this will be a strategy in building peace within a community.
Hybrid multigrid methods for high-order discontinuous Galerkin discretizations
Creators: name: Fehn, Niklas
name: Munch, Peter
name: Wall, Wolfgang A.
name: Kronbichler, Martin
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The present work develops hybrid multigrid methods for high-order discontinuous Galerkin discretizations of elliptic problems. Fast matrix-free operator evaluation on tensor product elements is used to devise a computationally efficient PDE solver. The multigrid hierarchy exploits all possibilities of geometric, polynomial, and algebraic coarsening, targeting engineering applications on complex geometries. Additionally, a transfer from discontinuous to continuous function spaces is performed within the multigrid hierarchy. This does not only further reduce the problem size of the coarse-grid problem, but also leads to a discretization most suitable for state-of-the-art algebraic multigrid methods applied as coarse-grid solver. The relevant design choices regarding the selection of optimal multigrid coarsening strategies among the various possibilities are discussed with the metric of computational costs as the driving force for algorithmic selections. We find that a transfer to a continuous function space at highest polynomial degree (or on the finest mesh), followed by polynomial and geometric coarsening, shows the best overall performance. The success of this particular multigrid strategy is due to a significant reduction in iteration counts as compared to a transfer from discontinuous to continuous function spaces at lowest polynomial degree (or on the coarsest mesh). The coarsening strategy with transfer to a continuous function space on the finest level leads to a multigrid algorithm that is robust with respect to the penalty parameter of the SIPG method. Detailed numerical investigations are conducted for a series of examples ranging from academic test cases to more complex, practically relevant geometries. Performance comparisons to state-of-the-art methods from the literature demonstrate the versatility and computational efficiency of the proposed multigrid algorithms.
Turbulent Threshold for Continuum Calogero-Moser Models
Creators: name: Hogan, James
name: Kowalski, Matthew
Publisher: name: arXiv
Year: 2024
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37K10, 35Q55

description: We determine the sharp mass threshold for Sobolev norm growth for the focusing continuum Calogero--Moser model. It is known that below the mass of $2π$, solutions to this completely integrable model enjoy uniform-in-time $H^s$ bounds for all $s \geq 0$. In contrast, we show that for arbitrarily small $\varepsilon > 0$ there exists initial data $u_0 \in H^\infty_+$ of mass $2π+ \varepsilon$ such that the corresponding maximal lifespan solution $u : (T_-, T_+) \times \mathbb{R} \to \mathbb{C}$ satisfies $\lim_{t \to T_\pm} \|u(t)\|_{H^s} = \infty$ for all $s > 0$. As part of our proof, we demonstrate an orbital stability statement for the soliton and a dispersive decay bound for solutions with suitable initial data.
description: 13 pages
Overexpansion-dominated Coronal Mass Ejection Formation and Induced Radio Bursts
Creators: name: Wang, B. T.
name: Cheng, X.
name: Song, H. Q.
name: Ding, M. D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Aims. Coronal Mass Ejections (CMEs) are the most fascinating explosion in the solar system; however, their formation is still not fully understood. Methods. Here, we investigate a well-observed CME on 2021 May 07 that showed a typical three-component structure and was continuously observed from 0 to 3 Rsun by a combination of SDO/AIA (0--1.3 Rsun), PROBA2/SWAP (0--1.7 Rsun) and MLSO/K-Cor (1.05--3 Rsun). Furthermore, we compare the morphological discrepancy between the CME white-light bright core and EUV blob. In the end, we explore the origin of various radio bursts closely related to the interaction of the CME overexpansion with nearby streamer. Results. An interesting finding is that the height increases of both the CME leading front and bright core are dominated by the overexpansion during the CME formation. The aspect ratios of the CME bubble and bright core, quantifying the overexpansion, are found to decrease as the SO/STIX 4--10 keV and GOES 1--8 A soft X-ray flux of the associated flare increases near the peaks, indicating an important role of the flare reconnection in the first overexpansion. The CME bubble even takes place a second overexpansion although relatively weak, which is closely related to the compression with a nearby streamer and likely arises from an ideal MHD process. Moreover, the CME EUV blob is found to be relatively lower and wider than the CME white-light bright core, may correspond to the bottom part of the growing CME flux rope. The interaction between the CME and the streamer leads to two type II radio bursts, one normally drifting and one stationary, which are speculated to be induced at two different sources of the CME-driven shock front. The bidirectional electrons evidenced by series of "C-shaped" type III bursts suggest that the interchange reconnection be also involved during the interaction of the CME and streamer.