cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Validation of EDGES Low-Band Antenna Beam Model
Creators: name: Mahesh, Nivedita
name: Bowman, Judd D.
name: Mozdzen, Thomas J.
name: Rogers, Alan E. E.
name: Monsalve, Raul A.
name: Murray, Steven G.
name: Lewis, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The response of the antenna is a source of uncertainty in measurements with the Experiment to Detect the Global EoR Signature (EDGES). We aim to validate the beam model of the low-band (50-100 MHz) dipole antenna with comparisons between models and against data. We find that simulations of a simplified model of the antenna over an infinite perfectly conducting ground plane are, with one exception, robust to changes of numerical electromagnetic solver code or algorithm. For simulations of the antenna with the actual finite ground plane and realistic soil properties, we find that two out of three numerical solvers agree well. Applying our analysis pipeline to a simulated driftscan observation from an early EDGES low-band instrument that had a 10 m $\times$ 10 m ground plane, we find residual levels after fitting and removing a five-term foreground model to data binned in Local Sidereal Time (LST) average about 250 mK with $\pm$40 mK variation between numerical solvers. A similar analysis of the primary 30 m $\times$ 30 m sawtooth ground plane reduced the LST-averaged residuals to about 90 mK with $\pm$10 mK between the two viable solvers. More broadly we show that larger ground planes generally perform better than smaller ground planes. Simulated data have a power which is within 4$\%$ of real observations, a limitation of net accuracy of the sky and beam models. We observe that residual spectral structures after foreground model fits match qualitatively between simulated data and observations, suggesting that the frequency dependence of the beam is reasonably represented by the models. We find that soil conductivity of 0.02 Sm$^{-1}$ and relative permittivity of 3.5 yield good agreement between simulated spectra and observations. This is consistent with the soil properties reported by Sutinjo et al. (2015) for the Murchison Radio-astronomy Observatory, where EDGES is located.
description: 19 pages, 17 figures
Micromechanics of twin nucleation and growth in magnesium alloys
Creators: name: Paramatmuni, Chaitanya
Publisher: name: Imperial College London
Year: 2020

description: This thesis presents an integrated experimental and computational study that investigates the mechanistic drivers of twin nucleation, variant selection and twin growth in magnesium alloys. The analyses investigate microstructure sensitivity of twin nucleation in both 2D free surfaces and full 3D microstructures, while twin growth is extensively studied in pseudo-3D microstructures. It is shown that the total stored (dislocation) energy density identifies the experimentally observed locations of both classical (favourably oriented parent grains) and non-classical (unfavourable parent grains) twins. In both the cases, a critical total stored energy density of the order 0.015 Jm-2 is determined below which twin nucleation does not occur. In the case of classical twins, the local twin resolved shear stresses drive the variant selection, while it is the local shear stored energy density (that stored within the twin embryo) in the case of non-classical twins. Once these twins propagate, it is shown that the local deformation characteristics that govern their subsequent growth are influenced mainly by their crystallographic orientations. The experimental observations indicate that the intra-twin geometrically necessary dislocations (GND) density and twin-resolved shear stress (TRSS) differences within twin vary with twin crystallographic orientation, which is characterised in terms of inclination angle (that between the loading direction and twin c-axis). Further, model predictions, where the twin transformation is considered as a sequential process of reorientation followed by shear, and experimental measurements show that intra-twin average GND density increases with inclination angle, and that a reversal in the sign of intra-twin TRSS occurs as the inclination angle increases. This implies that the TRSS (backstress) within a twin is not always negative, which further suggests that the rate of twin growth is influenced by its own crystallographic orientation instead of global Schmid factor (which is based on parent grain orientation).
Spin-transfer torques in anti-ferromagnetic metals from first principles
Creators: name: Xu, Yuan
name: Wang, Shuai
name: Xia, Ke
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In spite of the absence of a macroscopic magnetic moment, an anti-ferromagnet is spin-polarized on an atomic scale. The electric current passing through a conducting anti-ferromagnet is polarized as well, leading to spin-transfer torques when the order parameter is textured, such as in anti-ferromagnetic non-collinear spin valves and domain walls. We report a first principles study on the electronic transport properties of anti-ferromagnetic systems. The current-induced spin torques acting on the magnetic moments are comparable with those in conventional ferromagnetic materials, leading to measurable angular resistances and current-induced magnetization dynamics. In contrast to ferromagnets, spin torques in anti-ferromagnets are very nonlocal. The torques acting far away from the center of an anti-ferromagnetic domain wall should facilitate current-induced domain wall motion.
description: The paper has substantially been rewritten, 4 pages, 5 figures
The targum (1948:Nov. 3 - 1948:Nov. 30)
Creators: name: No Name Supplied
Publisher: name: Targum Association
Year: 1948

description: Some University historians indicate that the Targum was first published as an annual in 1867, but of this we have no extant evidence. In January 1869, the Targum as we now know it, made its appearance as a monthly paper that concerned itself with student “literary contributions” and college news as well as serving as a vehicle for bringing news to alumni and the general public. The newspaper, which originally was for sale, varied in frequency over the years as did its title (The Targum, Rutgers Targum, Rutgers Daily Targum, and Daily Targum). The newspaper has continuously been published since 1869 with the exception of 19 months during the second world war, between February 1944 and October 1945. The Targum was published by the students of Rutgers College, and later Rutgers University—New Brunswick represented through the years as the Targum Association, Rutgers Targum Association, and Rutgers College Targum. As a student organization, the Targum operated under the oversight of the dean of students and student government but in October 1980, the Targum became an independent college paper.
Density perturbations in axion-like particles: classical vs quantum field treatment
Creators: name: Chakrabarty, Sankha Subhra
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Axions and axion-like particles are bosonic quantum fields. They are often assumed to follow classical field equations due to their high degeneracy in the phase space. In this work, we explore the disparity between classical and quantum field treatments in the context of density and velocity fields of axions. Once the initial density and velocity field are specified, the evolution of the axion fluid is unique in the classical field treatment. However, in the quantum field treatment, there are many quantum states consistent with the given initial density and velocity field. We show that evolutions of the density perturbations for these quantum states are not necessarily identical and, in general, differ from the unique classical evolution. To illustrate the underlying physics, we consider a system of large number of bosons in a one-dimensional box, moving under the gravitational potential of a heavy static point-mass. We ignore the self-interactions between the bosons here. Starting with homogeneous number density and zero velocity field, we determine the density perturbations in the linear regime in both quantum and classical field theories. We find that classical and quantum evolutions are identical in the linear regime if only one single-particle state is occupied by all the bosons and the self-interaction is absent. If more than one single-particle states are occupied, the density perturbations in quantum evolutions differ from the classical prediction after a certain time which depends upon the parameters of the system.
description: 17 pages, 2 figures. Comments are welcome
Hopf images and inner faithful representations
Creators: name: Banica, Teodor
name: Bichon, Julien
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Algebra (math.QA)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 16W30

description: We develop a general theory of Hopf image of a Hopf algebra representation, with the associated concept of inner faithful representation, modelled on the notion of faithful representation of a discrete group. We study several examples, including group algebras, enveloping algebras of Lie algebras, pointed Hopf algebras, function algebras, twistings and cotwistings, and we present a Tannaka duality formulation of the notion of Hopf image.
description: 23 pages. Introduction rewritten and several modifications
Development of detectors and simulation method for measurement of hadrons from neutrino interactions
Creators: name: Nonnenmacher, Toby
Publisher: name: Imperial College London
Year: 2020

description: As neutrino physics enters the precision era, the need for more data and better interpretation of those data grows ever more crucial. Building new detectors with improved sensitivity that can make novel kinematic measurements underpins the drive for more data and allowing data to be used to best effect in particle physics analyses requires constant improvement on the understanding of neutrino physics models and their implementation in simulation. This thesis describes both work on a new neutrino detector with sensitivity to low momentum hadrons from neutrino interactions, and development of the NEUT interaction generator for providing better handling of the final state interactions of such hadrons. Described herein, a prototype high pressure time projection chamber with optical and charge readout was built, commissioned, and operated at a beam test at the T10 beamline at the European Organization for Nuclear Research (CERN). A characterisation of the beam is presented based on simulation and analysis of two time of flight systems, as well as a description of techniques used for analysing the time projection chamber optical readout. This thesis also includes development of variable parameters governing nucleon final state interactions in the NEUT generator used by the Tokai to Kamiokande (T2K) experiment. A method of reweighting was produced to allow the use of these parameters in analyses, and extensive validations of this method are presented.
Network-wide traffic signal control optimization using a multi-agent deep reinforcement learning
Creators: name: Li, Zhenning
name: Yu, Hao
name: Zhang, Guohui
name: Dong, Shangjia
name: Xu, Cheng-Zhong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Inefficient traffic control may cause numerous problems such as traffic congestion and energy waste. This paper proposes a novel multi-agent reinforcement learning method, named KS-DDPG (Knowledge Sharing Deep Deterministic Policy Gradient) to achieve optimal control by enhancing the cooperation between traffic signals. By introducing the knowledge-sharing enabled communication protocol, each agent can access to the collective representation of the traffic environment collected by all agents. The proposed method is evaluated through two experiments respectively using synthetic and real-world datasets. The comparison with state-of-the-art reinforcement learning-based and conventional transportation methods demonstrate the proposed KS-DDPG has significant efficiency in controlling large-scale transportation networks and coping with fluctuations in traffic flow. In addition, the introduced communication mechanism has also been proven to speed up the convergence of the model without significantly increasing the computational burden.
Evolution of Magnetic Fields in Freely Decaying Magnetohydrodynamic Turbulence
Creators: name: Campanelli, Leonardo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the evolution of magnetic fields in freely decaying magnetohydrodynamic turbulence. By quasi-linearizing the Navier-Stokes equation, we solve analytically the induction equation in quasi-normal approximation. We find that, if the magnetic field is not helical, the magnetic energy and correlation length evolve in time respectively as E_B \propto t^{-2(1+p)/(3+p)} and ξ_B \propto t^{2/(3+p)}, where p is the index of initial power-law spectrum. In the helical case, the magnetic helicity is an almost conserved quantity and forces the magnetic energy and correlation length to scale as E_B \propto (log t)^{1/3} t^{-2/3} and ξ_B \propto (log t)^{-1/3} t^{2/3}.
description: 4 pages, 2 figures; accepted for publication in PRL
Aspects of phase separation in an experimental mixer-settler using two solvent extraction systems
Creators: name: Eckert, Norbert L.
Publisher: name: University of British Columbia
Year: 2010

description: An experimental investigation was undertaken to study the factors affecting phase separation in a specially constructed, laboratory scale mixer-settler. Two phase systems were used: 1. A laboratory prepared HSLIX64N-copper phase system, similar to that used in commercial copper solvent extraction processes. 2. A phase system obtained directly from the uranium extraction circuit of the Key Lake Mining Corporation, Sask., millsite. A settler scale-up criterion relating dispersion band thickness to specific settler flow of dispersed phase, was found to have considerable merit. Besides being dependent on specific settler flow, the dispersion band thickness was found to be a function of the phase ratio (for system 2 only), dispersion introduction level (for system 2 only), and temperature. Mixing intensity had no appreciable effect with either system. Microscopic examination of the dispersion produced with system 2 revealed the existence of double dispersions; that is, drops within drops. A photomicroscopic technique was used to undertake a drop size investigation of the dispersion produced with system 2. Drop size was found to be independent of dispersion throughput, a weak function of impellor speed and a relatively strong function of the phase ratio. With the exception of organic continuous operation with system 1, it was possible, based on the holdup and drop size profile within the dispersion band, to distinguish two horizontal sublayers within the dispersion band. In the "even concentration sublayer", comprising the majority of the dispersion band, the holdup and average drop size is nearly constant throughout. In the "dense concentration sublayer", both the holdup and the average drop size increase sharply as the coalescence front is approached.
The Araucaria Project. The Distance of the Large Magellanic Cloud from Near-Infrared Photometry of RR Lyrae Variables
Creators: name: Szewczyk, Olaf
name: Pietrzynski, Grzegorz
name: Gieren, Wolfgang
name: Storm, Jesper
name: Walker, Alistair
name: Rizzi, Luca
name: Kinemuchi, Karen
name: Bresolin, Fabio
name: Kudritzki, Rolf-Peter
name: Dall'Ora, Massimo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have obtained deep infrared $J$ and $K$ band observations of five fields located in the Large Magellanic Cloud (LMC) bar with the ESO New Technology Telescope equipped with the SOFI infrared camera. In our fields, 65 RR Lyrae stars catalogued by the OGLE collaboration were identified. Using different theoretical and empirical calibrations of the period-luminosity-metallicity relation, we find consistent LMC distance moduli values. Since the observed fields are situated very close to the center of the LMC, the correction for the tilt of the LMC bar with respect to the line of sight is negligible. Our adopted best true distance modulus to the LMC of $18.58 \pm 0.03$ (statistical) $\pm$ 0.11 (systematic) mag agrees very well with most independent determinations to this galaxy.
description: 30 pages, including 5 figures and 8 tables. AJ submitted and accepted
Some Applications of Ricci Flow in Physics
Creators: name: Woolgar, E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: I discuss certain applications of the Ricci flow in physics. I first review how it arises in the renormalization group (RG) flow of a nonlinear sigma model. I then review the concept of a Ricci soliton and recall how a soliton was used to discuss the RG flow of mass in 2-dimensions. I then present recent results obtained with Oliynyk on the flow of mass in higher dimensions. The final section discusses one way in which Ricci flow may arise in general relativity, particularly for static metrics.
description: Minor corrections in Sections IV and VI. Invited talk at Theory Canada III meeting, June 2007; submitted to Proceedings. Dedicated to Rafael D Sorkin on the occasion of his 60th birthday
Hypocenter interval statistics between successive earthquakes in the two-dimensional Burridge-Knopoff model
Creators: name: Hasumi, Tomohiro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study statistical properties of spatial distances between successive earthquakes, the so-called hypocenter intervals, produced by a two-dimensional (2D) Burridge-Knopoff model involving stick-slip behavior. It is found that cumulative distributions of hypocenter intervals can be described by the $q$-exponential distributions with $q<1$, which is also observed in nature. The statistics depend on a friction and stiffness parameters characterizing the model and a threshold of magnitude. The conjecture which states that $q_t+q_r \sim 2$, where $q_t$ and $q_r$ are an entropy index of time intervals and spatial intervals, respectively, can be reproduced semi-quantitatively. It is concluded that we provide a new perspective on the Burridge-Knopoff model which addresses that the model can be recognized as a realistic one in view of the reproduction of the spatio-temporal interval statistics of earthquakes on the basis of nonextensive statistical mechanics.
description: 9 pages, 4 figures
Computer simulation of microvascular exchange after thermal injury
Creators: name: Gu, Xiaozheng
Publisher: name: University of British Columbia
Year: 2010

description: A computer model is developed to study the fluid and protein redistribution after thermal injuries in rats. This model is derived by including the burned skin as a fourth compartment in the microvascular exchange model developed by Bert et al. [6]. The pathological changes that occur after thermal injuries are introduced into the burn model as perturbations. The simulations of short-term and long-term responses were then made in this four compartment (burn) model for two cases: 10% and 40% percent surface area burns. Appropriate ranges of the perturbations were estimated based on the available information in the literature. The perturbations for the 10% burn include: the plasma leak coefficient in the injured skin, the tissue pressure in the injured skin, the fluid exchange coefficients in the injured skin, the arterial capillary pressure in the injured skin and the lymph flow characteristics in the injured skin. The perturbations for the 40% burn include the perturbations for the 10% burn plus the plasma leak coefficients in the intact tissues, the fluid exchange coefficients in the intact tissues and the lymph flow characteristics in the intact tissues. The dynamic responses of the system using these perturbations were plotted. Comparisons between the simulation predictions and the experimental data were characterized in terms of sum-of-squares of differences between simulation results and experimental data. Compared to the limited amount of data available in the literature, the burn model describes microvascular exchange after thermal injuries reasonably well. The work in this thesis could easily be extended to account for fluid resuscitation following a thermal injury in rats and, it is hoped that this approach might eventually be applied to the resuscitation management of burn patients.
Stability of associated primes of monomial ideals
Creators: name: Hoa, Lê Tuân
Publisher: name: arXiv
Year: 2007
Subjects: subject: Commutative Algebra (math.AC)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 13A15, 13D45

description: Let $I$ be a monomial ideal of a polynomial ring $R$. In this paper we determine a number $B$ such that $\Ass (I^n/I^{n+1}) = \Ass (I^{B}/I^{B+1})$ for all $n\geq B$.
Uncertainty guided semi-supervised segmentation of retinal layers in OCT images
Creators: name: Sedai, Suman
name: Antony, Bhavna
name: Rai, Ravneet
name: Jones, Katie
name: Ishikawa, Hiroshi
name: Schuman, Joel
name: Gadi, Wollstein
name: Garnavi, Rahil
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Deep convolutional neural networks have shown outstanding performance in medical image segmentation tasks. The usual problem when training supervised deep learning methods is the lack of labeled data which is time-consuming and costly to obtain. In this paper, we propose a novel uncertainty-guided semi-supervised learning based on a student-teacher approach for training the segmentation network using limited labeled samples and a large number of unlabeled images. First, a teacher segmentation model is trained from the labeled samples using Bayesian deep learning. The trained model is used to generate soft segmentation labels and uncertainty maps for the unlabeled set. The student model is then updated using the softly segmented samples and the corresponding pixel-wise confidence of the segmentation quality estimated from the uncertainty of the teacher model using a newly designed loss function. Experimental results on a retinal layer segmentation task show that the proposed method improves the segmentation performance in comparison to the fully supervised approach and is on par with the expert annotator. The proposed semi-supervised segmentation framework is a key contribution and applicable for biomedical image segmentation across various imaging modalities where access to annotated medical images is challenging
description: MICCAI,19
Enhancing value in time-sensitive service delivery systems using intelligent scheduling
Creators: name: Seakhoa-King, Shireen
Publisher: name: Imperial College London
Year: 2019

description: In a typical service delivery system, a provider offers a service to a customer, based on an agreed commitment. Frequently, customer service requests are time-sensitive requiring prompt processing. Indeed, service providers are aware that the timely completion of processing of such requests can enhance the value which is accrued from the service encounter by both customer and service provider. However, the challenge facing many service providers is that time-sensitive requests are increasing superlinearly while resources available to carry them out remain limited, highly utilised and subject to much weaker growth rates. The problem is exacerbated when service durations are highly stochastic. In this context, the aim of this research is to enhance value to the service provider in time-sensitive service delivery systems through intelligent scheduling. The contributions are fourfold. Firstly, through an analysis of previous literature, key dimensions of a time-sensitive service delivery system are revealed and subsequently, a new taxonomy of service delivery systems is developed. Emerging from this, a quantitative concept which captures the varying value of service delivery as a function of time is proposed, namely the Time Value of Service function. Secondly, a Service Delivery Framework that supports modelling and decision-making for time-sensitive application domains is designed and implemented with the objective of enhancing value to the service provider. Thirdly, a new scheduling algorithm is proposed, the Least Lost Value (LLV) algorithm, that takes set of service requests, each comprising a Time Value of Service function and a duration distribution function, and outputs an ordered list of prioritised service requests for processing. Finally, the application of the framework and the LLV algorithm is demonstrated in the context of three case studies: (1) Big Data Processing, (2) Drone Delivery Service and (3) Emergency Services, where LLV outperforms traditional scheduling algorithms in enhancing value to the service provider. In the big data processing case study LLV extracted 300% more value than First Come First Served (FCFS), 200% more value than Earliest Deadline First (EDF), 160% more value than Shortest Remaining Time First (SRTF) and 110% more value than Highest Utility Density (HUD) algorithms. In the drone service delivery case study LLV extracted 48% and 31% more value than FCFS and Shortest Job First (SJF) in terms of realised revenue. Finally, in the emergency services case study LLV extracted 500% more value than the FCFS strategy.
Relaxation Based Modeling of GMD Induced Cascading Failures in PowerModelsGMD.jl
Creators: name: Mate, Adam
name: Barnes, Arthur K.
name: Morley, Steven K.
name: Friz-Trillo, Jacob A.
name: Cotilla-Sanchez, Eduardo
name: Blake, Sean P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: Space Physics (physics.space-ph)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences

description: A major risk of geomagnetic disturbances (GMDs) is cascading failure of electrical grids. The modeling of GMD events and cascading outages in power systems is difficult, both independently and jointly, because of the many different mechanisms and physics involved. This paper introduces a relaxation based modeling of GMD-induced cascading failures:~the dc approximation-based DCSIMSEP solver was adapted to simulate cascading as a result of GMDs, the full set of ac power flow equations were relaxed to guarantee optimality, and the reactive power losses were modeled while keeping the problem convex. The developed algorithm was implemented in PowerModelsGMD.jl - an open-source software specifically designed to model and analyze geomagnetic hazards - and demonstrated to work on the RTS-GMLC-GIC-EAST synthetic test network.
description: 7 pages. 5 figures. 3 tables
Minimax Model Learning
Creators: name: Voloshin, Cameron
name: Jiang, Nan
name: Yue, Yisong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: We present a novel off-policy loss function for learning a transition model in model-based reinforcement learning. Notably, our loss is derived from the off-policy policy evaluation objective with an emphasis on correcting distribution shift. Compared to previous model-based techniques, our approach allows for greater robustness under model misspecification or distribution shift induced by learning/evaluating policies that are distinct from the data-generating policy. We provide a theoretical analysis and show empirical improvements over existing model-based off-policy evaluation methods. We provide further analysis showing our loss can be used for off-policy optimization (OPO) and demonstrate its integration with more recent improvements in OPO.
Results and Frontiers in Lattice Baryon Spectroscopy
Creators: name: Bulava, John
name: Edwards, Robert
name: Fleming, George
name: Juge, K. Jimmy
name: Lichtl, Adam C.
name: Mathur, Nilmani
name: Morningstar, Colin
name: Richards, David
name: Wallace, Stephen J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The Lattice Hadron Physics Collaboration (LHPC) baryon spectroscopy effort is reviewed. To date the LHPC has performed exploratory Lattice QCD calculations of the low-lying spectrum of Nucleon and Delta baryons. These calculations demonstrate the effectiveness of our method by obtaining the masses of an unprecedented number of excited states with definite quantum numbers. Future work of the project is outlined.
description: To appear in the proceedings for the VII Latin American Symposium of Nuclear Physics and Applications
Emergence of radial Rashba spin-orbit fields in twisted van der Waals heterostructures
Creators: name: Frank, Tobias
name: Faria Junior, Paulo E.
name: Zollner, Klaus
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2024
Subjects: subject: 530 Physik

description: Rashba spin-orbit coupling is a quintessential spin interaction appearing in virtually any electronic heterostructure. Its paradigmatic spin texture in the momentum space forms a tangential vector field. Using first-principles investigations, we demonstrate that in twisted homobilayers and hetero-multilayers, the Rashba coupling can be predominantly radial, parallel to the momentum. Specifically, we study four experimentally relevant structures: twisted bilayer graphene (Gr), twisted bilayer WSe2, and twisted multilayers WSe2/Gr/WSe2 and WSe2/Gr/Gr/WSe2. We show, that the Rashba spin-orbit field texture in such structures can be controlled by an electric field, allowing to tune it from radial to tangential. Such spin-orbit engineering should be useful for designing novel spin-charge conversion and spin-orbit torque schemes, as well as for controlling correlated phases and superconductivity in van der Waals materials.
Building a testable shear viscosity across the QCD phase diagram
Creators: name: McLaughlin, Emma
name: Rose, Jacob
name: Dore, Travis
name: Parotto, Paolo
name: Ratti, Claudia
name: Noronha-Hostler, Jacquelyn
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Current experiments at the Relativistic Heavy Ion Collider (RHIC) are probing finite baryon densities where the shear viscosity to enthalpy ratio $ηT/w$ of the Quark Gluon Plasma remains unknown. We use the Hadron Resonance Gas (HRG) model with the most up-to-date hadron list to calculate $ηT/w$ at low temperatures and at finite baryon densities $ρ_B$. We then match $ηT/w$ to a QCD-based shear viscosity calculation within the deconfined phase to create a table across $\left\{T,μ_B\right\}$ for different cross-over and critical point scenarios at a specified location. We find that these new $ηT/w(T,μ_B)$ values would require initial conditions at significantly larger $ρ_B$, compared to ideal hydrodynamic trajectories, in order to reach the same freeze-out point.
Perceived Ethnic-Racial Socialization and Parenting Styles on Asian American College Students' Depressive Symptoms
Creators: name: Ahn, Lydia HaRim
Publisher: name: Digital Repository at the University of Maryland
Year: 2018
Subjects: subject: Ethnic studies
subject: Asian American studies
subject: Mental health
subject: Asian American
subject: Depression
subject: Ethnic-racial socialization
subject: Parenting styles

description: The present study examines how perceived mothers’ culturally relevant parenting styles and ethnic-racial socialization (ERS) are associated with depressive symptoms among 280 Asian American college students (M =19.53, SD = 1.57). We hypothesized that perceived ERS will predict depressive symptoms, and perceived authoritarian, authoritative, and training parenting styles will moderate this association. We used a cross-sectional, quantitative design to measure this model through an online questionnaire. Depressive symptoms were dependent on the parenting style and the type of ERS message. Results indicated that 1) training parenting style (high in guidance and care for children) was negatively associated with depressive symptoms, 2) the combination of promotion of equality messages and training parenting style was negatively linked with depressive symptoms, and 3) authoritarian parenting was positively correlated with depressive symptoms. Findings highlight the importance of culturally sensitive parenting on mental health.
Evolution of mass, surface layer composition and light scattering of evaporating, single microdroplets of SDS/DEG suspension. Shrinking droplet surface as the micelles generator
Creators: name: Kolwas, Maciej
name: Jakubczyk, Daniel
name: Archer, Justice
name: Duc, Tho Do
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study the evolution of the mass of evaporating single microdroplets of sodium do-decyl sulphate (SDS) / diethylene glycol (DEG) mixture. First, we recognise and deconvolute the influence of residual water evaporation [Kolwas et al. Soft Matter 2019;15:1825], which accelerates the composite droplet evaporation, a simple exponential decay of the evaporating droplet surface change rate. This enables us to study the influence of SDS concentration on the composite droplet evaporation. Next, we establish a simple relationship between the average SDS concentration and the droplet evaporation rate to enable the study of the evolution of SDS concentration at the droplet surface. The oscillatory nature of surface SDS concentration indicates cyclic changes in the surface monolayer associated with the cyclic creation of vesicles (micelles) at the surface. The model we developed, allows the determination of SDS critical micelles concentration (CMC) in DEG as 60+/-2 mM.
description: 19 pages, 10 figures, 2 Appendices
The SDSS-UKIDSS Fundamental Plane of Early-type Galaxies
Creators: name: La Barbera, F.
name: Busarello, G.
name: Merluzzi, P.
name: de la Rosa, I.
name: Coppola, G.
name: Haines, C. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We derive the Fundamental Plane (FP) relation for a sample of 1430 early-type galaxies in the optical (r band) and the near-infrared (K band), by combining SDSS and UKIDSS data. With such a large, homogeneous dataset, we are able to assess the dependence of the FP on the waveband. Our analysis indicates that the FP of luminous early-type galaxies is essentially waveband independent, with its coefficients increasing at most by 8% from the optical to the NIR. This finding fits well into a consistent picture where the tilt of the FP is not driven by stellar populations, but results from other effects, such as non-homology. In this framework, the optical and NIR FPs require more massive galaxies to be slightly more metal rich than less massive ones, and to have highly synchronized ages, with an age variation per decade in mass smaller than a few percent.
description: 7 pages, 2 figures, accepted for publication on ApJ
Predicting another doubly charmed molecular resonance $T_{cc}^{\prime+}(3876)$
Creators: name: Chen, Rui
name: Huang, Qi
name: Liu, Xiang
name: Zhu, Shi-Lin
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The isospin breaking effect plays an essential role in generating hadronic molecular states with a very tiny binding energy. Very recently, the LHCb Collaboration observed a very narrow doubly charmed tetraquark $T_{cc}^+$ in the $D^0D^0π$ mass spectrum, which lies just below the $D^0D^{*+}$ threshold around 273 keV. In this work, we study the $D^0D^{*+}/D^+D^{*0}$ interactions with the one-boson-exchange effective potentials and consider the isospin breaking effect carefully. We not only reproduce the mass of the newly observed $T_{cc}^+$ very well in the doubly charmed molecular tetraquark scenario, but also predict the other doubly charmed partner resonance $T_{cc}^{\prime+}$ with $m=3876~\text{MeV}$, and $Γ= 412~\text{keV}$. The prime decay modes of the $T_{cc}^{\prime+}$ are $D^0D^+γ$ and $D^+D^0π^0$. The peculiar characteristic mass spectrum of the $D^0D^{*+}/D^+D^{*0}$ molecular systems can be applied to identify the doubly charmed molecular states.
description: 5 pages, 3 figures
การศึกษาความเป็นไปได้ทางการเงินของโครงการลงทุนก่อสร้างอาคารตรวจบัตรโดยสาร ภายนอกอาคารผู้โดยสาร ณ ท่าอากาศยานนานาชาติภูเก็ต
Creators: name: บัณฑิต ผังนิรันดร์
Publisher: name: สมาคมนักวิจัย
Year: 2557
Subjects: ท่าอากาศยาน,เส้นทางบิน,อากาศยาน,เที่ยวบินในประเทศ,เที่ยวบินระหว่างประเทศ

description: 2, 19, วารสารสมาคมนักวิจัย
On invariant linearization of Lie groupoids
Creators: name: del Hoyo, Matias
name: de Melo, Mateus
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: The Linearization Theorem for proper Lie groupoids organizes and generalizes several results for classic geometries. Despite the various approaches and recent works on the subject, the problem of understanding invariant linearization remains somehow open. We address it here, by first giving a counter-example to a previous conjecture, and then proving a sufficient criterion that uses compatible complete metrics and covers the case of proper group actions. We also show a partial converse that fixes and extends previous results in the literature.
description: 12 pages
Deep Chandra Observation of the Pulsar Wind Nebula Powered by the Pulsar J1846-0258 in the Supernova Remnant Kes 75
Creators: name: Ng, C. -Y.
name: Slane, P. O.
name: Gaensler, B. M.
name: Hughes, J. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of detailed spatial and spectral analysis of the pulsar wind nebula (PWN) in supernova remnant Kes 75 (G29.7-0.3) using a deep exposure with Chandra X-ray observatory. The PWN shows a complex morphology with clear axisymmetric structure. We identified a one-sided jet and two bright clumps aligned with the overall nebular elongation, and an arc-like feature perpendicular to the jet direction. Further spatial modeling with a torus and jet model indicates a position angle $207\arcdeg\pm8 \arcdeg$ for the PWN symmetry axis. We interpret the arc as an equatorial torus or wisp and the clumps could be shock interaction between the jets and the surrounding medium. The lack of any observable counter jet implies a flow velocity larger than 0.4c. Comparing to an archival observation 6 years earlier, some small-scale features in the PWN demonstrate strong variability: the flux of the inner jet doubles and the peak of the northern clump broadens and shifts 2" outward. In addition, the pulsar flux increases by 6 times, showing substantial spectral softening from $Γ$=1.1 to 1.9 and an emerging thermal component which was not observed in the first epoch. The changes in the pulsar spectrum are likely related to the magnetar-like bursts of the pulsar that occurred 7 days before the Chandra observation, as recently reported from RXTE observations.
description: Accepted by ApJ, 8 figures, some of them have been scaled down in resolution
แนวทางการวิจัยและพัฒนาองค์ความรู้ ด้านการสร้างสรรค์ศิลปะวิชาการ
Creators: name: ปรีชา เถาทอง
Publisher: name: สมาคมนักวิจัย
Year: 2557
Subjects: องค์ความรู้ด้านการสร้างสรรค์ศิลปะวิชาการ

description: 2, 19, วารสารสมาคมนักวิจัย
Two-Fermion Bound States within the Bethe-Salpeter Approach
Creators: name: Dorkin, S. M.
name: Beyer, M.
name: Semikh, S. S.
name: Kaptari, L. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: To solve the spinor-spinor Bethe-Salpeter equation in Euclidean space we propose a novel method related to the use of hyperspherical harmonics. We suggest an appropriate extension to form a new basis of spin-angular harmonics that is suitable for a representation of the vertex functions. We present a numerical algorithm to solve the Bethe-Salpeter equation and investigate in detail the properties of the solution for the scalar, pseudoscalar and vector meson exchange kernels including the stability of bound states. We also compare our results to the non relativistic ones and to the results given by light front dynamics.
description: 32 pages, XIII Tables, 8 figures
จริยธรรมกับทักษะแห่งศตวรรษที่ 21
Creators: name: ขวัญหญิง ศรีประเสริฐภาพ
Publisher: name: ศูนย์คุณธรรม (องค์การมหาชน)
Year: 2012
Subjects: ทักษะ,ทักษะการเรียนรู้,ศตวรรษที่ 21

description: 1, 1, วารสารวิชาการคุณธรรมความดี
The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle
Creators: name: Callanan, Daniel
name: Longmore, Steven N.
name: Kruijssen, J. M. Diederik
name: Schruba, Andreas
name: Ginsburg, Adam
name: Krumholz, Mark R.
name: Bastian, Nate
name: Alves, Joao
name: Henshaw, Jonathan D.
name: Knapen, Johan H.
name: Chevance, Melanie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In the centres of the Milky Way and M83, the global environmental properties thought to control star formation are very similar. However, M83's nuclear star formation rate (SFR), as estimated by synchrotron and H-alpha emission, is an order of magnitude higher than the Milky Way's. To understand the origin of this difference we use ALMA observations of HCN (1-0) and HCO+ (1-0) to trace the dense gas at the size scale of individual molecular clouds (0.54", 12pc) in the inner ~500 pc of M83, and compare this to gas clouds at similar resolution and galactocentric radius in the Milky Way. We find that both the overall gas distribution and the properties of individual clouds are very similar in the two galaxies, and that a common mechanism may be responsible for instigating star formation in both circumnuclear rings. Given the considerable similarity in gas properties, the most likely explanation for the order of magnitude difference in SFR is time variability, with the Central Molecular Zone (CMZ) currently being at a more quiescent phase of its star formation cycle. We show M83's SFR must have been an order of magnitude higher 5-7 Myr ago. M83's `starburst' phase was highly localised, both spatially and temporally, greatly increasing the feedback efficiency and ability to drive galactic-scale outflows. This highly dynamic nature of star formation and feedback cycles in galaxy centres means (i) modeling and interpreting observations must avoid averaging over large spatial areas or timescales, and (ii) understanding the multi-scale processes controlling these cycles requires comparing snapshots of a statistical sample of galaxies in different evolutionary stages.
description: 31 pages, 22 figures, accepted by MNRAS
Time-extensive classical and quantum correlations in thermal machines
Creators: name: Aguilar, Milton
name: Paz, Juan Pablo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study intraenvironmental classical and quantum correlations in a thermal machine, which is modeled as a driven quantum system coupled with thermal reservoirs. We compute the mutual information, the quantum discord, and the entanglement between two parts of the environment formed by oscillators centered around two different frequencies. We show that there are only two processes that generate time-extensive correlations in the long-time limit. First, there is a resonant process which is responsible for the transport of excitations between different environmental modes due to the absorption (or emission) of energy from (or into) the driving field. Second, there is a nonresonant process that transforms the energy from the external driving into pairs of excitations in two environmental modes. We show that there is a regime when the mutual information and the quantum discord between the parts of the environment correlated by these two processes grow quadratically in time, while entanglement production is time-extensive.
Borel resummation of transverse momentum distributions
Creators: name: Bonvini, Marco
name: Forte, Stefano
name: Ridolfi, Giovanni
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a new prescription for the resummation of contributions due to soft gluon emission to the trasverse momentum distribution of processes such as Drell-Yan production in hadronic collisions. We show that familiar difficulties in obtaining resummed results as a function of transverse momentum starting from impact-parameter space resummation are related to the divergence of the perturbative expansion of the momentum-space result. We construct a resummed expression by Borel resummation of this divergent series, removing the divergence in the Borel inversion through the inclusion of a suitable higher twist term. The ensuing resummation prescription is free of numerical instabilities, is stable upon the inclusion of subleading terms, and the original divergent perturbative series is asymptotic to it. We compare our results to those obtained using alternative prescriptions, and discuss the ambiguities related to the resummation procedure.
description: 18 pages, 4 figures, LaTeX. Final version, to be published in N.P.B. References 10-11 added, several typos corrected
Multidimensional fluid motions with planar waves
Creators: name: Golovin, Sergey V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In the classical one-dimensional solution of fluid dynamics equations all unknown functions depend only on time t and Cartesian coordinate x. Although fluid spreads in all directions (velocity vector has three components) the whole picture of motion is relatively simple: trajectory of one fluid particle from plane x=const completely determines motion of the whole plane. Basing on the symmetry analysis of differential equations we propose generalization of this solution allowing movements in different directions of fluid particles belonging to plane x=const. At that, all functions but an angle determining the direction of particle's motion depend on t and x only, whereas the angle depends on all coordinates. In this solution the whole picture of motion superposes from identical trajectories placed under different angles in 3D space. Orientations of the trajectories are restricted by a finite relation possessing functional arbitrariness. The solution describes three-dimensional nonlinear processes and singularities in infinitely conducting plasma, gas or incompressible liquid.
description: 21 pages, 13 figures