cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On the Use of Field RR Lyrae as Galactic Probes. III. The $α$-element abundances
Creators: name: Crestani, J.
name: Braga, V. F.
name: Fabrizio, M.
name: Bono, G.
name: Sneden, C.
name: Preston, G. W.
name: Ferraro, I.
name: Iannicola, G.
name: Nonino, M.
name: Fiorentino, G.
name: Thévenin, F.
name: Lemasle, B.
name: Prudil, Z.
name: Alves-Brito, A.
name: Altavilla, G.
name: Chaboyer, B.
name: Dall'Ora, M.
name: D'Orazi, V.
name: Gilligan, C. K.
name: Grebel, E.
name: Koch-Hansen, A. J.
name: Lala, H.
name: Marengo, M.
name: Marinoni, S.
name: Marrese, P. M.
name: Martínez-Vázquez, C. E.
name: Matsunaga, N.
name: Monelli, M.
name: Mullen, J. P.
name: Neeley, J.
name: da Silva, R.
name: Stetson, P. B.
name: Salaris, M.
name: Storm, J.
name: Valenti, E.
name: Zoccali, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We provide the largest and most homogeneous sample of $α$-element (Mg, Ca, Ti) and iron abundances for field RR Lyrae (RRLs, 162 variables) by using high-resolution spectra. The current measurements were complemented with similar abundances available in the literature for 46 field RRLs brought to our metallicity scale. We ended up with a sample of old (t$\ge$ 10 Gyr), low-mass stellar tracers (208 RRLs: 169 fundamental, 38 first overtone, 1 mixed mode) covering three dex in iron abundance (-3.00$\le$[Fe/H]$\le$0.24). We found that field RRLs are $\sim$0.3 dex more $α$-poor than typical Halo tracers in the metal-rich regime, ([Fe/H]$\ge$-1.2) while in the metal-poor regime ([Fe/H]$\le$-2.2) they seem to be on average $\sim$0.1 dex more $α$-enhanced. This is the first time that the depletion in $α$-elements for solar iron abundances is detected on the basis of a large, homogeneous and coeval sample of old stellar tracers. Interestingly, we also detected a close similarity in the [$α$/Fe] trend between $α$-poor, metal-rich RRLs and red giants (RGs) in the Sagittarius dwarf galaxy as well as between $α$-enhanced, metal-poor RRLs and RGs in ultra faint dwarf galaxies. These results are supported by similar elemental abundances for 46 field Horizontal Branch (HB) stars. These stars share with RRLs the same evolutionary phase and the same progenitors. This evidence further supports the key role that old stellar tracers play in constraining the early chemical enrichment of the Halo and, in particular, in investigating the impact that dwarf galaxies have had in the mass assembly of the Galaxy.
Topological States of Matter
Creators: name: Parente, Vincenzo
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2012

description: My research program is focused on the study of elastic deformation and topological defects in two materials: graphene and topological insulators. In both systems at low energies the electrons have a nearly linear spectrum, i.e. they behave like relativistic fermions. This allows the study of the effects of defects and deformations on the dynamics of electrons trough the formalism of Dirac equation on curved space-time. In this setting it’ s possible to derive correction to observables properties of the systems like the conductivity for example. In the case of graphene I have derived the contribution to conductivity in the Born approximation of  the metric arising from the so-called bumps and made a comparison with the scattering on the gauge potential arising from the elastic deformation. A particular defect, the edge dislocation, is found to be a possible responsible for the behaviour of the conductivity at low energies. The topological insulators are a class of band insulators showing gapless edge states, capable of conduction. This situation is similar to Quantum Hall Effect, both physically and formally. Indeed, as in QHE topological invariants (Chern numbers) classify the behaviour of the material. I am thus focused on the study of these material both formally, on the ground of differential geometry, and physically, studying topological defect in topological insulators. Further investigation has been devoted to the analysis of electron-phonon interaction at the surface of a 3D TI, analysing superconductive instability.
From Awareness to Action: Strengthening The Global Fight Against  Rabies
Creators: name: Anita, Shongsir Warson Monsang
Publisher: name: Bio Vet Innovator Magazine
Year: 2024

description: The world’s most diabolical virus; Rabies is one of the oldest recognized diseases affecting warm blooded animals and it remains to be one of the most important zoonotic diseases affecting the developed countries causing heavy losses in human and livestock population. Dogs play an important role in maintenance and spread of rabies across the world resulting in nearly 10,000 human death every year in the country. The widespread of this disease is due to poor implantation of intervention strategies that included dog bite wound management practices, unavailability, and unaffordability of post exposure prophylaxis (PEP), failure to control the disease in free roaming dogs, improper dog population management, weak surveillance and diagnostic facilities and a lack of ‘One Health’ approach to this disease. The Global Action Plan (GAP) constitutes rabies elimination centered platform supported by the World Health Organization (WHO), the Food and Agriculture Organization (FAO) and the World Organization of Animal Health (OIE). Aptly called ‘United Against Rabies’ (UAR), these three organizations are collaborating towards the fruition of common objectives to eliminate the disease from the world by 2030.
Structural and dynamical properties of gel networks
Creators: name: Gimperlein, Matthias
name: Schmiedeberg, Michael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The competition of depletion attractions and longer-ranged repulsions between colloidal particles in colloid-polymer mixtures leads to the formation of heterogeneous gel-like structures. For instance, gel networks, i.e., states where the colloids arrange in thin strands that span the whole system occur at low packing fractions for attractions that are stronger than those at the binodal line of equilibrium liquid-fluid phase separation. By using Brownian dynamics simulations we explore the formation, structure, and ageing dynamics of gel networks. We determine reduced network that focus on the essential connections in a gel network. We compare the observed properties to those of bulky gels or cluster fluids. Our results demonstrate that both the structure as well as the (often slow) dynamics of the stable or meta-stable heterogenous states in colloid-polymer mixtures possess distinct features on various length and time scales and thus are richly divers.
description: 9 pages, 11 figures
Suppression of nuclear spin fluctuations in an InGaAs quantum dot ensemble by GHz-pulsed optical excitation
Creators: name: Evers, Eiko
name: Kopteva, Nataliia E.
name: Yugova, Irina A.
name: Yakovlev, Dmitri R.
name: Reuter, Dirk
name: Wieck, Andreas D.
name: Bayer, Manfred
name: Greilich, Alex
Publisher: name: TU Dortmund
Year: 2021
Subjects: subject: Quantum dots
subject: Qubits
subject: Spintronics
subject: 530

description: The coherent electron spin dynamics of an ensemble of singly charged (In,Ga)As/GaAs quantum dots in a transverse magnetic field is driven by periodic optical excitation at 1 GHz repetition frequency. Despite the strong inhomogeneity of the electron g factor, the spectral spread of optical transitions, and the broad distribution of nuclear spin fluctuations, we are able to push the whole ensemble of excited spins into a single Larmor precession mode that is commensurate with the laser repetition frequency. Furthermore, we demonstrate that an optical detuning of the pump pulses from the probed optical transitions induces a directed dynamic nuclear polarization and leads to a discretization of the total magnetic field acting on the electron ensemble. Finally, we show that the highly periodic optical excitation can be used as universal tool for strongly reducing the nuclear spin fluctuations and preparation of a robust nuclear environment for subsequent manipulation of the electron spins, also at varying operation frequencies.
description: npj Quantum information;7
Rabies Day Special: Bridging the Gap between Science and Safety
Creators: name: Vijayalakshmi, Sarita, Triveni T
Publisher: name: Bio Vet Innovator Magazine
Year: 2024

description: Dogs hold significant importance and are revered for their loyalty, protection, and association with various deities. They symbolize fidelity and faithfulness, protection, vigilance, devotion, and unwavering commitment. Therefore, dogs are considered as a member of a family in the present society. To keep them healthy it is mandated to vaccinate as it guards them against several infectious diseases and prevents us from acquiring zoonotic infections. The most important fatal zoonotic disease is rabies, which is mankind's oldest known disease.  It is caused by singlestranded, negative-sense RNA viruses of the Lyssavirus genus, family Rhabdoviridae. The term is derived from the Latin rabies, madness. This in turn may be related to the Sanskrit Rabhas, to rage. The Greeks derived the word lyssa from violent; this root is used in the genus name of the rabies virus, Lyssavirus. Rabies has been known since 2000 B.C.  Rabies is transmitted through the bite of animals infected with rabies, primarily dogs. All warm-blooded creatures, including humans, dogs, cats, foxes, wolves, vampire bats, cattle, horses, sheep, and goats are the hosts. Symptomless carriers and reservoirs of infection are vampire bats. Before 1885, there was a high mortality rate which was 100% fatal due to rabies. The development of the first efficacious rabies vaccine by French scientist and Microbiologist Louis Pasteur in 1885 revolutionized the prevention and treatment of rabies significantly reducing mortality rates. In recognition of his pioneering work, World Rabies Day is observed worldwide on September 28, the anniversary of Pasteur's death.
title: Moving Together: Affect, Time and The Political in-between Bodies
Creators: name: Ozbay, Semiha Muge
Publisher: name: Goldsmiths, University of London
Year: 2022

description: This thesis investigates the affective, temporal and political aspects of dancing together. I endeavour to theorize the affective field in-between dancing bodies with references to transmission of affects, imitative and emotional contagion, attunement, rhythmic entrainment, and mimicry. The temporal aspects of dancing together is understood in terms of Deleuze’s philosophy of time, particularly his concepts such as the Aion, the event, caesura, the virtual, and the three syntheses of time. At the intersection of affects and time, the potentials of the virtual imply the political. The political is conceived as the potential of the creative endeavours and the affective intensities activated by dancing together besides more overt political implications of the various political movements and historical moments. In order to develop these arguments in case studies, I introduce the experiences of a dancing community in Istanbul (Çatı, Association of Independent Contemporary Dancers); dancing rhythmically as part of political struggles during protests, strikes and the Gezi Uprising; and the relationship between the dancer and the audience in Hallo!, a choreographic work by Aydin Teker which is co-composed affectively by the spectators and the performer.
A study of submillimeter methanol absorption toward PKS1830-211: Excitation, invariance of the proton-electron mass ratio, and systematics
Creators: name: Muller, S.
name: Ubachs, W.
name: Menten, K. M.
name: Henkel, C.
name: Kanekar, N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Methanol is an important tracer to probe physical and chemical conditions in the interstellar medium of galaxies. Methanol is also the most sensitive target molecule for probing potential space-time variations of the proton-electron mass ratio, mu, a dimensionless constant of nature. We present an extensive ALMA study of the strongest submillimeter absorption lines of methanol [...] in the z=0.89 molecular absorber toward PKS1830-211, the only high-redshift object in which methanol has been detected. Our goals are to constrain the excitation of the methanol lines and to investigate the cosmological invariance of mu based on their relative kinematics. [...] We explore methanol excitation by running the non local thermal equilibrium radiative transfer code RADEX [...] The excitation analysis points to a cool (~10-20 K) and dense (~10^{4-5} cm-3) methanol gas. [...] In addition, we measure an abundance ratio A/E = 1.0 +/- 0.1, an abundance ratio CH3OH/H2 ~ 2 x 10^{-8}, and a 12CH3OH/13CH3OH ratio 62 +/- 3. Our analysis shows that the bulk velocities of the different transitions are primarily correlated with the observing epoch due to morphological changes in the background quasar's emission. There is a weaker correlation between bulk velocities and the lower level energies of the transitions, which could be a signature of temperature-velocity gradients in the absorbing gas. As a result, we do not find evidence for variations of mu, and we estimate Dmu/mu = (-1.8 +/- 1.2) x 10^{-7} at 1sigma from our multivariate linear regression. We set a robust upper limit | \Dmu/mu | < 3.6 x 10^{-7} (3sigma) for the invariance of mu at a look-back time of half the present age of the Universe. Our analysis highlights that systematics need to be carefully taken into account in future radio molecular absorption studies aimed at testing Dmu/mu below the 10^{-7} horizon. (Abridged)
description: Accepted for publication in A&A
On convergence of the extended strong-property-fluctuation theory for bianisotropic homogenized composites
Creators: name: Cui, Jiajia
name: Mackay, Tom G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The strong-property-fluctuation theory (SPFT) provides a sophisticated means of estimating the effective constitutive parameters of a homogenized composite material (HCM), which takes account of the statistical distribution of the component particles. We present an extended version of the third-order SPFT in which the component particles are represented as depolarization regions of nonzero volume. Numerical results are provided for a bianisotropic homogenization scenario wherein the HCM is a Faraday chiral medium. Thereby, convergence of the extended SPFT at the second-order level of approximation is demonstrated within the long-wavelength regime.
Energy dependence of underlying-event observables from RHIC to LHC energies
Creators: name: Ortiz, Antonio
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A study of the charged-particle density (number density) in the transverse region of the di-hadron correlations exploiting the existing pp and p$\bar{\rm p}$ data from RHIC to LHC energies is reported. This region has contributions from the Underlying Event (UE) as well as from Initial- and Final-State Radiation (ISR-FSR). Based on the data, a two-component model is built. This has the functional form $\propto s^α+β\log(s)$, where the logarithmic (($β= 0.140 \pm 0.007$)) and the power-law ($α= 0.270 \pm 0.005$) terms describe the components more sensitive to the ISR-FSR and UE contributions, respectively. The model describes the data from RHIC to LHC energies, the extrapolation to higher energies indicates that at around $\sqrt{s} \approx 100$\,TeV the number density associated to UE will match that from ISR-FSR. Although this behaviour is not predicted by PYTHIA~8.244, the power-law behaviour of the UE contribution is consistent with the energy dependence of the parameter that regulates Multiparton Interactions. Using simulations, KNO-like scaling properties of the multiplicity distributions in the regions sensitive to either UE or ISR-FSR are also discussed. The results presented here can be helpful to constrain QCD-inspired Monte Carlo models at the Future Circular Collider energies, as well as to characterize the UE-based event classifiers which are currently used at the LHC.
description: 6 pages, 4 figures
Turbulent combustion of gas-air mixtures in a spark ignition engine
Creators: name: Boisvert, Julie
Publisher: name: University of British Columbia
Year: 2010

description: An engine simulation model has been developed to describe turbulent combustion of gas-air mixtures in a spark-ignition engine. The model incorporates a turbulent entrainment combustion theory proposed by Daneshyar and Hill which is based on Tennekes' model of turbulence and the vortex bursting principle of Chomiak. Flame propagation was based on turbulent entrainment. The flame was modelled as a thick spherical shell composed of burned and unburned gases. Inside the thick flame, pockets of initial size A, the Taylor microscale, are consumed at a rate of the order of the laminar burning velocity. To compare the model to experimental data, turbulence levels were measured in a motored Ricardo Hydra engine using hot wire anemometry. Combustion pressure data were measured with a piezoelectric transducer. Results indicate that the model is successful in predicting trends in overall combustion rates when the engine speed and air-fuel ratio are varied. The model also provided insight into the structure of turbulent flames in engines.
Modeling the COVID-19 pandemic: A primer and overview of mathematical epidemiology
Creators: name: Saldaña, Fernando
name: Velasco-Hernández, Jorge X
Publisher: name: arXiv
Year: 2021
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences
subject: 92Bxx

description: Since the start of the still ongoing COVID-19 pandemic, there have been many modeling efforts to assess several issues of importance to public health. In this work, we review the theory behind some important mathematical models that have been used to answer questions raised by the development of the pandemic. We start revisiting the basic properties of simple Kermack-McKendrick type models. Then, we discuss extensions of such models and important epidemiological quantities applied to investigate the role of heterogeneity in disease transmission e.g. mixing functions and superspreading events, the impact of non-pharmaceutical interventions in the control of the pandemic, vaccine deployment, herd-immunity, viral evolution and the possibility of vaccine escape. From the perspective of mathematical epidemiology, we highlight the important properties, findings, and, of course, deficiencies, that all these models have.
description: 42 pages, 4 figures
Ammonia volatilization losses from manure during and following application to land
Creators: name: Cha, Daniel
Publisher: name: University of British Columbia
Year: 2010

description: Volatilization loss of ammonia during and following land application of liquid manure was measured in six experiments carried out on three different farms in British Columbia. Ammonia loss during application was determined by comparing the ammonia content of manure in the tanker and the ammonia content of manure in the collection trays on the field. Ammonia volatilization after spreading was determined by measuring the ammoniacal-N concentration of soil cores immediately following spreading, and at day 1, day 2 and day 5. The percentage of ammonia volatilized during the application of manure varied from 4.0 to 12.0% in summer depending on the spreading method (high or low spray). Losses from the high spray system were significantly higher than from the low spray system. The percentage of ammonia lost during application of manure during summer was always greater than during winter. Over the temperature range of 4 to 25°C, each increase of 10°C resulted in an increase in ammonia loss of 2.4%. The percentage of ammonia loss during the first 24 hours after application was a function of temperature, manure type, soil moisture content, and manure application rate. The percentage of ammonia lost after application during summer was always greater than the percentage lost during winter. The percentage of ammonia lost from dairy manure 24 hours after application was higher than that from swine manure by a factor of about 2. An increase in soil moisture content by a factor of two increased the percentage of ammonia loss in 24 hours by approximately the same factor. A much thinner manure cover at 52 t ha⁻¹ resulted in a greater percentage of ammonia loss (54.7%) in 24 hours than that of 138 t ha⁻¹ (42.0%). The percentage of ammonia lost 48 hours after application varied from 43.3 to 84.8%. The differences in loss are attributed to temperature, manure type, and manure application rate. The percentage of ammonia lost 5 days after application varied from 50.0 to 93.9%. Temperature and a 30 cm snow cover during the winter study were the primary factors responsible for the differences in ammonia loss after 5 days.
Cooling dynamics of pure and random Ising chains
Creators: name: Suzuki, Sei
Publisher: name: arXiv
Year: 2008
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Dynamics of quenching temperature is studied in pure and random Ising chains. Using the Kibble-Zurek argument, we obtain for the pure Ising model that the density of kinks after quenching decays as 1/\sqrtτ with the quench rate of temperature 1/τfor large τ. For the random Ising model, we show that decay rates of the density of kinks and the residual energy are 1/\lnτand 1/(\lnτ)^2 for large τrespectively. Analytic results for the random Ising model are confirmed by the Monte-Carlo simulation. Our results reveal a clear difference between classical and quantum quenches in the random Ising chain.
description: 10 pages and 2 figures, published version
Fractional dynamics in the Lévy quantum kicked rotor
Creators: name: Romanelli, Alejandro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the quantum kicked rotor in resonance subjected to momentum measurements with a Lévy waiting time distribution. We find that the system has a sub-ballistic behavior. We obtain an analytical expression for the exponent of the power law of the variance as a function of the characteristic parameter of the Lévy distribution and connect this anomalous diffusion with a fractional dynamics.
Spin conductivity in almost integrable spin chains
Creators: name: Jung, Peter
name: Rosch, Achim
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The spin conductivity in the integrable spin-1/2 XXZ-chain is known to be infinite at finite temperatures T for anisotropies -1 < Delta < 1. Perturbations which break integrability, e.g. a next-nearest neighbor coupling J', render the conductivity finite. We construct numerically a non-local conserved operator J_parallel which is responsible for the finite spin Drude weight of the integrable model and calculate its decay rate for small J'. This allows us to obtain a lower bound for the spin conductivity sigma_s >= c(T) / J'^2, where c(T) is finite for J' to 0. We discuss the implication of our result for the general question how non-local conservation laws affect transport properties.
description: 6 pages, 5 figures
Capturing High-level Nondeterminism in Concurrent Programs for Practical Concurrency Model Agnostic Record & Replay
Creators: name: Aumayr, Dominik
name: Marr, Stefan
name: Kaleba, Sophie
name: Boix, Elisa Gonzalez
name: Mössenböck, Hanspeter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: With concurrency being integral to most software systems, developers combine high-level concurrency models in the same application to tackle each problem with appropriate abstractions. While languages and libraries offer a wide range of concurrency models, debugging support for applications that combine them has not yet gained much attention. Record & replay aids debugging by deterministically reproducing recorded bugs, but is typically designed for a single concurrency model only. This paper proposes a practical concurrency-model-agnostic record & replay approach for multi-paradigm concurrent programs, i.e. applications that combine concurrency models. Our approach traces high-level nondeterministic events by using a uniform model-agnostic trace format and infrastructure. This enables orderingbased record & replay support for a wide range of concurrency models, and thereby enables debugging of applications that combine them. In addition, it allows language implementors to add new concurrency models and reuse the model-agnostic record & replay support. We argue that a concurrency-model-agnostic record & replay is practical and enables advanced debugging support for a wide range of concurrency models. The evaluation shows that our approach is expressive and flexible enough to support record & replay of applications using threads & locks, communicating event loops, communicating sequential processes, software transactional memory and combinations of those concurrency models. For the actor model, we reach recording performance competitive with an optimized special-purpose record & replay solution. The average recording overhead on the Savina actor benchmark suite is 10% (min. 0%, max. 23%). The performance for other concurrency models and combinations thereof is at a similar level. We believe our concurrency-model-agnostic approach helps developers of applications that mix and match concurrency models. We hope that this substrate inspires new tools and languages making building and maintaining of multi-paradigm concurrent applications simpler and safer.
Thermophysical Modeling of 20 Themis Family Asteroids with WISE/NEOWISE Observations
Creators: name: Jiang, Haoxuan
name: Ji, Jianghui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Themis family is one of the largest and oldest asteroid populations in the main-belt. Water-ice may widely exist on the parent body (24) Themis. In this work, we employ the Advanced Thermophysical Model as well as mid-infrared measurements from NASA's Wide-Field Infrared Survey Explorer to explore thermal parameters of 20 Themis family members. Here we show that the average thermal inertia and geometric albedo are ~$39.5\pm26.0 ~\rm J m^{-2} s^{-1/2} K^{-1}$ and $0.067\pm0.018$, respectively. The family members have a relatively moderate roughness fraction on their surfaces. We find that the relatively low albedos of Themis members are consistent with the typical values of B-type and C-type asteroids. As aforementioned, Themis family bears a very low thermal inertia, which indicates a fine and mature regolith on their surfaces. The resemblance of thermal inertia and geometric albedo of Themis members may reveal their close connection in origin and evolution. In addition, we present the compared results of thermal parameters for several prominent families.
description: 22 pages, 25 figures, accepted for publication in AJ
Introduction to Digital Preservation
Creators: name: Markus, Katharina
Publisher: name: Zenodo
Year: 2024

description: These slides introducing digital preservation (also long-term preservation) were presented in the workshop on Preservation of Life Science Data which was organized by NFDI4Microbiota. They contain exemplary cases of data loss, define digital preservation (with references to various digital preservation initatives), introduce the "Object Levels of Preservation" model, relevant metadata standards, preservation policies and certification in the context of digital preservation.
Modeling approach to regime shifts of primary production in shallow coastal ecosystems
Creators: name: Zaldivar, J. M.
name: Bacelar, F. S.
name: Dueri, S.
name: Marinov, D.
name: Viaroli, P.
name: Hernandez-Garcia, E.
name: .
Publisher: name: arXiv
Year: 2008
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences

description: Pristine coastal shallow systems are usually dominated by extensive meadows of seagrass species, which are assumed to take advantage of nutrient supply from sediment. An increasing nutrient input is thought to favour phytoplankton, epiphytic microalgae, as well as opportunistic ephemeral macroalgae that coexist with seagrasses. The primary cause of shifts and succession in the macrophyte community is the increase of nutrient load to water; however temperature plays also an important role. A competition model between rooted seagrass (Zostera marina), macroalgae (Ulva sp), and phytoplankton has been developed to analyse the succession of primary producer communities in these systems. Successions of dominance states, with different resilience characteristics, are found when modifying the input of nutrients and the seasonal temperature and light intensity forcing.
description: 33 pages, including 10 figures. To appear in Ecological Complexity
Periodic Modulation of Extraordinary Optical Transmission through Subwavelength Hole Arrays using Surrounding Bragg Mirrors
Creators: name: Lindquist, Nathan C.
name: Lesuffleur, Antoine
name: Oh, Sang-Hyun
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The enhanced light transmission through an array of subwavelength holes surrounded by Bragg mirrors is studied, showing that the mirrors act to confine the surface plasmons associated with the Extraordinary Optical Transmission effect, forming a surface resonant cavity. The overall effect is increased light transmission intensity by more than a factor of three beyond the already enhanced transmission, independent of whether the Bragg mirrors are on the input or the output side of the incident light. The geometry of the Bragg mirror structures controls the enhancement, and can even reduce the transmission in half. By varying these geometric parameters, we were able to periodically modulate the transmission of light for specific wavelengths, consistent with the propagation and interference of surface plasmon waves in a resonant cavity. FDTD simulations and a wave propagation model verify this effect.
description: 9 pages, 5 figures
Bringing discrete-time Langevin splitting methods into agreement with thermodynamics
Creators: name: Finkelstein, Joshua
name: Cheng, Chungho
name: Fiorin, Giacomo
name: Seibold, Benjamin
name: Grønbech-Jensen, Niels
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In light of the recently published complete set of statistically correct Gronbech-Jensen (GJ) methods for discrete-time thermodynamics, we revise a differential operator splitting method for the Langevin equation in order to comply with the basic GJ thermodynamic sampling features, namely the Boltzmann distribution and Einstein diffusion, in linear systems. This revision, which is based on the introduction of time scaling along with flexibility of a discrete-time velocity attenuation parameter, provides a direct link between the ABO splitting formalism and the GJ methods. This link brings about the conclusion that any GJ method has at least weak second order accuracy in the applied time step. It further helps identify a novel half-step velocity, which simultaneously produces both correct kinetic statistics and correct transport measures for any of the statistically sound GJ methods. Explicit algorithmic expressions are given for the integration of the new half-step velocity into the GJ set of methods. Numerical simulations, including quantum-based molecular dynamics (QMD) using the QMD suite LATTE, highlight the discussed properties of the algorithms as well as exhibit the direct application of robust, time step independent stochastic integrators to quantum-based molecular dynamics.
description: Accepted for publication in Journal of Chemical Physics
Finding Bugs with Specification-Based Testing is Easy!
Creators: name: Chin, Janice
name: Pearce, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: Automated specification-based testing has a long history with several notable tools having emerged. For example, QuickCheck for Haskell focuses on testing against user-provided properties. Others, such as JMLUnit, use specifications in the form of pre- and post-conditions to drive testing. An interesting (and under-explored) question is how effective this approach is at finding bugs in practice. In general, one would assume automated testing is less effective at bug finding than static verification. But, how much less effective? To shed light on this question, we consider automated testing of programs written in Whiley -- a language with first-class support for specifications. Whilst originally designed with static verification in mind, we have anecdotally found automated testing for Whiley surprisingly useful and cost-effective. For example, when an error is detected with automated testing, a counterexample is always provided. This has motivated the more rigorous empirical examination presented in this paper. To that end, we provide a technical discussion of the implementation behind an automated testing tool for Whiley. Here, a key usability concern is the ability to parameterise the input space, and we present novel approaches for references and lambdas. We then report on several large experiments investigating the tool's effectiveness at bug finding using a range of benchmarks, including a suite of 1800+ mutants. The results indicate the automated testing is effective in many cases, and that sampling offers useful performance benefits with only modest reductions in bug-finding capability. Finally, we report on some real-world uses of the tool where it has proved effective at finding bugs (such as in the standard library).
An Algorithm for Computing Cusp Points in the Joint Space of 3-RPR Parallel Manipulators
Creators: name: Zein, Mazen
name: Wenger, Philippe
name: Chablat, Damien
Publisher: name: arXiv
Year: 2007
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This paper presents an algorithm for detecting and computing the cusp points in the joint space of 3-RPR planar parallel manipulators. In manipulator kinematics, cusp points are special points, which appear on the singular curves of the manipulators. The nonsingular change of assembly mode of 3-RPR parallel manipulators was shown to be associated with the existence of cusp points. At each of these points, three direct kinematic solutions coincide. In the literature, a condition for the existence of three coincident direct kinematic solutions was established, but has never been exploited, because the algebra involved was too complicated to be solved. The algorithm presented in this paper solves this equation and detects all the cusp points in the joint space of these manipulators.
Regularity of Solutions to Regular Shock Reflection for Potential Flow
Creators: name: Bae, Myoungjean
name: Chen, Gui-Qiang
name: Feldman, Mikhail
Publisher: name: arXiv
Year: 2008
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35M10, 35J65, 35R35, 35J70, 76H05, 35B60, 35B65 (Primary); 35L65, 35L67, 76L05 (Secondary)

description: The shock reflection problem is one of the most important problems in mathematical fluid dynamics, since this problem not only arises in many important physical situations but also is fundamental for the theory of multidimensional conservation laws. However, most of the fundamental issues for shock reflection have not been understood. Therefore, it is important to establish the regularity of solutions to shock reflection in order to understand fully the phenomena of shock reflection. On the other hand, for a regular reflection configuration, the potential flow governs the exact behavior of the solution in $C^{1,1}$ across the pseudo-sonic circle even starting from the full Euler flow, that is, both of the nonlinear systems are actually the same in an physically significant region near the pseudo-sonic circle; thus, it becomes essential to understand the optimal regularity of solutions for the potential flow across the pseudo-sonic circle and at the point where the pseudo-sonic circle meets the reflected shock. In this paper, we study the regularity of solutions to regular shock reflection for potential flow. In particular, we prove that the $C^{1,1}$-regularity is optimal for the solution across the pseudo-sonic circle and at the point where the pseudo-sonic circle meets the reflected shock. We also obtain the $C^{2,α}$ regularity of the solution up to the pseudo-sonic circle in the pseudo-subsonic region. The problem involves two types of transonic flow: one is a continuous transition through the pseudo-sonic circle from the pseudo-supersonic region to the pseudo-subsonic region; the other a jump transition through the transonic shock as a free boundary from another pseudo-supersonic region to the pseudo-subsonic region.
description: 1 texfile, 2 figures
The effect of molecular structure and operating conditions on the solubility of triglycerides in supercritical CO₂
Creators: name: Cheok, Nai Tin
Publisher: name: University of British Columbia
Year: 2010

description: In order to assess the feasibility of using supercritical fluid as a solvent for oil extraction in the oil and fat industry, basic information is required on oil solubility as a function of various system parameters. Such information would be useful in the design of extraction systems. This research work studied the effects of temperature and pressure on the equilibrium solubilities of triglycerides in supercritical carbon dioxide which is considered one of the best solvents for supercritical fluid extraction. A series of experiments was carried out using a modified liquid chromatograph. Samples tested included pure simple triglycerides that are saturated and unsaturated, and triglyceride mixtures. Extraction experiments were extended to cocoa butter, palm kernel oil and their mixtures with various weight, ratios. The effect of sample water content on the oil solubility was investigated using cocoa butter/water mixtures in different proportions. The solubilities of simple triglycerides were found to depend strongly on pressure and temperature. Triglycerides with a longer carbon chain (C18) exhibit lower solubilities over the range of temperatures and pressures studied. Unsaturated triglycerides were more soluble than their saturated counterparts. Furthermore, for the saturated triglycerides, the solubilities varied inversely as their molecular weights. Significant fractionation occured during the extraction of simple triglyceride mixtures at 36 MPa and 55 °C. Results of tests on cocoa butter and palm kernel oil separately indicated that no fractionation had taken place during the extraction process. However, significant fractionation was again observed when the two oils were mixed. Sample water content up to 50% by weight had negligible effect on the oil extractability and its equilibrium solubility in CO₂.
Lane level context and hidden space characterization for autonomous driving
Creators: name: Sanchez, Corentin
name: Xu, Philippe
name: Armand, Alexandre
name: Bonnifait, Philippe
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: For an autonomous vehicle, situation understand-ing is a key capability towards safe and comfortable decision-making and navigation. Information is in general provided bymultiple sources. Prior information about the road topology andtraffic laws can be given by a High Definition (HD) map whilethe perception system provides the description of the spaceand of road entities evolving in the vehicle surroundings. Incomplex situations such as those encountered in urban areas,the road user behaviors are governed by strong interactionswith the others, and with the road network. In such situations,reliable situation understanding is therefore mandatory to avoidinappropriate decisions. Nevertheless, situation understandingis a complex task that requires access to a consistent andnon-misleading representation of the vehicle surroundings. Thispaper proposes a formalism (an interaction lane grid) whichallows to represent, with different levels of abstraction, thenavigable and interacting spaces which must be considered forsafe navigation. A top-down approach is chosen to assess andcharacterize the relevant information of the situation. On a highlevel of abstraction, the identification of the areas of interestwhere the vehicle should pay attention is depicted. On a lowerlevel, it enables to characterize the spatial information in aunified representation and to infer additional information inoccluded areas by reasoning with dynamic objects.
Evolution of self-assembled InAs/Gas(001) quantum dots grown by growth-interrupted molecular beam epitaxy
Creators: name: Balzarotti, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Self-assembled InAs quantum dots (QDs) grown on GaAs(001) surface by molecular beam epitaxy under continuous and growth-interruption modes exhibit two families of QDs, quasi-3D (Q3D) and 3D QDs, whose volume density evolution is quantitatively described by a rate-equation kinetic model. The volume density of small Q3D QDs decreases exponentially with time during the interruption, while the single-dot mean volume of the large QDs increases by Ostwald ripening. The kinetics of growth involves conversion of quasi-3D to 3D QDs at a rate determined by superstress and participation of the wetting layer adatoms. The data analysis excludes that quasi-3D QDs are extrinsic surface features due to inefficient cooling after growth.
Superfluidity of isotopically doped parahydrogen clusters
Creators: name: Mezzacapo, Fabio
name: Boninsegni, Massimo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: It is shown by computer simulations that superfluid {\it para}-hydrogen clusters of more than 22 molecules can be turned insulating and "solidlike" by the replacement of as few as one or two molecules, with ones of the heavier {\it ortho}-deuterium isotope. A much smaller effect is observed with substitutional {\it ortho}-hydrogen. Substitutional {\it ortho}-deuterium molecules prevalently sit in the inner part of the cluster, whereas {\it ortho}-hydrogen impurities reside primarily in the outer shell, near the surface. Implications on the superfluidity of pure {\it para}-hydrogen clusters are discussed.
description: 4 pages, 5 figures
The GOGREEN survey: the internal dynamics of clusters of galaxies at redshift 0.9-1.4
Creators: name: Biviano, A.
name: van der Burg, R. F. J.
name: Balogh, M. L.
name: Munari, E.
name: Cooper, M. C.
name: De Lucia, G.
name: Demarco, R.
name: Jablonka, P.
name: Muzzin, A.
name: Nantais, J.
name: Old, L. J.
name: Rudnick, G.
name: Vulcani, B.
name: Wilson, G.
name: Yee, H. K. C.
name: Zaritsky, D.
name: Cerulo, P.
name: Chan, J.
name: Finoguenov, A.
name: Gilbank, D.
name: Lidman, C.
name: Pintos-Castro, I.
name: Shipley, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We aim to determine the mass, velocity anisotropy, and pseudo phase-space density profiles (M(r), beta(r), and Q(r), respectively) of clusters of galaxies at the highest redshifts investigated in detail so far. We combine the GOGREEN and GCLASS spectroscopic data-sets for 14 clusters with mass M200 > 10^14 Msolar at redshifts 0.9 < z < 1.4. We stack these 14 clusters into an ensemble cluster of 581 member galaxies with stellar mass > 10^9.5 M_solar. We use the MAMPOSSt method and the inversion of the Jeans equation technique to determine M(r) and beta(r). We then combine the results of the M(r) and beta(r) analysis to determine Q(r) for the ensemble cluster. The concentration c200 of the ensemble cluster M(r) is in excellent agreement with predictions from LambdaCDM cosmological numerical simulations, and with previous determinations for clusters of similar mass and at similar redshifts, obtained from gravitational lensing and X-ray data. We see no significant difference between the total mass density and either the galaxy number density distributions or the stellar mass distribution. Star-forming galaxies are spatially significantly less concentrated than quiescent galaxies. The orbits of cluster galaxies are isotropic near the center and more radial outside. Star-forming galaxies and galaxies of low stellar mass tend to move on more radially elongated orbits than quiescent galaxies and galaxies of high stellar mass. Q(r), determined either using the total mass or the number density profile, is very close to the power-law behavior predicted by numerical simulations. The internal dynamics of clusters at the highest redshift probed in detail so far are very similar to those of lower-redshift clusters, and in excellent agreement with predictions of numerical simulations. The clusters in our sample have already reached a high degree of dynamical relaxation. (Abridged)
description: Accepted for publication in A&A. 17 pages, 11 figures. New version after language editing by A&A
The GMRT Search for Reionization
Creators: name: Pen, Ue-Li
name: Chang, Tzu-Ching
name: Peterson, Jeff B.
name: Roy, Jayanta
name: Gupta, Yashwant
name: Bandura, Kevin
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an overview for the reionization search at GMRT. The forecast sensitivities are promising for an early detection. RFI mitigation has been successful. Several hundred hours of telescope time have already been invested in this ongoing effort, and analysis of the data is in progress.
description: 7 pages, invited talk at Arecibo conference "The Evolution of Galaxies through the Neutral Hydrogen Window"
Modular multi-wire drift chambers for the TRIUMF QQD-spectrometer
Creators: name: Forster, Brigitta Monica
Publisher: name: University of British Columbia
Year: 2010

description: A modular, multiwire drift chamber was built and tested in the M13 area. The resolution obtained with six sense wires, was in the horizontal drift direction σ(mean) < (79.9± .2)µm, with an angular resolution of (9.37±.02)mrads. With the drift chamber mounted in the first wire chamber position of the QQD-spectrometer, this corresponds to a resolution of 1.97mm FWHM at the position of the scattering target. In the vertical direction, using a charge division method, the best achieved resolution was < 2mm FWHM per wire, which gives an angular resolution of 71mrads or 15mm FWHM at the target position. The chamber was run at rates in excess of 10⁶ particles/sec. A multi-chamber system was tested, consisting of two modular four cell drift chambers for the horizontal direction, and one eight cell modular drift chamber, located in between and rotated by 90°, was used for the vertical position determination. The resolution for one four cell chamber was σ(mean) < (108.5± .9)µm, and for the eight cell chamber σ(mean) < (79.9± .2)µm. The angular resolution for this system was 1.37 mrad horizontally and 9.37mrads vertically; in connection with the QQD-spectrometer, this corresponds to FWHM of 0.267mm and 1.12mm respectively at the target spot.