cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Software-Intensive Product Engineering in Start-Ups: A Taxonomy
Creators: name: Klotins, Eriks
name: Unterkalmsteiner, Michael
name: Gorschek, Tony
Publisher: name: arXiv
Year: 2023
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Software start-ups are new companies aiming to launch an innovative product to mass markets fast with minimal resources. However, most start-ups fail before realizing their potential. Poor software engineering, among other factors, could be a significant contributor to the challenges that start-ups experience. Little is known about the engineering context in start-up companies. On the surface, start-ups are characterized by uncertainty, high risk, and minimal resources. However, such a characterization isn't granular enough to support identification of specific engineering challenges and to devise start-up-specific engineering practices. The first step toward an understanding of software engineering in start-ups is the definition of a Start-Up Context Map - a taxonomy of engineering practices, environment factors, and goals influencing the engineering process. This map aims to support further research on the field and serve as an engineering decision support tool for start-ups. This article is part of a theme issue on Process Improvement.
Linking turbulent waves and bubble diffusion in self-aerated open-channel flows: Two-state air concentration
Creators: name: Kramer, Matthias
name: Valero, Daniel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: High Froude-number flows become self-aerated when the destabilizing effect of turbulence overcomes gravity and surface tension forces. Traditionally, the resulting air concentration profile has been explained using single-layer approaches that invoke solutions of the advection-diffusion equation for air in water, i.e., bubbles' dispersion. Based on a wide range of experimental evidences, we argue that the complete air concentration profile shall be explained through the weak interaction of different canonical turbulent flows, namely a Turbulent Boundary Layer (TBL) and a Turbulent Wavy Layer (TWL). Motivated by a decomposition of the streamwise velocity into a pure wall flow and a free-stream flow [Krug et al., J. Fluid Mech. (2017), vol. 811, pp. 421--435], we present a physically consistent two-state formulation of the structure of a self-aerated flow. The air concentration is mathematically built upon a modified Rouse profile and a Gaussian error function, resembling vertical mass transport in the TBL and the TWL. We apply our air concentration theory to over 500 profiles from different data sets, featuring excellent agreement. Finally, we show that the turbulent Schmidt number, characterizing the momentum-mass transfer, ranges between 0.2 to 1, which is consistent with previous mass-transfer experiments in TBLs. Altogether, the proposed flow conceptualization sets the scene for more physically-based numerical modelling of turbulent mass diffusion in self-aerated flows.
description: 17 pages, 7 figures
Discrete projection: Highly correlated arrays and ghosts for image reconstruction
Creators: name: CEKO, MATTHEW STEVEN
Publisher: name: Monash University
Year: 2021
Subjects: Image processing
Applied mathematics not elsewhere classified

description: Tomography studies the reconstruction of images from projected observations made at various angles. This thesis focuses explicitly on discrete projections, which sum only points across a regular finite grid that intersect straight lines. Discrete projection methods are used in this thesis to assemble highly structured arrays where individual points are purposefully positioned to amplify or reduce the spatial correlations between neighbourhoods, or as tilings with shapes that leave tomographic projections unchanged. These arrays find use in imaging, communication technology, online security, crystallography and material science. Algorithms are provided to perform these tasks efficiently.
Lithium in Open Cluster Red Giants Hosting Substellar Companions
Creators: name: Carlberg, Joleen K.
name: Smith, Verne V.
name: Cunha, Katia
name: Carpenter, Kenneth G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We have measured stellar parameters, [Fe/H], lithium abundances, rotation, and 12C/13C in a small sample of red giants in three open clusters that are each home to a red giant star that hosts a substellar companion (NGC2423 3, NGC4349 127, and BD+12 1917 in M67). Our goal is to explore whether the presence of substellar companions influences the Li content. Both 12C/13C and stellar rotation are measured as additional tracers of stellar mixing. One of the companion hosts, NGC2423 3, is found to be Li-rich with A(Li)_NLTE=1.56 dex, and this abundance is significantly higher than the A(Li) of the two comparison stars in NGC2423. All three substellar companion hosts have the highest A(Li) and 12C/13C when compared to the control red giants in their respective clusters; however, except for NGC2423 3, at least one control star has similarly high abundances within the uncertainties. Higher A(Li) could suggest that the formation or presence of planets plays a role in the degree of internal mixing on or before the red giant branch. However, a multitude of factors affect A(Li) during the red giant phase, and when the abundances of our sample are compared to abundances of red giants in other open clusters available in the literature, we find that they all fall well within a much larger distribution of A(Li) and 12C/13C. Thus, even the high Li in NGC2423 3 cannot be concretely tied to the presence of the substellar companion.
description: 10 pages; Accepted for publication in ApJ
Test-Case Quality -- Understanding Practitioners' Perspectives
Creators: name: Tran, Huynh Khanh Vi
name: Ali, Nauman Bin
name: Börstler, Jürgen
name: Unterkalmsteiner, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Background: Test-case quality has always been one of the major concerns in software testing. To improve test-case quality, it is important to better understand how practitioners perceive the quality of test-cases. Objective: Motivated by that need, we investigated how practitioners define test-case quality and which aspects of test-cases are important for quality assessment. Method: We conducted semi-structured interviews with professional developers, testers and test architects from a multinational software company in Sweden. Before the interviews, we asked participants for actual test cases (written in natural language) that they perceive as good, normal, and bad respectively together with rationales for their assessment. We also compared their opinions on shared test cases and contrasted their views with the relevant literature. Results: We present a quality model which consists of 11 test-case quality attributes. We also identify a misalignment in defining test-case quality among practitioners and between academia and industry, along with suggestions for improving test-case quality in industry. Conclusion: The results show that practitioners' background, including roles and working experience, are critical dimensions of how test-case quality is defined and assessed.
description: PROFES 2019: 37-52
Phase diagram of the B-B2O3 system at pressures to 24 GPa
Creators: name: Turkevich, Vladimir Z.
name: Turkevich, Dmitry V.
name: Solozhenko, Vladimir L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The evolution of topology of the B-B2O3 phase diagram has been studied at pressures up to 24 GPa using models of phenomenological thermodynamics with interaction parameters derived from experimental data on phase equilibria at high pressures and high temperatures.
Reproductive and energetic consequences of fishing capture on chondrichthyan species
Creators: name: FINOTTO, LICIA
Publisher: name: Monash University
Year: 2021
Subjects: Conservation and biodiversity
Marine and estuarine ecology (incl. marine ichthyology)
Ecology not elsewhere classified

description: Given the poor conservation status of chondrichthyans (sharks, rays and chimeras) and the severe impairments caused by fishing activity in animals that are released, the aim of my research was to investigate energetic and reproductive consequences of fishing-capture stress in chondrichthyans. Results show that animals invest more energy to face the stress and survive, but, when the stress is too severe, a prolonged metabolic depression is triggered, saving the little energy left for life sustenance. However, this reduces energy allocation to pregnancy in viviparous species and, in turn, causes impairments in neonates, possibly impacting neonate survival and population abundance.
Persistent current in a 2D Josephson junction array wrapped around a cylinder
Creators: name: Garanin, D. A.
name: Chudnovsky, E. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study persistent currents in a Josephson junction array wrapped around a cylinder. The $T=0$ quantum statistical mechanics of the array is equivalent to the statistical mechanics of a classical $xy$ spin system in 2+1 dimensions at the effective temperature $T^{*}=\sqrt{2JU}$, with $J$ being the Josephson energy of the junction and $U$ being the charging energy of the superconducting island. It is investigated analytically and numerically on lattices containing over one million sites. For weak disorder and $T^{*}\ll J$ the dependence of the persistent current on disorder and $T^{*}$ computed numerically agrees quantitatively with the analytical result derived within the spin-wave approximation. The high-$T^{*}$ and/or strong-disorder behavior is dominated by instantons corresponding to the vortex loops in 2+1 dimensions. The current becomes destroyed completely at the quantum phase transition into the Cooper-pair insulating phase.
description: 6 pages, 5 figures
Two-element interferometer for millimeter-wave solar flare observations
Creators: name: Yu, Yonglin
name: Xu, Shuo
name: Zhang, Lei
name: Shang, Ziqian
name: Qiao, Chenglong
name: Li, Shuqi
name: Wu, Zhao
name: Su, Yanrui
name: Song, Hongqiang
name: Chen, Yao
name: Yan, Fabao
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In this paper, we present the design and implementation of a two-element interferometer working in the millimeter wave band (39.5 GHz - 40 GHz) for observing solar radio emissions through nulling interference. The system is composed of two 50 cm aperture Cassegrain antennas mounted on a common equatorial mount, with a separation of 230 wavelengths. The cross-correlation of the received signals effectively cancels the quiet solar component of the large flux density (~3000 sfu) that reduces the detection limit due to atmospheric fluctuations. The system performance is obtained as follows: the noise factor of the AFE in the observation band is less than 2.1 dB, system sensitivity is approximately 12.4 K (~34 sfu) with an integration time constant of 0.1 ms (default), the frequency resolution is 153 kHz, and the dynamic range is larger than 30 dB. Through actual testing, the nulling interferometer observes a quiet sun with a low level of output fluctuations (of up to 50 sfu) and has a significantly lower radiation flux variability (of up to 190 sfu) than an equivalent single-antenna system, even under thick cloud cover. As a result, this new design can effectively improve observation sensitivity by reducing the impact of atmospheric and system fluctuations during observation.
Interaction of chiral rafts in self-assembled colloidal membranes
Creators: name: Xie, Sheng
name: Pelcovits, Robert A.
name: Hagan, Michael F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Colloidal membranes are monolayer assemblies of rodlike particles that capture the long-wavelength properties of lipid bilayer membranes on the colloidal scale. Recent experiments on colloidal membranes formed by chiral rodlike viruses showed that introducing a second species of virus with different length and opposite chirality leads to the formation of rafts --- micron-sized domains of one virus species floating in a background of the other viruses [Sharma et al., Nature 513, 77 (2014)]. In this article we study the interaction of such rafts using liquid crystal elasticity theory. By numerically minimizing the director elastic free energy, we predict the tilt angle profile for both a single raft and two rafts in a background membrane, and the interaction between two rafts as a function of their separation. We find that the chiral penetration depth in the background membrane sets the scale for the range of the interaction. We compare our results with the experimental data and find good agreement for the strength and range of the interaction. Unlike the experiments, however, we do not observe a complete collapse of the data when rescaled by the tilt angle at the raft edge.
description: 18 pages, 10 figures
Spilomicrus pelion Nixon 1980
Creators: name: Notton, David G.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Diapriidae
Spilomicrus
Spilomicrus pelion

description: Spilomicrus pelion Nixon, 1980: 17, figs 33, 40.
Valid name
Spilomicrus crassiclavis Kieffer, 1911.
Summary of types
Holotype ♂, BMNH number 9.811, by original designation. Paratype ♂.
Primary type data
Surrey / Horsley/ 14.vi.1930 / G.Nixon; Spilomicrus / pelion Nixon / type ♂, 197.
Type locality
England, Surrey, Horsley.
Remarks
The holotype is mounted on a card point and is entire.
description: Published as part of Notton, David G., 2014, A catalogue of the types of Diapriinae (Hymenoptera, Diapriidae) at the Natural History Museum, London, pp. 1-123 in European Journal of Taxonomy 75 on page 95, DOI: 10.5852/ejt.2014.75, http://zenodo.org/record/3862773
Can prompt cusps of WIMP dark matter be detected as individual gamma-ray sources?
Creators: name: Delos, M. Sten
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Prompt $ρ\propto r^{-1.5}$ density cusps are the densest and most abundant dark matter systems. If the dark matter is a weakly interacting massive particle (WIMP), recent studies have shown that prompt cusps dominate the aggregate dark matter annihilation rate. This article explores whether individual prompt cusps could be detected as gamma-ray sources. At the Fermi telescope's point-source sensitivity, WIMPs with the canonical annihilation cross section could form detectable prompt cusps if the particle mass is of order 10 GeV. These objects could be 10-100 pc away and weigh under a solar mass; they would subtend around 0.1 degrees on the sky. For GeV-scale dark matter particles with below-canonical cross sections, searches for individual prompt cusps can be more sensitive than searches for the annihilation signals from galactic dark matter halos.
description: 8 pages, 5 figures; accepted by Physical Review D
The Host Galaxy of FRB 20171020A Revisited
Creators: name: Lee-Waddell, Karen
name: James, Clancy W.
name: Ryder, Stuart D.
name: Mahony, Elizabeth K.
name: Bahramian, Arash
name: Koribalski, Baerbel S.
name: Kumar, Pravir
name: Marnoch, Lachlan
name: North-Hickey, Freya O.
name: Sadler, Elaine M.
name: Shannon, Ryan
name: Tejos, Nicolas
name: Thorne, Jessica E.
name: Wang, Jing
name: Wayth, Randall
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The putative host galaxy of FRB 20171020A was first identified as ESO 601-G036 in 2018, but as no repeat bursts have been detected, direct confirmation of the host remains elusive. In light of recent developments in the field, we re-examine this host and determine a new association confidence level of 98%. At 37 Mpc, this makes ESO 601-G036 the third closest FRB host galaxy to be identified to date and the closest to host an apparently non-repeating FRB (with an estimated repetition rate limit of < 0.011 bursts per day above 10 erg). Due to its close distance, we are able to perform detailed multi-wavelength analysis on the ESO 601-G036 system. Follow-up observations confirm ESO 601-G036 to be a typical star-forming galaxy with HI and stellar masses of log(M_HI/M_sol) ~ 9.2 and log(M_*/M_sol) = 8.64, and a star formation rate of SFR = 0.09 +/- 0.01 M_sol/yr. We detect, for the first time, a diffuse gaseous tail (log(M_HI/M_sol) ~ 8.3) extending to the south-west that suggests recent interactions, likely with the confirmed nearby companion ESO 601-G037. ESO 601-G037 is a stellar shred located to the south of ESO 601-G036 that has an arc-like morphology, is about an order of magnitude less massive, and has a lower gas metallicity that is indicative of a younger stellar population. The properties of the ESO 601-G036 system indicate an ongoing minor merger event, which is affecting the overall gaseous component of the system and the stars within ESO 601-G037. Such activity is consistent with current FRB progenitor models involving magnetars and the signs of recent interactions in other nearby FRB host galaxies.
description: 16 pages, 9 figures, accepted for publication in PASA
Capture of planetesimals by waning circumplanetary gas disks
Creators: name: Suetsugu, Ryo
name: Ohtsuki, Keiji
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: When gas giant protoplanets grow sufficiently massive, circumplanetary disks would form. While solid bodies captured by the circumplanetary disks likely contribute to the growth of the planets and regular satellites around them, some of captured bodies would remain in planet-centered orbits after the dispersal of the disk. We examine capture and subsequent orbital evolution of planetesimals in waning circumplanetary gas disks using three-body orbital integration. We find that some of captured planetesimals can survive in the circumplanetary disk for a long period of time under such weak gas drag. Captured planetesimals have semi-major axes smaller than about one third of the planet's Hill radius. Distributions of their eccentricities and inclinations after disk dispersal depend on the strength of gas drag and the timescale of disk dispersal, and initially strong gas drag and quick disk dispersal facilitates capture and survival of planetesimals. However, in such a case, final orbital eccentricities and inclinations of captured bodies remain rather large. Although our results suggest that some of the present irregular satellites of gas giant planets with small semi-major axes would have been captured by gas drag, other mechanisms are required to fully explain their current orbital characteristics.
description: 46 pages, 18 figures, accepted for publication in ApJ
On the Nature of Neutron Stars in Accreting Systems
Creators: name: GOODWIN, ADELLE JANE
Publisher: name: Monash University
Year: 2021
Subjects: High energy astrophysics and galactic cosmic rays
Astroparticle physics and particle cosmology

description: Neutron stars, the dense remnants of dead stars, are unique laboratories of fundamental physics. Isolated neutron stars are hard to find, but neutron stars with binary companions may emit X-rays due to the supply of gas from the other star. This high-energy radiation enables us to detect them with telescopes. Such “accreting” neutron stars give us direct information from the extremes of physics: from the densest matter known, through nuclear reactions in energetic environments, to how material moves in strong magnetic and gravitational fields. This research aims to further understand accreting neutron star systems by using computer models and observations.
Testing space-time geometries and theories of gravity at the Galactic Center with pulsar's time delay
Creators: name: Della Monica, Riccardo
name: de Martino, Ivan
name: de Laurentis, Mariafelicia
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We developed a numerical methodology to compute the fully-relativistic propagation time of photons emitted by a pulsar in orbit around a massive compact object, like the supermassive black hole Sagittarius A* in the Galactic Center, whose gravitational field is described by a generic spherically symmetric space-time. Pulsars at the Galactic Center are usually regarded as the next major precision probe for theories of gravity, filling the current experimental gap between horizon-scale gravity tests and those at larger scales. We retain a completely general approach, which allows us to apply our code to the Schwarzschild space-time (by which we successfully validate our methodology) and to three different well-motivated alternatives to the standard black hole paradigm. The results of our calculations highlight departures spanning several orders of magnitudes in timing residuals, that are supposed to be detectable with future observing facilities like the Square Kilometer Array.
description: 15 pages, 8 figures, 1 table. Accepted for publication in MNRAS
Particle-Hole Symmetry in Generalized Seniority, Microscopic Interacting Boson (Fermion) Model, Nucleon-Pair Approximation, and Others
Creators: name: Jia, L. Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The particle-hole symmetry (equivalence) of the full shell-model Hilbert space is straightforward and routinely used in practical calculations. In this work we show that this symmetry is preserved in the subspace truncated at a certain generalized seniority, and give the explicit transformation between the states in the two types (particle and hole) of representations. Based on the results, we study the particle-hole symmetry in popular theories that could be regarded as further truncations on top of the generalized seniority, including the microscopic interacting boson (fermion) model, the nucleon-pair approximation, and others.
Propagation and Attribution of Uncertainty in Medical Imaging Pipelines
Creators: name: Feiner, Leonhard F.
name: Menten, Martin J.
name: Hammernik, Kerstin
name: Hager, Paul
name: Huang, Wenqi
name: Rueckert, Daniel
name: Braren, Rickmer F.
name: Kaissis, Georgios
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Uncertainty estimation, which provides a means of building explainable neural networks for medical imaging applications, have mostly been studied for single deep learning models that focus on a specific task. In this paper, we propose a method to propagate uncertainty through cascades of deep learning models in medical imaging pipelines. This allows us to aggregate the uncertainty in later stages of the pipeline and to obtain a joint uncertainty measure for the predictions of later models. Additionally, we can separately report contributions of the aleatoric, data-based, uncertainty of every component in the pipeline. We demonstrate the utility of our method on a realistic imaging pipeline that reconstructs undersampled brain and knee magnetic resonance (MR) images and subsequently predicts quantitative information from the images, such as the brain volume, or knee side or patient's sex. We quantitatively show that the propagated uncertainty is correlated with input uncertainty and compare the proportions of contributions of pipeline stages to the joint uncertainty measure.
Millennial Perspectives on Tropical Environmental Variability from the Last Glacial through to the Holocene: a palaeoecological analysis from Lynch's Crater, northeast Queensland, Australia
Creators: name: RULE, SUSAN DOROTHY
Publisher: name: Monash University
Year: 2020
Subjects: Other environmental sciences not elsewhere classified

description: Using a range of fossil and sediment data together with a robust chronology, this study refines a key palaeoecological record of humid tropical vegetation in Australia through the last 50,000 years. It cements the importance of fire, operating through millennial and orbital scale climate variability as well as human activity, to changes in the distribution and composition of vegetation, and should contribute significantly to future landscape management.
Atomically precise low-dimensional metal-organic nanostructures with tailored electronic properties
Creators: name: MARINA CASTELLI
Publisher: name: Monash University
Year: 2020
Subjects: Applied Physics

description: Electronic devices rely on technologies allowing for the control of the flow of electron in a semiconducting material. This behaviour depends on the electronic properties of the material, at the atomic level. In particular, we focus on two different systems consisting of atomically precise low-dimensional metal-organic nanostructures on a noble metal surface, with potential for optoelectronics applications. Our experimental low temperature scanning probe microscopy and photoelectron spectroscopy measurements demonstrate the close relation between the implementation of these systems (single units or layers) and the resulting electronic properties. Our results constitute an important step for the translation of these nanosystems onto new technologies such as: catalysis, molecular electronics, light-harvesting.
Forward-backward correlations with the $Σ$ quantity in the wounded constituent framework at LHC energies
Creators: name: Sputowska, Iwona Anna
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: $Σ$ is a new correlation measure, quite recently introduced to heavy-ion physics. This measure, defined in the independent source model as a strongly intensive quantity, is expected to be free of the effects of system volume and volume fluctuations. This paper discusses the forward-backward correlation quantified with the $Σ$ observable calculated in the framework of the wounded nucleon model (WNM) and wounded quark model (WQM). Findings show that the wounded constituent approach outperforms the commonly used heavy-ion Monte Carlo generators, such as HIJING, AMPT or EPOS, by accurately describing the experimental data on FB correlations with $Σ$ measured by ALICE in Xe--Xe reactions at $\sqrt{s_{\rm{NN}}}$=5.44 TeV and in Pb--Pb collisions at $\sqrt{s_{\rm{NN}}}$= 2.76 and 5.02 TeV. This paper demonstrates that $Σ$ can be a unique tool for determining the fragmentation function of a wounded constituent in a symmetric nucleus-nucleus collision. However, in the wounded constituent framework, it is no longer a strongly intensive quantity.
description: 16 pages, 10 figures
Implications of time-dependent molecular chemistry in metal-poor dwarf stars
Creators: name: Deshmukh, S. A.
name: Ludwig, H. -G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Binary molecules such as CO, OH, CH, CN, and C$_2$ are often used as abundance indicators in stars. These species are usually assumed to be formed in chemical equilibrium. The time-dependent effects of hydrodynamics can affect the formation and dissociation of these species and may lead to deviations from chemical equilibrium. We aim to model departures from chemical equilibrium in dwarf stellar atmospheres by considering time-dependent chemical kinetics alongside hydrodynamics and radiation transfer. We examine the effects of a decreasing metallicity and an altered C/O ratio on the chemistry when compared to the equilibrium state. We used the radiation-(magneto)hydrodynamics code CO5BOLD, and its own chemical solver to solve for the chemistry of 15 species and 83 reactions. The species were treated as passive tracers and were advected by the velocity field. The steady-state chemistry was also computed to isolate the effects of hydrodynamics. In most of the photospheres in the models we present, the mean deviations are smaller than $0.2$ dex, and they generally appear above $\logτ = -2$. The deviations increase with height because the chemical timescales become longer with decreasing density and temperature. A reduced metallicity similarly results in longer chemical timescales and in a reduction in yield that is proportional to the drop in metallicity; a decrease by a factor $100$ in metallicity loosely corresponds to an increase by factor $100$ in chemical timescales. As both CH and OH are formed along reaction pathways to CO, the C/O ratio means that the more abundant element gives faster timescales to the constituent molecular species. Overall, the carbon enhancement phenomenon seen in very metal-poor stars is not a result of an improper treatment of molecular chemistry for stars up to a metallicity as low as [Fe/H] = $-3.0$.
description: 29 pages
PENELLOPE IV. A comparison between optical forbidden lines and $\rm H_2$ UV lines in the Orion OB1b and $σ$-Ori associations
Creators: name: Gangi, M.
name: Nisini, B.
name: Manara, C. F.
name: France, K.
name: Antoniucci, S.
name: Biazzo, K.
name: Giannini, T.
name: Herczeg, G. J.
name: Alcalá, J. M.
name: Frasca, A.
name: Maucó, K.
name: Campbell-White, J.
name: Siwak, M.
name: Venuti, L.
name: Schneider, P. C.
name: Kóspál, Á.
name: Garatti, A. Caratti o
name: Fiorellino, E.
name: Rigliaco, E.
name: Yadav, R. K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Observing the spatial distribution and excitation processes of atomic and molecular gas in the inner regions (< 20 au) of young (< 10 Myr) protoplanetary disks helps us to understand the conditions for the formation and evolution of planetary systems. In the framework of the PENELLOPE and ULLYSES projects, we aim to characterize the atomic and molecular component of protoplanetary disks in a sample of 11 Classical T Tauri Stars (CTTs) of the Orion OB1 and $σ$-Orionis associations. We analyzed the flux-calibrated optical-forbidden lines and the fluorescent ultraviolet $\rm H_2$ progressions using spectra acquired with ESPRESSO at VLT, UVES at VLT and HST-COS. Line morphologies were characterized through Gaussian decomposition. We then focused on the properties of the narrow low-velocity (FWHM < 40 $km$ $s^{-1}$ and |$v_p$| < 30 $km$ $s^{-1}$) component (NLVC) of the [OI] 630 nm line, compared with the properties of the UV-$\rm H_2$ lines. We found that the [OI]630 NLVC and the UV-$\rm H_2$ lines are strongly correlated in terms of peak velocities, full width at half maximum, and luminosity. The luminosities of the [OI]630 NLVC and UV-$\rm H_2$ correlate with the accretion luminosity with a similar slope, as well as with the luminosity of the CIV 154.8, 155 nm doublet. We discuss such correlations in the framework of the currently suggested excitation processes for the [OI]630 NLVC. Our results can be interpreted in a scenario in which the [OI]630 NLVC and UV-$\rm H_2$ have a common disk origin with a partially overlapped radial extension. We also suggest that the excitation of the [OI] NLVC is mainly induced by stellar FUV continuum photons more than being of thermal origin. This study demonstrates the potential of contemporaneous wide-band high-resolution spectroscopy in linking different tracers of protoplanetary disks.
description: 24 pages, 15 figures, 6 tables. Accepted for publication in Astronomy & Astrophysics
Madelung transform and variational asymptotics in Born-Oppenheimer molecular dynamics
Creators: name: Bergold, Paul
name: Tronci, Cesare
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mathematical Physics (math-ph)
subject: Symplectic Geometry (math.SG)
subject: Chaotic Dynamics (nlin.CD)
subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: While Born-Oppenheimer molecular dynamics (BOMD) has been widely studied by resorting to powerful methods in mathematical analysis, this paper presents a geometric formulation in terms of Hamilton's variational principle and Euler-Poincaré reduction by symmetry. Upon resorting to the Lagrangian hydrodynamic paths made available by the Madelung transform, we show how BOMD arises by applying asymptotic methods to the variational principles underlying different continuum models and their particle closure schemes. In particular, after focusing on the hydrodynamic form of the fully quantum dynamics, we show how the recently proposed bohmion scheme leads to an on-the-fly implementation of BOMD. In addition, we extend our analysis to models of mixed quantum-classical dynamics.
description: 13 pages, no figure. To appear in Lecture Notes in Comput. Sci, Minor corrections to version 1
Low-energy neutrinos
Creators: name: Ludhova, Livia
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the feld of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artifcial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three felds, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.
description: Proceedings of TAUP 2015, 7-11 September 2015, Torino (Italy)
Gravitational Waves from Black-Hole Encounters: Prospects for Ground- and Galaxy-Based Observatories
Creators: name: Dandapat, Subhajit
name: Ebersold, Michael
name: Susobhanan, Abhimanyu
name: Rana, Prerna
name: Gopakumar, Achamveedu
name: Tiwari, Shubhanshu
name: Haney, Maria
name: Lee, Hyung Mok
name: Kolhe, Neel
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Close hyperbolic encounters of black holes (BHs) generate certain Burst With Memory (BWM) events in the frequency windows of the operational, planned, and proposed gravitational wave (GW) observatories. We present detailed explorations of the detectable parameter space of such events that are relevant for the LIGO-Virgo-KAGRA and the International Pulsar Timing Array (IPTA) consortia. The underlying temporally evolving GW polarization states are adapted from Cho et al. [Phys. Rev. D 98, 024039 (2018)] and therefore incorporate general relativistic effects up to the third post-Newtonian order. Further, we provide a prescription to ensure the validity of our waveform family while describing close encounters. Preliminary investigations reveal that optimally placed BWM events should be visible to megaparsec distances for the existing ground-based observatories. In contrast, maturing IPTA datasets should be able to provide constraints on the occurrences of such hyperbolic encounters of supermassive BHs to gigaparsec distances.
description: 19 pages, 11 figures, accepted for publication in Phys. Rev. D
ALMA Lensing Cluster Survey: average dust, gas, and star formation properties of cluster and field galaxies from stacking analysis
Creators: name: Guerrero, Andrea
name: Nagar, Neil
name: Kohno, Kotaro
name: Fujimoto, Seiji
name: Kokorev, Vasily
name: Brammer, Gabriel
name: Jolly, Jean-Baptiste
name: Knudsen, Kirsten
name: Sun, Fengwu
name: Bauer, Franz E.
name: Caminha, Gabriel B.
name: Caputi, Karina
name: Neumann, Gerald
name: Orellana-González, Gustavo
name: Cerulo, Pierluigi
name: González-López, Jorge
name: Laporte, Nicolas
name: Koekemoer, Anton M.
name: Ao, Yiping
name: Espada, Daniel
name: Arancibia, Alejandra M. Muñoz
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We develop new tools for continuum and spectral stacking of ALMA data, and apply these to the ALMA Lensing Cluster Survey (ALCS). We derive average dust masses, gas masses and star formation rates (SFR) from the stacked observed 260~GHz continuum of 3402 individually undetected star-forming galaxies, of which 1450 are cluster galaxies and 1952 field galaxies, over three redshift and stellar mass bins (over $z = 0$-1.6 and log $M_{*} [M_{\odot}] = 8$-11.7), and derive the average molecular gas content by stacking the emission line spectra in a SFR-selected subsample. The average SFRs and specific SFRs of both cluster and field galaxies are lower than those expected for Main Sequence (MS) star-forming galaxies, and only galaxies with stellar mass of log $M_{*} [M_{\odot}] = 9.35$-10.6 show dust and gas fractions comparable to those in the MS. The ALMA-traced average `highly obscured' SFRs are typically lower than the SFRs observed from optical to near-IR spectral analysis. Cluster and field galaxies show similar trends in their contents of dust and gas, even when field galaxies were brighter in the stacked maps. From spectral stacking we find a potential CO ($J=4\to3$) line emission (SNR $\sim4$) when stacking cluster and field galaxies with the highest SFRs.
description: 13 pages, 8 figures, 1 table (+4 pages, 4 figures in Appendix). Accepted for publication in MNRAS
Towards the prediction of properties in large clusters of ionic liquids with quantum chemical methods
Creators: name: ZOE LUISA ELEANOR SEEGER
Publisher: name: Monash University
Year: 2020
Subjects: subject: 30701 Quantum Chemistry
subject: FOS: Chemical sciences
subject: Computational Chemistry

description: Ionic liquids have many potential applications such as a green alternative to electrolytes in batteries. This thesis develops computational models that can be used to predict their properties such that task-specific ionic liquids can be identified.
Trade-offs in high-contrast integral field spectroscopy for exoplanet detection and characterisation: Young gas giants in emission
Creators: name: Landman, Rico
name: Snellen, Ignas
name: Keller, Cristoph
name: N'Diaye, Mamadou
name: Fagginger-Auer, Fedde
name: Desgrange, Célia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Context: Combining high-contrast imaging with medium- or high-resolution integral field spectroscopy has the potential to boost the detection rate of exoplanets, especially at small angular separations. Furthermore, it immediately provides a spectrum of the planet that can be used to characterise its atmosphere. The achievable spectral resolution, wavelength coverage, and FOV of such an instrument are limited by the number of available detector pixels. Methods: The trade-offs are studied through end-to-end simulations of a typical high-contrast imaging instrument, analytical considerations, and atmospheric retrievals. The results are then validated with archival VLT/SINFONI data of the planet beta Pictoris b. Results: We show that molecular absorption spectra generally have decreasing power towards higher spectral resolution and that molecule mapping is already powerful for moderate resolutions (R>300). When choosing between wavelength coverage and spectral resolution for a given number of spectral bins, it is best to first increase the spectral resolution until R~2,000 and then maximise the bandwidth within an observing band. We find that T-type companions are most easily detected in the J/H band through methane and water features, while L-type companions are best observed in the H/K band through water and CO features. Such an instrument does not need to have a large FOV, as most of the gain in contrast is obtained in the speckle-limited regime close to the star. We show that the same conclusions are valid for the constraints on atmospheric parameters such as the C/O ratio, metallicity, surface gravity, and temperature, while higher spectral resolution (R~10,000) is required to constrain the radial velocity and spin of the planet.
description: Accepted for publication in A&A
A new star-forming region in Canis Major
Creators: name: Magakian, T. Yu.
name: Movsessian, T. A.
name: Bally, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A new southern star-formation region, located at an estimated distance of ~1.5 kpc in the Lynds 1664 dark cloud in Canis Major, is described. Lynds 1664 contains several compact star clusters, small stellar groups, and young stars associated with reflection nebulae. Narrow-band Hα and [SII] images obtained with 4-m CTIO telescope reveal more than 20 new Herbig-Haro objects associated with several protostellar outflows.
description: 9 pages, 12 figures
A new class of exact coherent states: enhanced quantization of motion on the half-line
Creators: name: Bergeron, Hervé
name: Gazeau, Jean-Pierre
name: Małkiewicz, Przemysław
name: Peter, Patrick
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We have discovered a class of dynamically stable coherent states for motion on the half-line. The regularization of the half-line boundary and the consequent quantum motion are expounded within the framework of covariant affine quantization, although alternative approaches are also feasible. The former approach is rooted in affine coherent states and offers a consistent semiclassical representation of quantum motion. However, this method has been known to possess two shortcomings: (a) the dependence of affine coherent states on the choice of a vector, denoted as 'fiducial vector' (which remains unspecified), introduces significant arbitrariness in boundary regularization, and (b) regardless of the choice of 'fiducial vector,' affine coherent states fail to evolve parametrically under the Schrödinger equation, thus limiting the accuracy of the semiclassical description. This limitation, in particular, hampers their suitability for approximating the evolution of compound observables. We demonstrate that a distinct and more refined definition of affine coherent states can simultaneously address both of these issues. In other words, these new affine coherent states exhibit parametric evolution only when the 'fiducial vector,' denoted as $|ψ_0>$, possesses a highly specific character, such as being an eigenstate of a well-defined Hamiltonian. Our discovery holds significant relevance in the field of quantum cosmology, particularly in scenarios where the positive variable is the scale factor of the universe, and its regularized motion plays a crucial role in avoiding the big-bang singularity.
description: 15 pages, 3 figures
Uncommon 2D Diamond-like Carbon Nanodots Derived from Nanotubes: Atomic Structure, Electronic States and Photonic Properties
Creators: name: Boukhvalov, D. W.
name: Zatsepin, D. A.
name: Kuznetsova, Yu. A.
name: Pryakhina, V. I.
name: Zatsepin, A. F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: In this article, we report the results of relatively facile fabrication of carbon nanodots from single-walled and multi-walled carbon nanotubes (SWCNT and MWCNT). The results of X-ray photoelectron spectroscopy (XPS) and Raman measurements show that the obtained carbon nanodots are quasi-two-dimensional objects with a diamond-like structure. Based on the characterization results, a theoretical model of synthesized carbon nanodots was developed. The measured absorption spectra demonstrate the similarity of the local atomic structure of carbon nanodots synthesized from single-walled and multi-walled carbon nanotubes. However, the photoluminescence (PL) spectra of nanodots synthesized from both sources turned out to be completely different. Carbon dots fabricated from MWCNTs exhibit PL spectra similar to nanoscale carbon systems with sp3 hybridization and a valuable edge contribution. At the same time nanodots synthesized from SWCNTs exhibit PL spectra which are typical for quantum dots with an estimated size of ~0.6-1.3 nm.
description: 22 pages, 9 figures, to appear in PCCP
An investigation into the occurrence and migration of 239,240Pu in the Australian environment
Creators: name: COOK, MEGAN LOUISE
Publisher: name: Monash University
Year: 2020
Subjects: Other environmental sciences not elsewhere classified
Environmental assessment and monitoring
Radiation and matter

description: Plutonium is a hazardous radioactive contaminant that persists in the soil as fallout from nuclear weapons testing and incidents at nuclear facilities. This thesis examines the plutonium present in Australian soils; the particles that are formed, how it is transported and the effects of specific climates. This data will help improve and validate radioecological models, risk characterisations and impact assessments for radiation protection in Australia and similar environments.
The Causes and Consequences of Variation in Metabolic Rate in a Sessile Marine Invertebrate
Creators: name: SCHUSTER, LUKAS
Publisher: name: Monash University
Year: 2020
Subjects: Evolutionary biology not elsewhere classified
Animal physiology - biophysics
Animal physiology - cell
Animal physiology - systems
Ecology not elsewhere classified

description: Metabolic rate determines the rate at which individuals transform resources from the environment into energy and use this energy to live. Within a population, metabolic rate varies among individuals, even after accounting for differences in body size, temperature, age, and sex. Although we are starting to understand the drivers and the maintenance of this variation in metabolic rate over time, its consequences for both individual- and population-level processes remain largely unclear. My work presents novel insights into how metabolic rate can affect individual performance and how such processes can scale up to affect population-level dynamics in the field.