cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Approximation numbers of composition operators on $H^p$ spaces of Dirichlet series
Creators: name: Bayart, Frédéric
name: Queffélec, Hervé
name: Seip, Kristian
Publisher: name: arXiv
Year: 2014
Subjects: subject: Functional Analysis (math.FA)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: By a theorem of Bayart, $φ$ generates a bounded composition operator on the Hardy space $\Hp$of Dirichlet series ($1\le p1/2$ if $c_0=0$ and is either identically zero or maps the right half-plane into itself if $c_0$ is positive. It is shown that the $n$th approximation numbers of bounded composition operators on $\Hp$ are bounded below by a constant times $r^n$ for some $00$ when $c_0$ is positive. Both results are best possible. Estimates rely on a combination of soft tools from Banach space theory ($s$-numbers, type and cotype of Banach spaces, Weyl inequalities, and Schauder bases) and a certain interpolation method for $\Ht$, developed in an earlier paper, using estimates of solutions of the $\overline{\partial}$ equation. A transference principle from $H^p$ of the unit disc is discussed, leading to explicit examples of compact composition operators on $\Ho$ with approximation numbers decaying at a variety of sub-exponential rates. Finally, a new Littlewood--Paley formula is established, yielding a sufficient condition for a composition operator on $\Hp$ to be compact.
description: This is the final version of the paper, to appear in Annales de l'Institut Fourier
The Yedoma cliff of Sobo Sise Island, eastern Lena Delta - insights into past and modern permafrost dynamics and related organic matter stock and release
Creators: name: Wetterich, Sebastian
name: Fuchs, Matthias
name: Kizyakov, Alexander I.
name: Strauss, Jens
name: Nitze, Ingmar
name: Fritz, Michael
name: Wolter, Juliane
name: Opel, Thomas
name: Meyer, Hanno
name: Aksenov, Aleksei
name: Schirrmeister, Lutz
name: Grosse, Guido
Publisher: name: Zenodo
Year: 2020

description: The Lena Delta in eastern Siberia is the largest Arctic delta. Its terrestrial surface is shaped by four geomorphologic units. The oldest unit is built of remnants of late Pleistocene Yedoma Ice Complex (IC) and its degradation features. The studied Yedoma cliff on Sobo Sise Island in the South-Eastern part of the delta ranges from the river level to about 28 m height and is about 1.7 km long. During a field campaign in 2018, the entire permafrost sequence of the Sobo Sise Yedoma cliff has been sampled in 0.5-m vertical intervals. The geochronological record of the Sobo Sise Yedoma spans the last 52 ka cal BP based on radiocarbon dating and age-height modelling. The sequence differentiates into three cryostratigraphic units that are MIS3 Yedoma IC (52–28 ka cal BP), MIS2 Yedoma IC (28–15 ka cal BP) and MIS1 Holocene cover (7–0 ka cal BP). The cryostratigraphic sequence is not continuous, but has chronological gaps at 36–32.5 ka cal BP, at 20.5–18 ka cal BP and at 12.5–9 cal ka BP. These gaps represent traces of past changes in permafrost deposition and/or erosion regimes and climatic conditions. The cryostratigraphic units of the Yedoma cliff are characterized by differing properties of their clastic, organic and ice components. All units are built of poorly sorted sandy silt but differ in prevalent grain-size fractions ranging from fine silt to middle sand. The organic matter (OM) content is highest in the thin MIS1 Holocene cover (TOC of 11.3±9.9 wt%, TN of 0.6±0.3 wt%), but still substantial in MIS3 Yedoma IC (TOC of 4.5±2.5 wt%, TN of 0.3±0.1 wt%) and in MIS2 Yedoma IC (TOC of 2.1±1.3 wt%, TN of 0.2±0.1 wt%). The presence of syngenetic ice wedges in all units and the high content of intrasedimentary ice amount to a total volumetric ice content of 88.4 vol%. The high ice content in combination with the exposition of the cliff towards the main river channel results in a very high susceptibility to thaw and thermo-erosion. The high mean cliff erosion rate of 10.3 m yr−1 (1975-2018) results in large OM quantities entering the Lena River (3.2±2.1 kt organic carbon per year, 0.3±0.1 kt nitrogen per year along the 1.7 km long Yedoma cliff). Ongoing fluvial dynamics and changing runoff regimes with extended ice-free seasons and warmer water will most likely maintain high permafrost cliff erosion rates in the future and further facilitate high fluxes of terrestrial fossil OM into the riverine and eventually marine ecosystems.
Tailoring boundary geometry to optimize heat transport in turbulent convection
Creators: name: Toppaladoddi, Srikanth
name: Succi, Sauro
name: Wettlaufer, John S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: By tailoring the geometry of the upper boundary in turbulent Rayleigh-Bénard convection we manipulate the boundary layer -- interior flow interaction, and examine the heat transport using the Lattice Boltzmann method. For fixed amplitude and varying boundary wavelength $λ$, we find that the exponent $β$ in the Nusselt-Rayleigh scaling relation, $Nu-1 \propto Ra^β$, is maximized at $λ\equiv λ_{\text{max}} \approx (2 π)^{-1}$, but decays to the planar value in both the large ($λ\gg λ_{\text{max}}$) and small ($λ\ll λ_{\text{max}}$) wavelength limits. The changes in the exponent originate in the nature of the coupling between the boundary layer and the interior flow. We present a simple scaling argument embodying this coupling, which describes the maximal convective heat flux.
description: 6 pages, 6 figures
Equity Scores for Public Transit Lines from Open-Data and Accessibility Measures
Creators: name: Badeanlou, Amirhesam
name: Araldo, Andrea
name: Diana, Marco
name: Gauthier, Vincent
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computers and Society (cs.CY)
subject: General Economics (econ.GN)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business
subject: J.4
subject: 62H11

description: Current transit suffers from an evident inequity: the level of service of transit in suburbs is much less satisfying than in city centers. As a consequence, private cars are still the dominant transportation mode for suburban people, which results in congestion and pollution. To achieve sustainability goals and reduce car-dependency, transit should be (re)designed around equity. To this aim, it is necessary to (i) quantify the "level of equity" of the transit system and (ii) provide an indicator that scores the transit lines that contribute the most to keep transit equitable. This indicator could suggest on which lines the transit operator must invest to increase the service level (frequency or coverage) in order to reduce inequity in the system. To the best of our knowledge, this paper is the first to tackle (ii). To this aim, we propose efficient scoring methods that rely solely on open data, which allows us to perform the analysis on multiple cities (7 in this paper). Our method can be used to guide large-scale iterative optimization algorithms to improve accessibility equity.
Prograde and Retrograde Gas Flow around Disk-embedded Companions: Dependence on Eccentricity, Mass and Disk Properties
Creators: name: Chen, Yi-Xian
name: Bailey, Avery
name: Stone, James M.
name: Zhu, Zhaohuan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We apply 3D hydrodynamical simulations to study the rotational aspect of gas flow patterns around eccentric companions embedded in an accretion disk around its primary host. We sample a wide range of companion mass ratio q and disk aspect ratio h, and confirm a generic transition from prograde (steady tidal interaction dominated) to retrograde (background Keplerian shear dominated) circum-companion flow when orbital eccentricity exceeds a critical value et. We find et \sim h for sub-thermal companions while et \sim (q/h)^1/3 for super-thermal companions, and propose an empirical formula to unify the two scenarios. Our results also suggest that et is insensitive to modest levels of turbulence, modeled in the form of a kinematic viscosity term. In the context of stellar-mass Black Holes (sBHs) embedded in AGN accretion disks, the bifurcation of their circum-stellar disk (CSD) rotation suggest the formation of a population of nearly anti-aligned sBHs, whose relevance to low spin gravitational waves (GW) events can be probed in more details with future population models of sBH evolution in AGN disks, making use of our quantitative scaling for et; In the context of circum-planetary disks (CPDs), our results suggest the possibility of forming retrograde satellites in-situ in retrograde CPDs around eccentric planets.
description: Accepted to ApJL, 10 pages, 5 figures
Characteristics polynomial of normalized Laplacian for trees
Creators: name: Banerjee, Anirban
name: Mehatari, Ranjit
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 05C50, 05C05

description: Here, we find the characteristics polynomial of normalized Laplacian of a tree. The coefficients of this polynomial are expressed by the higher order general Randić indices for matching, whose values depend on the structure of the tree. We also find the expression of these indices for starlike tree and a double-starlike tree, $H_m(p,q)$. Moreover, we show that two cospectral $H_m(p,q)$ of the same diameter are isomorphic.
description: 11 pages, 1 table, 2 Figures
Multi-technique approach to explore the mixed micellization behavior of promazine hydrochloride drug and cetyltrimethylammonium bromide surfactant in aqueous glycine, glycylglycine (dipeptide) and glycylglycylglycine (tripeptide) solutions
Creators: name: Banipal, Parampaul K.
name: Sharma, Jyoti
name: Banipal, Tarlok S.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Biochemistry
subject: Physical Sciences not elsewhere classified
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified

description: The aggregation properties of amphiphiles and their mixtures are of theoretical and applied importance. Therefore, mixed micellization behavior of promazine hydrochloride (PMZ) drug and cetyltrimethylammonium bromide (CTAB) surfactant at different mole fractions, αPMZ = (0.2, 0.4, 0.6 and 0.8) has been scrutinized in water and (0.025, 0.050 and 0.100) mol·kg−1 aqueous solutions of glycine, glycylglycine (dipeptide) and glycylglycylglycine (tripeptide) at T = (298.15 to 318.15) K, by means of multiple techniques. Thermodynamic parameters of micellization (ΔG°m, ΔH°m, and ΔS°m) along with excess Gibbs free energy of mixing (ΔGmex), the molecular interaction parameter (βint), and the degree of ionization (α), have been attained from the conductivity measurements. The partial specific volumes (φv), partial specific isentropic compression (φκ) as well as isentropic compressibilities (κs) were computed from the measured density and speed of sound data. UV-Visible absorption, fluorescence emission and proton (1H) NMR spectra were recorded for the pure PMZ and mixed (PMZ + CTAB) system in the presence of glycine(aq), glycylglycine(aq) and glycylglycylglycine(aq) solutions. Dynamic light scattering (DLS) study was carried out to measure the hydrodynamic diameters (DH) of mixed micellar systems. The prevalence of hydrophobic-hydrophobic interactions amid the hydrophobic groups of PMZ drug (tricyclic scaffolding), CTAB (–C16H33), glycine, di- and tri-peptides (–CH2), and electrostatic interactions amid the hydrophilic/ionic groups of PMZ{tertiary amine part and +NH (CH3)2, Cl−}, CTAB (–N (CH3)3+, Br‒) and glycine, di- and tri-peptides {zwitterion (NH3+, COO−} have been depicted from the aforementioned studies.
Spin State Evolution of (99942) Apophis during its 2029 Earth Encounter
Creators: name: Benson, C. J.
name: Scheeres, D. J.
name: Brozovic, M.
name: Chesley, S.
name: Pravec, P.
name: Scheirich, P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We explore the effects of the 2029 Earth encounter on asteroid (99942) Apophis' non-principal axis spin state, leveraging refined orbit, spin state, and inertia information provided by more recent optical and radar observations. Propagating the asteroids' coupled orbit and rigid body attitude dynamics through the flyby, we present the range of possible post-flyby spin states. These spin state distributions will be valuable for planning Apophis observation campaigns and spacecraft missions, most notably OSIRIS-APEX. The simulations indicate that gravitationally induced changes to the asteroid's tumbling periods and rotational angular momentum direction (pole) will likely be significant and measurable. For the current spin state and inertia estimates and their uncertainties, Apophis is likely to remain in a short axis mode (SAM) tumbling state but its effective spin rate could halve or double. Its pole is likely to shift by 10 degrees or more and increase in longitude while moving closer to the ecliptic plane. These spin state changes are very sensitive to the asteroid's close approach attitude and mass distribution. With ground-based tracking of the asteroid's spin state through the encounter, this sensitivity will help refine mass distribution knowledge. We also discuss the implications of this abrupt spin state alteration for Apophis' Yarkovsky acceleration and geophysical properties, identifying possible pathways for surface and internal changes, most notably if Apophis is a contact binary. Comparison of the pre and post-flyby inertia estimates obtained from the ground-based observations will help assess the extent of possible geophysical changes.
Small scale quantum ergodicity in negatively curved manifolds
Creators: name: Han, Xiaolong
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Dynamical Systems (math.DS)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: 58G25, 35P20, 37D20, 58G15

description: The main theorem has been slightly generalized to include a larger class of symbols.
description: 22 pages
Stellar age determination in the Mass-Luminosity Plane
Creators: name: Higgins, Erin R.
name: Vink, Jorick S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The ages of stars have historically relied on isochrone fitting of standardised grids of models. While these stellar models have provided key constraints on observational samples of massive stars, they inherit many systematic uncertainties, mainly in the internal mixing mechanisms applied throughout the grid, fundamentally undermining the isochrone method. In this work, we utilise the M-L plane of Higgins & Vink as a method of determining stellar age, with mixing-corrected models applying a calibrated core overshooting alpha_ov and rotation rate to fit the observational data. We provide multiple test-beds to showcase our new method, while also providing comparisons to the commonly-used isochrone method, highlighting the dominant systematic errors. We reproduce the evolution of individual O stars, and analyse the wider sample of O and B supergiants from the VLT-FLAMES Tarantula Survey, providing dedicated models with estimates for alpha_ov, Omega/Omega_crit, and ultimately stellar ages. The M-L plane highlights a large discrepancy in the spectroscopic masses of the O supergiant sample. Furthermore the M-L plane also demonstrates that the evolutionary masses of the B supergiant sample are inappropriate. Finally, we utilise detached eclipsing binaries, VFTS 642 and VFTS 500, and present their ages resulting from their precise dynamical masses, offering an opportunity to constrain their interior mixing. For the near-TAMS system, VFTS 500, we find that both components require a large amount of core overshooting (alpha_ov ~ 0.5), implying an extended main-sequence width. We hence infer that the vast majority of B supergiants are still burning hydrogen in their cores.
description: 13 pages, 13 figures. Accepted for publication in MNRAS. Comments welcome
The anisotropic photorefractive effect in lithium sulfo-phosphate glass system doped with nickel ions
Creators: name: Reddy, A. Siva Sesha
name: Kityk, A. V.
name: Jedryka, J.
name: Purnachand, N.
name: Rakus, P.
name: Wojciechowski, A.
name: Andrushchak, A. S.
name: Kumar, V. Ravi
name: Veeraiah, N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: In this work, nonlinear optical (NLO) studies of nickel oxide doped (ranging from 0.2 to 1.0 mol%) Li2SO4-MgO-P2O5 glasses are reported. A combination of femtosecond (fs) laser, as a pumping light source and a high-accuracy polarimeter with low power probing laser, is used to investigate the light-induced optical anisotropy (OA) in these glass materials. The light-induced birefringence (LIB) exhibits slow relaxation tendency up to about 10 s suggesting on anisotropic photorefractive effect evidently dominated fast Kerr effect. This behavior is evaluated in the light of other results reported recently and is explained by the glass polymerization mechanisms. The photorefractive birefringence increases with increase of the quantity of NiO up to 0.8 mol% and it is attributed to the enhanced degree of depolymerization of the glass network due to the hike in the concentration of Ni2+ ions that occupy octahedral (Oh) positions. Further increase of NiO content (>0.8 mol%) causes, however, a certain decrease of the photorefractive birefringence. Notable change in concentration trend is interpreted by rising of phonon losses due to increasing portion of the nickel ions occupying tetrahedral (Th) sites that facilitates the polymerization of the glass network. The doped glasses with the NiO content of about 0.8 mol% may be considered as optimal in the sense of photorefractive efficiency. Relevant samples exhibit largest magnitudes of the photorefractive birefringence and appear to be favorable for potential applications.
description: 5 pages, 4 figures
Modelling Cosmic Radiation Events in the Tree-ring Radiocarbon Record
Creators: name: Zhang, Qingyuan
name: Sharma, Utkarsh
name: Dennis, Jordan A.
name: Scifo, Andrea
name: Kuitems, Margot
name: Buentgen, Ulf
name: Owens, Mathew J.
name: Dee, Michael W.
name: Pope, Benjamin J. S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Geophysics (physics.geo-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Annually-resolved measurements of the radiocarbon content in tree-rings have revealed rare sharp rises in carbon-14 production. These 'Miyake events' are likely produced by rare increases in cosmic radiation from the Sun or other energetic astrophysical sources. The radiocarbon produced is not only circulated through the Earth's atmosphere and oceans, but also absorbed by the biosphere and locked in the annual growth rings of trees. To interpret high-resolution tree-ring radiocarbon measurements therefore necessitates modelling the entire global carbon cycle. Here, we introduce 'ticktack', the first open-source Python package that connects box models of the carbon cycle with modern Bayesian inference tools. We use this to analyse all public annual 14C tree data, and infer posterior parameters for all six known Miyake events. They do not show a consistent relationship to the solar cycle, and several display extended durations that challenge either astrophysical or geophysical models.
description: Accepted Proceedings of the Royal Society A. 19 pages 6 figures body, 12 pages appendices which are supplementary material in the published version
Removal of direct blue 71 and methylene blue from water by graphene oxide: effects of charge interaction and experimental parameters
Creators: name: Tran, Dinh-Trinh
name: Nguyen, Thi-Hanh
name: Doan, Thi-Hoa
name: Dang, Viet-Cuong
name: Nghiem, Long D.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: Physical Sciences not elsewhere classified
Medicine
Environmental Sciences not elsewhere classified
Chemical Sciences not elsewhere classified
Biological Sciences not elsewhere classified
Computational Biology

description: Graphene oxide (GO) was synthesized by modified the Hummers method and used as an effective adsorbent for removing direct blue 71 (DB 71) and methylene blue (MB) from water. Surface characteristics of the produced GO materials and related physiochemical properties of the organic dyes were systematically examined to reveal removal mechanisms. Thermodynamics, kinetics, and regeneration of GO adsorbent were also studied to disclose the nature of the adsorption and the reusability of adsorbent. GO adsorbed the cationic MB better than the anionic DB 71 mainly due to the electrostatic attraction between negatively charged GO’s surface and the positively charged MB molecules. Langmuir isotherm better described MB and DB 71 adsorption than the Freundlich model. The adsorption capacities of GO of 476.19 mg/g (for MB) and 175.41 mg/g (for DB 71) were considerably higher than those of other adsorbents such as activated carbon, chitosan, and biochar. MB and DB 71 adsorption process was spontaneous, endothermic, and governed by both physisorption and chemisorption. GO could be regenerated by methanol and dilute HCl solutions, and reused as an efficient adsorbent. This study provides a comprehensive data on the MB and DB71 adsorption processes, and an efficient approach on the regeneration of GO adsorbent.
SleepMore: Inferring Sleep Duration at Scale via Multi-Device WiFi Sensing
Creators: name: Zakaria, Camellia
name: Yilmaz, Gizem
name: Mammen, Priyanka
name: Chee, Michael
name: Shenoy, Prashant
name: Balan, Rajesh
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The availability of commercial wearable trackers equipped with features to monitor sleep duration and quality has enabled more useful sleep health monitoring applications and analyses. However, much research has reported the challenge of long-term user retention in sleep monitoring through these modalities. Since modern Internet users own multiple mobile devices, our work explores the possibility of employing ubiquitous mobile devices and passive WiFi sensing techniques to predict sleep duration as the fundamental measure for complementing long-term sleep monitoring initiatives. In this paper, we propose SleepMore, an accurate and easy-to-deploy sleep-tracking approach based on machine learning over the user's WiFi network activity. It first employs a semi-personalized random forest model with an infinitesimal jackknife variance estimation method to classify a user's network activity behavior into sleep and awake states per minute granularity. Through a moving average technique, the system uses these state sequences to estimate the user's nocturnal sleep period and its uncertainty rate. Uncertainty quantification enables SleepMore to overcome the impact of noisy WiFi data that can yield large prediction errors. We validate SleepMore using data from a month-long user study involving 46 college students and draw comparisons with the Oura Ring wearable. Beyond the college campus, we evaluate SleepMore on non-student users of different housing profiles. Our results demonstrate that SleepMore produces statistically indistinguishable sleep statistics from the Oura ring baseline for predictions made within a 5% uncertainty rate. These errors range between 15-28 minutes for determining sleep time and 7-29 minutes for determining wake time, proving statistically significant improvements over prior work. Our in-depth analysis explains the sources of errors.
description: 32 pages, 24 figures, 14 tables
Human Resource Management - Case Study Analysis report
Creators: name: Bazla Aziz
Publisher: name: Zenodo
Year: 2020

description: Case study analysis report on Harvard Model in Syarikat Pertanian Tropikal Utama
description: {"references": ["Musa, S. F. P. D. H., Pg Hj Idris, P. S. R., & Basir, K. H. (2020). Inspiring Agripreneurs of Brunei. UNISSA Press, Universiti Islam Sultan Sharif Ali.", "Wills,T. A. (2020). Five Recommendations for Human Resource Management. Forbes.", "Katz, B.R., du Preez, N.D., & Louw, L.. (2016). Alignment of internal and external business and innovation domains. South African Journal of Industrial Engineering, 27(1), 61 74. https://dx.doi.org/10.7166/27-1-1247", "Nooratini Haji Abas. (2020). Jangan terlalu banyak bergantung pada tenaga pekerja asing. Pelita Brunei,", "Kukreja, S. (2018). Management Study HQ."]}
On calmness of a class of multifunctions
Creators: name: Henrion, René
name: Jourani, Abderrahim
name: Outrata, Jiří
Publisher: name: Weierstrass Institute
Year: 2001
Subjects: subject: calmness
subject: multifunctions
subject: constraint qualifications
subject: nonsmooth calculus
subject: solution stability
subject: equilibrium problems
subject: weak sharp minima
subject: 90C31
subject: 49J52

description: The paper deals with calmness of a class of multifunctions in finite dimensions. Its first part is devoted to various calmness criteria which are derived in terms of coderivatives and subdifferentials. The second part demonstrates the importance of calmness in several areas of nonsmoooth analysis. In particular, we focus on nonsmooth calculus and solution stability in mathematical programming and in equilibrium problems. The derived conditions find a number of applications there.
Experimental investigations on thermo-physical properties and stability of diamond-alumina based hybrid nanofluids
Creators: name: Arora, Neeti
name: Gupta, Munish
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Space Science
subject: Physical Sciences not elsewhere classified
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Developmental Biology
subject: Hematology

description: In recent years, the demand of hybrid nanofluids (HNFs) is growing due to their quintessential thermo-physical properties (TPP) and good stability. In this work, nano-diamond (ND) (<10 nm) and nano-alumina (Al2O3) (<80 nm) based mono and HNFs are taken in to consideration. Good thermal conductivity (TC) of ND particles and good physical properties of Al2O3 particles combine to form better HNF when dispersed in water. In-depth and critical experimental investigation has been conducted on TPP and stability analysis of nanofluids. Particle characterization is performed with Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM) assisted with energy dispersive analysis of X-rays (EDAX). Two-step method is employed for constructing Al2O3/water, ND/water, ND-Al2O3/water nanofluids at different weight fractions (0.01–0.3 wt.%). KD2 Pro TC analyzer and Anton Paar MCR 302e rheometer are used for determining TC and viscosity of nanofluids, respectively. The maximum enhancement of 4.2%, 16.93%, and 22.93% are observed in TC at 80 °C for 0.3 wt.% of Al2O3/water, ND-Al2O3/water, and ND/water nanofluids, respectively in comparison with that of distilled water. Correlations are developed for TC and viscosity and compared with experimental values. For evaluating stability of nanofluids, three methods applied such as visual inspection, UV–vis spectroscopy, and zeta-potential (ZP) are used. Stability period of nanofluids represented as ND/water (55 days) > ND-Al2O3/water (45 days) > Al2O3/water (30 days). Both TPP and stability enhanced for ND-Al2O3/water (hybrid) nanofluid compared to Al2O3/water (mono) nanofluid, thus used in various thermo-fluidic industries.
On homological stability for configuration spaces on closed background manifolds
Creators: name: Cantero, Federico
name: Palmer, Martin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55R80, 55P60, 55R25

description: We introduce a new map between configuration spaces of points in a background manifold - the replication map - and prove that it is a homology isomorphism in a range with certain coefficients. This is particularly of interest when the background manifold is closed, in which case the classical stabilisation map does not exist. We then establish conditions on the manifold and on the coefficients under which homological stability holds for configuration spaces on closed manifolds. These conditions are sharp when the background manifold is a two-dimensional sphere, the classical counterexample in the field. For field coefficients this extends results of Church (2012) and Randal-Williams (2013) to the case of odd characteristic, and for $p$-local coefficients it improves results of Bendersky--Miller (2014).
description: 44 pages. Theorem A has been improved and some counterexamples have been added. A discussion of homological periodicity and number of stable homologies has been added around the new Corollary F. Note: Version 3 was not correctly uploaded, version 4 corrects this
Coalitional Game-Theoretical Approach to Coinvestment with Application to Edge Computing
Creators: name: Patanè, Rosario
name: Araldo, Andrea
name: Chahed, Tijani
name: Kiedanski, Diego
name: Kofman, Daniel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences
subject: C.2
subject: 91A80,

description: We propose in this paper a coinvestment plan between several stakeholders of different types, namely a physical network owner, operating network nodes, e.g. a network operator or a tower company, and a set of service providers willing to use these resources to provide services as video streaming, augmented reality, autonomous driving assistance, etc. One such scenario is that of deployment of Edge Computing resources. Indeed, although the latter technology is ready, the high Capital Expenditure (CAPEX) cost of such resources is the barrier to its deployment. For this reason, a solid economical framework to guide the investment and the returns of the stakeholders is key to solve this issue. We formalize the coinvestment framework using coalitional game theory. We provide a solution to calculate how to divide the profits and costs among the stakeholders, taking into account their characteristics: traffic load, revenues, utility function. We prove that it is always possible to form the grand coalition composed of all the stakeholders, by showing that our game is convex. We derive the payoff of the stakeholders using the Shapley value concept, and elaborate on some properties of our game. We show our solution in simulation.
Optimization and modeling of adsorption of Congo Red and Rhodamine B dyes onto Carpobrotus edulis plant
Creators: name: Dabagh, Abdelkader
name: Abali, M’hamed
name: Ichou, Abdeljalil Ait
name: Benhiti, Ridouan
name: Sinan, Fouad
name: Zerbet, Mohamed
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Space Science
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Plant Biology

description: This paper deals with the valorization of the native Carpobrotus edulis plant (C. edulis) as a bioadsorbent for the removal of toxic dyes such as Rhodamine B (RB) and Congo Red (CR). This plant was further characterized by BET, SEM, EDX, and FT-IR methods. The colorants were applied in a batch adsorption experiment that included measurements of adsorbent ratio, ionic strength, contact time, initial concentration, pH, and temperature. It was observed that for 100 mg/L initial dye concentration, 0.2 g of C. edulis showed maximum adsorption efficiency for RB (> 75%), while 0.4 g for CR (> 70%). For both dyes on the biomaterial tested, ionic strength and pH have no significant impact on the adsorption. Adsorption fits a pseudo-second order kinetic model and Langmuir isotherm. The optimum adsorbed amount of C. edulis was indicated at 56.18 and 19.84 mg/g for RB and CR, respectively. The results of the thermodynamic study show that the adsorption process of the dyes by the biomaterial is spontaneous and exothermic with a decrease in the randomness of the adsorption process. The results of the regeneration indicate that the bioadsorbent was efficiently recycled with 55.80% and 36.26% uptake for RB and CR dyes, respectively, after 3rd cycles of desorption-adsorption. Operational factors were studied using Taguchi’s experimental design. Our experimental results confirm the importance of the influence of initial concentration, adsorbent ratio, and contact time on adsorption with maximum adsorption of RB and CR was found to be 76.06% and 68.18% dye, respectively.
Bayesian Estimation of the $S$ Factor and Thermonuclear Reaction Rate for $^{16}$O(p,$γ$)$^{17}$F
Creators: name: Iliadis, Christian
name: Palanivelrajan, Vimal
name: de Souza, Rafael S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The $^{16}$O(p,$γ$)$^{17}$F reaction is the slowest hydrogen-burning process in the CNO mass region. Its thermonuclear rate sensitively impacts predictions of oxygen isotopic ratios in a number of astrophysical sites, including AGB stars. The reaction has been measured several times at low bombarding energies using a variety of techniques. The most recent evaluated experimental rates have a reported uncertainty of about 7.5\% below $1$~GK. However, the previous rate estimate represents a best guess only and was not based on rigorous statistical methods. We apply a Bayesian model to fit all reliable $^{16}$O(p,$γ$)$^{17}$F cross section data, and take into account independent contributions of statistical and systematic uncertainties. The nuclear reaction model employed is a single-particle potential model involving a Woods-Saxon potential for generating the radial bound state wave function. The model has three physical parameters, the radius and diffuseness of the Woods-Saxon potential, and the asymptotic normalization coefficients (ANCs) of the final bound state in $^{17}$F. We find that performing the Bayesian $S$ factor fit using ANCs as scaling parameters has a distinct advantage over adopting spectroscopic factors instead. Based on these results, we present the first statistically rigorous estimation of experimental $^{16}$O(p,$γ$)$^{17}$F reaction rates, with uncertainties ($\pm 4.2$\%) of about half the previously reported values.
description: 3 figures
Upper Limit to the Transverse to Longitudinal Motion Coupling of a Waveguide Mirror
Creators: name: Leavey, S.
name: Barr, B. W.
name: Bell, A. S.
name: Kley, E-B.
name: Gordon, N.
name: Gräf, C.
name: Hild, S.
name: Huttner, S. H.
name: Kroker, S.
name: Macarthur, J.
name: Messenger, C.
name: Pitkin, M.
name: Sorazu, B.
name: Strain, K.
name: Tünnermann, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Waveguide mirrors possess nano-structured surfaces which can potentially provide a significant reduction in thermal noise over conventional dielectric mirrors. To avoid introducing additional phase noise from motion of the mirror transverse to the reflected light, however, they must possess a mechanism to suppress the phase effects associated with the incident light translating across the nano-structured surface. It has been shown that with carefully chosen parameters this additional phase noise can be suppressed. We present an experimental measurement of the coupling of transverse to longitudinal displacements in such a waveguide mirror designed for 1064 nm light. We place an upper limit on the level of measured transverse to longitudinal coupling of one part in seventeen thousand with 95% confidence, representing a significant improvement over a previously measured grating mirror.
Small-scale chromospheric spectropolarimetric observables in the internetwork from a 3D radiative MHD model
Creators: name: Martínez-Sykora, Juan
name: Dalda, Alberto Sainz
name: Gošić, Milan
name: De Pontieu, Bart
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The presence of the magnetic field is critical to transport energy through the solar atmosphere. The new generation of telescopes will provide new insight into how the magnetic field arrives into the chromosphere and its role in the energy balance of the solar atmosphere. We have used a 3D radiative MHD numerical model of the solar atmosphere with high spatial resolution (4~km) calculated with the Bifrost code. This code solves the full MHD equations with non-grey and non-LTE radiative transfer and thermal conduction along magnetic field lines. The model shows how the lower chromosphere in the internetwork, a region dominated by magneto-acoustic shocks and where plasma beta is greater than 1, is able to generate magnetic field in-situ Martinez-Sykora et al 2019. We have synthesized full-polarimetric Stokes profiles from this model for several spectral lines formed in the photosphere and the chromosphere. These synthetic profiles illustrate the types of observables expected from DKIST and IRIS. Our work provides insight into how to interpret observations from these observatories. We find that in order to discern the chromospheric magnetic observables it is crucial to compensate for Doppler shift rather than use fix wavelength range.
description: Submitted to ApJ
Multi-stage Progressive Compression of Conformer Transducer for On-device Speech Recognition
Creators: name: Rathod, Jash
name: Dawalatabad, Nauman
name: Singh, Shatrughan
name: Gowda, Dhananjaya
Publisher: name: arXiv
Year: 2022
Subjects: subject: Sound (cs.SD)
subject: Machine Learning (cs.LG)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The smaller memory bandwidth in smart devices prompts development of smaller Automatic Speech Recognition (ASR) models. To obtain a smaller model, one can employ the model compression techniques. Knowledge distillation (KD) is a popular model compression approach that has shown to achieve smaller model size with relatively lesser degradation in the model performance. In this approach, knowledge is distilled from a trained large size teacher model to a smaller size student model. Also, the transducer based models have recently shown to perform well for on-device streaming ASR task, while the conformer models are efficient in handling long term dependencies. Hence in this work we employ a streaming transducer architecture with conformer as the encoder. We propose a multi-stage progressive approach to compress the conformer transducer model using KD. We progressively update our teacher model with the distilled student model in a multi-stage setup. On standard LibriSpeech dataset, our experimental results have successfully achieved compression rates greater than 60% without significant degradation in the performance compared to the larger teacher model.
description: Published in INTERSPEECH 2022
Asymptotics for periodic systems
Creators: name: Paunonen, Lassi
name: Seifert, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Functional Analysis (math.FA)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35B40, 47D06, 35B10, 47A10, 35L05

description: This paper investigates the asymptotic behaviour of solutions of periodic evolution equations. Starting with a general result concerning the quantified asymptotic behaviour of periodic evolution families we go on to consider a special class of dissipative systems arising naturally in applications. For this class of systems we analyse in detail the spectral properties of the associated monodromy operator, showing in particular that it is a so-called Ritt operator under a natural 'resonance' condition. This allows us to deduce from our general result a precise description of the asymptotic behaviour of the corresponding solutions. In particular, we present conditions for rational rates of convergence to periodic solutions in the case where the convergence fails to be uniformly exponential. We illustrate our general results by applying them to concrete problems including the one-dimensional wave equation with periodic damping.
description: 18 pages, 2 figures
Unraveling the Determinants of G Protein Activation as a Measure of Relative Opioid Drug Efficacy
Creators: name: Venes, Angelica
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2023
Subjects: Opioids
Efficacy
GPCR

description: Opioids are powerful and effective drugs used for pain management, but their therapeutic usage is limited due to their side effects. Therefore, obtaining an extensive understanding of the pharmacological properties that underlie the actions of these drugs is much needed. Efficacy is the extent to which an agonist can stimulate the activity of the receptor it interacts with, and many studies have claimed to determine the efficacy of a wide range of opioid agonists. However, these opioids reportedly appear to be full agonists in some studies but seem to be partial agonists in others. Discrepancies from previous findings hamper the determination of accurate measurements of the efficacy of these drugs. As such, several assays focus on different aspects of opioid receptor signaling to deduce how efficacious these drugs may be. In this study, we focus on the μ-opioid receptor (MOR) as agonists that act on it represent the majority of clinically used opioids. We take advantage of a unique cellular model that captures the differential activation of each Gαi/o/z protein on top of measuring the relative efficacies of each tested opioid agonist. Using various cell-based assays, we demonstrate that these can be tools used to directly look at the interaction between the receptor and its effectors through the coupling of inhibitory heterotrimeric G proteins. The distinctions between each functional readout reveal insights about the nature of each established system, highlighting their advantages as well as their limitations. Key details about the mechanistic basis of inhibitory G protein activation are also uncovered. Precise determination of the efficacy of opioids could ultimately impact the understanding of opioid-mediated neuromodulation, as further links can be made between this important pharmacological parameter and the extent in which it induces analgesia and limits the side effects typically associated with opioid intake.
Existence and uniqueness of global classical solutions to a two species cancer invasion haptotaxis model
Creators: name: Giesselmann, Jan
name: Kolbe, Niklas
name: Lukacova-Medvidova, Maria
name: Sfakianakis, Nikolaos
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35A01, 35B65, 35Q92, 92C17

description: We consider a haptotaxis cancer invasion model that includes two families of cancer cells. Both families, migrate on the extracellular matrix and proliferate. Moreover the model describes an epithelial-to-mesenchymal-like transition between the two families, as well as a degradation and a self-reconstruction process of the extracellular matrix. We prove positivity and conditional global existence and uniqueness of the classical solutions of the problem for large initial data.
Analytical modeling and interpretation of ultrasound-assisted adsorption mechanism of fuchsine dye on MgZnFeO nanocomposites
Creators: name: Jethave, Ganesh
name: Fegade, Umesh
name: Attarde, Sanjay
name: Inamuddin
name: Altalhi, Tariq
name: Khan, Mohd. Farhan
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Space Science
subject: Physical Sciences not elsewhere classified
subject: Medicine
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified

description: An efficient co-precipitation followed by ultrasonication process is used for the synthesis of trimetallic MgZnFeO nanocomposites (MZFONCs) and further characterized by FE-SEM, FT-IR, XRD, EDX, etc. spectroscopic techniques. The adsorption process is applied for the removal of toxic cationic Basic Fuchsine (BF) dye using batch experiments. To enhance removal efficiency, the effect of deviation in parameters including shaking time; adsorbent dose; pH; etc. are studied. Qmax obtained by Langmuir is found to be 250 mg/g for BF on the MZFONCs surface, at pH = 6.5; 40 min of agitation time, and a small dose of nanoparticles. The best match for the adsorption of BF on MZFONCs is a double-layer method which also describes the adsorption mechanism. The ‘n’ parameter value (0.507–0.628) is obtained from the statistical physics model, which shows mixed-orientation type adsorption of BF molecules on MZFONCs adsorbents. The calculated energies for BF dye adsorption are found to be less than 30 KJ/mol, hence implying an endothermic and physical adsorption mechanism.
Finite Chains inside Thin Subsets of ${\Bbb R}^d$
Creators: name: Bennett, Mike
name: Iosevich, Alex
name: Taylor, Krystal
Publisher: name: arXiv
Year: 2014
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Combinatorics (math.CO)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 28A75, 42B20, 52C10

description: In a recent paper, Chan, Łaba, and Pramanik investigated geometric configurations inside thin subsets of the Euclidean set possessing measures with Fourier decay properties. In this paper we ask which configurations can be found inside thin sets of a given Hausdorff dimension without any additional assumptions on the structure. We prove that if the Hausdorff dimension of $E \subset {\Bbb R}^d$, $d \ge 2$, is greater than $\frac{d+1}{2}$, then there exists a non-empty interval $I$ such that given any sequence $\{t_1, t_2, \dots, t_k; t_j \in I\}$, there exists a sequence ${\{x^j\}}_{j=1}^{k+1}$, such that $x^j \in E$ and $|x^{i+1}-x^i|=t_j$, $1 \leq i \leq k$. In other words, $E$ contains vertices of a chain of arbitrary length with prescribed gaps.
description: 2 figures