cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
PHiLIP on the HiL: Automated Multi-platform OS Testing with External Reference Devices
Creators: name: Weiss, Kevin
name: Rottleuthner, Michel
name: Schmidt, Thomas C.
name: Wählisch, Matthias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: Operating Systems (cs.OS)
subject: Software Engineering (cs.SE)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: B.8.1; D.2.5; C.3; D.4

description: Developing an operating system (OS) for low-end embedded devices requires continuous adaptation to new hardware architectures and components, while serviceability of features needs to be assured for each individual platform under tight resource constraints. It is challenging to design a versatile and accurate heterogeneous test environment that is agile enough to cover a continuous evolution of the code base and platforms. This mission is even morehallenging when organized in an agile open-source community process with many contributors such as for the RIOT OS. Hardware in the Loop (HiL) testing and Continuous Integration (CI) are automatable approaches to verify functionality, prevent regressions, and improve the overall quality at development speed in large community projects. In this paper, we present PHiLIP (Primitive Hardware in the Loop Integration Product), an open-source external reference device together with tools that validate the system software while it controls hardware and interprets physical signals. Instead of focusing on a specific test setting, PHiLIP takes the approach of a tool-assisted agile HiL test process, designed for continuous evolution and deployment cycles. We explain its design, describe how it supports HiL tests, evaluate performance metrics, and report on practical experiences of employing PHiLIP in an automated CI test infrastructure. Our initial deployment comprises 22 unique platforms, each of which executes 98 peripheral tests every night. PHiLIP allows for easy extension of low-cost, adaptive testing infrastructures but serves testing techniques and tools to a much wider range of applications.
title: Fire Safety Engineering: Professional Development Report 6 of 8
Creators: name: Lange, David
name: Johnson, Peter
name: Torero, Jose
name: Hidalgo, Juan P
name: Maluk, Cristian
name: Wiesner, Felix
Publisher: name: The Warren Centre for Advanced Engineering
Year: 2020

description: The Professional Development Report addresses the resource and skill constraints hindering the full professionalisation of fire safety engineering, in order to one day achieve a sustainable provision of fire safety engineering professionals.
Marcinkiewicz regularity for singular parabolic $p$-Laplace type equations with measure data
Creators: name: Park, Jung-Tae
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35K92 (Primary) 35R06, 35B65 (Secondary)

description: We consider quasilinear parabolic equations with measurable coefficients when the right-hand side is a signed Radon measure with finite total mass, having $p$-Laplace type: $$u_t - \textrm{div} \, \mathbf{a}(Du,x,t) = μ\quad \textrm{in} \ Ω\times (0,T) \subset \mathbb{R}^n \times \mathbb{R}.$$ In the singular range $\frac{2n}{n+1}
description: Major revision, 18 pages
Quantum cohomology of symplectic flag manifolds
Creators: name: Guo, Jirui
name: Zou, Hao
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We compute the quantum cohomology of symplectic flag manifolds. Symplectic flag manifolds can be described by non-abelian GLSMs with superpotential. Although the ring relations cannot be directly read off from the equations of motion on the Coulomb branch due to complication introduced by the non-abelian gauge symmetry, it can be shown that they can be extracted from the localization formula in a gauge-invariant form. Our result is general for all symplectic flag manifolds, which reduces to previously established results on symplectic Grassmannians and complete symplectic flag manifolds derived by other means. We also explain why a (0,2) deformation of the GLSM does not give rise to a deformation of the quantum cohomology.
description: 28 pages, LaTeX; v2: reference added; v3: comments added
Automated computation of topological derivatives with application to nonlinear elasticity and reaction-diffusion problems
Creators: name: Gangl, Peter
name: Sturm, Kevin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: While topological derivatives have proven useful in applications of topology optimisation and inverse problems, their mathematically rigorous derivation remains an ongoing research topic, in particular in the context of nonlinear partial differential equation (PDE) constraints. We present a systematic yet formal approach for the computation of topological derivatives of a large class of PDE-constrained topology optimization problems with respect to arbitrary inclusion shapes. Scalar and vector-valued as well as linear and nonlinear elliptic PDE constraints are considered in two and three space dimensions including a nonlinear elasticity model and nonlinear reaction-diffusion problems. The systematic procedure follows a Lagrangian approach for computing topological derivatives. For problems where the exact formula is known, the numerically computed values show good coincidence. Moreover, by inserting the computed values into the topological asymptotic expansion, we verify that the obtained values satisfy the expected behaviour also for other, previously unknown problems, indicating the correctness of the procedure. We present a systematic approach for the computation of topological derivatives that is applicable to a large class of problems. Most notably, our approach covers the topological derivative for a nonlinear elasticity problem, which has not been reported in the literature.
Time-Like Heavy-Flavour Thresholds for Fragmentation Functions: the Light-Quark Matching Condition at NNLO
Creators: name: Biello, Christian
name: Bonino, Leonardo
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Matching conditions are universal ingredients that describe how fragmentation functions change when heavy-flavour thresholds are crossed during the factorisation scale evolution. They are the last missing piece for a consistent description of observables with identified final-state hadrons at next-to-next-to leading order accuracy in quantum chromodynamics. We present an analytical form of the matching condition for light-flavour to hadron fragmentation function at next-to-next-to leading order. The derivation is performed by extending the formalism employed in the extraction of the next-to leading order matching conditions to the subsequent order, making use of $e^+e^-$ annihilation cross sections. We obtain the first non-trivial heavy-quark effect in the light-quark fragmentation functions and provide results in Mellin space.
description: 17 pages, 3 figures, ancillary file with analytical results; matches the published version: added gluon master formula, updated ancillary files and plots
title: A rare cause of exertional dyspnoea in SLE – Shrinking lung syndrome
Creators: name: Menezes, Anna Rachel
Publisher: name: EURORAD
Year: 2022
Subjects: subject: Chest imaging
subject: Thorax
subject: CT
subject: CT-High Resolution
subject: Ultrasound
subject: Ultrasound-Colour Doppler
subject: Clinical Cases

description: Clinical History: A 48-year-old female, on irregular follow-up for systemic lupus erythematosus (SLE), came to the pulmonary medicine outpatient department with a 2-year history of easy fatiguability and exertional dyspnea progressing to current dyspnea at rest. She had no history of orthopnea or paroxysmal nocturnal dyspnea.

description: 48 years, female
Bayesian Inference of Fine-Features of Nuclear Equation of State from Future Neutron Star Radius Measurements to 0.1km Accuracy
Creators: name: Li, Bao-An
name: Grundler, Xavier
name: Xie, Wen-Jie
name: Zhang, Nai-Bo
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: To more precisely constrain the Equation of State (EOS) of supradense neutron-rich nuclear matter, future high-precision X-ray and gravitational wave observatories are proposed to measure the radii of neutron stars (NSs) with an accuracy better than about 0.1 km. However, it remains unclear what particular aspects (other than the stiffness generally spoken of in the literature) of the EOS and to what precision they will be better constrained. In this work, within a Bayesian framework using a meta-model EOS for NSs, we infer the posterior probability distribution functions (PDFs) of incompressibility $K_{0}$ and skewness $J_{0}$ of symmetric nuclear matter (SNM) as well as the slope $L$, curvature $K_{\rm{sym}}$, and skewness $J_{\rm{sym}}$ characterizing the density dependence of nuclear symmetry energy $E_{\rm{sym}}(ρ)$, respectively, from mean values of NS radii consistent with existing observations and an expected accuracy $ΔR$ ranging from about 1.0 km to 0.1 km. We found that (1) the $ΔR$ has little effect on inferring the stiffness of SNM at suprasaturation densities, (2) smaller $ΔR$ reveals more accurately not only the PDFs but also pairwise correlations among parameters characterizing high-density $E_{\rm{sym}}(ρ)$, (3) a double-peak feature of the PDF($K_{\rm{sym}}$) corresponding to the strong $K_{\rm{sym}}-J_{\rm{sym}}$ and $K_{\rm{sym}}-L$ anti-correlations is revealed when $ΔR$ is less than about 0.2 km, and the locations of the two peaks are sensitive to the maximum value of $J_{\rm{sym}}$ reflecting the stiffness of $E_{\rm{sym}}(ρ)$ above about 3 times the saturation density $ρ_0$ of SNM, (4) the high-precision radius measurement for canonical NSs is more useful than that for massive ones for constraining the EOS of nucleonic matter around $(2-3)ρ_0$.
description: 34 pages with additional results, discussions and appendices. Phys. Rev. D in press
Probe and Prejudice: Classification of compact objects and model comparison using EOS knowledge
Creators: name: Koehn, Hauke
name: Wouters, Thibeau
name: Rose, Henrik
name: Pang, Peter T. H.
name: Somasundaram, Rahul
name: Tews, Ingo
name: Dietrich, Tim
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Nuclear theory and experiments, alongside astrophysical observations, constrain the equation of state (EOS) of supranuclear-dense matter. Conversely, knowledge of the EOS allows an improved interpretation of nuclear or astrophysical data. In this article, we use several established constraints on the EOS and the new NICER measurement of PSR J0437-4715 to comment on the nature of the primary companion in GW230529 and the companion of PSR J0514-4002E. We find that, with a probability of $\gtrsim 84\%$ and $\gtrsim 68\%$, respectively, both objects are black holes. These likelihoods increase to above $95\%$ when one uses GW170817's remnant as an upper limit on the TOV mass. We also demonstrate that the current knowledge of the EOS substantially disfavors high masses and radii for PSR J0030+0451, inferred recently when combining NICER with XMM-Newton background data and using particular hot-spot models. Finally, we also use our obtained EOS knowledge to comment on measurements of the nuclear symmetry energy, finding that the large value predicted by the PREX-II measurement displays some mild tension with other constraints on the EOS.
description: 14 pages, 5 figures, published in PRD, v3 contains minor correction for the Pb-208 dipole
Groups of finite Morley rank with a generically multiply transitive action on an abelian group
Creators: name: Berkman, Ayşe
name: Borovik, Alexandre
Publisher: name: arXiv
Year: 2021
Subjects: subject: Group Theory (math.GR)
subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 20F11, 03C60

description: We investigate the configuration where a group of finite Morley rank acts definably and generically $m$-transitively on an elementary abelian $p$-group of Morley rank $n$, where $p$ is an odd prime, and $m\geqslant n$. We conclude that $m=n$, and the action is equivalent to the natural action of $\operatorname{GL}_n(F)$ on $F^n$ for some algebraically closed field $F$. This strengthens our earlier result in arXiv:1802.05222, and partially answers two problems posed in [9].
description: To appear in \textit{Model Theory}. The manuscript will undergo copy editing, typesetting, and review of the resulting proof before it is published
Intelligent Urban Traffic Management via Semantic Interoperability across Multiple Heterogeneous Mobility Data Sources
Creators: name: Scrocca, Mario
name: Grassi, Marco
name: Comerio, Marco
name: Carriero, Valentina Anita
name: Dias, Tiago Delgado
name: Da Silva, Ana Vieira
name: Celino, Irene
Publisher: name: arXiv
Year: 2024
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: The integrated exploitation of data sources in the mobility domain is key to providing added-value services to passengers, transport companies and authorities. Indeed, multiple stakeholders operate and maintain different kinds of data but several interoperability issues limit their effective usage. In this paper, we present an architecture enabled by Semantic Web technologies to overcome such issues and facilitate the development of an integrated solution for mobility stakeholders. The proposed solution is composed of different components that address challenges for enabling data interoperability, from the findability of data sources to their integrated consumption adopting standardised data formats. We report on the implementation and validation in four European cities of the TANGENT solution enabling data-driven tools for the dynamic management of multimodal traffic. Finally, we discuss the feedback received by users testing the solution and the lessons learnt during its development.
description: In Use paper accepted for publication at the 23rd International Semantic Web Conference (ISWC) 2024. This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this contribution will be published in the conference proceedings
Machine Learning in Communications: A Road to Intelligent Transmission and Processing
Creators: name: Wang, Shixiong
name: Li, Geoffrey Ye
Publisher: name: arXiv
Year: 2024
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Prior to the era of artificial intelligence and big data, wireless communications primarily followed a conventional research route involving problem analysis, model building and calibration, algorithm design and tuning, and holistic and empirical verification. However, this methodology often encountered limitations when dealing with large-scale and complex problems and managing dynamic and massive data, resulting in inefficiencies and limited performance of traditional communication systems and methods. As such, wireless communications have embraced the revolutionary impact of artificial intelligence and machine learning, giving birth to more adaptive, efficient, and intelligent systems and algorithms. This technological shift opens a road to intelligent information transmission and processing. This overview article discusses the typical roles of machine learning in intelligent wireless communications, as well as its features, challenges, and practical considerations.
description: Invited by and Accepted to "Communications of Huawei Research"
Physics-informed neural networks for solving Reynolds-averaged Navier$\unicode{x2013}$Stokes equations
Creators: name: Eivazi, Hamidreza
name: Tahani, Mojtaba
name: Schlatter, Philipp
name: Vinuesa, Ricardo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Machine Learning (cs.LG)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Physics-informed neural networks (PINNs) are successful machine-learning methods for the solution and identification of partial differential equations (PDEs). We employ PINNs for solving the Reynolds-averaged Navier$\unicode{x2013}$Stokes (RANS) equations for incompressible turbulent flows without any specific model or assumption for turbulence, and by taking only the data on the domain boundaries. We first show the applicability of PINNs for solving the Navier$\unicode{x2013}$Stokes equations for laminar flows by solving the Falkner$\unicode{x2013}$Skan boundary layer. We then apply PINNs for the simulation of four turbulent-flow cases, i.e., zero-pressure-gradient boundary layer, adverse-pressure-gradient boundary layer, and turbulent flows over a NACA4412 airfoil and the periodic hill. Our results show the excellent applicability of PINNs for laminar flows with strong pressure gradients, where predictions with less than 1% error can be obtained. For turbulent flows, we also obtain very good accuracy on simulation results even for the Reynolds-stress components.
description: Proc. 13th ERCOFTAC Symp. on Engineering Turbulence Modeling and Measurements (ETMM13), Rhodes, Greece, September 15-17, 2021
Worst case expansions of complete theories
Creators: name: Braunfeld, Samuel
name: Laskowski, Michael C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics

description: Given a complete theory $T$ and a subset $Y \subseteq X^k$, we precisely determine the {\em worst case complexity}, with respect to further monadic expansions, of an expansion $(M,Y)$ by $Y$ of a model $M$ of $T$ with universe $X$. In particular, although by definition monadically stable/NIP theories are robust under arbitrary monadic expansions, we show that monadically NFCP (equivalently, mutually algebraic) theories are the largest class that is robust under anything beyond monadic expansions. We also exhibit a paradigmatic structure for the failure of each of monadic NFCP/stable/NIP and prove each of these paradigms definably embeds into a monadic expansion of a sufficiently saturated model of any theory without the corresponding property.
description: 15 pages; to appear in Model Theory
Precision bounds for quantum phase estimation using two-mode squeezed Gaussian states
Creators: name: Zhang, Jian-Dong
name: Li, Chuang
name: Hou, Lili
name: Wang, Shuai
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum phase estimation based on Gaussian states plays a crucial role in many application fields. In this paper, we study the precision bound for the scheme using two-mode squeezed Gaussian states. The quantum Fisher information is calculated and its maximization is used to determine the optimal parameters. We find that two single-mode squeezed vacuum states are the optimal inputs and the corresponding precision bound is superior to the Heisenberg limit by a factor of 2. For practical purposes, we consider the effects originating from photon loss. The precision bound can still outperform the shot-noise limit when the lossy rate is below 0.4. Our work may demonstrate a significant and promising step towards practical quantum metrology.
Constraining $λ_{B_s}$ by $B_s\to γ^*$ and $B_s\to ϕ$ form factors
Creators: name: Ivanov, Mikhail A.
name: Melikhov, Dmitri
name: Simula, Silvano
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the form factors $F_{V}(q^2,q'^2)$ and $F_{TV}(q^2,q'^2)$ describing the $B_s\to γ^*$ transition induced by the vector and tensor weak currents in a broad range of values of $q^2$ and $q'^2$ far below the quark thresholds in both $q^2$ and $q'^2$ channels. These form factors are calculated via the distribution amplitudes of the $B_s$-meson. We then interpolate the obtained results by a formula that contains pole at $q'^2=M_ϕ^2$ and extract the residue which gives the $B_s\to ϕ$ transition form factors $V(q^2)$ and $T_1(q^2)$. In this way we obtain theoretical predictions for these form factors without invoking quark-hadron duality and QCD sum rules. Furthermore, we calculate the relationship between $V(0)$ and $T_1(0)$ and the parameter $λ_{B_s}(μ)$, the inverse moment of the $B_s$-meson distribution amplitude. Using the available predictions for $V(0)$ and $T_1(0)$ coming from approaches not referring to the $B_s$-meson distribution amplitudes, we obtain the estimate $λ_{B_s}(μ\simeq m_b)=(0.62\pm 0.10)$ GeV.
description: 11 pages, small text changes, version to be published in PRD
Computational Mean-field information dynamics associated with Reaction diffusion equations
Creators: name: Li, Wuchen
name: Lee, Wonjun
name: Osher, Stanley
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We formulate and compute a class of mean-field information dynamics for reaction-diffusion equations. Given a class of nonlinear reaction-diffusion equations and entropy type Lyapunov functionals, we study their gradient flows formulations with generalized optimal transport metrics and mean-field control problems. We apply the primal-dual hybrid gradient algorithm to compute the mean-field control problems with potential energies. A byproduct of the proposed method contains a new and efficient variational scheme for solving implicit in time schemes of mean-field control problems. Several numerical examples demonstrate the solutions of mean-field control problems.
description: 38 pages
TeV Scale Modified Type-II Seesaw and Dark Matter in a Gauged $U(1)_{\rm B-L}$ Symmetric Model
Creators: name: Ghosh, Purusottam
name: Mahapatra, Satyabrata
name: Narendra, Nimmala
name: Sahu, Narendra
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In an endeavor to explain the light neutrino masses and dark matter (DM) simultaneously, we study a gauged $U(1)_{\rm B-L}$ extension of the standard model (SM). The neutrino masses are generated through a variant of type-II seesaw mechanism in which one of the scalar triplets has a mass in a scale that is accessible at the present generation colliders. Three SM singlet right chiral fermions $χ_{iR}$($i=e,μ,τ$) with $\rm B-L$ charges -4, -4, +5 are invoked to cancel the $\rm B-L$ gauge anomalies and the lightest one among these three fermions becomes a viable DM candidate as their stability is guaranteed by a remnant $\mathcal Z_2$ symmetry to which $U(1)_{\rm B-L}$ gauge symmetry gets spontaneously broken. Interestingly in this scenario, the neutrino mass and the co-annihilation of DM are interlinked through the breaking of $U(1)_{\rm B-L}$ symmetry. Apart from giving rise to the observed neutrino mass and dark matter abundance, the model also predicts exciting signals at the colliders. Especially we see a significant enhancement in the production cross-section of the TeV scale doubly charged scalar in presence of the $Z_{\rm BL}$ gauge boson. We discuss all the relevant constraints on model parameters from observed DM abundance and null detection of DM at direct and indirect search experiments as well as the constraints on the $\rm B-L$ gauge boson from recent colliders.
description: 52 Pages, 23 captioned figures, Version accepted for publication in Phys. Rev. D
Ocean Disposal in the New York Bight Technical Briefing Report Number 1
Creators: name: No Name Supplied
Publisher: name: No Publisher Supplied
Year: 1974

description: The purpose of this technical document, to be updated and released semi-annually, is to brief interested agencies and individuals on EPA's program in carrying out its mandated re­sponsibilities under the Marine Protection, Research, and Sanctuaries Act of 1972 (PublicLaw92-532). Two previously issued reports, "Ocean Dumping in the New York Bight, Facts and Figures, July 1973" and "Briefing Report, Ocean Dumping in theNew York Bight Since 1973, April 1974", indicate proposed alternate sites to be used for ocean disposal; describe the complexities of this overall environmental problem; detail the sources and volumes of wastes being disposed of into the ocean; and outline the general and special conditions of municipal and industrial permits issued by EPA.
Current fluctuations in the symmetric exclusion process beyond the one-dimensional geometry
Creators: name: Berlioz, Théotim
name: Venturelli, Davide
name: Grabsch, Aurélien
name: Bénichou, Olivier
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The symmetric simple exclusion process (SEP) is a paradigmatic model of transport, both in and out-of-equilibrium. In this model, the study of currents and their fluctuations has attracted a lot of attention. In finite systems of arbitrary dimension, both the integrated current through a bond (or a fixed surface), and its fluctuations, grow linearly with time. Conversely, for infinite systems, the integrated current displays different behaviours with time, depending on the geometry of the lattice. For instance, in 1D the integrated current fluctuations are known to grow sublinearly with time, as $\sqrt{t}$. Here we study the fluctuations of the integrated current through a given lattice bond beyond the 1D case by considering a SEP on higher-dimensional lattices, and on a comb lattice which describes an intermediate situation between 1D and 2D. We show that the different behaviours of the current originate from qualitatively and quantitatively different current-density correlations in the systems, which we compute explicitly.
description: 29 pages, 13 figures
$H^s$ Bounds for the Derivative Nonlinear Schrödinger Equation
Creators: name: Bahouri, Hajer
name: Leslie, Trevor M.
name: Perelman, Galina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We study the derivative nonlinear Schrödinger equation on the real line and obtain global-in-time bounds on high order Sobolev norms.
description: 20 pages
Qualification of the low-pressure cold gas spraying for the additive manufacturing of copper-nickel-diamond grinding wheels
Creators: name: Tillmann, Wolfgang
name: Zajaczkowski, Jonas
name: Baumann, Ingor
name: Kipp, Monika
name: Biermann, Dirk
Publisher: name: TU Dortmund
Year: 2021
Subjects: subject: Additive manufacturing
subject: Cold spraying
subject: Diamond grinding wheel
subject: Grinding
subject: Low pressure cold spraying
subject: 620
subject: 670
subject: Rapid Prototyping
subject: Kaltspritzen
subject: Diamantschleifscheibe
subject: Schleifen
subject: Thermisches Spritzen
subject: Niederdruck

description: Grinding wheels are usually manufactured by powder metallurgical processes, i.e., by molding and sintering. Since this requires the production of special molds and the sintering is typically carried out in a continuous furnace, this process is time-consuming and cost-intensive. Therefore, it is only worthwhile for medium and large batches. Another influencing factor of the powder metallurgical process route is the high thermal load during the sintering process. Due to their high thermal sensitivity, superabrasives such as diamond or cubic boron nitride are very difficult to process in this way. In this study, a novel and innovative approach is presented, in which superabrasive grinding wheels are manufactured by thermal spraying. For this purpose, flat samples as well as grinding wheel bodies were coated by low-pressure (LP) cold gas spraying with a blend of a commercial Cu-Al2O3 cold gas spraying powder and nickel-coated diamonds. The coatings were examined metallographically in terms of their composition. A well-embedded superabrasive content of 12 % was achieved. After the spraying process, the grinding wheels were conditioned and tested for the grinding application of cemented carbides and the topographies of both the grinding wheel and the cemented carbide were evaluated. Surface qualities of the ground surface that are comparable to those of other finishing processes were reached. This novel process route offers great flexibility in the combination of binder and hard material as well as a cost-effective single-part and small-batch production.
description: Journal of thermal spray technology;Bd 31. 2022, H. 1/2, S. 206-216
Simulating the chromatin mediated phase separation of model proteins with multiple domains
Creators: name: Ancona, Marco
name: Brackley, Chris A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We perform simulations of a system containing simple model proteins and a polymer representing chromatin. We study the interplay between protein-protein and protein-chromatin interactions, and the resulting condensates which arise due to liquid-liquid phase separation, or a via a 'bridging-induced attraction' mechanism. For proteins which interact multivalently, we obtain a phase diagram which includes liquid-like droplets, droplets with absorbed polymer, and coated polymer regimes. Of particular interest is a regime where protein droplets only form due to interaction with the polymer; here, unlike a standard phase separating system, droplet density rather than size varies with the overall protein concentration. We also observe that protein dynamics within droplets slow down as chromatin is absorbed. If the protein-protein interactions have a strictly limited valence, fractal or gel-like condensates are instead observed. Together this provides biologically relevant insights into the nature of protein-chromatin condensates in living cells.
description: Main article: 10 pages, 6 figures; Supplementary Material: 16 pages, 15 figures
Tunneling maps of interacting electrons in real time: anomalous tunneling in quantum point-contacts beyond the steady state regime
Creators: name: Hutak, Taras
name: Skorobagatko, Gleb
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Strongly correlated transport of interacting electrons through the one-dimensional tunnel contact is considered within the Luttinger liquid model of one-dimensional electrodes on arbitrary time scales $ t> \hbar /Λ_{g} $. Using previous results, namely, the Self-equilibration theorem proven in Ref.[G.Skorobagatko, Ann.Phys., 422, 168298 (2020)] the exact distribution functions $ P(N,t) $ for the probabilities of $ N $ electrons to tunnel through the contact during the fixed time interval $ t $ are derived and plotted as 3D intensity graphs called real-time tunneling maps in a whole available region of Luttinger liquid correlation parameter values, bias voltages, and temperatures. The tunneling maps being obtained reveal tunneling anomalies -unusually high tunneling probabilities for the small numbers of electrons on the short-time scales beyond the steady state regime of electron tunnel transport. Especially, this concerns the case of strong short-range electron-electron interaction in the leads at $ g \lesssim 1/2 $. The effect being found can be treated as the direct consequence of the self-equilibration phenomenon. It is shown that features of such an anomalous electron tunneling beoynd the steady state regime can be used for precise experimental measurements of small differences between Luttinger liquid correlation parameter values in different one-dimensional quantum-point contacts.
description: 8 pages, 2 figures
Stochastic Games with Disjunctions of Multiple Objectives (Technical Report)
Creators: name: Winkler, Tobias
name: Weininger, Maximilian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Complexity (cs.CC)
subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences

description: Stochastic games combine controllable and adversarial non-determinism with stochastic behavior and are a common tool in control, verification and synthesis of reactive systems facing uncertainty. Multi-objective stochastic games are natural in situations where several - possibly conflicting - performance criteria like time and energy consumption are relevant. Such conjunctive combinations are the most studied multi-objective setting in the literature. In this paper, we consider the dual disjunctive problem. More concretely, we study turn-based stochastic two-player games on graphs where the winning condition is to guarantee at least one reachability or safety objective from a given set of alternatives. We present a fine-grained overview of strategy and computational complexity of such \emph{disjunctive queries} (DQs) and provide new lower and upper bounds for several variants of the problem, significantly extending previous works. We also propose a novel value iteration-style algorithm for approximating the set of Pareto optimal thresholds for a given DQ.
description: Technical report including appendix with detailed proofs, 29 pages
Yukawa Black Holes from Interacting Vacuum
Creators: name: Maier, Rodrigo
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper we obtain an exact solution of Einstein field equations assuming an interaction between a vacuum component and the Maxwell field. The key feature of such interaction refers to a simple stress exchange so that the electromagnetic field naturally incorporates the Yukawa potential. It is shown that the resulting spacetime thus obtained can either be a naked singularity or a black hole with an inner Cauchy horizon $R_-$ and an exterior event horizon $R_+$. For this latter configuration we examine the group velocity of test photons in the region $R>R_+$. Beyond a lower bound for the frequency we show that superluminal velocities arise in a neighbourhood of the event horizon and that the coupling parameter of the interaction is actually connected to a nonvanishing rest mass for the photon.
description: Accepted for publication in Classical and Quantum Gravity
Slug flow as tool for selectivity control in the homogeneously catalysed solvent-free epoxidation of methyl oleate
Creators: name: Gladius, Anoj Winston
name: Vondran, Johanna
name: Ramesh, Yashwanth
name: Seidensticker, Thomas
name: Agar, David W.
Publisher: name: TU Dortmund
Year: 2021
Subjects: subject: Phase transfer catalysis
subject: Flow chemistry
subject: Epoxidation
subject: Peroxopolyoxotungstates
subject: Slug flow
subject: 660

description: Catalytic oxidation of sustainable raw materials like unsaturated fats and oils, or fatty acids and their esters, lead to biobased, high-value products. Starting from technical grade methyl oleate, hydrogen peroxide as a green oxidant produces only water as by-product. A commercially available, cheap water-soluble tungsten catalyst is combined with Aliquat® 336 as a phase-transfer agent in solvent-free reaction conditions. In this study, we first report the transfer of this well-known batch system into continuous mode. The space–time yield is improved from 0.08 kg/L.h in batch to 1.29 kg/L.h in flow mode. The improved mass transfer and reduced back mixing of the biphasic liquid–liquid slug flow allows for selectivity control depending on physical parameters of slug flow namely volumetric phase ratio, volumetric flow rate, and slug length. Even though the product, methyl 9,10-epoxystearate is obtained at a maximum selectivity of only 58% in flow mode, higher space time yield combined with possible reactant recycling in flow mode offers a promising avenue of research. This work analyses the use of slug flow parameters as tools for controlling selectivity towards oxidation products of methyl oleate.
description: Journal of flow chemistry;Bd 11. 2021, H. 3, S. 407-427
Massive-vortex realization of a Bosonic Josephson Junction
Creators: name: Bellettini, Alice
name: Richaud, Andrea
name: Penna, Vittorio
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the mass exchange between two rotating, quantum massive vortices in a two-component Bose-Einstein condensate. The vortices, in the majority component, exhibit a filled core, where the in-filling minority component undergoes a quantum tunneling effect. Remarkably, we observe that the two-vortex system features stable Josephson oscillations, as well as all the nonlinear phenomena, including the macroscopic quantum self-trapping, that characterize a Bosonic Josephson Junction (BJJ). We propose an analytical model for describing the inter-vortex tunneling, obtained by implementing the a coherent-state representation of the two-mode Bose-Hubbard model. This allows us to give the explicit expression of the model's parameters in terms of the physical macroscopic parameters of the two-vortex system. The comparison of the dynamical scenario predicted by the model with that emerging from the Gross-Pitaevskii equations is very good for sufficiently small particle numbers, while at larger particle numbers it grows less precise, presumably due to the partial exclusion of the many-body interactions from our model. The definition of an effective self-interaction parameter allows us to include the many-body effects, thus restoring a quite good agreement with the numerical results. Interestingly, the recognition of the bosonic Josephson dynamics paves the way to the investigation of new dynamical behaviors in multi-vortex configurations.
description: 13 pages, 14 figures
Light propagation through optical media using metric contact geometry
Creators: name: García-Peláez, D.
name: López-Monsalvo, C. S.
name: Ponce, A. Rubio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this work, we show that the orthogonality between rays and fronts of light propagation in a medium is expressed in terms of a suitable metric contact structure of the optical medium without boundaries. Moreover, we show that considering interfaces (modeled as boundaries) orthogonality is no longer fulfilled, leading to optical aberrations and in some cases total internal reflection. We present some illustrative examples of this latter point.
description: 8 pages, 7 figures
Non-convex Generalized Nash Games for Energy Efficient Power Allocation and Beamforming in mmWave Networks
Creators: name: Wang, Wenbo
name: Leshem, Amir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Network management is a fundamental ingredient for efficient operation of wireless networks. With increasing bandwidth, number of antennas and number of users, the amount of information required for network management increases significantly. Therefore, distributed network management is a key to efficient operation of future networks. This paper focuses on the problem of distributed joint beamforming control and power allocation in ad-hoc mmWave networks. Over the shared spectrum, a number of multi-input-multi-output links attempt to minimize their supply power by simultaneously finding the locally optimal power allocation and beamformers in a self-organized manner. Our design considers a family of non-convex quality-of-service constraint and utility functions characterized by monotonicity in the strategies of the various users. We propose a two-stage, decentralized optimization scheme, where the adaptation of power levels and beamformer coefficients are iteratively performed by each link. We first prove that given a set of receive beamformers, the power allocation stage converges to an optimal generalized Nash equilibrium of the generalized power allocation game. Then we prove that iterative minimum-mean-square-error adaptation of the receive beamformer results in an overall converging scheme. Several transmit beamforming schemes requiring different levels of information exchange are also compared in the proposed allocation framework. Our simulation results show that allowing each link to optimize its transmit filters using the direct channel results in a near optimum performance with very low computational complexity, even though the problem is highly non-convex.
description: to appear in IEEE Transactions on Signal Processing
Dual Description of Gauge Theories from an Iterative Noether Approach
Creators: name: Banerjee, Rabin
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An iterative Noether scheme, advocated by Deser, is used to introduce gauge invariant couplings to nonrelativistic matter with global symmetries related to usual charge conservation and dipole conservation recently discussed in fractonic theories. No reference to any gauge principle, fractonic or otherwise, is required. A dual description is found where the theory is defined either in terms of the usual vector gauge field or, alternatively, in terms of higher derivatives of a symmetric tensor field. A connection between these two descriptions is obtained by providing an explicit map between the vector and tensor fields. This method yields a novel `minimal' prescription for the tensor fields which is identified with the usual minimal prescription for the vector fields by using the mapping. It also spells out the structure of the pure gauge field action in both formulations. Extension of the abelian $U(1)$ invariance to the nonabelian $SU(N)$ invariance is done for the standard formulation.
description: 18 pages, some textual modifications in V2, minor additions in V3 (this version to appear in Nucl. Phys. B)
On the small scale turbulent dynamo in the intracluster medium: A comparison to dynamo theory
Creators: name: Steinwandel, Ulrich P.
name: Boess, Ludwig M.
name: Dolag, Klaus
name: Lesch, Harald
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present non-radiative, cosmological zoom-simulations of galaxy cluster formation with magnetic fields and (anisotropic) thermal conduction of one very massive galaxy cluster with a mass at redshift zero that corresponds to $M_\mathrm{vir} \sim 2 \times 10^{15} M_{\odot}$. We run the cluster on three resolution levels (1X, 10X, 25X), starting with an effective mass resolution of $2 \times 10^8M_{\odot}$, subsequently increasing the particle number to reach $4 \times 10^6M_{\odot}$. The maximum spatial resolution obtained in the simulations is limited by the gravitational softening reaching $ε=1.0$ kpc at the highest resolution level, allowing to resolve the hierarchical assembly of the structures in very fine detail. All simulations presented, have been carried out with the SPMHD-code Gadget-3 with a heavily updated SPMHD prescription. The primary focus is to investigate magnetic field amplification in the Intracluster Medium (ICM). We show that the main amplification mechanism is the small scale-turbulent-dynamo in the limit of reconnection diffusion. In our two highest resolution models we start to resolve the magnetic field amplification driven by this process and we explicitly quantify this with the magnetic power-spectra and the magnetic tension that limits the bending of the magnetic field lines consistent with dynamo theory. Furthermore, we investigate the $\nabla \cdot \mathbf{B}=0$ constraint within our simulations and show that we achieve comparable results to state-of-the-art AMR or moving-mesh techniques, used in codes such as Enzo and Arepo. Our results show for the first time in a fully cosmological simulation of a galaxy cluster that dynamo action can be resolved in the framework of a modern Lagrangian magnetohydrodynamic (MHD) method, a study that is currently missing in the literature.
description: 31 pages, 21 Figures, submitted to ApJ, comments very much appreciated
Assessing diffusion model impacts on enstrophy and flame structure in turbulent lean premixed flames
Creators: name: Fillo, Aaron J.
name: Hamlington, Peter E.
name: Niemeyer, Kyle E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Diffusive transport of mass occurs at small scales in turbulent premixed flames. As a result, multicomponent mass diffusion, which is often neglected in direct numerical simulations (DNS) of premixed combustion, has the potential to impact both turbulence and flame characteristics at small scales. In this study, we evaluate these impacts by examining enstrophy dynamics and the internal structure of the flame for lean premixed hydrogen-air combustion, neglecting secondary Soret and Dufour effects. We performed three-dimensional DNS of these flames by implementing the Stefan-Maxwell equations in the code NGA to represent multicomponent mass transport, and we simulated statistically planar lean premixed hydrogen-air flames using both mixture-averaged and multicomponent models. The mixture-averaged model underpredicts the peak enstrophy by up to 13% in the flame front. Comparing the enstrophy budgets of these flames, the multicomponent simulation yields larger peak magnitudes compared to the mixture-averaged simulation in the reaction zone, showing differences of 17% and 14% in the normalized stretching and viscous effects terms. In the super-adiabatic regions of the flame, the mixture-averaged model overpredicts the viscous effects by up to 13%. To assess the effect of these differences on flame structure, we reconstructed the average local internal structure of the turbulent flame through statistical analysis of the scalar gradient field. Based on this analysis, we show that large differences in viscous effects contribute to significant differences in the average local flame structure between the two models.
description: 15 pages, 6 figures
ИНВЕНТАРИЗАЦИЯ ДЕЙСТВУЮЩИХ И ЗАБРОШЕННЫХ ПЛОДОВО-ЯГОДНЫХ НАСАЖДЕНИЙ ЗАЛОЖЕННЫХ В XIX–XX ВВ. НА ТЕРРИТОРИИ ЗАВОЛЖСКО-УРАЛЬСКОГО РЕГИОНА
Creators: name: Татьяна, Березина
Publisher: name: Zenodo
Year: 2020
Subjects: плодовые насаждения, яблоня, экологические условия, микроусловия, паспорт сада, чек-лист

description: Обследование действующих и заброшенных садов позволяет нам определить экологические микроусловия необходимые для произрастания видов рода Malus в условиях региона. Сохранившиеся сорта и формы являются устойчивыми для исследуемой области и могут быть использованы в селекции для создания местных сортов, в качестве подвоя, а также для озеленения и создания защитных лесных полос. По результатам проделанной работы проведена инвентаризация сохранившихся плодовых садов региона, и на ее основе подготовлен к изданию атлас «Плодово-ягодные насаждения Оренбургской области».