cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fate of conventional pollutants and persistent pharmaceuticals during single-stage and sequential sludge digestion processes
Creators: name: Ahmad, Muneer
Publisher: name: University of British Columbia
Year: 2018

description: The consumption of pharmaceuticals is rapidly increasing each year. Ingested pharmaceuticals are excreted in urine or feces, hence they end up in wastewater. Wastewater treatment plants (WWTPs) are not designed to remove pharmaceuticals and therefore act as a main pathway for pharmaceuticals to enter the environment. Due to the incomplete elimination of pharmaceuticals in WWTPs, many of the most resistant pharmaceuticals accumulate in wastewater sludge. The objective of this research was to study the fate of six pharmaceuticals: azithromycin (AZI), bezafibrate (BZF), carbamazepine (CBZ), diclofenac (DCF), mefenamic acid (MFA), ibuprofen (IBP) and one ibuprofen metabolite 1-hydroxy ibuprofen (1-OH IBP) in single-stage and sequential sludge digestion. The selected pharmaceuticals are refractory and have endocrine disrupting potential (except AZI), while the endocrine disrupting potential of 1-OH IBP is not yet known. A multi-residual analytical method was developed for the determination of selected pharmaceuticals using ultra-performance liquid chromatograph tandem mass spectrometer (UPLC-MS/MS). A comparative study of the selected pharmaceuticals was carried out at thermophilic (TH) temperatures in single-stage conventional anaerobic (AN) and sequential anaerobic/aerobic/anoxic (AN/AERO/ANOX) sludge digestion. Sequential AN/AERO/ANOX digestion showed an advantage in treating pharmaceuticals by either removing them or by decreasing their accumulation compared to single-stage digestion. While CBZ, MFA and DCF showed an accumulation trend in both single-stage as well as sequential digestion systems, the rate of accumulation for MFA was significantly lower (91%) in sequential digestion compared to single-stage digestion (998%). In comparison to single-stage digestion, IBP and 1-OH IBP demonstrated 50% removal and a 34% accumulation in sequential digestion, respectively. Azithromycin showed 27% removal in single-stage and 33 to 35% removal in the sequential digestion systems. Moreover, the use of sequential AN/AERO/ANOX digestion demonstrated secondary benefits over single-stage digestion in conventional digester performance parameters as well. These benefits included reduced ammonia generation (44.5%), improved solids removal (4.2%), reduced corrosive and odor-causing sulfur compounds in the headspace of the digester, and enhanced digestate dewaterability (20%). Overall, the removal efficiencies of most of the pharmaceuticals as well as conventional parameters were improved by increasing the duration of the AERO phase in the second stage AERO/ANOX digester.
title: Bewegte Lebenswelten – Einblicke in Raum- und Bewegungserleben in Ganztagsschulen aus Sicht von Kindern
Creators: name: Gumz, Heike
Publisher: name: Universität Kassel
Year: 2020
Subjects: subject: Bewegung im Ganztag
subject: informelle Bildung
subject: Teilhabegerechtigkeit
subject: Kindheitsforschung
subject: Partizipation
subject: Aneignungstheorie
subject: movements in all-day schools
subject: informal education
subject: educational justice
subject: childhood research
subject: participation
subject: appropriation theory
subject: 300
subject: 370
subject: Ganztagsschule
subject: Körperliche Aktivität
subject: Informelles Lernen
subject: Kindheitsforschung
subject: Partizipation
subject: Aneignung
subject: Unterricht

description: Gefördert im Rahmen des Projekts DEAL
Future Full-Ocean Deep SSPs Prediction based on Hierarchical Long Short-Term Memory Neural Networks
Creators: name: Lu, Jiajun
name: Zhang, Hao
name: Wu, Pengfei
name: Li, Sijia
name: Huang, Wei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The spatial-temporal distribution of underwater sound velocity affects the propagation mode of underwater acoustic signals. Therefore, rapid estimation and prediction of underwater sound velocity distribution is crucial for providing underwater positioning, navigation and timing (PNT) services. Currently, sound speed profile (SSP) inversion methods have a faster time response rate compared to direct measurement methods, however, most SSP inversion methods focus on constructing spatial dimensional sound velocity fields and are highly dependent on sonar observation data, thus high requirements have been placed on observation data sources. To explore the distribution pattern of sound velocity in the time dimension and achieve future SSP prediction without sonar observation data, we propose a hierarchical long short-term memory (H-LSTM) neural network for SSP prediction. By our SSP prediction method, the sound speed distribution could be estimated without any on-site data measurement process, so that the time efficiency could be greatly improved. Through comparing with other state-of-the-art methods, H-LSTM has better accuracy performance on prediction of monthly average sound velocity distribution, which is less than 1 m/s in different depth layers.
description: arXiv admin note: text overlap with arXiv:2310.09522
Structural Modification and Metamagnetic Anomaly in the Ordered State of CeOs2Al10
Creators: name: Muro, Y.
name: Kajino, J.
name: Umeo, K.
name: Nishimoto, K.
name: Tamura, R.
name: Takabatake, T.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A caged compound CeOs2Al10, crystallizing in the orthorhombic YbFe2Al10-type structure, undergoes a mysterious phase transition at T_0=29 K. We report the results of electron diffraction, magnetization, and magnetoresistance for single crystals. Superlattice reflections characterized by a wave vector q = (0, -2/3, 2/3) observed at 15 K indicate a structural modification in the ordered state. Activation-type behavior of the electrical resistivity along the three principal axes below 50 K suggests gap opening in the conduction band. The magnetic susceptibility χ= M/B is highly anisotropic, χ_a>χ_c>χ_b, all of which sharply decrease on cooling below T_0. Furthermore, a metamagnetic anomaly in the magnetization and a step in the magnetoresistance occur at B=6-8 T only when the magnetic field is applied parallel to the orthorhombic c axis. However, T_0 hardly changes under magnetic fields up to 14 T, irrespective of the field direction. By using these data, we present a B-T phase diagram and discuss several scenarios for the mysterious transition.
description: 6 pages, 7 figures, accepted for publication in Phys. Rev. B
The kinematic characteristics of magnetic O-type stars
Creators: name: Hubrig, S.
name: Kharchenko, N. V.
name: Schoeller, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Although magnetic fields have been discovered in ten massive O-type stars during the last years, the origin of their magnetic fields remains unknown. Among the magnetic O-type stars, two stars, HD36879 and HD57682, were identified as candidate runaway stars in the past, and theta^1 Ori C was reported to move rapidly away from its host cluster. We search for an explanation for the occurrence of magnetic fields in O-type stars by examining the assumption of their runaway status. We use the currently best available astrometric, spectroscopic, and photometric data to calculate the kinematical status of seven magnetic O-type stars with previously unknown space velocities. The results of the calculations of space velocities suggest that five out of the seven magnetic O-type stars can be considered as candidate runaway stars. Only two stars, HD155806 and HD164794, with the lowest space velocities, are likely members of Sco OB4 and NGC6530, respectively. However, the non-thermal radio emitter HD164794 is a binary system with colliding winds, for which the detected magnetic field has probably a different origin in comparison to other magnetic O-type stars.
description: 5 pages, 2 tables, accepted for publication in Astronomische Nachrichten
Minimal clones with weakly abelian representations
Creators: name: Waldhauser, Tamás
Publisher: name: arXiv
Year: 2011
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 08A40, 20N02

description: We show that a minimal clone has a nontrivial weakly abelian representation iff it has a nontrivial abelian representation, and that in this case all representations are weakly abelian.
description: 12 pages
Influence of interlayer exchange coupling on ultrafast laser-induced magnetization reversal in ferromagnetic spin valves
Creators: name: Igarashi, Junta
name: Guen, Yann Le
name: Hohlfeld, Julius
name: Mangin, Stephane
name: Gorchon, Jon
name: Hehn, Michel
name: Malinowski, Gregory
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this study, we explore the influence of interlayer exchange coupling on magnetization reversal triggered by femtosecond laser pulses in ferromagnetic spin valves. Our experiments, focused on femtosecond laser-induced magnetization reversal, methodically vary the thickness of the copper (Cu) spacer layer. We identify a critical Cu thickness threshold at 2.32 nm. Above this threshold, a stable reversed magnetic domain is consistently generated upon exposure to a single laser pulse. Conversely, with a Cu spacer thinner than 2.32 nm, the observed magnetization reversal from parallel (P) to anti-parallel (AP) states occurs only under continuous laser irradiation. Once the laser is stopped, the magnetic configuration relaxes back to its initial P state, influenced by ferromagnetic exchange coupling. This research enhances our understanding of the mechanisms that drive optically induced ultrafast magnetization reversal in ferromagnetic spin valves.
description: After resubmission. Supplemetary Materials added
Development and mechanistic analysis of n-heterocyclic carbene-catalyzed reactions
Creators: name: Berry, Matthew T.
Publisher: name: University of British Columbia
Year: 2018

description: A new class of N-heterocyclic carbene (NHC) organocatalysts were developed based on the 1,2,3-triazolium core architecture. These catalysts were found to facilitate the oxidative esterification of aromatic aldehydes, and a small substrate scope was examined. Using reaction progress monitoring by HPLC, a detailed kinetic analysis was performed. Mechanistic studies showed the reaction to be positive order in both aldehyde and base, and zero order in oxidant and methanol. A key carbene-aldehyde adduct was isolated and characterized by X-ray crystallography, and it was shown to exhibit catalytic activity. The NHC-catalyzed oxidative acylation of electron-poor nucleophiles was also developed, using a 1,2,4-triazolium salt precatalyst. A brief substrate scope was examined, and a kinetic analysis was performed using ¹H NMR reaction monitoring. The mechanistic analysis revealed that the reaction is positive order in aldehyde and base, and zero order in catalyst, oxidant, and sulfonamide nucleophile. In addition, the origin of catalyst deactivation was investigated in the NHC-catalyzed oxidative amidation of aldehydes with amines. Two carbene-amine adducts were discovered, and they were characterized by 1-D and 2-D NMR techniques. A minor carbene-carbene condensation product was also discovered, and characterized by X-ray crystallography. Finally, a new method of synthesizing dihydropyrimidone precursors for isothiourea organocatalysts was developed, and a brief substrate scope was examined. Experimental and computational results showed that the cyclization reaction proceeds through an alpha,beta-unsaturated mixed imide intermediate, rather than by direct conjugate addition to the alpha,beta-unsaturated amide starting material. These computational results also revealed a 7.6 kcal/mol difference between the imide cyclization pathway and the direct acrylamide cyclization pathway. Using HPLC reaction monitoring methods, a preliminary mechanistic analysis was performed. These preliminary results showed that electron-withdrawing substituents on the benzothiazole ring slow down the reaction, while electron-donating substituents do not enhance the reaction rate.
An Updated Lagrangian particle hydrodynamics (ULPH) implementation of heat conduction model in weakly-compressive fluid
Creators: name: Xiong, Junsong
name: Wang, Zhen
name: Lai, Xin
name: Liu, Lisheng
name: Liu, Xiang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Heat conduction is quite common in natural, industrial, and military applications. In this work, the updated Lagrangian particle hydrodynamics (ULPH) theory, is utilized and applied to solve heat conduction problems. Since heat conduction is a second-order problem, the high-order ULPH theory is employed to establish the governing equations of heat conduction in ULPH, which is then validated using various numerical simulations. In this work, numerical simulations have been carried out to solve both static heat conduction problems and dynamic heat convection problems. The results show good accuracy and capability of the ULPH heat conduction model, suggesting promising prospects of the ULPH theory in multiphysics problems. The findings of this paper suggest that ULPH is effective in addressing convective heat transfer problems.
description: 16 pages, 12 figures, original research article. Comp. Part. Mech. (2024)
Weyl theory and explicit solutions of direct and inverse problems for a Dirac system with rectangular matrix potential
Creators: name: Fritzsche, B.
name: Kirstein, B.
name: Roitberg, I. Ya.
name: Sakhnovich, A. L.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Spectral Theory (math.SP)
subject: Systems and Control (eess.SY)
subject: Classical Analysis and ODEs (math.CA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 34B20, 34L40, 15A15, 93B15

description: A non-classical Weyl theory is developed for Dirac systems with rectangular matrix potentials. The notion of the Weyl function is introduced and the corresponding direct problem is treated. Furthermore, explicit solutions of the direct and inverse problems are obtained for the case of rational Weyl matrix functions.
title: Trait means or variance — what determines plant species' local and regional occurrence in fragmented dry grasslands?
Creators: name: Bergholz, Kolja
name: Kober, Klarissa
name: Jeltsch, Florian
name: Schmidt, Kristina
name: Weiss, Lina
Publisher: name: Universität Potsdam
Year: 2021
Subjects: subject: 500 Naturwissenschaften und Mathematik
subject: 570 Biowissenschaften; Biologie

description: One of the few laws in ecology is that communities consist of few common and many rare taxa. Functional traits may help to identify the underlying mechanisms of this community pattern, since they correlate with different niche dimensions. However, comprehensive studies are missing that investigate the effects of species mean traits (niche position) and intraspecific trait variability (ITV, niche width) on species abundance. In this study, we investigated fragmented dry grasslands to reveal trait-occurrence relationships in plants at local and regional scales. We predicted that (a) at the local scale, species occurrence is highest for species with intermediate traits, (b) at the regional scale, habitat specialists have a lower species occurrence than generalists, and thus, traits associated with stress-tolerance have a negative effect on species occurrence, and (c) ITV increases species occurrence irrespective of the scale. We measured three plant functional traits (SLA = specific leaf area, LDMC = leaf dry matter content, plant height) at 21 local dry grassland communities (10 m × 10 m) and analyzed the effect of these traits and their variation on species occurrence. At the local scale, mean LDMC had a positive effect on species occurrence, indicating that stress-tolerant species are the most abundant rather than species with intermediate traits (hypothesis 1). We found limited support for lower specialist occurrence at the regional scale (hypothesis 2). Further, ITV of LDMC and plant height had a positive effect on local occurrence supporting hypothesis 3. In contrast, at the regional scale, plants with a higher ITV of plant height were less frequent. We found no evidence that the consideration of phylogenetic relationships in our analyses influenced our findings. In conclusion, both species mean traits (in particular LDMC) and ITV were differently related to species occurrence with respect to spatial scale. Therefore, our study underlines the strong scale-dependency of trait-abundance relationships.
description: Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1151
Ferrimagnetism of the magnetoelectric compound Cu$_2$OSeO$_3$ probed by $^{77}$Se NMR
Creators: name: Belesi, M.
name: Rousochatzakis, I.
name: Wu, H. C.
name: Berger, H.
name: Shvets, I. V.
name: Mila, F.
name: Ansermet, J. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a thorough $^{77}$Se NMR study of a single crystal of the magnetoelectric compound Cu$_2$OSeO$_3$. The temperature dependence of the local electronic moments extracted from the NMR data is fully consistent with a magnetic phase transition from the high-T paramagnetic phase to a low-T ferrimagnetic state with 3/4 of the Cu$^{2+}$ ions aligned parallel and 1/4 aligned antiparallel to the applied field of 14.09 T. The transition to this 3up-1down magnetic state is not accompanied by any splitting of the NMR lines or any abrupt modification in their broadening, hence there is no observable reduction of the crystalline symmetry from its high-T cubic \textit{P}2$_1$3 space group. These results are in agreement with high resolution x-ray diffraction and magnetization data on powder samples reported previously by Bos {\it et al.} [Phys. Rev. B, {\bf 78}, 094416 (2008)]. We also develop a mean field theory description of the problem based on a microscopic spin Hamiltonian with one antiferromagnetic ($J_\text{afm}\simeq 68$ K) and one ferromagnetic ($J_\text{fm}\simeq -50$ K) nearest-neighbor exchange interaction.
Radiative transfer in stellar atmospheres
Creators: name: Kubat, Jiri
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: This review presents basic equations for the solution of the NLTE radiative transfer problem for trace elements and methods for its solution are summarized. The importance of frequency coupling in radiative transfer in stellar atmospheres is emphasized.
description: presented at the workshop held in Nice, France, 30.7.-4.8.2007, to appear in Non-LTE Line Formation for Trace Elements in Stellar Atmospheres, R. Monier et al. eds., EAS Publ. Ser
Gemini GMOS spectroscopy of HeII nebulae in M33
Creators: name: Kehrig, C.
name: Oey, M. S.
name: Crowther, P. A.
name: Fogel, J.
name: Pellegrini, E.
name: Schnurr, O.
name: Schaerer, D.
name: Massey, P.
name: Roth, K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We have carried out a narrow-band survey of the Local Group galaxy, M33, in the HeII4686 emission line, to identify HeII nebulae in this galaxy. With spectroscopic follow-up observations, we confirm three of seven candidate objects, including identification of two new HeII nebulae, BCLMP651, HBW673. We also obtain spectra of associated ionizing stars for all the HII regions, identifying two new WN stars. We demonstrate that the ionizing source for the known HeII nebula, MA 1, is consistent with being the early-type WN star MC8 (M33-WR14), by carrying out a combined stellar and nebular analysis of MC8 and MA1. We were unable to identify the helium ionizing sources for HBW 673 and BCLMP 651, which do not appear to be Wolf-Rayet stars. According to the [OIII]5007/Hbeta vs [NII]6584/Halpha diagnostic diagram, excitation mechanisms apart from hot stellar continuum are needed to account for the nebular emission in HBW 673, which appears to have no stellar source at all.
description: Accepted for publication in Astronomy and Astrophysics. 22 pages, 10 figures
Scalable Gaussian Process Computations Using Hierarchical Matrices
Creators: name: Geoga, Christopher J.
name: Anitescu, Mihai
name: Stein, Michael L.
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Neuroscience
subject: Biotechnology
subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Marine Biology
subject: Cancer
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: We present a kernel-independent method that applies hierarchical matrices to the problem of maximum likelihood estimation for Gaussian processes. The proposed approximation provides natural and scalable stochastic estimators for its gradient and Hessian, as well as the expected Fisher information matrix, that are computable in quasilinear O(n log 2n) complexity for a large range of models. To accomplish this, we (i) choose a specific hierarchical approximation for covariance matrices that enables the computation of their exact derivatives and (ii) use a stabilized form of the Hutchinson stochastic trace estimator. Since both the observed and expected information matrices can be computed in quasilinear complexity, covariance matrices for maximum likelihood estimators (MLEs) can also be estimated efficiently. In this study, we demonstrate the scalability of the method, show how details of its implementation effect numerical accuracy and computational effort, and validate that the resulting MLEs and confidence intervals based on the inverse Fisher information matrix faithfully approach those obtained by the exact likelihood. Supplementary materials for this article are available online.
Supporting traversable wormholes: the case for noncommutative geometry
Creators: name: Kuhfittig, Peter K. F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: While wormholes may be just as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, a wormhole can only be held open by violating the null energy condition, calling for the existence of "exotic matter." An equally serious problem is the enormous radial tension at the throat of a typical Morris-Thorne wormhole unless the wormhole has an extremely large throat size. It has been proposed that noncommutative geometry, an offshoot of string theory, may be the proper tool for addressing these issues. The purpose of this paper is two-fold: (1) to refine previous arguments to make a stronger and more detailed case for this proposal and (2) to obtain a complete wormhole solution from the given conditions.
description: 9 pages, no figures. arXiv admin note: substantial text overlap with arXiv:2312.05266
Nucleon Magnetic Moments and Electric Polarizabilities
Creators: name: Detmold, William
name: Tiburzi, Brian C.
name: Walker-Loud, Andre
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Electromagnetic properties of the nucleon are explored with lattice QCD using a novel technique. Focusing on background electric fields, we show how the electric polarizability can be extracted from nucleon correlation functions. A crucial step concerns addressing contributions from the magnetic moment, which affects the relativistic propagation of nucleons in electric fields. By properly handing these contributions, we can determine both magnetic moments and electric polarizabilities. Lattice results from anisotropic clover lattices are presented. Our method is not limited to the neutron; we show results for the proton as well.
description: 7 pages, 3 figures, talk given at the XXVIII International Symposium on Lattice Field Theory, Villasimius, Italy, June 14-19, 2010
High Temperature Superconductivity: the explanation
Creators: name: Alexandrov, A. S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Soon after the discovery of the first high temperature superconductor by Georg Bednorz and Alex Mueller in 1986 the late Sir Nevill Mott answering his own question "Is there an explanation?" [Nature v 327 (1987) 185] expressed a view that the Bose-Einstein condensation (BEC) of small bipolarons, predicted by us in 1981, could be the one. Several authors then contemplated BEC of real space tightly bound pairs, but with a purely electronic mechanism of pairing rather than with the electron-phonon interaction (EPI). However, a number of other researchers criticized the bipolaron (or any real-space pairing) scenario as incompatible with some angle-resolved photoemission spectra (ARPES), with experimentally determined effective masses of carriers and unconventional symmetry of the superconducting order parameter in cuprates. Since then the controversial issue of whether the electron-phonon interaction (EPI) is crucial for high-temperature superconductivity or weak and inessential has been one of the most challenging problems of contemporary condensed matter physics. Here I outline some developments in the bipolaron theory suggesting that the true origin of high-temperature superconductivity is found in a proper combination of strong electron-electron correlations with a significant finite-range (Froehlich) EPI, and that the theory is fully compatible with the key experiments.
description: 8 pages, 2 figures, invited comment to Physica Scripta
Statistical equilibrium equations for trace elements in stellar atmospheres
Creators: name: Kubat, Jiri
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The conditions of thermodynamic equilibrium, local thermodynamic equilibrium, and statistical equilibrium are discussed in detail. The equations of statistical equilibrium and the supplementary equations are shown together with the expressions for radiative and collisional rates with the emphasize on the solution for trace elements.
description: presented at the workshop held in Nice, France, 30.7.-4.8.2007, to appear in Non-LTE Line Formation for Trace Elements in Stellar Atmospheres, R. Monier et al. eds., EAS Publ.Ser
32109: Just Beyond Oxford
Creators: name: Project, Lockdown2020 and Beyond
Publisher: name: University of Oxford
Year: 2023
Subjects: classificationCode: 479999
subject: Other language, communication and culture not elsewhere classified

description: My daily walks avoiding people as much as possible have led me to find beautiful places beyond the usual square mile I've known for the last 4 years. In those long walks I felt like I was seeing more of my world in lockdown than before.
Managing Library Software Development: A Case Study in Developing an Inventory Management System for Off-Site Storage Using an Outside Contractor
Creators: name: Bales, Aaron
name: VanNevel, Miranda R.
name: Fox, Robert
Publisher: name: University of Notre Dame
Year: 2023

description: Hesburgh Libraries of Notre Dame established an off-site storage facility in 2015, with only one year to transfer 450,000 items. This necessitated the implementation of an inventory management system (IMS) to track the location of and efficiently retrieve individual items. After conducting an environmental scan of other institutions, the library decided to develop an open source IMS and to contract a developer for the purposes of implementing a working prototype. Working with a contractor required a well-planned development process and a close working relationship. This article describes the project management challenges, development workflow, and lessons learned.
Pacer cell response to periodic Zeitgebers
Creators: name: Beersma, Domien G. M.
name: Broer, Henk W.
name: Efstathiou, Konstantinos
name: Gargar, Kim A.
name: Hoveijn, Igor
Publisher: name: arXiv
Year: 2010
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Almost all organisms show some kind of time periodicity in their behavior. Especially in mammals the neurons of the suprachiasmatic nucleus form a biological clock regulating the activity-inactivity cycle of the animal. This clock is stimulated by the natural 24-hour light-dark cycle. In our model of this system we consider each neuron as a so called phase oscillator, coupled to other neurons for which the light-dark cycle is a Zeitgeber. To simplify the model we first take an externally stimulated single phase oscillator. The first part of the phase interval is called the active state and the remaining part is the inactive state. Without external stimulus the oscillator oscillates with its intrinsic period. An external stimulus, be it from activity of neighboring cells or the periodic daylight cycle, acts twofold, it may delay the change form active to inactive and it may advance the return to the active state. The amount of delay and advance depends on the strength of the stimulus. We use a circle map as a mathematical model for this system. This map depends on several parameters, among which the intrinsic period and phase delay and advance. In parameter space we find Arnol'd tongues where the system is in resonance with the Zeitgeber. Thus already in this simplified system we find entrainment and synchronization. Also some other phenomena from biological experiments and observations can be related to the dynamical behavior of the circle map.
On the spin period distribution of millisecond pulsars
Creators: name: Liu, Xiao-Jin
name: You, Zhi-Qiang
name: Chen, Zu-Cheng
name: Du, Shen-Shi
name: Li, Ang
name: Zhu, Xing-Jiang
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Spin period distribution provides important clues to understand the formation of millisecond pulsars (MSPs). To uncover the intrinsic period distribution, we analyze three samples of radio MSPs in the Galactic field and in globular clusters. The selection bias due to pulse broadening has been corrected but turns out to be negligible. We find that all the samples can be well described by a Weibull distribution of spin frequencies. Considering MSPs in the Galactic field or in globular clusters, and in isolation or in binary systems, we find no significant difference in the spin distribution among these subpopulations. Based on the current known population of MSPs, we find that sub-millisecond pulsars are unlikely to be discovered by the Square Kilometer Array, although up to $\sim10$ discoveries of pulsars that spin faster than the current record holder of $P=1.4$~ms are expected.
description: 14 pages, 7 figures. Accepted by the ApJ for publication
Gaussian approximation and single-spin measurement in OSCAR MRFM with spin noise
Creators: name: Raghunathan, Shesha
name: Brun, Todd A.
name: Goan, Hsi-Sheng
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A promising technique for measuring single electron spins is magnetic resonance force microscopy (MRFM), in which a microcantilever with a permanent magnetic tip is resonantly driven by a single oscillating spin. If the quality factor of the cantilever is high enough, this signal will be amplified over time to the point that it can be detected by optical or other techniques. An important requirement, however, is that this measurement process occur on a time scale short compared to any noise which disturbs the orientation of the measured spin. We describe a model of spin noise for the MRFM system, and show how this noise is transformed to become time-dependent in going to the usual rotating frame. We simplify the description of the cantilever-spin system by approximating the cantilever wavefunction as a Gaussian wavepacket, and show that the resulting approximation closely matches the full quantum behavior. We then examine the problem of detecting the signal for a cantilever with thermal noise and spin with spin noise, deriving a condition for this to be a useful measurement.
description: 12 pages, 8 figures in EPS format, RevTeX 4.1
Removal of calcifications from distal canals of mandibular molars with the gentlewave™ system
Creators: name: Szabo, Deb
Publisher: name: University of British Columbia
Year: 2018

description: Objective: Radiographic examination of teeth often reveals the presence of calcified structures in pulp chambers. Many studies have also reported the presence of calcifications throughout the root canal system. These can complicate root canal therapy by obliterating the pulp chamber or blocking root canals. Many studies have proposed techniques to remove calcifications using instrumentation. GentleWave is a novel system for non-instrumentational cleaning of root canals, however, its ability to remove calcifications has not been established. The aim of our study was to determine the efficiency of the GentleWave system in removing calcifications from the root canal system. Methods: Mandibular molars were accessed, and all canals identified. Patency of the distal canals was ensured with a size 10 K-File and the pulp chambers were irrigated with NaOCl. Micro-CT images were obtained to evaluate the initial volume of calcification in the distal canals. Teeth were then treated with the GentleWave system as recommended by the manufacturer and a second set of micro-CT images were obtained to assess for changes in the calcification volume. The Mann-Whitney test was used to compare calcification volumes before and after GentleWave treatment. The significance level was set at P ≤ .05. Results: All distal canals showed calcifications prior to GentleWave treatment. In teeth treated with the GentleWave system, distal canals showed statistically significant reduction in calcification volume when compared to the initial volume of calcification. Mean reduction in volume was 87.6%, with overall values ranging from 60-100%. Root canal volume prior to and after GentleWave treatment did not show any significant change. Conclusions: The GentleWave system showed significant reduction in root canal calcification after treatment. Almost half (42%) of the distal canals showed complete elimination of calcification after GentleWave treatment. Acknowledgements: Supported by the Canadian Academy of Endodontics. Sonendo provided the GentleWave unit for the cleaning of the teeth.
Flavor structure of E6 GUT models
Creators: name: Kawase, Hidetoshi
name: Maekawa, Nobuhiro
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It has been pointed out that in E6 grand unified theory with SU(2) family symmetry, the spontaneous CP violation can solve the supersymmetric CP problem. The scenario predicts V_{ub} \sim O(λ^4) rather than O(λ^3) which is naively expected value, because of a cancellation at the leading order. Since the experimental value of V_{ub} is O(λ^4), it must be important to consider the reason and the conditions for the cancellation. In this paper, we give a simple reason for the cancellation and show that in some E6 models such a cancellation requires that the vacuum expectation value (VEV) of the adjoint Higgs does not break U(1)_{B-L}. Note that this direction of the VEV plays an important role in solving the doublet-triplet splitting problem by Dimopoulos-Wilczek mechanism. In this E6 models, the experiments may measure the direction of the adjoint Higgs VEV by measuring the size of V_{ub} \sim O(λ^4).
description: 16 pages
Characterization and testing of ferrous granules as an abrasive for water jet cutting
Creators: name: Lemus Fonseca, Sebastian Camilo
Publisher: name: University of British Columbia
Year: 2018

description: In this research, the cutting performance of ferrous granules (FG), a by-product from a lead/zinc smelting operation, was evaluated as an abrasive for water jet cutting. The FG were characterized using scanning electron microscopy, X-EDS analysis, XRD analysis, optical microscopy and mechanical sieving. Then, the FG were crushed through different methods to obtain abrasive particles suitable for the abrasive water jet (AWJ) cutter, and the efficiency of each crushing method was evaluated based on: 1) throughput, and 2) variability of final particle size. Additionally, refining techniques were tested on the crushed FG in order to improve the mass flow rate of the FG-based abrasive entering the waterjet cutter. Finally, cutting tests were performed following a 2³ full factorial experiment selecting pressure, standoff distance and traverse speed as the AWJ process parameters of interest. The effect of these parameters on the cutting performance was evaluated by measuring the ratio of completeness, top and bottom kerf width, taper of cut and angle of striations. The effect of the process parameters on the quality indicators of the cutting process were estimated through statistical analysis and the most influential parameters were identified for each quality indicator. The results showed that the FG-based abrasive was able to successfully cut through an AISI 1020 steel plate up to 1 inch in thickness, with a ratio of completeness comparable to the ratio achieved using regular garnet abrasive with water jet tooling in advanced wear conditions. However, the cuts performed with FG-based abrasive presented surface finish and geometric quality that were below average compared to the cuts performed with garnet abrasive, with extensive surface defects on the cut surfaces. Furthermore, these cuts presented a distinctive cutting mechanism in the bottom section of the cut, which may be different from typical cutting mechanisms described in the literature. It is suggested that these effects are related to the cutting jet energy profile and coherency, which in turn have an impact on the studied quality indicators.
One-step implementation of nonadiabatic geometric fSim gate in superconducting circuits
Creators: name: Yun, M. -R.
name: Shan, Zheng
name: Sun, Li-Li
name: Yan, L. -L.
name: Su, Yu Jia S. -L.
name: Chen, G.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Due to its significant application in reducing algorithm depth, fSim gates have attracted a lot of attention. However, during the implementation of quantum gates, fluctuations in control parameters and decoherence caused by the environment may lead to a decrease in the fidelity of the gate. Implementing the fSim gate that is robust to these factors in one step remains an unresolved issue. In this manuscript, we propose a one-step implementation of the nonadiabatic geometric fSim gate composed of a nonadiabatic holonomic controlled phase (CP) gate and a nonadiabatic noncyclic geometric iSWAP gate with parallel paths in a tunable superconducting circuit. Compared to the composite nonadiabatic geometric fSim gate composed of a nonadiabatic holonomic CP gate and a nonadiabatic geometric iSWAP gate, our scheme only takes half the time and demonstrates robustness to parameter fluctuations, as well as to environmental impacts. Moreover, the scheme does not require complex controls, making it very easy to implement in experiments, and can be achieved in various circuit structures. Our scheme may provide a promising path toward quantum computation and simulation.
The importance of using the averaged mutual information when quantifying quantum objectivity
Creators: name: Chisholm, Diana A.
name: Innocenti, Luca
name: Palma, G. Massimo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the context of quantum objectivity, a standard way to quantify the classicality of a state is via the mutual information between a system and different fractions of its environment. Many of the tools developed in the relevant literature to quantify quantum objectivity via quantum mutual information rely on the assumption that information about the system leaks symmetrically into its environment. In this work, we highlight the importance of taking this assumption into account, and in particular, analyse how taking non-averaged quantum mutual information as a quantifier of quantum objectivity can be severely misleading whenever information about the system is encoded into the environment in a non-homogeneous way. On the other hand, the averaged mutual information always provides results with a clear operative interpretation.
description: 7 pages, 4 figures, Comments welcome
Giant Stark effect in the emission of single semiconductor quantum dots
Creators: name: Bennett, Anthony. J.
name: Patel, Raj. B.
name: Skiba-Szymanska, Joanna
name: Nicoll, Christine A.
name: Farrer, Ian
name: Ritchie, David A.
name: Shields, Andrew J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the quantum-confined Stark effect in single InAs/GaAs quantum dots embedded within a AlGaAs/GaAs/AlGaAs quantum well. By significantly increasing the barrier height we can observe emission from a dot at electric fields of -500 kV/cm, leading to Stark shifts of up to 25 meV. Our results suggest this technique may enable future applications that require self-assembled dots with transitions at the same energy.
title: Νιτροποίηση σε εδάφη θερμοκηπίων
title: Nitrification in greenhouse soils
Creators: name: Σπυροπουλος Ιωαννης
Publisher: name: Technical University of Crete
Year: 2021

description: Η παρούσα διπλωματική εργασία έχει ως θέμα την “Νιτροποίηση σε εδάφη θερμοκηπίων” και αποσκοπεί στην αναλυτική παρουσίαση των αντιδράσεων που σχετίζονται με τον βιογεωχημικό κύκλο του αζώτου, εστιάζοντας στην συνεισφορά που έχουν τα Αρχαία σε εδάφη θερμοκηπίου  .
    Αρχικά, γίνεται μια βιβλιογραφική ανασκόπηση σε ότι αφορά τον μετασχηματισμό  του αζώτου με έμφαση στην νιτροποίηση την συνεισφορά των Αρχαίων καθώς και των βακτηρίων που συμμετέχουν στην νιτροποίηση και τις αγρονομικές τεχνικές που παρεμποδίζουν την δράση των νιτροποιητικών βακτηρίων. Κατόπιν, ακολουθεί το πειραματικό μέρος της εργασίας με μετρήσεις νιτρικών και αμμωνιακών σε εδάφη θερμοκηπίου τα οποία διαχωρίζονται ανάλογα με την  μεταχείριση τους η μη με παρεμποδιστή καθώς και την επώαση τους σε διαφορετικές θερμοκρασίες και τα αποτελέσματα  μέσω της ανάλυσης των διαγραμμάτων μέσων όρων των συγκεντρώσεων.
description: This diploma thesis is entitled "Nitration in greenhouse soils" and aims to present in detail the reactions related to the biogeochemical cycle of nitrogen in these soils, focusing on the contribution of the Archaea to greenhouse soils.
    First, a literature review is made regarding the transformation of nitrogen with emphasis on nitrification, the contribution of the Archaea as well as the bacteria involved in nitrification and the agronomic techniques that inhibit the action of nitrifying bacteria. Then follows the experimental part of the work with measurements of nitrate and ammonium in greenhouse soils which are discriminated according to their treatment or not with the  inhibitor as well as their incubation at different temperatures and the results through the analysis of the diagrams of average concentrations.
Physical Yukawa Couplings in Heterotic String Compactifications
Creators: name: Butbaia, Giorgi
name: Peña, Damián Mayorga
name: Tan, Justin
name: Berglund, Per
name: Hübsch, Tristan
name: Jejjala, Vishnu
name: Mishra, Challenger
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: One of the challenges of heterotic compactification on a Calabi-Yau threefold is to determine the physical $(\mathbf{27})^3$ Yukawa couplings of the resulting four-dimensional $\mathcal{N}=1$ theory. In general, the calculation necessitates knowledge of the Ricci-flat metric. However, in the standard embedding, which references the tangent bundle, we can compute normalized Yukawa couplings from the Weil-Petersson metric on the moduli space of complex structure deformations of the Calabi-Yau manifold. In various examples (the Fermat quintic, the intersection of two cubics in $\mathbb{P}^5$, and the Tian-Yau manifold), we calculate the normalized Yukawa couplings for $(2,1)$-forms using the Weil-Petersson metric obtained from the Kodaira-Spencer map. In cases where $h^{1,1}=1$, this is compared to a complementary calculation based on performing period integrals. A third expression for the normalized Yukawa couplings is obtained from a machine learned approximate Ricci-flat metric making use of explicit harmonic representatives. The excellent agreement between the different approaches opens the door to precision string phenomenology.
description: 33 pages, 11 figures, 2 tables, 3 lemmas, 1 theorem. v2: Minor edits
Theoretical Limits on Agegraphic Quintessence from Weak Gravity Conjecture
Creators: name: Liu, Xiang-Lai
name: Zhang, Jingfei
name: Zhang, Xin
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we investigate the possible theoretical constraint on the parameter $n$ of the agegraphic quintessence model by considering the requirement of the weak gravity conjecture that the variation of the quintessence scalar field $ϕ$ should be less than the Planck mass $M_{\rm{p}}$. We obtain the theoretical upper bound $n\lesssim 2.5$ that is inconsistent with the current observational constraint result $2.637
description: 14 pages, 3 figures
Characteristics of a Junctionless Nanowire Transistor
Creators: name: Angelov, George
Publisher: name: Zenodo
Year: 2021
Subjects: Junctionless Nanowire Transistor

description: Channel length influence on the nanowire parameters and characteristics at different gate voltages for applications in junctionless transistors (JLTs) are analyzed. The density-gradient effective mass tensor of the charge carriers is studied. The results obtained are used to indicate a compromise between performance and minimum dimensions for JLT sensor applications. We also demonstrated technology modeling of the devices in two commercial simulators: COMSOL and Sentaurus. Both produced comparable results at comparable device parameters.