cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Host Galaxy Line Diagnostics for the Candidate Tidal Disruption Events XMMSL1 J111527.3+180638 and PTF09axc
Creators: name: Inkenhaag, Anne
name: Jonker, Peter G.
name: Cannizzaro, Giacomo
name: Sánchez, Daniel Mata
name: Saxton, Richard D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present results of our analysis of spectra of the host galaxies of the candidate Tidal Disruption Events (TDEs) XMMSL1 J111527.3+180638 and PTF09axc to determine the nature of these transients. We subtract the starlight component from the host galaxy spectra to determine the origin of the nuclear emission lines. Using a Baldwin-Phillips-Terlevich (BPT) diagram we conclude that the host galaxy of XMMSL1 J111527.3+180638 is classified as a Seyfert galaxy, suggesting this transient is likely to be caused by (extreme) variability in the active galactic nucleus. We find that the host of PTF09axc falls in the 'star-forming' region of the BPT-diagram, implying that the transient is a strong TDE candidate. For both galaxies we find a WISE-colour difference of $W1-W2<0.8$, which means there is no indication of a dusty torus and therefore an active galactic nucleus, seemingly contradicting our BPT finding for the host of XMMSL1 J111527.3+180638. We discuss possible reasons for the discrepant results obtained through the two methods.
description: 7 pages, 6 figures, 1 table, 1 appendix (2 additional figures, 1 additional table). Accepted for publication in MNRAS
Investigation of electric quadrupole strength in ¹³N using the ¹²C(p,Ύ₀)¹³N reaction
Creators: name: Helmer, Richard Lloyd
Publisher: name: University of British Columbia
Year: 2010

description: The E2 cross section for the ¹²C(p,Ύ₀)¹³N reaction has been measured from 10 MeV to 17 MeV in the laboratory system by bombarding an enriched carbon-12 target with beams of polarized protons. A 10 in. φ x 10 in, Nal(Tl) detector with a plastic anti-coincidence shield was used to detect the gamma rays. The total E2 capture cross sections were of the order of 0.2 ybarns and no resonance effects were observed. The amount of the E2 energy-weighted sum rule depleted in this energy range is (10.3 ± 4.0)%. Calculations based on a direct semi-direct capture model provide a good description of the experimental results by including only direct E2 capture and direct plus collective E1 capture.
Roma, tra storia ed archeologia: religione, istituzioni, territorio nell'epoca delle origini
Creators: name: Cairo, Giambattista <1974>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: L-ANT/03 Storia romana

description: My research tells about the origins of Rome. I think that Rome became a civil community under king Tullus Hostilius who transformed a federation of villages in a city. Perhaps he retook a project of his grandfather, Hostus Hostilius. I think also that the tradition on the early Rome was elaborated by Servius Tullius’ court and his motivations must be researched in the relations between this king and Tarquin’s dynasty. Finally I formulated some particular theories on the comitia centuriata and their evolution and on the international politic of Servius Tullius.
The Effectiveness of the Clean Development Mechanism – A law and economics analysis
Creators: name: Vasa, Alexander <1980>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2012
Subjects: SECS-P/01 Economia politica

description: Climate change has been acknowledged as a threat to humanity. Most scholars agree that to avert dangerous climate change and to transform economies into low-carbon
societies, deep global emission reductions are required by the year 2050. Under the framework of the Kyoto Protocol, the Clean Development Mechanism (CDM) is the only market-based instrument that encourages industrialised countries to pursue emission reductions in developing countries. The CDM aims to pay the incremental finance necessary to operationalize emission reduction projects which are otherwise not financially viable. 

According to the objectives of the Kyoto Protocol, the CDM should finance projects that are additional to those which would have happened anyway, contribute to sustainable
development in the countries hosting the projects, and be cost-effective. To enable the identification of such projects, an institutional framework has been established by the Kyoto Protocol which lays out responsibilities for public and private actors. This thesis examines whether the CDM has achieved these objectives in practice and can thus be considered an effective tool to reduce emissions.
To complete this investigation, the book applies economic theory and analyses the CDM from two perspectives. The first perspective is the supply-dimension which answers the
question of how, in practice, the CDM system identified additional, cost-effective, sustainable projects and, generated emission reductions. The main contribution of this book is the second perspective, the compliance-dimension, which answers the question of whether industrialised countries effectively used the CDM for compliance with their Kyoto targets.

The application of the CDM in the European Union Emissions Trading Scheme (EU ETS) is used as a case-study. Where the analysis identifies inefficiencies within the supply or the
compliance dimension, potential improvements of the legal framework are proposed and discussed.
Electrospun nanofibrous interleaves in composite laminate materials
Creators: name: Palazzetti, Roberto <1984>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: ING-IND/14 Progettazione meccanica e costruzione di macchine

description: The present work aims for investigate the influence of electrospun Nylon 6,6 nanofibrous mat on the behavior of composite laminates. The main idea is that nanofibrous interleaved into particular ply-to-ply interfaces of a laminate can lead to significant improvements of mechanical properties and delamination/damage resistance. Experimental campaigns were performed to investigate how nanofibers affect both the static and dynamic behavior of the laminate in which they are interleaved.
Fracture mechanics tests were initially performed on virgin and 8 different configuration of nanomodified specimens. The purposes of this first step of the work are to understand which geometrical parameters of the nanointerleave influence the behavior of the laminate and, to find the optimal architecture of the nanofibrous mat in order to obtain the best reinforcement. In particular, 3 morphological parameters are investigated: nanofibers diameter, nanofibers orientation and thickness of the reinforce. Two different values for each parameter have been used, and it leads to 8 different configurations of nanoreinforce. Acoustic Emission technique is also used to monitor the tests.
Once the optimum configuration has been found, attention is focused on the mechanism of reinforce played by the nanofibers during static and dynamic tests. Low velocity impacts and free decay tests are performed to attest the effect of nanointerlayers and the reinforce mechanism during the dynamic loads. Bump tests are performed before and after the impact on virgin and two different nanomodified laminates configurations. The authors focused their attention on: vibrational behavior, low velocity impact response and post-impact vibration behavior of the nano-interleaved laminates with respect to the response of non-nanomodified ones.
Experiments attest that nanofibers significantly strength the delamination resistance of the laminates and increase some mechanical properties. It is demonstrated that the nanofibers are capable to continue to carry on the loads even when the matrix around them is broken.
Stamdataregister for vindmøller
Creators: Energistyrelsen
Publisher: name: Rigsarkivet
Year: 2022

description: Energistyrelsen har sammen med den systemansvarlige virksomhed, Energinet.dk og netvirksomhederne opbygget et landsdækkende register for vindkraftanlæg.
Registret anvendes til administration, statistik og kontrol af prisafregninger, herunder fuldlasttimeopgørelser samt i forbindelse med EU direktivet om fremme af elektricitet produceret fra vedvarende energikilder.
Lymphogranuloma venereum: a new face for an old disease.
Our experience in the Bologna area.
Creators: name: Bellavista, Sara <1979>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: MED/35 Malattie cutanee e veneree

description: Lymphogranuloma venereum (LGV) is a sexual transmitted infection due to Clamydia trachomatis biovar L, endemic in part of Africa, Asia, South America and the Caribbean, but rare in industrialized countries up to 10 years ago. In 2003, a cluster of cases of LGV among men who have sex with men (MSM) was reported in Rotterdam. Since then, several reports of LGV have been reported in the largest cities in Europe, the United States and Australia. They have usually occurred with an anorectal syndrome.
The purpose of this study is to summarize the expertise provided by the international literature about the new LGV outbreaks and to offer the first data collected on the presence of this disease in the Bologna area. In fact, we examine  5 cases of LGV proctitis diagnosed and treated at the Clinic of Sexually Transmitted Disease (STD) of the Dermatology Section at Sant’Orsola-Malpighi Hospital, Bologna. Particular attention will be paid to the laboratory method that allows identification and typing of the microorganism C. trachomatis serovar L1, L2, L3, leading to an etiologic diagnosis of certainty. The diagnosed cases of LGV will be described and compared with the international literature, trying to assess the risk factors, the most effective diagnostic and therapeutic procedure and the best approach to the patient.
A mixture model for determining SARS-Cov-2 variant composition in pooled samples
Creators: name: Valieris, Renan
name: Drummond, Rodrigo
name: Defelicibus, Alexandre
name: Dias-Neto, Emannuel
name: Rosales, Rafael A.
name: da Silva, Israel Tojal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Genomics (q-bio.GN)
subject: Applications (stat.AP)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences

description: Despite of the fast development of highly effective vaccines to control the current COVID$-$19 pandemic, the unequal distribution and availability of these vaccines worldwide and the number of people infected in the world lead to the continuous emergence of SARS-CoV-2 (Severe Acute Respiratory Syndrome coronavirus 2) variants of concern. It is likely that real-time genomic surveillance will be continuously needed as an unceasing monitoring tool, necessary to follow the spillover of the disease spread and the evolution of the virus. In this context, new genomic variants of SARS-CoV-2 that may emerge as a response to selective pressure, including variants refractory to current vaccines, makes genomic surveillance programs tools of utmost importance. Here propose a statistical model for the estimation of the relative frequencies of SARS-CoV-2 variants in pooled samples. This model is built by considering a previously defined selection of genomic polymorphisms that characterize SARS-CoV-2 variants. The methods described here support both raw sequencing reads for polymorphisms-based markers calling and predefined markers in the VCF format. Results obtained by using simulated data show that our method is quite effective in recovering the correct variant proportions. Further, results obtained by considering longitudinal data from wastewater samples of two locations in Switzerland agree well with those describing the epidemiological evolution of COVID-19 variants in clinical samples of these locations. Our results show that the described method can be a valuable tool for tracking the proportions of SARS-CoV-2 variants.
description: 19 pages, 8 figures
Stiffness modeling for near field acoustic levitation bearings
Creators: name: Wang, Yaoke
name: Guo, Ping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The dynamic characteristics of near-field levitation bearings have been investigated in this study. Through theoretical analysis, two different types of system stiffness are defined and derived analytically. The dynamic stiffness relates the excitation amplitude to the dynamic force amplitude, while the effective stiffness governs the time-averaged force-displacement relationship. The results indicate two non-linear and asymmetric spring constants that can effectively predict levitation force and height. The models are verified with a carefully designed experimental setup to eliminate the structural resonance effect. Besides, some unique dynamic behaviors are investigated and predicted based on the proposed stiffness model.
Python Crypto Misuses in the Wild
Creators: name: Wickert, Anna-Katharina
name: Baumgärtner, Lars
name: Breitfelder, Florian
name: Mezini, Mira
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences
subject: D.2.2

description: Background: Previous studies have shown that up to 99.59 % of the Java apps using crypto APIs misuse the API at least once. However, these studies have been conducted on Java and C, while empirical studies for other languages are missing. For example, a controlled user study with crypto tasks in Python has shown that 68.5 % of the professional developers write a secure solution for a crypto task. Aims: To understand if this observation holds for real-world code, we conducted a study of crypto misuses in Python. Method: We developed a static analysis tool that covers common misuses of 5 different Python crypto APIs. With this analysis, we analyzed 895 popular Python projects from GitHub and 51 MicroPython projects for embedded devices. Further, we compared our results with the findings of previous studies. Results: Our analysis reveals that 52.26 % of the Python projects have at least one misuse. Further, some Python crypto libraries API design helps developers from misusing crypto functions, which were much more common in studies conducted with Java and C code. Conclusion: We conclude that we can see a positive impact of the good API design on crypto misuses for Python applications. Further, our analysis of MicroPython projects reveals the importance of hybrid analyses.
description: 6 pages, to be published in the proceedings of the 15th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM) (ESEM 21), October 11-15, 2021, Bari Italy
AstroSat and MAXI view of Cygnus X-1: Signature of an `extreme' soft nature
Creators: name: Kushwaha, Ankur
name: Agrawal, V. K.
name: Nandi, Anuj
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present a detailed spectral and timing analysis of Cygnus X-1 with multi-epoch observations, during $2016$ to $2019$, by SXT and LAXPC on-board AstroSat. We model the spectra in broad energy range of $0.5\!-\!70.0\,\rm{keV}$ to study the evolution of spectral properties while Cygnus X-1 transited from hard state to an extreme soft state via intermediate states in 2017. Simultaneous timing features are also examined by modelling the power density spectra in $3.0\!-\!50.0\,\rm{keV}$ . We find that during high-soft state observations, made by AstroSat on Oct $24,\,2017$ (MJD $58050$), the energy spectrum of the source exhibits an inner disk temperature (kT$\rm_{in}$) of $0.46\!\pm\!0.01\,\rm{keV}$ , a very steep photon index ($Γ$) of $3.15\!\pm\!0.03$ along with a fractional disk flux contribution of $\sim\!45\%$. The power density spectrum in the range of $0.006\!-\!50.0\,\rm{Hz}$ is also very steep with a power-law index of $1.12\!\pm\!0.04$ along with a high RMS value of $\sim\!25\%$. Comparing the spectral softness of high-soft state with those of previously reported, we confirm that {\it AstroSat} observed Cygnus X-1 in the `softest' state. The lowest MAXI spectral hardness ratio of $\sim\!0.229$ corroborates the softest nature of the source. Moreover, we estimate the spin of the black hole by continuum-fitting method, which indicates that Cygnus X-1 is a maximally rotating `hole'. Further, Monte Carlo (MC) simulations are performed to estimate the uncertainty in spin parameter, which is constrained as a$_{\ast}>0.9981$ with $3σ$ confidence interval. Finally, we discuss the implications of our findings.
description: 13 pages, 8 figures
Giant Spin Lifetime Anisotropy and Spin-Valley Locking in Silicene and Germanene from First-Principles Density-Matrix Dynamics
Creators: name: Xu, Junqing
name: Takenaka, Hiroyuki
name: Habib, Adela
name: Sundararaman, Ravishankar
name: Ping, Yuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Through First-Principles real-time Density-Matrix (FPDM) dynamics simulations, we investigate spin relaxation due to electron-phonon and electron-impurity scatterings with spin-orbit coupling in two-dimensional Dirac materials - silicene and germanene, at finite temperatures and under external fields. We discussed the applicability of conventional descriptions of spin relaxation mechanisms by Elliott-Yafet (EY) and D'yakonov-Perel' (DP) compared to our FPDM method, which is determined by a complex interplay of intrinsic spin-orbit coupling, external fields, and electron-phonon coupling strength, beyond crystal symmetry. For example, the electric field dependence of spin relaxation time is close to DP mechanism for silicene at room temperature, but rather similar to EY mechanism for germanene. Due to its stronger spin-orbit coupling strength and buckled structure in sharp contrast to graphene, germanene has a giant spin lifetime anisotropy and spin valley locking effect under nonzero Ez and relatively low temperature. More importantly, germanene has extremely long spin lifetime (~100 ns at 50 K) and ultrahigh carrier mobility, which makes it advantageous for spin-valleytronic applications.
description: 9 pages, 4 figures
Photoluminescence studies of the electron-hole droplet and the impurity band in Si(P)
Creators: name: Rostworowski, Juan Adalberto
Publisher: name: University of British Columbia
Year: 2010

description: The photoluminescence spectrum of phosphorus-doped silicon at 17 _ 3 19-3 dopant concentrations ranging from 1.2 x 10¹⁷ cm⁻³ to 4.0 x 10¹⁹ cm⁻³ is studied as a function of excitation intensity. The spectra are interpreted tn terms of two types of recombination events', one' attributed to the recombination of oppositely charged carriers inside an electron-hole droplet and the other outside due to the recombination -of free holes with electrons in the impurity band. The latter type of event gives rise to a new photoluminescence peak observed for the first time. The line shape of this peak compares very well with a first principle calculation of the impurity band density of states within the Hubbard model. Existing theories for the ground state energy of an electron-hole droplet in n-type heavily doped silicon are reviewed and new numerical results are presented. However, within the present model droplets are not theoretically understood at this time in heavily-doped silicon.
Strong field ionization of atoms and molecules studied by phase-of-the-phase spectroscopy
Creators: name: Skruszewicz, Slawomir
Publisher: name: Universität Rostock
Year: 2015
Subjects: subject: 530 Physics

description: Coherent superposition of 800 nm laser field with its second-harmonic generates laser pulses with asymmetrical electric field distribution. Controlling a time-lag between the w-2w fields with sub-fs precision enables for electron trajectory tagging. Here, we propose two-color phase-of-the-phase spectroscopy (PoP) which applied to atoms provides relative-phase-tagged photoelectron spectra. We show that a relative phase contrast (RPC) and the-phase-of-the-phase (PP) obtained from Fourier transformed electron spectra gain information which are beyond conventional photoelectron spectroscopy.
Stringy Bubbles Solve de Sitter Troubles
Creators: name: Berglund, Per
name: Hübsch, Tristan
name: Minic, Djordje
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Finding four-dimensional de Sitter spacetime solutions in string theory has been a vexing quest ever since the discovery of the accelerating expansion of the universe. Building on a recent analysis of bubble-nucleation in the decay of (false-vacuum) AdS backgrounds where the interfacing bubbles themselves exhibit a de Sitter geometry we show that this resonates strongly with a stringy cosmic brane construction that naturally provides for an exponential mass-hierarchy, and localization of both gravity and matter, in addition to an exponentially suppressed positive cosmological constant. Finally, we argue that these scenarios can be realized in terms of a generalization of a small resolution of a conifold singularity in the context of a (Lorentzian) Calabi-Yau 5-fold, where the isolated (Lorentzian) two complex dimensional Fano variety is a four-dimensional de Sitter spacetime.
description: 22 pages, 3 figures
Two regimes of tidal-stream circularization by supermassive black holes
Creators: name: Rossi, Joseph
name: Servin, Juan
name: Kesden, Michael
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Stars that approach a supermassive black hole (SMBH) too closely can be disrupted by the tidal gravitational field of the SMBH. The resulting debris forms a tidal stream orbiting the SMBH which can collide with itself due to relativistic apsidal precession. These self-collisions dissipate energy, causing the stream to circularize. We perform kinematic simulations of these stream self-collisions to estimate the efficiency of this circularization as a function of SMBH mass $M_\bullet$ and penetration factor $β$, the ratio of the tidal radius to the pericenter distance. We uncover two distinct regimes depending on whether the time $t_c$ at which the most tightly bound debris circularizes is greater or less than the time $t_{\rm fb}$ at which the mass fallback rate peaks. The bolometric light curve of energy dissipated in the stream self-collisions has a single peak at $t > t_{\rm fb}$ in the slow circularization regime ($t_c > t_{\rm fb}$), but two peaks (one at $t < t_{\rm fb}$ and a second at $t_{\rm fb}$) in the fast circularization regime ($t_c < t_{\rm fb}$). Tidal streams will circularize in the slow (fast) regime for apsidal precession angles less (greater) than 0.2 radians which occur for $β\lesssim (\gtrsim) (M_\bullet/10^6M_\odot)^{-2/3}$. The observation of prominent double peaks in bolometric TDE light curves near the transition between these two regimes would strongly support our model of tidal-stream kinematics.
description: 14 pages, 11 figures, submitted to PRD
CIFRA National Survey: Uruguay April 2008
Creators: name: CIFRA, In Bogliaccini, Juan, And Queirolo Rosario Laboratorio De Opinión Pública And Redes Sociales En Uruguay Collection (Social Networks And Public Opinion Lab Collection)
Publisher: name: Roper Center for Public Opinion Research
Year: 2021

description: Alcoholic habits; personal banking choices; voting in primary elections; Uruguayan soldiers involvment with UN in Haiti; healthcare reform; likability of politicians and presidential candidates; previous presidents' tenures; approval of district mayor; approval of President Tabaré Vázquez; implementation of new plant mills in Uruguay; political spectrum position; past voting history; potential future voting choices; recent feelings of depression; sleeping problems; effects of depression on daily life. National Agency for Research and Innovation (ANII) Collection.
Eliminating Climate Impact From Aviation - Potential Pathways That Are Currently Explored in DLR's EXACT Project
Creators: name: Hartmann, Johannes
Publisher: name: Zenodo
Year: 2021
Subjects: aviation
aircraft
design
energy
climate
operation
technology
fuel cell
hydrogen
LH2
CO2
NOX
range
aerolectures2021
aerolectures

description: Green energy is the key for climate neutral air mobility. In order to identify sustainable solutions for a green air transport system, the aviation sector has to go hand in hand with the energy sector. In EXACT, capabilities from four DLR divisions (energy, aviation, space, transport) are contributing to the EXACT project.
description: Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de
Large-amplitude longitudinal oscillations in solar prominences simulated with different resolutions
Creators: name: Liakh, Valeriia
name: Luna, Manuel
name: Khomenko, Elena
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Large-amplitude longitudinal oscillations (LALOs) in solar prominences have been widely studied in the last decades. However, their damping and amplification mechanisms are not well understood. In this study, we investigate the attenuation and amplification of LALOs using high-resolution numerical simulations with progressively increasing spatial resolutions. We performed time-dependent numerical simulations of LALOs using the 2D magnetic configuration that contains a dipped region. After the prominence mass loading in the magnetic dips, we triggered LALOs by perturbing the prominence mass along the magnetic field. We performed the experiments with four values of spatial resolution. In the simulations with the highest resolution, the period shows a good agreement with the pendulum model. The convergence experiment revealed that the damping time saturates at the bottom prominence region with improving the resolution, indicating the existence of a physical reason for the damping of oscillations. At the prominence top, the oscillations are amplified during the first minutes and then are slowly attenuated. The characteristic time suggests more significant amplification in the experiments with the highest spatial resolution. The analysis revealed that the energy exchange between the bottom and top prominence regions is responsible for the attenuation and amplification of LALOs. The high-resolution experiments are crucial for the study of the periods and the damping mechanism of LALOs. The period agrees with the pendulum model only when using high enough spatial resolution. The results suggest that numerical diffusion in simulations with insufficient spatial resolution can hide important physical mechanisms, such as amplification of oscillations.
description: 12 pages, 13 figures, accepted for publication in Astronomy and Astrophysics
CIFRA National Survey: Uruguay August 2015
Creators: name: CIFRA, In Bogliaccini, Juan, And Queirolo Rosario Laboratorio De Opinión Pública And Redes Sociales En Uruguay Collection (Social Networks And Public Opinion Lab Collection)
Publisher: name: Roper Center for Public Opinion Research
Year: 2021

description: Traveling to foreign countries; personal banking choices; internet connection; cellphone usage; main problems in country; confidence in different institutions; information on gas plant in Montevideo; approval of President Tabaré Vázquez; approval of Ministers of different sectors; approval of unions' performances; strikes on teachers' salaries; political spectrum position; economic situation of the country; likability of politicians and presidential candidates; past voting history; public vs. private employment. National Agency for Research and Innovation (ANII) Collection.
Conformal and Uniformizing Maps in Borel Analysis
Creators: name: Costin, Ovidiu
name: Dunne, Gerald V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Other Condensed Matter (cond-mat.other)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Perturbative expansions in physical applications are generically divergent, and their physical content can be studied using Borel analysis. Given just a finite number of terms of such an expansion, this input data can be analyzed in different ways, leading to vastly different precision for the extrapolation of the expansion parameter away from its original asymptotic regime. Here we describe how conformal maps and uniformizing maps can be used, in conjunction with Pad'e approximants, to increase the precision of the information that can be extracted from a finite amount of perturbative input data. We also summarize results from the physical interpretation of Pad'e approximations in terms of electrostatic potential theory.
description: 15 pages, 10 figures
Hydrogen – A Universal Solution for Aviation?
Creators: name: Neuland, Tanja
Publisher: name: Zenodo
Year: 2021
Subjects: aviation
aircraft
design
energy
climate
operation
technology
fuel cell
hydrogen
LH2
CO2
NOX
aerolectures2021
aerolectures

description: How can hydrogen contribute to climate-neutral aviation? What are the potentials of using it as fuel, and what does this mean for the aviation industry in the long term? Tanja Neuland reports about the current state of hydrogen-research at Airbus and how hydrogen potentials can be exploited and optimized in the future.
description: Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de
Minimum entropy production, detailed balance and Wasserstein distance for continuous-time Markov processes
Creators: name: Dechant, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the problem of minimizing the entropy production for a physical process that can be described in terms of a Markov jump dynamics. We show that, without any further constraints, a given time-evolution may be realized at arbitrarily small entropy production, yet at the expense of diverging activity. For a fixed activity, we find that the dynamics that minimizes the entropy production is given in terms of conservative forces. The value of the minimum entropy production is expressed in terms of the graph-distance based Wasserstein distance between the initial and final configuration. This yields a new kind of speed limit relating dissipation, the average number of transitions and the Wasserstein distance. It also allows us to formulate the optimal transport problem on a graph in term of a continuous-time interpolating dynamics, in complete analogy to the continuous space setting. We demonstrate our findings for simple state networks, a time-dependent pump and for spin flips in the Ising model.
description: 23 pages, 6 figures
Energy refurbishment of historic districts. A techno-economic and environmental analysis of a case study
Creators: name: Menn, Claudio
name: Geissler, Achim
Publisher: name: Advanced Building Skins
Year: 2016
Subjects: energy refurbishment
historic district
techno-economic analysis
environmental analysis

description: A techno-economic and environmental analysis of proposed energetic refurbishment measures combined with energy supply variants for a historic district in Switzerland (303 entities; 64’546 m2 energy reference area (AE)) is given. The economic evaluation is based on the Net Present Value (NPV) method and the environmental impact is quantified in “eco-points” (German: “Umweltbelastungspunkte” (UBP)) and equivalent CO2 emissions. Data for the analysis is provided by the Swiss building certification (German: “Gebäudeenergieausweis der Kantone” (GEAK)) and secondary literature. A total of three variants, V I through V III is analysed. The results show how current limit values for heating demand can be met with energetic refurbishment measures (including aerogel-super-insulation materials) which conform to requirements of the regional monument protection. It is found that a local heat distribution system based on a Brine/Water Heat Pump (B/W HP) (V I) can reduce the environmental impact for heating, hot water, ventilation, auxiliary energy (HWVA) from currently 1.8 tons CO2 eq per capita and annum (p.c.a.) (1.5 Million UBP’s p.c.a.) for the fossil fuel based system to 118 kg CO2 eq p.c.a. (325 thousand UBP’s p.c.a.). The environmental impact of a central wood chip plant (Combined heat and power (CHP)) in V II or a district heating based system in V III is slightly higher than in V I. Negative NPV (for a 30 years’ time frame) is found for all three mentioned energy supply systems in combination with energetic refurbishment measures (V I: -147.- CHF/m2 AE, V II: -125.- CHF/m2 AE, V III: -98.- CHF/m2 AE). However, it can be shown that reducing the energetic refurbishment costs by one third leads to a positive NPV for all three variants mentioned. Furthermore, the NPV-results do not differ significantly between the variants and should therefore not be the sole basis for decision-making. A sensitivity analysis shows a great impact of materials’ lifetime on the NPV. Therefore, reliable estimates for e.g. aerogel-super-insulation materials are important data for a NPV evaluation. Furthermore, the environmental impact was calculated for HWVA, only. This system boundary should be extended to domestic electricity consumption, embodied energy in insulation materials and PV in further research. Keywords: aerogel-super-insulation, historic district, energetic refurbishment, energy supply variants, sustainability assessment
Interpreting connexive principles in coherence-based probability logic
Creators: name: Pfeifer, Niki
name: Sanfilippo, Giuseppe
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic (math.LO)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60A05, 03B48

description: We present probabilistic approaches to check the validity of selected connexive principles within the setting of coherence. Connexive logics emerged from the intuition that conditionals of the form "If $\sim A$, then $A$", should not hold, since the conditional's antecedent $\sim A$ contradicts its consequent $A$. Our approach covers this intuition by observing that for an event A the only coherent probability assessment on the conditional event $A|\overline{A}$ is $p(A|\overline{A})=0$. Moreover, connexive logics aim to capture the intuition that conditionals should express some "connection" between the antecedent and the consequent or, in terms of inferences, validity should require some connection between the premise set and the conclusion. This intuition is covered by a number of principles, a selection of which we analyze in our contribution. We present two approaches to connexivity within coherence-based probability logic. Specifically, we analyze connections between antecedents and consequents firstly, in terms of probabilistic constraints on conditional events (in the sense of defaults, or negated defaults) and secondly, in terms of constraints on compounds of conditionals and iterated conditionals. After developing different notions of negations and notions of validity, we analyze the following connexive principles within both approaches: Aristotle's Theses, Aristotle's Second Thesis, Abelard's First Principle and selected versions of Boethius' Theses. We conclude by remarking that coherence-based probability logic offers a rich language to investigate the validity of various connexive principles.
description: The final authenticated publication will be available online at https://www.springer.com/gp/book/9783030867713
Near-field imaging of plasmonic nanopatch antennas with integrated semiconductor quantum dots
Creators: name: Iyer, Vasudevan
name: Phang, Yoong Sheng
name: Butler, Andrew
name: Chen, Jiyang
name: Lerner, Brian
name: Argyropoulos, Christos
name: Hoang, Thang
name: Lawrie, Benjamin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Plasmonic nanopatch antennas that incorporate dielectric gaps hundreds of picometers to several nanometers thick have drawn increasing attention over the past decade because they confine electromagnetic fields to grossly sub-diffraction limited volumes. Substantial control over the optical properties of excitons and color centers confined within these plasmonic cavities has already been demonstrated with far-field optical spectroscopies, but near-field optical spectroscopies are essential to an improved understanding of the plasmon-emitter interaction at the nanoscale. Here, we characterize the intensity and phase-resolved plasmonic response of isolated nanopatch antennas with cathodoluminescence microscopy. Further, we explore the distinction between optical and electron-beam spectroscopies of coupled plasmon-exciton heterostructures to identify constraints and opportunities for future nanoscale characterization and control of hybrid nanophotonic structures. While we observe substantial Purcell enhancement in time-resolved photoluminescence spectroscopies, negligible Purcell enhancement is observed in cathodoluminescence spectroscopies of hybrid nanophotonic structures. The substantial differences in measured Purcell enhancement for electron-beam and laser excitation can be understood as a result of the different selection rules for these complementary experiments. These results provide a fundamentally new understanding of near-field plasmon-exciton interactions in nanopatch antennas that is essential to myriad emerging quantum photonic devices.
Spatial characteristics of nickel-titanium shape memory alloy fabricated by continuous directed energy deposition
Creators: name: Gao, Shiming
name: Weng, Fei
name: Bodunde, Ojo Philip
name: Qin, Mian
name: Liao, Wei-Hsin
name: Guo, Ping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Additive manufacturing has been adopted to process nickel-titanium shape memory alloys due to its advantages of flexibility and minimal defects. The current layer-by-layer method is accompanied by a complex temperature history, which is not beneficial to the final characteristics of shape memory alloys. In this study, a continuous directed energy deposition method has been proposed to improve microstructure uniformity. The spatial characterization of nickel-titanium shape memory alloy fabricated by continuous directed energy deposition is investigated to study the temperature history, phase constituent, microstructure, and mechanical properties. The results indicate that the fabricated specimen has a monotonic temperature history, relatively uniform phase distribution and microstructure morphology, as well as high compressive strength (2982 MPa~3105 MPa) and strain (37.7%~41.1%). The reported method is expected to lay the foundation for spatial control during the printing of functional structures.
Molten pool characteristics of a nickel-titanium shape memory alloy for directed energy deposition
Creators: name: Gao, Shiming
name: Feng, Yuncong
name: Wang, Jianjian
name: Qin, Mian
name: Bodunde, Ojo Philip
name: Liao, Wei-Hsin
name: Guo, Ping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Fabrication of nickel-titanium shape memory alloy through additive manufacturing has attracted increasing interest due to its advantages of flexible manufacturing capability, low-cost customization, and minimal defects. The process parameters in directed energy deposition (DED) have a crucial impact on its molten pool characteristics (geometry, microstructure, etc.), thus influencing the final properties of shape memory effect and pseudoelasticity. In this paper, a three-dimensional numerical model considering heat transfer, phase change, and fluid flow has been developed to simulate the cladding geometry, melt pool depth, and deposition rate. The experimental and simulated results indicated that laser power plays a critical role in determining the melt pool width and deposition rate while scan speed and powder feed rate have less effect on cladding geometry and deposition rate. The fluid velocity has a huge influence on the distribution of elements in the molten pool. The temperature gradient G, solidification rate R, as well as shape factor G/R were calculated to illustrate the underlying mechanisms of grain structure evolution. The grain morphology distribution of cross-section from the experimental samples agreed well with the simulation results. The model reported in this paper is expected to shed light on the optimization of the deposition process and grain structure prediction.
The SVS13-A Class I chemical complexity as revealed by S-bearing species. SOLIS XIII
Creators: name: Codella, C.
name: Bianchi, E.
name: Podio, L.
name: Mercimek, S.
name: Ceccarelli, C.
name: Lopez-Sepulcre, A.
name: Bachiller, R.
name: Caselli, P.
name: Sakai, N.
name: Neri, R.
name: Fontani, F.
name: Favre, C.
name: Balucani, N.
name: Lefloch, B.
name: Viti, S.
name: Yamamoto, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Aims: The goal is to obtain a census of S-bearing species using interferometric images, towards SVS13-A, a Class I object associated with a hot corino rich in interstellar complex organic molecules. Methods: We used data at 3mm and 1.4mm obtained with IRAM-NOEMA in the framework of the Large Program SOLIS. Results: We imaged the spatial distribution of the line emission of 32SO, 34SO, C32}S, C34S, C33S, OCS, H2C32S, H2C34S, and NS. The low excitation (9 K) 32SO line is tracing the fast collimated jet driven by the nearby SVS13-B. Conversely, the rest of the lines are confined in the inner SVS13-A region, where complex organics have been previously imaged. The non-LTE LVG analysis of SO, SO2, and H2CS indicates a hot corino origin (60-120 au). Temperatures between 50 K and 300 K, and volume densities larger than 10^5 cm-3 have been derived. The abundances are in the following ranges: 0.3-6 10^-6 (CS), 7 10^-9} - 1 10^-7 (SO), 1-10 10^-7 (SO2), a few 10^-10 (H2CS and OCS), and 10^{-10} - 10^{-9}(NS). The N(NS)/N(NS^+) ratio is larger than 10, supporting that the NS^+ ion is mainly formed in the extended envelope. Conclusions: The [H2CS]/[H2CO] ratio increases with time (from Class 0 to Class II objects) by more than one order of magnitude. This suggests that [S]/[O] changes along the Sun-like star forming process. The estimate of the [S]/[H] budget in SVS13-A is 2%-17% of the Solar System value (1.8 10^-5), being consistent with what was previously measured towards Class 0 objects (1%-8%). This supports that the enrichment of the sulphuretted species with respect to dark clouds keeps constant from the Class 0 to the Class I stages of low-mass star formation. The present findings stress the importance of investigating the chemistry of star forming regions using large observational surveys as well as sampling regions on a Solar System scale.
description: A&A, in press
Neutrino Oscillations through the Earth's Core
Creators: name: Denton, Peter B.
name: Pestes, Rebekah
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Neutrinos have two properties that make them fairly unique from other known particles: extremely low cross sections and flavor changing oscillations. With a good knowledge of the oscillation parameters soon in hand, it will become possible to detect low-energy atmospheric neutrinos sensitive to the forward elastic scattering off electrons in the Earth's core providing a measurement of the core properties and the matter effect itself. As the dynamics of the Earth's core are complicated and in a difficult to probe environment, additional information from upcoming neutrino experiments will provide feedback into our knowledge of geophysics as well as useful information about exoplanet formation and various new physics scenarios including dark matter. In addition, we can probe the existence of the matter effect in the Earth and constrain the non-standard neutrino interaction parameter $ε_{ee}^\oplus$. We show how DUNE's sensitivity to low-energy atmospheric neutrino oscillations can provide a novel constraint on the density and radius of the Earth's core at the 9\% level and the Earth's matter effect at the 5\% level. Finally, we illuminate the physics behind low-energy atmospheric neutrino resonances in the Earth.
description: 9 pages, 5 figures, 1 Earth's core. Comments welcome!
Solar oxygen abundance
Creators: name: Bergemann, Maria
name: Hoppe, Richard
name: Semenova, Ekaterina
name: Carlsson, Mats
name: Yakovleva, Svetlana A.
name: Voronov, Yaroslav V.
name: Bautista, Manuel
name: Nemer, Ahmad
name: Belyaev, Andrey K.
name: Leenaarts, Jorrit
name: Mashonkina, Lyudmila
name: Reiners, Ansgar
name: Ellwarth, Monika
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Motivated by the controversy over the surface metallicity of the Sun, we present a re-analysis of the solar photospheric oxygen (O) abundance. New atomic models of O and Ni are used to perform Non-Local Thermodynamic Equilibrium (NLTE) calculations with 1D hydrostatic (MARCS) and 3D hydrodynamical (Stagger and Bifrost) models. The Bifrost 3D MHD simulations are used to quantify the influence of the chromosphere. We compare the 3D NLTE line profiles with new high-resolution, R = 700 000, spatially-resolved spectra of the Sun obtained using the IAG FTS instrument. We find that the O I lines at 777 nm yield the abundance of log A(O) = 8.74 +/- 0.03 dex, which depends on the choice of the H-impact collisional data and oscillator strengths. The forbidden [O I] line at 630 nm is less model-dependent, as it forms nearly in LTE and is only weakly sensitive to convection. However, the oscillator strength for this transition is more uncertain than for the 777 nm lines. Modelled in 3D NLTE with the Ni I blend, the 630 nm line yields an abundance of log A(O) = 8.77 +/- 0.05 dex. We compare our results with previous estimates in the literature and draw a conclusion on the most likely value of the solar photospheric O abundance, which we estimate at log A(O) = 8.75 +/- 0.03 dex.
description: 22 pages, accepted for publication in MNRAS
Tunneling Effect in Gapped Graphene Disk in Magnetic Flux and Electrostatic Potential
Creators: name: Cheikh, A. Babe
name: Bouhlal, A.
name: Jellal, A.
name: Atmani, E. H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the tunneling effect of a Corbino disk in graphene in the presence of a variable magnetic flux $Φ_{i}$ created by a solenoid piercing the inner disk under the effect of a finite mass term in the disk region $ (R_1< r
description: 12 pages, 10 figures