cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Recycling Lithium‐Ion Battery Waste: A Meta‐Analysis of Production, Techniques, and Efficiency
Creators: name: Mona Tiwari, Vikrant Jain
Publisher: name: Zenodo
Year: 2025

description: The rapid growth in lithium‐ion battery (LIB) production—driven primarily by the electric vehicle(EV) and portable electronics sectors—has led to an unprecedented surge in end‐of‐life (EoL) batterywaste. This meta‐analysis synthesizes findings from approximately 10 global studies and reviews toevaluate the state‐of‐the‐art in LIB recycling. The analysis focuses on three core aspects: (1) theproduction and material flow dynamics of LIB waste; (2) recycling techniques, includingpyrometallurgical, hydrometallurgical, and direct recycling methods; and (3) the overall efficiency of theserecycling processes in terms of material recovery, energy consumption, and environmental impact. Ourreview shows that while pyrometallurgy remains the most industrially mature option, its high energydemand and suboptimal lithium recovery pose significant challenges. In contrast, hydrometallurgicaltechniques achieve high recovery rates for critical transition metals but produce large volumes ofwastewater, and emerging direct recycling methods promise to retain the electrochemical properties ofcathode materials with lower environmental burdens. Although direct recycling holds potential forincreased efficiency and cost‐savings, scale‐up and process standardization remain hurdles. The discussionalso highlights economic considerations and policy drivers, including regulatory mandates and investmenttrends aimed at achieving a circular battery economy. We conclude that a hybrid approach—integratingdirect recycling with optimized hydrometallurgical processes—could deliver improved material recoveryand lower emissions, provided that technological and economic challenges are addressed throughcoordinated global R&D efforts.
Restricted Log-Exp-Analytic Functions and some Differentiability Results
Creators: name: Opris, Andre
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic (math.LO)
subject: Algebraic Geometry (math.AG)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 03C64, 14P15, 26A09, 26E05, 26E10, 32B20

description: In this article we define restricted log-exp-analytic functions as compositions of log-analytic functions and exponentials whose logarithm are locally bounded. We prove that the derivative of a restricted log-exp-analytic function is again restricted log-exp-analytic and that such a function exhibits strong quasianalytic properties. We establish the parametric version of Tamm's theorem for this class of functions.
description: arXiv admin note: text overlap with arXiv:2112.08161
Fate of the topological susceptibility in two-color dense QCD
Creators: name: Kawaguchi, Mamiya
name: Suenaga, Daiki
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We explore the topological susceptibility at finite quark chemical potential and zero temperature in two-color QCD (QC$_2$D) with two flavors. Through the Ward-Takahashi identities of QC$_2$D, we find that the topological susceptibility in the vacuum solely depends on three observables: the pion decay constant, the pion mass, and the $η$ mass in the low-energy regime of QC$_2$D. Based on the identities, we numerically evaluate the topological susceptibility at finite quark chemical potential using the linear sigma model with the approximate Pauli-Gursey $SU(4)$ symmetry. Our findings indicate that, in the absence of $U(1)_A$ anomaly effects represented by the Kobayashi-Maskawa-'t Hooft-type determinant interaction, the topological susceptibility vanishes in both the hadronic and baryon superfluid phases. On the other hand, when the $U(1)_A$ anomaly effects are present, the constant and nonzero topological susceptibility is induced in the hadronic phase, reflecting the mass difference between the pion and $η$ meson. Meanwhile, in the superfluid phase it begins to decrease smoothly. The asymptotic behavior of the decrement is fitted by the continuous reduction of the chiral condensate in dense QC$_2$D, which is similar to the behavior observed in hot three-color QCD matter. In addition, effects from the finite diquark source on the topological susceptibility are discussed. We expect that the present study provides a clue to shed light on the role of the $U(1)_A$ anomaly in cold and dense QCD matter.
description: 37 pages, 8 figures, some references added, version accepted in JHEP
Optimal Dynamic Subset Sampling: Theory and Applications
Creators: name: Yi, Lu
name: Wang, Hanzhi
name: Wei, Zhewei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: We study the fundamental problem of sampling independent events, called subset sampling. Specifically, consider a set of $n$ events $S=\{x_1, \ldots, x_n\}$, where each event $x_i$ has an associated probability $p(x_i)$. The subset sampling problem aims to sample a subset $T \subseteq S$, such that every $x_i$ is independently included in $S$ with probability $p_i$. A naive solution is to flip a coin for each event, which takes $O(n)$ time. However, the specific goal is to develop data structures that allow drawing a sample in time proportional to the expected output size $μ=\sum_{i=1}^n p(x_i)$, which can be significantly smaller than $n$ in many applications. The subset sampling problem serves as an important building block in many tasks and has been the subject of various research for more than a decade. However, most of the existing subset sampling approaches are conducted in a static setting, where the events or their associated probability in set $S$ is not allowed to be changed over time. These algorithms incur either large query time or update time in a dynamic setting despite the ubiquitous time-evolving events with changing probability in real life. Therefore, it is a pressing need, but still, an open problem, to design efficient dynamic subset sampling algorithms. In this paper, we propose ODSS, the first optimal dynamic subset sampling algorithm. The expected query time and update time of ODSS are both optimal, matching the lower bounds of the subset sampling problem. We present a nontrivial theoretical analysis to demonstrate the superiority of ODSS. We also conduct comprehensive experiments to empirically evaluate the performance of ODSS. Moreover, we apply ODSS to a concrete application: influence maximization. We empirically show that our ODSS can improve the complexities of existing influence maximization algorithms on large real-world evolving social networks.
description: ACM SIGKDD 2023
Quench dynamics of the Schwinger model via variational quantum algorithms
Creators: name: Nagano, Lento
name: Bapat, Aniruddha
name: Bauer, Christian W.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the real-time dynamics of the $(1+1)$-dimensional U(1) gauge theory known as the Schwinger model via variational quantum algorithms. Specifically, we simulate quench dynamics in the presence of an external electric field. First, we use a variational quantum eigensolver to obtain the ground state of the system in the absence of an external field. With this as the initial state, we perform real-time evolution under an external field via a fixed-depth, parameterized circuit whose parameters are updated using McLachlan's variational principle. We use the same Ansatz for initial state preparation and time evolution, by which we are able to reduce the overall circuit depth. We test our method with a classical simulator and confirm that the results agree well with exact diagonalization.
description: 11 pages, 4 figures
Challenges of Pre-Shipment Export Credit Financing In the Commercial Bank of Ethiopia
Creators: name: Shimeles, Mengistu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: This study was carried out to establish challenges of pre-shipment export credit financing in the Commercial Bank of Ethiopia. It specifically focused on pre sanction appraisal and post sanction control of pre-shipment export credit financing. The study looked at the trend of non performing pre-shipment loans during the period 2009-2013 and identified factors that account for bad loans. Primary and secondary data were used in the study. Poor quality of information obtained from the bank's Management Information Services (MIS), sub-standard credit information obtained from the National Bank of Ethiopia, lack of procedural guidelines or memo that demand the communication between the designated CATS (Customer Accounts Transaction Services) Process Team, the Trade Service Process Team and Credit Management Team of the Bank as well as insufficient logistics facilities for executing proper loan follow up are challenges faced by the credit performers. Since pre- shipment credit facility is one among a number of credit products, it is difficult to generalize the findings of the study to other credit products of the bank. The findings showed that the bank recorded quite substantial amount of non performing pre-shipment loans during the period under consideration. The study identified volatility in international market, ineffective credit monitoring and loan diversion as major factors accounting for bad pre-shipment loans. To improve on the quality of the bank's pre-shipment loans, ensuring proper integration of the various processes involved in the pre-shipment financing process; availing the necessary resources required for effective monitoring; improving the quality of information used for credit appraisal and decision and requesting adequate collateral for inexperienced and highly leveraged exporters are recommended. Key words: Pre-shipment Financing, Non-performing Loans, Pre-sanction Appraisal, Post- sanction Control.
Generalized torsion elements and bi-orderability of 3-manifold groups
Creators: name: Motegi, Kimihiko
name: Teragaito, Masakazu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Geometric Topology (math.GT)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 57M25, 57M05, 06F15, 20F05, 20F60

description: It is known that a bi-orderable group has no generalized torsion element, but the converse does not hold in general. We conjecture that the converse holds for the fundamental groups of 3-manifolds, and verify the conjecture for non-hyperbolic, geometric 3-manifolds. We also confirm the conjecture for some infinite families of closed hyperbolic 3-manifolds. In the course of the proof, we prove that each standard generator of the Fibonacci group F(2,m) (m>2) is a generalized torsion element.
description: 14 pages, no figure
Effect of physical aging on the flexural creep in 3D printed thermoplastic
Creators: name: Fischbach, Marcel
name: Weinberg, Kerstin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Extrusion-based 3D printing has become one of the most common additive manufacturing methods and is widely used in engineering. This contribution presents the results of flexural creep experiments on 3D printed PLA specimens, focusing on changes in creep behavior due to physical aging. It is shown experimentally that the creep curves obtained on aged specimens are shifted to each other on the logarithmic time scale in a way that the theory of physical aging can explain. The reason for the physical aging of 3D printed thermoplastics is assumed to be the special heat treatment that the polymer undergoes during extrusion. Additionally, results of a long-term flexural creep experiment are shown, demonstrating that non-negligible creep over long periods can be observed even at temperatures well below the glass transition temperature. Such creep effects should be considered for designing components made of 3D printed thermoplastics.
description: This is a preprint of the following chapter: Fischbach, M., Weinberg, K., Effect of Physical Aging on the Flexural Creep in 3D Printed Thermoplastic, published in Creep in Structures VI, edited by Altenbach, H., Naumenko, K., 2023, Springer reproduced with permission of Springer Nature Switzerland AG
Isolating the linear signal when making redshift space distortion measurements
Creators: name: Chapman, Michael J.
name: Zhai, Zhongxu
name: Percival, Will J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Constraints on the linear growth rate, $fσ_8$, using small scale redshift space distortion measurements have a significant statistical advantage over those made on large scales. However, these measurements need to carefully disentangle the linear and non-linear information when interpreting redshift space distortions in terms of $fσ_8$. It is particularly important to do this given that some previous measurements found a significant deviation from the expectation based on the $Λ$CDM model constrained by Planck CMB data. We construct a new emulator-based model for small scale galaxy clustering with scaling parameters for both the linear and non-linear velocities of galaxies, allowing us to isolate the linear growth rate. We train the emulator using simulations from the AbacusCosmos suite, and apply it to data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) luminous red galaxy sample. We obtain a value of $fσ_8(z=0.737)=0.368\pm0.041$, in 2.3-$σ$ tension with the Planck 2018 $Λ$CDM expectation, and find less dependence on the minimum measurement scale than previous analyses.
description: 14 pages, 9 figures, submitted to MNRAS
Determinants of Customer Retention in Five Star Hotels in Addis Ababa
Creators: name: Shifferaw, Surafel
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: In contemporary business world one of the fundamental concepts that makes or breaks a firm's success is customer retention. Hence this study focused on examining the determinants of customer retention in five star hotels in Addis Ababa. Accordingly, three specific objectives were crafted and examined through nine independent variables: Quality of Object, Quality of Processes, Quality of Infrastructure, Quality of Atmosphere, Quality of Interaction, Trust, Commitment, Communication, and Conflict handling. The research used a Deductive Approach and quantitative method. In order to select the participants, both probability and non-probability sampling method were employed. The data was collected through self-administered questionnaire from each hotel and went through analysis using correlation as well as regression after it was cleaned and tested for reliability and validity. The result of the correlation analysis indicated that Quality of Interaction had high correlation with Quality of Infrastructure and therefore, was excluded from further analysis. The regression analysis showed that seven of the independent variables: Quality of Processes, Quality of Infrastructure, Quality of Atmosphere, Trust, Commitment, Communication, and Conflict handling have significant effect on customer retention while Quality of Object didn't
Cobordism and Deformation Class of the Standard Model
Creators: name: Wang, Juven
name: Wan, Zheyan
name: You, Yi-Zhuang
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: 't Hooft anomalies of quantum field theories (QFTs) with an invertible global symmetry G (including spacetime and internal symmetries) in a $d$d spacetime are known to be classified by a $d+1$d cobordism group TP$_{d+1}$(G), whose group generator is a $d+1$d cobordism invariant written as an invertible topological field theory (iTFT) Z$_{d+1}$. The deformation class of QFT is recently proposed to be specified by its symmetry G and an iTFT Z$_{d+1}$. Seemingly different QFTs of the same deformation class can be deformed to each other via quantum phase transitions. In this work, we ask which deformation class controls the 4d ungauged or gauged (SU(3)$\times$SU(2)$\times$U(1))/$\mathbb{Z}_q$ Standard Model (SM) for $q=1,2,3,6$ with a continuous or discrete $(\bf{B}-\bf{L})$ symmetry. We show that the answer contains some combination of 5d iTFTs: two $\mathbb{Z}$ classes associated with $(\bf{B}-\bf{L})^3$ and $(\bf{B}-\bf{L})$-(gravity)$^2$ 4d perturbative local anomalies, a mod 16 class Atiyah-Patodi-Singer $η$ invariant and a mod 2 class Stiefel-Whitney $w_2w_3$ invariant associated with 4d nonperturbative global anomalies, and additional $\mathbb{Z}_3\times\mathbb{Z}_2$ classes involving higher symmetries whose charged objects are Wilson electric or 't Hooft magnetic line operators. Out of $\mathbb{Z}$ classes of local anomalies and 24576 classes of global anomalies, we pin down a deformation class of SM labeled by $(N_f,n_{ν_{R}},$ p$',q)$, the family and "right-handed sterile" neutrino numbers, magnetic monopole datum, and mod $q$ relation. Grand Unifications and Ultra Unification that replaces sterile neutrinos with new exotic gapped/gapless sectors (e.g., topological or conformal field theory) or gravitational sectors with topological or cobordism constraints, all reside in an SM deformation class. Neighbor phases/transitions/critical regions near SM exhibit beyond SM phenomena.
description: 6 pages. Sequel to arXiv:1910.14668, arXiv:2006.16996, arXiv:2008.06499, arXiv:2012.15860, arXiv:2106.16248, arXiv:2111.10369, arXiv:2202.13498, arXiv:2204.08393. Related prior talks: https://www.youtube.com/results?search_query=cobordism+deformation+standard+model+ultra+unification+crticiality. v4: Phys. Rev. D (Letter)
Photography as a process of staging the self
Creators: name: Misic, Mark A.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Electronic Structure and Stability of the CH3NH3PbBr3 (001) Surface
Creators: name: Huang, Xin
name: Paudel, Tula R.
name: Dowben, Peter A.
name: Dong, Shuai
name: Tsymbal, Evgeny Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The energetics and the electronic structure of methylammonium lead bromine (CH3NH3PbBr3) perovskite (001) surfaces are studied based on density functional theory. By examining the surface grand potential, we predict that the CH3NH3Br-terminated (001) surface is energetically more favorable than the PbBr2-terminated (001) surface, under thermodynamic equilibrium conditions of bulk CH3NH3PbBr3. The electronic structure of each of these two different surface terminations retains some of the characteristics of the bulk, while new surface states are found near band edges which may affect the photovoltaic performance in the solar cells based on CH3NH3PbBr3. The calculated electron affinity of CH3NH3PbBr3 reveals a sizable difference for the two surface terminations, indicating a possibility of tuning the band offset between the halide perovskite and adjacent electrode with proper interface engineering.
description: 25 pages,5 figures,2 tables
Factors Affecting Brand Choice Of Automobile Buyers In Addis Ababa
Creators: name: Gemechu, Denaneso
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: Every customer in the market has his/her own brand choice. Customers consider certain attributes before purchasing products. The objective of this study was to identify factors affecting brand choice of automobile buyers in Addis Ababa. The variables included in this study are brand image, reliability, price, availability of spare part, safety, fuel consumption durability and social values of automobile. A sample of 400 automobile buyers was selected using convenience sampling technique with distributing structured questionnaire based on likert type scale was used to elicit information from the sampled respondents in the city of Addis Ababa. But 382 of them return correctly and within time. The data were analyzed using descriptive statistic to calculate general information of the respondent and inferential statistics to test like multiple regressions, normality, reliability, correlation and multicolinearity of data. The findings of the study showed that most of respondents were influenced by their brand image to choice the brands of automobile among available in the market. Particularly TOYOTA is found to be a top of mind and mostly preferred brands of all brands available in Ethiopia. The study revealed that brand image, reliability, price, availability of spare part and social values make a significant and positive contribution to automobile brand choice of consumers in Addis Ababa and the remaining variables like safety, fuel consumption and durability has no significant for brand choice of automobile in a city. Moreover, the study finding shows that, there is variation on brand choice based on respondent's income level.
Assessing the interactivity and prescriptiveness of faculty professional development workshops: The Real-Time Professional Development Observation Tool (R-PDOT)
Creators: name: Olmstead, Alice
name: Turpen, Chandra
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: Professional development workshops are one of the primary mechanisms used to help faculty improve their teaching, and draw in many STEM instructors every year. Although workshops serve a critical role in changing instructional practices within our community, we rarely assess workshops through careful consideration of how they engage faculty. Initial evidence suggests that workshop leaders often overlook central tenets of education research that are well-established in classroom contexts, such as the role of interactivity in enabling student learning. As such, there is a need to develop more robust, evidence-based models of how best to support faculty learning in professional development contexts, and to activity support workshop leaders in relating their design decisions to familiar ideas form other educational contexts. In response to these needs, we have developed an observation tool, the Real-Time Professional Development Observation Tool (R-PDOT), to document the form and focus of faculty's engagement during workshops. In this paper, we describe the motivation and methodological considerations behind the development of the R-PDOT, justify our decisions to highlight particular aspects of workshop sessions, and demonstrate how the R-PDOT can be used to analyze three sessions from the Physics and Astronomy New Faculty Workshop. We also justify the accessibility and potential utility of the R-PDOT output as a reflective tool using preliminary data from interviews with workshop leaders, and consider the roles the R-PDOT could play in supporting future research on faculty professional development.
description: 28 pages, 4 figures, accepted to Physical Review Physics Education Research
Superconducting valence bond fluid in lightly doped 8-leg $t$-$J$ cylinders
Creators: name: Jiang, Hong-Chen
name: Kivelson, Steven A.
name: Lee, Dung-Hai
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Superconductivity in doped quantum paramagnets has been a subject of long theoretical inquiry. In this work we report a density matrix renormalization group study of lightly doped $t$-$J$ models on the square lattice (doped hole densities $δ= 1/12$ and 1/8) with parameters for which previous studies have suggested that the undoped system in 2D is either a quantum spin liquid or a valence bond crystal. Our studies are performed on cylinders with width up to 8. Ground-state correlations are found to be nearly identical for the ``doped quantum spin liquid'' and ``doped valence bond crystal''. Upon increasing the cylinder width from 4 to 8, we observed a significant strengthening of the quasi-long-range superconducting correlations, and a dramatic suppression of any ``competing'' charge-density-wave order. Extrapolating from the observed behavior of the width 8 cylinders, we speculate that the system has a nodeless d-wave superconducting ground-state in the 2D limit.
description: 12 pages, 9 figures and 1 table
Wannier-Stark localization in one-dimensional amplitude-chirped lattices
Creators: name: Zeng, Qi-Bo
name: Hou, Bo
name: Xiao, Han
Publisher: name: arXiv
Year: 2023
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the Wannier-Stark (WS) localization in one-dimensional amplitude-chirped lattices with the $j$th onsite potential modulated by a function $Fj\cos(2παj)$, where $F$ is the external field with a period determined by $α=p/q$ ($p$ and $q$ are coprime integers). In the Hermitian (or non-Hermitian) systems with real (or imaginary) fields, we can obtain real (or imaginary) WS ladders in the eigenenergy spectrum. In most cases with $q \geq 2$, there are multiple WS ladders with all the eigenstates localized in the strong field limit. However, in the lattices with $q=4$, the energy-dependent localization phenomenon emerges due to the presence of both spatially periodic and linearly increasing behaviors in the onsite potential. About half the number of eigenstates are gathered at the band center and can extend over a wide region or even the full range of the lattice, even when the field becomes very strong. Moreover, in the non-Hermitian lattices with odd $q$, some of the WS ladders become doubly degenerate, where the eigenstates are evenly distributed at two neighboring sites in a wide regime of field strength. Our work opens an avenue for exploring WS localization in both Hermitian and non-Hermitian amplitude-chirped lattices.
description: 8 pages, 9 figures (including supplementary)
Observation of large and all-season ozone losses over the tropics
Creators: name: Lu, Qing-Bin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: This paper reveals a large and all-season ozone hole in the lower stratosphere over the tropics (30degN-30degS) since the 1980s, where an O3 hole is defined as an area of O3 loss larger than 25% compared with the undisturbed atmosphere. The depth of this tropical O3 hole is comparable to that of the well-known springtime Antarctic O3 hole, whereas its area is about seven times that of the latter. Similar to the Antarctic O3 hole, approximately 80% of the normal O3 value is depleted at the center of the tropical O3 hole. The results strongly indicate that both Antarctic and tropical O3 holes must arise from an identical physical mechanism, for which the cosmic-ray-driven electron reaction (CRE) model shows good agreements with observations. The whole-year large tropical O3 hole could cause a serious global concern as it can lead to increases in ground-level ultraviolet radiation and affect 50% of Earth's surface area, home to approximately 50% of the world's population. Moreover, the presence of the tropical and polar O3 holes is equivalent to the formation of three 'temperature holes' observed in the stratosphere. These findings will have significances in understanding planetary physics, ozone depletion, climate change, and human health.
description: 17 pages, 6 figures
Studies on the unfolding of the atmospheric neutrino spectrum with IceCube 59 using the TRUEE algorithm
Creators: name: Milke, N.
name: Rhode, W.
name: Ruhe, T.
Publisher: name: Technische Universität Dortmund
Year: 2012
Subjects: subject: atmospheric neutrino
subject: energy spectrum
subject: IceCube
subject: regularized unfolding
subject: RUN
subject: TRUEE
subject: 004

description: The measurement of the atmospheric neutrino energy spectrum provides information about the diffuse neutrino flux from extragalactic sources. A relative increase of the spectrum toward higher energies could be evidence for neutrino producing hadronic processes in the cosmic high energy accelerators, such as active galactic nuclei or gamma ray bursts. IceCube is currently the largest neutrino detector on Earth and is placed in the antarctic ice at the geographic South Pole. IceCube permits the detection of neutrinos with energies beyond 10^6 GeV. Since the acceptance and the resolution of neutrino telescopes suffer from the finite resolution and limited acceptance, a regularized unfolding method is used to extract the energy distribution of neutrinos from the measured observables. For AMANDA, the unfolding was done with the RUN algorithm. Based on the basic concept of this program and for data analyses in the ROOT frame, a new deconvolution algorithm (TRUEE) has been written and tested. With this new algorithm, studies on the analysis of the atmospheric neutrino spectrum measured with the IceCube 59 string configuration are presented.
Circuit Quantum Electrodynamics Architecture for Gate-Defined Quantum Dots in Silicon
Creators: name: Mi, X.
name: Cady, J. V.
name: Zajac, D. M.
name: Stehlik, J.
name: Edge, L. F.
name: Petta, J. R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q = 5,400 is achieved by selectively etching away regions of the quantum well and by reducing photon losses through low-pass filtering of the gate bias lines. Homodyne measurements of the cavity transmission reveal DQD charge stability diagrams and a charge-cavity coupling rate g_c/2pi = 23 MHz. These measurements indicate that electrons trapped in a Si DQD can be effectively coupled to microwave photons, potentially enabling coherent electron-photon interactions in silicon.
An F-ratio-Based Method for Estimating the Number of Active Sources in MEG
Creators: name: Giri, Amita
name: Mosher, John C.
name: Adler, Amir
name: Pantazis, Dimitrios
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Magnetoencephalography (MEG) is a powerful technique for studying the human brain function. However, accurately estimating the number of sources that contribute to the MEG recordings remains a challenging problem due to the low signal-to-noise ratio (SNR), the presence of correlated sources, inaccuracies in head modeling, and variations in individual anatomy. To address these issues, our study introduces a robust method for accurately estimating the number of active sources in the brain based on the F-ratio statistical approach, which allows for a comparison between a full model with a higher number of sources and a reduced model with fewer sources. Using this approach, we developed a formal statistical procedure that sequentially increases the number of sources in the multiple dipole localization problem until all sources are found. Our results revealed that the selection of thresholds plays a critical role in determining the method`s overall performance, and appropriate thresholds needed to be adjusted for the number of sources and SNR levels, while they remained largely invariant to different inter-source correlations, modeling inaccuracies, and different cortical anatomies. By identifying optimal thresholds and validating our F-ratio-based method in simulated, real phantom, and human MEG data, we demonstrated the superiority of our F-ratio-based method over existing state-of-the-art statistical approaches, such as the Akaike Information Criterion (AIC) and Minimum Description Length (MDL). Overall, when tuned for optimal selection of thresholds, our method offers researchers a precise tool to estimate the true number of active brain sources and accurately model brain function.
Assessing Practices of Gender Equality and Women's Leadership in Public Enterprises in Ethiopia: The Case of Ethiopian Airlines in Addis Ababa
Creators: name: Dina, Assefa
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: he objective of this research is to assess how gender equality issues are addressed in Ethiopian Airlines, by taking the cases of headquarter, Addis Ababa. To meet the objective of this research data were collected from primary and secondary sources. The primary data were gathered through sets of questionnaires distributed to 140 randomly selected management level employees and 107 were collected. The researcher also conducted interviews with three officials, (Employee Benefit Team Leader, Change Management Officer and Employee Engagement Culture and Gender officer). In addition to this, the researcher also conducted two informal interviews with Human Resource Officers to see the recruitment process and women's representation in leadership positions. Ethiopian Airlines (ET) was established seven decades ago with the aim of providing safe, market driven and customer focused passenger and cargo transport, aviation training, flight catering, and ground services. ET is now becoming the fastest growing and most profitable airline in Africa and biggest public enterprise with extensive international exposure. This study, therefore, focused to assess the current gender equality practice in the organization, share best practices and recommend on identified gaps. In this perspective the study analyzes gender equality and women leadership in middle and top -level management positions. The finding shows that the number of women on top and middle management level is extremely low. On top of this there is very little gender awareness among staff members. However, the study also shows that there are some efforts demonstrated by the organization to address gender issues. For example, the organization gender and culture team are working to communicate gender issue messages to staff members. ET has also conducted all female flight for the forth times to show its commitment and encourage women employees. Finally, based on the findings and the conclusion drawn, recommendations were forwarded to the organization to conduct gender analysis to identify the real gap and challenges to bring women staff members to top-level management and mainstream gender equality in all sectors. In addition to this, it was also recommended to form a separate department or unit who will be fully engaged to address gender equality and women participation in leadership.
On the total energy conservation of the Alcubierre spacetime
Creators: name: Carneiro, F. L.
name: Ulhoa, S. C.
name: Maluf, J. W.
name: da Rocha-Neto, J. F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this article, we consider the Alcubierre spacetime, such a spacetime describes a ``bubble'' that propagates with arbitrary global velocity. This setting allows movement at a speed greater than that of light. There are some known problems with this metric, e.g., the source's negative energy and the violation of the source's energy conservation when the bubble accelerates. We address these two issues within the realm of the Teleparallel Equivalent of General Relativity (TEGR). The energy conservation problem can be solved when considering the energy of the gravitational field itself. The total energy of the spacetime, gravitational plus source, is conserved even in accelerated motion. We explicitly show the dependence of energy and gravitational energy flux on the frame of reference, one adapted to a static observer and the other to a free-falling one in the same coordinate system. Addressing the problem of energy negativity of the source, we find that a static observer measures positive energy of the source, while an Eulerian observer measures a negative one. Thus, we surmise that negative energy may be a reference problem.
description: 25 pages, 11 figures
Scalable stochastic gradient descent with improved confidence
Creators: name: Bockermann, Christian
name: Lee, Sangkyun
Publisher: name: Technische Universität Dortmund
Year: 2012
Subjects: subject: 004

description: Stochastic gradient descent methods have been quite successful for solving large- scale and online learning problems. We provide a simple parallel framework to obtain solutions of high confidence, where the confidence can be easily controlled by the number of processes, independently of the length of learning processes. Our framework is implemented as a scalable open-source software which can be configured for a single multicore machine or for a cluster of computers, where the training outcomes from independent parallel processes are combined to produce the final output.
Shear viscosity at the Ising-nematic quantum critical point in two dimensional metals
Creators: name: Eberlein, Andreas
name: Patel, Aavishkar A.
name: Sachdev, Subir
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In an isotropic strongly interacting quantum liquid without quasiparticles, general scaling arguments imply that the dimensionless ratio $(k_B /\hbar)\, η/s$, where $η$ is the shear viscosity and $s$ is the entropy density, is a universal number. We compute the shear viscosity of the Ising-nematic critical point of metals in spatial dimension $d=2$ by an expansion below $d=5/2$. The anisotropy associated with directions parallel and normal to the Fermi surface leads to a violation of the scaling expectations: $η$ scales in the same manner as a chiral conductivity, and the ratio $η/s$ diverges at low temperature ($T$) as $T^{-2/z}$, where $z$ is the dynamic critical exponent for fermionic excitations dispersing normal to the Fermi surface.
description: Rewritten version with expanded supplement. 17 pages, 4 figures including supplementary material
Erratum: Quantum Transport through Ballistic Cavities: Soft vs Hard Quantum Chaos [Phys. Rev. Lett. 84, 5504 (2000)]
Creators: name: Huckestein, Bodo
name: Ketzmerick, Roland
name: Lewenkopf, Caio H.
Publisher: name: The American Physical Society
Year: 2001
Subjects: subject: 530

description: Physical Review Letters
Search for single production of a vector-like $T$ quark decaying into a Higgs boson and top quark with fully hadronic final states using the ATLAS detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A search is made for a vector-like $T$ quark decaying into a Higgs boson and a top quark in 13 TeV proton-proton collisions using the ATLAS detector at the Large Hadron Collider with a data sample corresponding to an integrated luminosity of 139 fb$^{-1}$. The Higgs-boson and top-quark candidates are identified in the all-hadronic decay mode, where $H\to b\bar{b}$ and $t\to b W \to b q \bar{q}^\prime$ are reconstructed as large-radius jets. The candidate Higgs boson, top quark, and associated B-hadrons are identified using tagging algorithms. No significant excess is observed above the background, so limits are set on the production cross-section of a singlet $T$ quark at 95% confidence level, depending on the mass, $m_T$, and coupling, $κ_T$, of the vector-like $T$ quark to Standard Model particles. In the considered mass range between 1.0 and 2.3 TeV, the upper limit on the allowed coupling values increases with $m_T$ from a minimum value of 0.35 for 1.07 < $m_T$ < 1.4 TeV to 1.6 for $m_T$ = 2.3 TeV.
description: 52 pages in total, author list starting at page 37, 10 figures, 2 tables, published in Phys. Rev. D 105 (2022) 092012. All figures are available at: https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2019-07/
Exchange Correlation Potentials from Full Configuration Interaction in a Slater Orbital Basis
Creators: name: Tribedi, Soumi
name: Dang, Duy-Khoi
name: Kanungo, Bikash
name: Gavini, Vikram
name: Zimmerman, Paul M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Ryabinkin-Kohut-Staroverov (RKS) theory builds a bridge between wave function theory and density functional theory by using quantities from the former to produce accurate exchange-correlation potentials needed by the latter. In this work, the RKS method is developed and tested alongside Slater atomic orbital basis functions for the first time. To evaluate this approach, Full Configuration Interaction computations in the Slater orbitals are employed to give quality input to RKS method, allowing full correlation to be present along with correct nuclei cusps and asymptotic decay of the wavefunction. The RKS method will be shown to be an efficient algorithm to arrive at exchange correlation potentials without unphysical artifacts in moderately-sized basis sets. Furthermore, enforcement of the nuclear cusp conditions will be shown to be vital for the success of the Slater-basis RKS method. Examples of weakly and strongly correlated molecular systems will demonstrate the main features of Slater RKS.
description: 10 pages, 9 figures
Quantum-statistical approach to electromagnetic wave propagation and dissipation inside dielectric media and nanophotonic and plasmonic waveguides
Creators: name: Zloshchastiev, Konstantin G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum-statistical effects occur during the propagation of electromagnetic (EM) waves inside the dielectric media or metamaterials, which include a large class of nanophotonic and plasmonic waveguides with dissipation and noise. Exploiting the formal analogy between the Schrodinger equation and the Maxwell equations for dielectric linear media, we rigorously derive the effective Hamiltonian operator which describes such propagation. This operator turns out to be essentially non-Hermitian in general, and pseudo-Hermitian in some special cases. Using the density operator approach for general non-Hermitian Hamiltonians, we derive a master equation that describes the statistical ensembles of EM wave modes. The method also describes the quantum dissipative and decoherence processes which happen during the wave's propagation, and, among other things, it reveals the conditions that are necessary to control the energy and information loss inside the above-mentioned materials.
description: Based on seminars given at the Aston Institute of Photonic Technologies (AIPT), Birmingham, UK (November 2015)
Studying ultrafast Rabi dynamics with a short-wavelength seeded free-electron laser
Creators: name: Nandi, Saikat
name: Olofsson, Edvin
name: Bertolino, Mattias
name: Carlström, Stefanos
name: Zapata, Felipe
name: Busto, David
name: Callegari, Carlo
name: Di Fraia, Michele
name: Eng-Johnsson, Per
name: Feifel, Raimund
name: Gallician, Guillaume
name: Gisselbrecht, Mathieu
name: Maclot, Sylvain
name: Neoričić, Lana
name: Peschel, Jasper
name: Plekan, Oksana
name: Prince, Kevin C.
name: Squibb, Richard J.
name: Zhong, Shiyang
name: Demekhin, Philipp V.
name: Meyer, Michael
name: Miron, Catalin
name: Badano, Laura
name: Danailov, Miltcho B.
name: Giannessi, Luca
name: Manfredda, Michele
name: Sottocorona, Filippo
name: Zangrando, Marco
name: Dahlström, Jan Marcus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Rabi oscillations are periodic modulations of populations in two-level systems interacting with a time-varying field. They are ubiquitous in physics with applications in different areas such as photonics, nano-electronics, electron microscopy, and quantum information. While the theory developed by Rabi was intended for fermions in gyrating magnetic fields, Autler and Townes realized that it could also be used to describe coherent light-matter interaction within the rotating wave approximation\cite. Although intense nanometer-wavelength light-sources have been available for more than a decade, Rabi dynamics at such short wavelengths have not been observed directly. Here we show that femtosecond extreme-ultraviolet pulses from a seeded free-electron laser can drive Rabi oscillations between the ground state and an excited state in helium atoms. The measured photoemission signal revealed an Autler-Townes doublet as well as an avoided crossing, phenomena that are both trademarks of quantum optics. Using theoretical analyses that go beyond the strong-field approximation, we found that the ultrafast build-up of the doublet structure follows from a quantum interference effect between resonant and non-resonant photoionization pathways. Given the recent availability of intense attosecond and few-femtosecond extreme-ultraviolet pulses, our results offer opportunities to carry out ultrafast manipulation of coherent processes at short wavelengths using free-electron lasers.
description: 38 pages, 10 figures
A Sensitive Test of Non-Gaussianity in Gravitational-wave Detector Data
Creators: name: Macas, Ronaldas
name: Lundgren, Andrew
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Methods for parameter estimation of gravitational-wave data assume that detector noise is stationary and Gaussian. Real data deviates from these assumptions, which causes bias in the inferred parameters and incorrect estimates of the errors. We develop a sensitive test of non-Gaussianity for real gravitational-wave data which measures meaningful parameters that can be used to characterize these effects. As a test case, we investigate the quality of data cleaning performed by the LIGO-Virgo-KAGRA collaboration around GW200129, a binary black hole signal which overlapped with the noise produced by the radio frequency modulation. We demonstrate that a significant portion of the non-Gaussian noise is removed below 50 Hz, yet some of the noise still remains after the cleaning; at frequencies above 85 Hz, there is no excess noise removed. We also show that this method can quantify the amount of non-Gaussian noise in continuous data, which is useful for general detector noise investigations. To do that, we estimate the difference in non-Gaussian noise in the presence and absence of light scattering noise.
description: 6 pages, 3 figures. PRD accepted