cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Orbital angular momentum-enhanced phase estimation using non-Gaussian state with photon loss
Creators: name: Chen, Yong-Jian
name: Gao, Jin-Wei
name: Han, Jin-Xuan
name: Yuan, Zhong-Hui
name: Li, Ruo-Qi
name: Jiang, Yong-Yuan
name: Song, Jie
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This study investigates the use of orbital angular momentum (OAM) to enhance phase estimation in Mach-Zehnder interferometers (MZIs) by employing non-Gaussian states as input resources in the presence of noise. Our research demonstrates that non-Gaussian states, particularly the photonsubtraction-then-addition (PSA) state, exhibit the best sensitivity in the presence of symmetric noise. Additionally, higher-order of Bose operator of non-Gaussian states provide better sensitivity for symmetric noise. OAM can mitigate the deterioration of noise, making it possible to estimate small phase shifts theta close to 0. OAM enhances the resolution and sensitivity of all input states and mitigating the deterioration caused by photon loss. Additionally, OAM enhances the resolution and sensitivity of all input states, enabling the sensitivity to approach the 1/N limit even under significant photon loss (e.g.,50% symmetric photon loss). These results hold promise for enhancing the sensitivity and robustness of quantum metrology, particularly in the presence of significant photon loss.
description: 14 pages, 18 figures
Transient Liquid Phase Diffusion Bonding of Magnesium Alloy (Mg-AZ31) to Titanium Alloy (Ti-6Al-4V)
Creators: name: Atieh, Anas Mahmoud
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Engineering--Industrial
subject: Materials Science
subject: Engineering--Mechanical
subject: TLP bonding, Ti-6Al-4V, Mg-AZ31, diffusion bonding, characterization, mechanical behaviour

description: The magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al-4V have physical characteristics and mechanical properties that makes it attractive for a wide range of engineering applications in the aerospace and automotive industries. However, the differences in melting temperature and coefficient of thermal expansion hinder the use of traditional fusion welding techniques. Transient liquid phase (TLP) bonding of magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al- 4V was performed and different interlayer types and configurations were used to facilitate joint formation. The joining of these alloys using Ni foils was successful at a bonding temperature of 515oC, bonding pressure 0.2 MPa, for bonding time of 5 minutes. At the Ni/Mg-AZ31 bond interface, the formation of a eutectic liquid between Mg and Ni was observed. The formation of Mg2Ni and Mg3AlNi2 were identified along the bond interface resulting in an isothermally solidified joint. At the Ni/Ti-6Al-4V interface, the solid-state diffusion process results in joint formation. The use of double Ni-Cu sandwich joint resulted in further enhancement in joint formation and this produced joints with greater shear strength values. The configuration of Mg-AZ31/Cu- Ni/Ti-6Al-4V or Mg-AZ31/Ni-Cu/Ti-6Al-4V influence the mechanism of bonding and the type of intermetallics formed within the joint. The application of thin Ni electrodeposited coatings resulted in further enhancements of joint quality due to better surface-to-surface contact and a reduction in the formation of intermetallics at the joint. The effect of Cu nano-particles in the coatings was found to decrease the eutectic zone width and this resulted in an increase the shear strength of the joints. The highest shear strength of 69 MPa was possible with bonds made using coatings containing Cu nano-particle dispersion.
SU(2)- and SU(1,1)-squeezing of interacting radiation modes
Creators: name: Abdalla, M. Sebawe
name: El-Orany, Faisal A. A.
name: Perina, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this communication we discuss SU(1,1)- and SU(2)-squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated.
description: 13 pages, 3 figures
Understanding the dynamics of photoionization-induced solitons in gas-filled hollow-core photonic crystal fibers
Creators: name: Saleh, Mohammed F.
name: Biancalana, Fabio
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present in detail our developed model [Saleh et al., Phys. Rev. Lett. 107] that governs pulse propagation in hollow-core photonic crystal fibers filled by an ionizing gas. By using perturbative methods, we find that the photoionization process induces the opposite phenomenon of the well-known Raman self-frequency red-shift of solitons in solid-core glass fibers, as was recently experimentally demonstrated [Hoelzer et al., Phys. Rev. Lett. 107]. This process is only limited by ionization losses, and leads to a constant acceleration of solitons in the time domain with a continuous blue-shift in the frequency domain. By applying the Gagnon-Bélanger gauge transformation, multi-peak `inverted gravity-like' solitary waves are predicted. We also demonstrate that the pulse dynamics shows the ejection of solitons during propagation in such fibers, analogous to what happens in conventional solid-core fibers. Moreover, unconventional long-range non-local interactions between temporally distant solitons, unique of gas plasma systems, are predicted and studied. Finally, the effects of higher-order dispersion coefficients and the shock operator on the pulse dynamics are investigated, showing that the resonant radiation in the UV [Joly et al., Phys. Rev. Lett. 106] can be improved via plasma formation.
description: 9 pages, 10 figures
Estimating Coronal Mass Ejection Mass and Kinetic Energy by Fusion of Multiple Deep-learning Models
Creators: name: Alobaid, Khalid A.
name: Abduallah, Yasser
name: Wang, Jason T. L.
name: Wang, Haimin
name: Fan, Shen
name: Li, Jialiang
name: Cavus, Huseyin
name: Yurchyshyn, Vasyl
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Machine Learning (cs.LG)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Coronal mass ejections (CMEs) are massive solar eruptions, which have a significant impact on Earth. In this paper, we propose a new method, called DeepCME, to estimate two properties of CMEs, namely, CME mass and kinetic energy. Being able to estimate these properties helps better understand CME dynamics. Our study is based on the CME catalog maintained at the Coordinated Data Analysis Workshops (CDAW) Data Center, which contains all CMEs manually identified since 1996 using the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). We use LASCO C2 data in the period between January 1996 and December 2020 to train, validate and test DeepCME through 10-fold cross validation. The DeepCME method is a fusion of three deep learning models, including ResNet, InceptionNet, and InceptionResNet. Our fusion model extracts features from LASCO C2 images, effectively combining the learning capabilities of the three component models to jointly estimate the mass and kinetic energy of CMEs. Experimental results show that the fusion model yields a mean relative error (MRE) of 0.013 (0.009, respectively) compared to the MRE of 0.019 (0.017, respectively) of the best component model InceptionResNet (InceptionNet, respectively) in estimating the CME mass (kinetic energy, respectively). To our knowledge, this is the first time that deep learning has been used for CME mass and kinetic energy estimations.
description: 10 pages, 7 figures
Empirical Investigations of the Impact of the Structure of a Standard on Accounting Quality: Comparison between United States GAAP and IFRS
Creators: name: Kallousa, Najlaa
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Accounting
subject: Rules-based
subject: Principles-based
subject: Accounting Irregularities
subject: US GAAP
subject: IFRS
subject: Accounting Quality

description: Following the wave of high-profile accounting scandals at the beginning of this century, the United States of America has witnessed increasing calls to move toward more principles-based accounting standards. As a result, the US announced a convergence project with the IASB (widely known as a provider of principles-based accounting standards) on September 18th, 2002. Therefore, the objective of this study is three-fold. First, the study investigates if there is a significant difference in rules-based characteristics between US GAAP and IFRS. Second, it attempts to test if the rules-based characteristics are a significant determinant of accounting irregularities. Third, the study seeks to examine if there is a significant difference in the quality of financial reporting between firms that report under US GAAP and those that report under IFRS. The empirical results document the following: US GAAP are less rules-based than IFRS. The structure of standards is not a significant determinant of accounting irregularities. Firms that report in accordance with US GAAP significantly outperform those that report according to IFRS with regard to analysts forecast errors and cost of capital. Firms that report under IFRS outperform those that report under US GAAP with regard to earnings predictability. US GAAP and IFRS are significantly indistinguishable with regard to earnings persistence and conservatism. Finally, the study failed to reach conclusive evidence with regard to accrual quality, earnings smoothness, earnings informativeness, and timely loss recognition. The study concludes that more caution is required by the US before taking further steps in the convergence project with the IASB.
On the spin modulated circular polarization from the intermediate polars NY Lup and IGRJ1509-6649
Creators: name: Potter, Stephen B.
name: Romero-Colmenero, Encarni
name: Kotze, Marissa
name: Zietsman, Ewald
name: Butters, O. W.
name: Pekeur, Nikki
name: Buckley, David A. H.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report on high time resolution, high signal/noise, photo-polarimetry of the intermediate polars NY Lup and IGRJ1509-6649. Our observations confirm the detection and colour dependence of circular polarization from NY Lup and additionally show a clear white dwarf, spin modulated signal. From our new high signal/noise photometry we have unambiguously detected wavelength dependent spin and beat periods and harmonics thereof. IGRJ1509-6649 is discovered to also have a particularly strong spin modulated circularly polarized signal. It appears double peaked through the I filter and single peaked through the B filter, consistent with cyclotron emission from a white dwarf with a relatively strong magnetic field. We discuss the implied accretion geometries in these two systems and any bearing this may have on the possible relationship with the connection between polars and soft X-ray-emitting IPs. The relatively strong magnetic fields is also suggestive of them being polar progenitors.
description: 8 pages, 6 figures and 1 table. Accepted for publication in MNRAS
Two Lines or Not Two Lines? That is the Question of Gamma Ray Spectra
Creators: name: Rajaraman, Arvind
name: Tait, Tim M. P.
name: Whiteson, Daniel
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Lines in the spectrum of cosmic gamma rays are considered one of the more robust signatures of dark matter annihilation. We consider such processes from an effective field theory vantage, and find that generically, two or more lines are expected, providing an interesting feature that can be exploited for searches and reveal details about the underlying theory of dark matter. Using the 130 GeV feature recently reported in the Fermi-LAT data as an example, we analyze the energy spectrum in the multi-line context and find the data to be consistent with a single $γγ$ line, a single $γZ$ line or both a $γγ$ and a $γZ$ line.
description: 7 pages, 5 figures
Infinite dimensional non-positively curved symmetric spaces of finite rank
Creators: name: Duchesne, Bruno
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: Group Theory (math.GR)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 53C35

description: This paper concerns a study of three families of non-compact type symmetric spaces of infinite dimension. Although they have infinite dimension they have finite rank. More precisely, we show they have finite telescopic dimension. We also show the existence of Furstenberg maps for some group actions on these spaces. Such maps appear as a first step toward superrigidity results.
description: Some references have been added
Novice and Expert Differences and Educational Interventions to Improve Veterinary Pathology Visual Diagnostic Reasoning Measured by Eye-tracking Technology
Creators: name: Warren, Amy Louise
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Education--Vocational
subject: Education
subject: Veterinary
subject: Pathology
subject: Visual
subject: Reasoning

description: Purpose: There were two objectives, to 1) to use eye-tracking to establish baseline quantitative and qualitative differences between novice and expert veterinary pathologists and explore dual process theory of clinical reasoning, and 2) determine if the introduction of two educational interventions, the active use of key diagnostic features and image repetition, improved novice visual diagnostic reasoning skills. Method: A pre-experimental static group comparison between novice and expert veterinary pathologists was used. Participants were shown 10 veterinary cytology images and asked to formulate a diagnosis while wearing eye-tracking equipment (10 slides) and while concurrently thinking aloud (5 slides). A quasi-experimental, pre-test and post-test comparison group design was used to compare the two teaching interventions to a comparison group using eye-tracking as an assessment method. The time to diagnosis and percentage time spent viewing an area of diagnostic interest (AOI) were compared using independent t-tests (novice and expert) and paired t-tests (time) and analysis of covariance (ANCOVA) (between groups) was used for the educational interventions. Diagnostic accuracy as a dichotomous variable was compared using chi-square tables. Results: Compared to novice, experts demonstrated significantly higher diagnostic accuracy (p < 0.017), shorter time to diagnosis (p < 0.017) and a higher percentage of time spent viewing AOIs (p < 0.017). Experts elicited more key-diagnostic features in the think-aloud protocol and had more efficient patterns of eye-movement. Students in the extended visual reasoning teaching intervention: active learning, image repetition behaved most like experts with no significant difference to experts for diagnostic accuracy, percentage time spent in the AOIs and a significantly faster time to diagnosis than experts (p < 0.017). Discussion: I suggest that experts’ fast time to diagnosis, efficient eye-movement patterns, and preference for viewing AOIs supports system 1 (pattern-recognition) reasoning and script-inductive knowledge structures with system 2 (analytic) reasoning to verify their diagnosis. Our results from the educational interventions suggest a greater level of improvement in the eye-tracking of students that were taught key-diagnostic features in an active learning forum and were shown multiple case examples.
title: Characterization of lake beds with the transient electromagnetic method
titleType: AlternativeTitle
Creators: name: Högenauer, Philipp
Publisher: name: TU Wien
Year: 2020
Subjects: subject: Geophysik
subject: elektromagnetische Sondierungen
subject: waterborne geophysik
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: transient electromagnetic soundings
subject: hydrogeology
subject: lake bed characterization

description: In the course of this thesis, transient electromagnetic (TEM) measurements were carried out on lakes. The aim of these measurements was to determine the geometry of the water bottom and the electrical resistivity of the water and the underlying geological layers. A buoyant ring was built for the application of TEM on the surface of the lakes. The cable for the TEM antenna was attached to this ring and the antenna was pulled over the water by a motorised boat where the measuring device was located.Another instrument used was a CTD (conductivity temperature depth)-probe. It was used to determine the electrical conductivity of the water in-situ. Based on the CTD data, accurate start models could be created and inversions with a-priori information could be performed. Electrical resistivity tomography (ERT) was also used to validate the results. For the collection of ERT, a cable with electrodes attached to the measuring device was pulled by a motorised boat. The measured value with ERT is the distribution of the electrical resistivity, resolved through the inversion of the field data. The methods used aimed at improving our understanding of the interaction between surface- and groundwater, as well as the geological settings of the lakes. In addition, hydrogeological systems can be examined for the effects of climate change using the methods mentioned above.The results from three case studies show that it is possible to determine the sedimentary layer underneath lakes with TEM. To avoid problems, a non-metal boat should be used. For ERT measurements it is important to make sure that the cable forms a line before starting each measurement. For verification of the TEM results, additional information is very useful. Therefore multi-methodical approaches are recommended.
Show Me the Data: Evaluating User Engagement with an Institutional Data Catalog for an Academic Medical Center
Creators: name: Yee, Michelle
name: Lamb, Ian
name: Contaxis, Nicole
Publisher: name: Zenodo
Year: 2023
Subjects: data catalog
data sharing
data discovery
secondary analysis
evaluation
data finding
FAIR

description: Data catalogs can promote the FAIR (findable, accessible, interoperable, and reusable) guiding principles by extending the reach of shared data. When research faculty at NYU Langone Health expressed a need for an institutional resource to help them locate and access secondary data as well as share their own data, developers at the NYU Health Sciences Library produced the NYU Data Catalog. While the catalog does not house data, it is an online, public-facing platform that connects researchers to data resources and permits researchers to control access to data that they share. The catalog does not duplicate indexing of all faculty datasets that have been deposited in public repositories such the Sequence Read Archive or Gene Expression Omnibus, but contains a curated selection of resources that are recommended by contributing faculty. This poster, presented at the AMIA 2023 Informatics Summit, presents an evaluation project which utilized catalog metadata and information collected through web analytics to understand data-seeking and sharing practices through the NYU Data Catalog.
Vortices ans Polynomials: Nonuniqueness of the Adler-Moser polynomials for the Tkachenko equation
Creators: name: Demina, Maria V.
name: Kudryashov, Nikolay A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: Stationary and translating relative equilibria of point vortices in the plane are studied. It is shown that stationary equilibria of a system containing point vortices with arbitrary choice of circulations can be described with the help of the Tkachenko equation. It is obtained that the Adler - Moser polynomial are not unique polynomial solutions of the Tkachenko equation. A generalization of the Tkachenko equation to the case of translating relative equilibria is derived. It is shown that the generalization of the Tkachenko equation possesses polynomial solutions with degrees that are not triangular numbers.
description: 15 pages, 2 figures
ISTE'MOLCHILAR HUQUQLARINING ISHONCHLI, KAFOLATLATLANGAN TIZIMI. "ESKROU" TIZIMI.
Creators: name: Qo'ldosheva, Maqsad
Publisher: name: Zenodo
Year: 2023

description: Ushbu maqolada bugungi kunda rivojlanib kelayotgan raqamli iqtisodiyot ko'rsatkichlari, ushbu sohanmi tartibga solib, rivojlantirishga qaratilgan mamlakatimizdagi normativ hujjatlar va dasturlar, elektron tijoratda shuningdek, fuqarolik-huquqiy shartnomalarda iste'molchilar huquqlari kafolatlarining kamchiliklari, ushbu muammolarni bartaraf etishning ishonchli kafolatgan tizim "Eskrou" tizimining afzalliklari, rivojlangan xorij davlatlari tajribasi, ular erishgan yutuqlar shu bilan birga ushbu tizimning qonunchiligimizga tatbiq etilishi sanab o'tiladi.
Four-constellation GNSS Reliability and the Estimation of Inter-system Time-offsets for Improved Performance in Challenging Signal Environments
Creators: name: Winit, Rasika
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Engineering
subject: GNSS
subject: GPS
subject: GLONASS
subject: Galileo
subject: BeiDou

description: The new GNSS constellations such as Galileo and BeiDou being planned and launched will result in a greatly increased number of available ranging sources, hence, improvement in constellation geometry and coverage. When using signals from multiple constellations, however, the challenges are not only to maximize the benefit from the additional ranging observations but also to deal with the differences among satellite systems such as the time-offset between the constellations. Also, challenges exist when using the ranging signal in GNSS degraded environments where GNSS users potentially see a limited number of satellites from multiple GNSS constellations. This work investigates the accuracy and reliably of position solutions when using ranging signals from combined GPS, GLONASS, BeiDou and Galileo constellations in urban environments. Furthermore, this study assesses the benefits of using a priori inter-system clock-offset information. The positioning performance of multiple GNSS constellations has been examined through covariance simulation and with live data. The benefit of using a priori clock-offset constraints has been demonstrated. It has been found that the benefits of using a priori clock-offset constraints to help enhance the availability of position solutions and fault detection and exclusion capabilities are particularly significant when the receiver is located in areas where limited GNSS signals are available such as in the urban-canyon environment.
When the fishing’s gone : understanding how fisheries management affects the informal economy and social capital in the Nuxalk Nation
Creators: name: Burke, Cynthia Lenore
Publisher: name: University of British Columbia
Year: 2010

description: In the field of resource management, the importance of understanding how policy affects people is now recognized as a fundamental aspect of sustainable management. This perspective underlies this study of how management policies within the British Columbia commercial fisheries have affected the Nuxalk Nation, located on the central coast of British Columbia. Though their contemporary participation in the commercial fisheries has been extensive, this community has witnessed a substantial decline in participation, roughly a 95% decline since 1953. Today about 12 community members hold commercial fishing licenses. Findings suggest that the virtual collapse of the local commercial fishery extends well beyond the visible losses such as employment, fishing boats, and related income. At a social and cultural level, the Nuxalkmc have witnessed changes in their ability to access and exchange traditional resources, engage in social and kinship networks, and perform acts of generalized reciprocity so important to social capital and resilience elsewhere. This study examines these dimensions by using theories of social capital and the informal economy as tools for unearthing the less visible and unaccounted losses in the Nuxalk Nation. Findings call for a reconsideration of the priority paid to direct versus indirect losses (wherein the latter may be more consequential than the former), and where the cultural and social consequences in particular may constitute what is elsewhere referred to as a ‘cascading’ loss. This study employs two primary research methods. First, we undertake a comprehensive review of relevant fisheries policies and historic information to evaluate the distinction between commercial and food fisheries. Second, semi-structured interviews with forty-one members of the Nuxalk Nation were conducted gather local articulations about social, cultural and economic changes associated with decreased involvement in the commercial fisheries.
Two-dimensional Noncommutative atom Gas with Anandan interaction
Creators: name: Yu, Xiaomin
name: Li, Kang
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Landau like quantization of the Anandan system in a special electromagnetic field is studied. Unlike the cases of the AC system and the HMW system, the torques of the system on the magnetic dipole and the electric dipole don't vanish. By constructing Heisenberg algebra, the Landau analog levels and eigenstates on commutative space, NC space and NC phase space are obtained respectively. By using the coherent state method, some statistical properties of such free atom gas are studied and the expressions of some thermodynamic quantities related to revolution direction are obtained. Two particular cases of temperature are discussed and the more simple expressions of the free energy on the three spaces are obtained. We give the relation between the value of $σ$ and revolution direction clearly, and find Landau like levels of the Anandan system are invariant and the levels between the AC system and the HMW system are interchanged each other under Maxwell dual transformations on the three spaces. The two sets of eigenstates labelled by $σ$ can be related by a supersymmetry transformation on commutative space, but the phenomenon don't occur on NC situation. We emphasize that some results relevant to Anandan interaction are suitable for the cases of AC interaction and HMW interaction under special conditions.
description: Latex, 10 pages
Unidirectional Nano-Modulated Binding and Electron Scattering in Epitaxial Borophene
Creators: name: Kamal, Sherif
name: Seo, Insung
name: Bampoulis, Pantelis
name: Jugovac, Matteo
name: Brondin, Carlo Alberto
name: Menteş, Tevfik Onur
name: Janković, Iva Šarić
name: Matetskiy, Andrey V.
name: Moras, Paolo
name: Sheverdyaeva, Polina M.
name: Michely, Thomas
name: Locatelli, Andrea
name: Gohda, Yoshihiro
name: Kralj, Marko
name: Petrović, Marin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A complex interplay between the crystal structure and electron behavior within borophene renders this material an intriguing 2D system with many of its electronic properties still undiscovered. Experimental insight into those properties is additionally hampered by the limited capabilities of the established synthesis methods, which in turn inhibits the realization of potential borophene applications. In this multi-method study, photoemission spectroscopies and scanning probe techniques complemented by theoretical calculations have been used to investigate the electronic characteristics of a high-coverage, single-layer borophene on Ir(111) substrate. Our results show that the binding of borophene to Ir(111) exhibits pronounced one-dimensional modulation and transforms borophene into a nano-grating. The scattering of photoelectrons from this structural grating gives rise to the replication of electronic bands. In addition, the binding modulation is reflected in the chemical reactivity of borophene and gives rise to its inhomogeneous aging effect. Such aging is easily reset by dissolving boron atoms in iridium at high temperature followed by their reassembly into a fresh atomically-thin borophene mesh. Besides proving electron-grating capabilities of the boron monolayer, our data provides a comprehensive insight into the electronic properties of epitaxial borophene which is vital for further examination of other boron systems of reduced dimensionality.
description: 12 pages, 5 figures, supporting information available
Plasmon-assisted electron-electron collisions at metallic surfaces
Creators: name: Kouzakov, Konstantin A.
name: Berakdar, Jamal
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present a theoretical treatment for the ejection of a secondary electron from a clean metallic surface induced by the impact of a fast primary electron. Assuming a direct scattering between the incident, primary electron and the electron in a metal, we calculate the electron-pair energy distributions at the surfaces of Al and Be. Different models for the screening of the electron-electron interaction are examined and the footprints of the surface and the bulk plasmon modes are determined and analyzed. The formulated theoretical approach is compared with the available experimental data on the electron-pair emission from Al.
description: 30 pages, 9 figures
Indirect Measurement of Fractional Impedances
Creators: name: Freeborn, Todd
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Engineering--Electronics and Electrical
subject: Fractional calculus
subject: Fractional impedance

description: This thesis investigates the measurement of fractional-order parameters that describe the electrical impedance of tissues and devices without requiring direct impedance measurements. Concepts from fractional calculus are imported to develop fractional circuit theory and derive the voltage and current excited step responses and magnitude responses of the single-dispersion Cole impedance model which is widely used in biomedicine and biology. Using these responses a numerical graph-fitting and non-linear least squares fitting routine have been applied to MATLAB simulations to assess the accuracy of this approach to extract the fractional impedance parameters that describe this model. Experimentally collected data from fruit tissues and ideal Cole models validate these methods. These fractional calculus concepts are further applied to develop the circuit theory to describe the current excited step response and magnitude response of the double-dispersion Cole impedance model. MATLAB and PSPICE simulations of assess the accuracy of this approach to extract the fractional impedance parameters that describe this model. Experimentally collected data from the current-excited step response and voltage excited magnitude response of apples validates these methods. Finally, the fractional circuit theory is applied to develop the expression for the voltage-excited step-response of a fractional model for a supercapacitor which is then used with non-linear least squares method extract the impedance parameters that characterize the model. This method is validated experimentally using results collected from low capacity supercapacitors with manufacturer ratings of 0.33 F, 1 F, and 1.5 F and high capacity supercapacitors with 1500 F and 3000 F manufacturer ratings.
On Flux Quantization in F-Theory II: Unitary and Symplectic Gauge Groups
Creators: name: Collinucci, Andres
name: Savelli, Raffaele
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the quantization of the M-theory G-flux on elliptically fibered Calabi-Yau fourfolds with singularities giving rise to unitary and symplectic gauge groups. We seek and find its relation to the Freed-Witten quantization of worldvolume fluxes on 7-branes in type IIB orientifold compactifications on Calabi-Yau threefolds. By explicitly constructing the appropriate four-cycles on which to calculate the periods of the second Chern class of the fourfolds, we find that there is a half-integral shift in the quantization of G-flux whenever the corresponding dual 7-brane is wrapped on a non-spin submanifold. This correspondence of quantizations holds for all unitary and symplectic gauge groups, except for SU(3), which behaves mysteriously. We also perform our analysis in the case where, in addition to the aforementioned gauge groups, there is also a 'flavor' U(1)-gauge group.
description: 33 pages, 4 figures
Building knowledge requires bricks, not sand: The critical role of familiar constituents in learning
Creators: name: Reder, Lynne M
name: Liu, Xiaonan L
name: Keinath, Alexander
name: Popov, Vencislav
Publisher: name: University of Illinois at Chicago
Year: 2023
Subjects: Uncategorized

description: Despite vast efforts to better understand human learning, some principles have been overlooked; specifically, that less familiar stimuli are more difficult to combine to create new knowledge and that this is because less familiar stimuli consume more working memory resources. Participants previously unfamiliar with Chinese characters were trained to discriminate visually similar characters during a visual search task over the course of a month, during which half of the characters appeared much more frequently. Ability to form associations involving these characters was tested via cued recall for novel associations consisting of two Chinese characters and an English word. Each week performance improved on the cued-recall task. Crucially, however, even though all Chinese character pairs were novel each week, those pairs consisting of more familiar characters were more easily learned. Performance on a working-memory task was better for more familiar stimuli, consistent with the claim that familiar stimuli consume fewer working memory resources. These findings have implications for optimal instruction, including second language learning.
A meta-analysis of state-of-the-art electoral prediction from Twitter data
Creators: name: Gayo-Avello, Daniel
Publisher: name: arXiv
Year: 2012
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computation and Language (cs.CL)
subject: Computers and Society (cs.CY)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: H.2.8; H.3.5; H.4.3; I.2.7; I.5.4; J.4; K.4.1

description: Electoral prediction from Twitter data is an appealing research topic. It seems relatively straightforward and the prevailing view is overly optimistic. This is problematic because while simple approaches are assumed to be good enough, core problems are not addressed. Thus, this paper aims to (1) provide a balanced and critical review of the state of the art; (2) cast light on the presume predictive power of Twitter data; and (3) depict a roadmap to push forward the field. Hence, a scheme to characterize Twitter prediction methods is proposed. It covers every aspect from data collection to performance evaluation, through data processing and vote inference. Using that scheme, prior research is analyzed and organized to explain the main approaches taken up to date but also their weaknesses. This is the first meta-analysis of the whole body of research regarding electoral prediction from Twitter data. It reveals that its presumed predictive power regarding electoral prediction has been rather exaggerated: although social media may provide a glimpse on electoral outcomes current research does not provide strong evidence to support it can replace traditional polls. Finally, future lines of research along with a set of requirements they must fulfill are provided.
description: 19 pages, 3 tables
Organoplatinum Hydroxo Compounds
Creators: name: Lohr, Tracy Lynn
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Chemistry--Inorganic
subject: Platinum hydroxides

description: A series of monomeric platinum (II) hydroxo supported by bulky diimine ligands have been synthesized and fully characterized. A thorough investigation of their corresponding reactivity have been carried out to determine if they participate in a water splitting cycle. Heating bis hydroxo at elevated temperatures (>80oC) in the presence of arene C-H bonds resulted in the double 1,2-C-H bond addition to form the corresponding bis phenyl complex with loss of H2O. This process was found to be catalyzed by in-situ produced platinum particles. 1,2-addition of H2 across the Pt-OH bonds was also observed but the corresponding platinum hydride species were too unstable to characterize or isolate. Several of the platinum (II) hydroxo species form stable adducts with silver bis-N-triflimide, where the silver cation was found to be engaging in a Lewis acid/base interaction with the hydroxide moiety. These silver supported adducts were found to activate aromatic C-H bonds at room temperature and a mechanistic study was carried out. The platinum (II) hydroxo compounds were also found to rapidly and reversible insert CO2. In one instance, insertion was followed by elimination of water to form an isolable carbonate species. The CO2 inserted products were found to be favoured at low temperature, and removal of CO2 from the system resulted in complete reversion back to the hydroxo species.
Depictions of Spartan Masculinity in Thucydides and Xenophon
Creators: name: Heydon, Kendell
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Literature--Classical
subject: Classical Literature
subject: Gender Studies
subject: Masculinity
subject: Ancient History
subject: Sparta

description: Because we have no Classical Spartan writing we are reliant on the views of outsiders to try to reconstruct their social mores. Using traditional philology combined with social constructionist theory I examine how Thucydides and Xenophon depict Spartan masculinity. I have found that these authors differ in their descriptions of the Spartan masculine subject, reflecting primarily the purposes for which they wrote. Despite this, both authors describe inter-Spartan relations and relations between Spartiates and “others”, both within the Spartan system and those external to it, so as to suggest that the employment of officially propagated images of Spartan masculinity played a significant role in Spartan dealings. Accounts of Spartan employment of masculine ideology correspond significantly to hegemonic frameworks discussed in social constructionist theories of masculinity, suggesting the veracity of these aspects in accounts of Spartan society as well as the applicability of constructionist frameworks to the study of Spartan masculinity.
Survival of magnetic correlations above ordering temperature in a ferromagnetically ordered classical kagomé magnet: Li9Cr3(P2O7)3(PO4)2
Creators: name: Kumar, R.
name: Chakraborty, A.
name: Fukuoka, S.
name: Damay, F.
name: Kermarrec, E.
name: Paulose, P. L.
name: Ihara, Y.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by the recent discovery of a semiclassical nematic spin liquid state in a Heisenberg kagomé antiferromagnet Li9Fe3(P2O7)3(PO4)2 (LFPO) with S=5/2 [Kermarrec et al. Phys. Rev. Lett. 127, 157202 (2021)], we now investigate the impact of spin quantum number S on the ground state properties by studying the isostructural kagomé magnet Li9Cr3(P2O7)3(PO4)2 (LCPO) with active t2g orbitals and S = 3/2. Thermodynamic measurements reveal that the ground state properties of LCPO is dominated by the ferromagnetic interactions with a mean-field temperature $θ\sim$ 3 K (J < 1 K) and the ordering temperature, Tc ~ 2.7 K, and the size of the ordered moment $\sim 1.05 \pm 0.25 $ ~$μ_B$ is significantly reduced from that of a fully ordered moment. The ab initio electronic structure calculations nicely corroborate the thermodynamic results and suggest the presence of additional in and out-of-plane further neighbor antiferromagnetic couplings, though significantly weaker in comparison to the dominant first-nearest neighbor ferromagnetic coupling. The spin-lattice relaxation rate measured with fields larger than the saturation field shows a magnetic field induced gap ($Δ\propto B$) in the excitation spectrum, and in $B \rightarrow 0$ limit the gap has a finite intercept ~ 3 K, equivalent to the mean-field scale. We interpret the origin of this gap is associated with the magnetic interactions inherent to the material. With our experimental results, we establish the stabilization of a ferromagnetic like ground state and the persistence of magnetic-correlations above the ordering temperature in LCPO.
description: 10 pages, 13 figures
Alpha-viscosity effects in slender tori
Creators: name: Horak, Jiri
name: Abramowicz, Marek
name: Levin, Lina
name: Slapak, Rikard
name: Straub, Odele
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We explore effects of the Shakura-Sunyaev alpha-viscosity on the dynamics and oscillations of slender tori. We start with a slow secular evolution of the torus. We show that the angular-momentum profile approaches the Keplerian one on the timescale longer than a dynamical one by a factor of the order of 1/α. Then we focus our attention on the oscillations of the torus. We discuss effects of various angular momentum distributions. Using a perturbation theory, we have found a rather general result that the high-order acoustic modes are damped by the viscosity, while the high-order inertial modes are enhanced. We calculate a viscous growth rates for the lowest-order modes and show that already lowest-order inertial mode is unstable for less steep angular momentum profiles or very close to the central gravitating object.
description: 9 pages, 5 figures, accepted by PASJ
Slow Light in Metamaterial Waveguides
Creators: name: Lavoie, Benjamin R.
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Optics
subject: Metamaterial
subject: Waveguide
subject: Nonlinear

description: Metamaterials, which are materials engineered to possess novel optical properties, have been increasingly studied. The ability to fabricate metamaterials has sparked an interest in determining possible applications. We investigate using a metamaterial for boundary engineering in waveguides. A metamaterial-clad cylindrical waveguide is used to provide confinement for an optical signal, thereby increasing the local electromagnetic energy density. We show that metamaterial-clad dielectric waveguides have unique optical properties, including new modes, which we call hybrid modes. These modes have properties of both ordinary guided modes and surface plasmon-polariton modes. We show that for certain metamaterial parameters, the surface plasmon-polariton modes of a metamaterial-clad guide have less propagation loss than those of a metal-clad waveguide with the same permittivity. This low-loss mode is exploited for all-optical control of weak fields. Embedding three-level Λ atoms in the dielectric core of a metamaterial-clad waveguide allows the use of electromagnetically induced transparency to control an optical signal propagating through the guide. Adjusting the pump field alters the group velocity of the signal, thereby controllably delaying pulses. The signal can even be stopped with applications to optical memory. Using the low-loss surface mode of a metamaterial-clad guide reduces losses by 20% over a metal cladding without sacrificing the group velocity reduction or confinement. In addition, we show that losses can be reduced by as much as 40% with sufficient reduction of the magnetic damping constant of the metamaterial. As this work aims for applications, practical considerations for fabricating and testing metamaterial-clad waveguides are discussed. An overview of the benefits and drawbacks for two different dielectric core materials is given. Also, a short discussion of other modes that could be used, along with some issues that may arise with their use, is given.
Two-Dimensional Stimulated Resonance Raman Spectroscopy of Molecules with Broadband X-ray Pulses
Creators: name: Biggs, Jason D.
name: Zhang, Yu
name: Healion, Daniel
name: Mukamel, Shaul
Publisher: name: arXiv
Year: 2012
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Expressions for the two-dimensional Stimulated x-ray Raman Spectroscopy (2D-SXRS) signal obtained using attosecond x-ray pulses are derived. The 1D- and 2D-SXRS signals are calculated for trans-N-methyl acetamide (NMA) with broad bandwidth (FWHM ~14.2eV, 181 as) pulses tuned to the oxygen and nitrogen K-edges. Crosspeaks in 2D signals reveal electronic Franck-Condon overlaps between valence orbitals and relaxed orbitals in the presence of the core hole.
SI-Hg D1 Protocol for the SI-traceable calibration of elemental mercury (Hg0) gas generators used in the field
Creators: name: de krom, Iris
name: van der Veen, Adriaan M.H.
name: Gugole, Federica
Publisher: name: Zenodo
Year: 2023
Subjects: elemental mercury
metrological traceability
calibration protocol
SI-Hg
validation
performance evaluation
mercury gas generators
mercury analysers

description: The monitoring of mercury concentrations in air is essential for the implementation of national and international legislation, and to demonstrate the progress in implementing international agreements such as the Minamata convention on mercury. Laboratories and other entities performing mercury concentration measurements usually calibrate their own equipment. For this calibration, mercury gas generators are generally used.
To set up a metrological traceability chain, the output of the gas generators needs to be comparable to reference standards, up to ultimately the primary measurement standards for mercury concentration held by national metrology institutes (NMI). Currently, there are no standardised procedures that ensures dissemination of the metrological traceability to testing laboratories and field measurements. This protocol describes such a standardised procedure for the characterisation and calibration of elemental mercury gas generators to demonstrate that their output is metrologically traceable to the International System of Units (SI). 
This protocol describes 1) the experimental procedures to compare the output of elemental mercury gas generators and 2) the data processing for determination of mercury concentration and the expanded uncertainty of the mercury concentration obtained from the elemental mercury gas generator. Demonstrating that a particular generator meets the requirements establishes that the requirements for performance and metrological traceability to the SI are met, and that an unbroken chain of comparisons is created. For applications, this protocol applies only to mercury monitoring system span concentrations in the range of micrograms per cubic meter (μg m-3) and nanograms per cubic meter (ng m-3).