cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Numerical Hermitian Yang-Mills Connections and Kahler Cone Substructure
Creators: name: Anderson, Lara B.
name: Braun, Volker
name: Ovrut, Burt A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We further develop the numerical algorithm for computing the gauge connection of slope-stable holomorphic vector bundles on Calabi-Yau manifolds. In particular, recent work on the generalized Donaldson algorithm is extended to bundles with Kahler cone substructure on manifolds with h^{1,1}>1. Since the computation depends only on a one-dimensional ray in the Kahler moduli space, it can probe slope-stability regardless of the size of h^{1,1}. Suitably normalized error measures are introduced to quantitatively compare results for different directions in Kahler moduli space. A significantly improved numerical integration procedure based on adaptive refinements is described and implemented. Finally, an efficient numerical check is proposed for determining whether or not a vector bundle is slope-stable without computing its full connection.
description: 38 pages, 10 figures
UBVI CCD Photometry of the Open Cluster NGC 4609 and Hogg 15
Creators: name: Kook, S. -H.
name: Sung, Hwankyung
name: Bessell, M. S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: UBVI CCD photometry is obtained for the open clusters NGC 4609 and Hogg 15 in Crux. For NGC 4609, CCD data are presented for the first time. From new photometry we derive the reddening, distance modulus and age of each cluster - NGC 4609 : E(B-V) = 0.37 +/- 0.03, V_0 - M_V = 10.60 +/- 0.08, log tau = 7.7 +/- 0.1; Hogg 15 : E(B-V) = 1.13 +/- 0.11, V_0 - M_V = 12.50 +/- 0.15, log tau <= 6.6. The young age of Hogg 15 strongly implies that WR 47 is a member of the cluster. We have also determined the mass function of these clusters and have obtained a normal slope (Gamma = -1.2 +/- 0.3) for NGC 4609 and a somewhat shallow slope (Gamma = -0.95 +/- 0.5) for Hogg 15.
description: 12 pages, 14 figures, JKAS, in press
Optical emission line properties of a sample of the broad-line AGNs: the Baldwin effect and eigenvector 1
Creators: name: Popovic, Luka C.
name: Kovacevic, Jelena
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We divide a sample of 302 type-1 AGNs into two subsamples based on the narrow line [OIII]/Hbeta_{NLR} ratio, since we expect that there will be a stronger starburst (HII region) contribution to the narrow line emission for R=log([OIII]/Hbeta_{NLR})<0.5. For the two samples we {find significant differences in correlations between} spectral properties of objects with $R<0.5$ and R>0.5. {We find similar differences when we divided the sample based on the FWHM ratios of [OIII] and broad Hbeta lines (R_1=log(FWHM[OIII]/FWHM Hbeta_broad)^>_0.5 and R_1-0.8 subsamples from the other side.} The most interesting difference is in the correlation between the broad Hbeta FWHM and luminosity in the R<0.5 (R_1>-0.8) sample that indicates a connection between the BLR kinematics and photoionization source. We discuss possible effects which can cause such differences in spectral properties of two subsamples.
description: Accepted in ApJ
China's SOE reforms in the 2000s and 2010s
Creators: name: Zhang, Hui
Publisher: name: University of British Columbia
Year: 2015

description: In the 2000s and 2010s, there is an influential phenomenon called “state advance and private retreat” in China’s SOE reforms in strategic industries related to the production and processing of petroleum, ferrous metals, tobacco and telecommunication. Although some indicators have shown SOEs’ decreasing proportions in these industries, considering SOEs’ paid- in capital and assets, the tide of state advance and private retreat does exist in the strategic industries. There are four variables influencing state advance and private retreat. For interest groups, the government-SOEs relationship cannot explain the existence of state advance and private retreat in the 2000s and 2010s since this relationship also existed before the 2000s. As SOEs’ strong representative in policy-making process, the SASAC has greatly contributed to SOEs’ march in the market after its establishment in 2003, while at the same time, private enterprises do not have enough access to policy making process. For political elites, differences between Jiang- Zhu leadership and Hu-Wen leadership are one of the causes. As for institutional factors, both the fiscal and financial systems have increased SOEs’ advantages in market competitions. For influential event, “Lang Whirlwind”, China’s accession to the WTO, and the 2008 financial crisis in the 2000s all greatly contributed to the emergence of state advance and private retreat.
Boolean versus continuous dynamics on simple two-gene modules
Creators: name: Gehrmann, Eva
name: Drossel, Barbara
Publisher: name: arXiv
Year: 2010
Subjects: subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences

description: We investigate the dynamical behavior of simple modules composed of two genes with two or three regulating connections. Continuous dynamics for mRNA and protein concentrations is compared to a Boolean model for gene activity. Using a generalized method, we study within a single framework different continuous models and different types of regulatory functions, and establish conditions under which the system can display stable oscillations. These conditions concern the time scales, the degree of cooperativity of the regulating interactions, and the signs of the interactions. Not all models that show oscillations under Boolean dynamics can have oscillations under continuous dynamics, and vice versa.
description: 8 pages, 10 figures
Supplementary appendix and table - Identifying underlying somatic causes of pediatric obesity: results of an extensive diagnostic approach and comparison to the guideline
Creators: name: L Kleinendorst
name: O Abawi
name: MM Van Haelst
name: ELT Van Den Akker
Publisher: name: Zenodo
Year: 2019

description: Supplementary appendix and table for journal article 'Identifying underlying somatic causes of pediatric obesity: results of an extensive diagnostic approach and comparison to the guideline'
Book Review: Estudos da história da Náutica e das navegações de alto-mar (Malhão Pereira)
Creators: name: Acevedo, Juan
Publisher: name: figshare
Year: 2021
Subjects: subject: 90904 Navigation and Position Fixing
subject: FOS: Environmental engineering
subject: 220206 History and Philosophy of Science (incl. Non-historical Philosophy of Science)
subject: FOS: Philosophy, ethics and religion
subject: Instrumentation, Techniques, and Astronomical Observations
subject: 220203 History and Philosophy of Engineering and Technology
subject: 210110 Maritime Archaeology
subject: FOS: History and archaeology

description: Estudos da história da Náutica e das navegações de alto-mar (Studies on Nautical History and High Seas Navigation), 4 vols produced between 2012 and 2021. Reviewed with an appraisal of the author’s oeuvre.
Radiation reaction and energy-momentum conservation
Creators: name: Gal'tsov, Dmitri
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss subtle points of the momentum balance for radiating particles in flat and curved space-time. An instantaneous balance is obscured by the presence of the Schott term which is a finite part of the bound field momentum. To establish the balance one has to take into account the initial and final conditions for acceleration, or to apply averaging. In curved space-time an additional contribution arises from the tidal deformation of the bound field. This force is shown to be the finite remnant from the mass renormalization and it is different both form the radiation recoil force and the Schott force. For radiation of non-gravitational nature from point particles in curved space-time the reaction force can be computed substituting the retarded field directly to the equations of motion. Similar procedure is applicable to gravitational radiation in vacuum space-time, but fails in the non-vacuum case. The existence of the gravitational quasilocal reaction force in this general case seems implausible, though it still exists in the non-relativistic approximation. We also explain the putative antidamping effect for gravitational radiation under non-geodesic motion and derive the non-relativistic gravitational quadrupole Schott term. Radiation reaction in curved space of dimension other than four is also discussed
description: Lecture given at the C.N.R.S. School "Mass and Motion in General Relativity", Orleans, France, 2008
Narrow Line Seyfert 1 galaxies at hard X-rays
Creators: name: Panessa, F.
name: De Rosa, A.
name: Bassani, L.
name: Bazzano, A.
name: Bird, A.
name: Landi, R.
name: Malizia, A.
name: Miniutti, G.
name: Molina, M.
name: Ubertini, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Narrow Line Seyfert 1 (NLSy1) galaxies are a peculiar class of type 1 AGN (BLSy1). The X-ray properties of individual objects belonging to this class are often extreme and associated with accretion at high Eddington ratios. Here we present a study on a sample of 14 NLSy1 galaxies selected at hard X-rays (> 20 keV) from the fourth INTEGRAL/IBIS catalogue. The 20-100 keV IBIS spectra show hard X-ray photon indeces flatly distributed (Gamma_{20-100 keV} ranging from ~1.3 to ~3.6) with an average value of = 2.3+/-0.7, compatible with a sample of hard X-ray BLSy1 average slope. Instead, NLSy1 show steeper spectral indeces with respect to BLSy1 when broad-band spectra are considered. Indeed, we combine XMM-Newton and Swift/XRT with INTEGRAL/IBIS data sets to obtain a wide energy spectral coverage (0.3-100 keV). A constraint on the high energy cut-off and on the reflection component is achieved only in one source, Swift J2127.4+5654 (E_{cut-off} ~ 50 keV, R=1.0{+0.5}_{-0.4}). Hard X-ray selected NLSy1 do not display particularly strong soft excess emission, while absorption fully or partially covering the continuum is often measured as well as Fe line emission features. Variability is a common trait in this sample, both at X-ray and at hard X-rays. The fraction of NLSy1 in the hard X-ray sky is likely to be ~15%, in agreement with estimates derived in optically selected NLSy1 samples. We confirm the association of NLSy1 with small black hole masses with a peak at 10^{7} M_{dot} in the distribution, however hard X-ray NLSy1 seem to occupy the lower tail of the Eddington ratios distribution of classical NLSy1.
description: Accepted to MNRAS, June, 15, 2011. 15 pages, 6 figures and 7 tables
Pharmacokinetic-pharmacodynamic analysis’ role in design of phase Ⅰ clinical trials of anticoagulant agents: a systematic review
Creators: name: Zhao, Nan
name: Xiang, Qian
name: Liu, Zhiyan
name: Zhao, Xia
name: Cui, Yimin
Publisher: name: Taylor & Francis
Year: 2020
Subjects: Space Science
Medicine
Pharmacology
Biological Sciences not elsewhere classified
Developmental Biology
Science Policy
Hematology

description: There remains an unmet need for better anticoagulants. The phase I clinical trial is of great significance in the development of anticoagulants, and the design is special. This system review aims to provide insights for the design of future phase I clinical trials of anticoagulants. We searched the database PubMed and ClinicalTrail.gov website, to collate the phase I clinical trial of anticoagulants in healthy people. The study protocol, inclusion-exclusion criteria, safety, and pharmacodynamic indexes were reviewed.
New anticoagulants under development focused on inhibiting one or more than one serine proteases within the coagulation cascade. Agents targeting intrinsic factors are in the pipeline of the drug development. The enrollment eligibility criteria have more restrictions on laboratory tests, medical history, or medication history related to bleeding and coagulation; more precautions were taken to assess and minimize the risk of hemorrhagic events. Pharmacodynamics markers were evaluated as a surrogate marker of anticoagulation potency to guide further dose selection in drug’s development. In future, the positive control study can be applied in phase I studies of new anticoagulants with appropriate pharmacodynamics markers, which can provide more favorable information on making ‘go/no’ decision in drug development.
Comparison of alternative advanced experimental techniques for measurement of hydrodynamic characteristics of gas-fluidized beds
Creators: name: Tebianian, Sina
Publisher: name: University of British Columbia
Year: 2015

description: A novel travelling fluidized bed, designed to facilitate deployment at different research centres, was used to compare advanced measurement techniques for the study of key hydrodynamic properties of gas-fluidized beds. Fast X-ray imaging was employed to visualize the internal flow structures of the bubbling and turbulent fluidization flow regimes. Transition between flow regimes based on X-ray system images were compared with results from pressure fluctuations. Average Shannon entropy reached a maximum plateau at superficial gas velocities close to Uc derived from pressure fluctuations, whereas average kurtosis and skewness leveled off at lower Ug’s. The degree of interference of a 4-mm intrusive probe inserted in the fluidized bed was found to be small by comparing the time-average voidage in a region with and without the probe present. Voidage data obtained by different measurement techniques in a previous study were extended by new data based on fast X-ray imaging and borescopy. Fair, but imperfect agreement among voidage results from alternate techniques was observed and quantified in terms of deviations from the overall average results of all measurement techniques at each gas velocity. Radial profiles of time-average particle velocity in FCC (a Geldart A powder) and sand (a Geldart B powder) fluidized beds at different operating conditions, obtained by radioactive particle tracking (RPT – non-invasive, Ecole Polytechnique), positron emission particle tracking (PEPT – non-invasive, University of Birmingham), optical fibre probe (invasive, UBC) and borescopic high-speed particle image velocimetry (invasive, PSRI) were directly compared. For FCC, each of these techniques provided similar trends with respect to profiles of time-average particle velocity, but with significant differences in some cases. For sand, there were significant quantitative differences among the profiles in many cases. The reasons for the discrepancies included lack of matching of tracer particles, probe intrusiveness, unmatched sensitivities to the direction of motion and different analysis procedures. The RPT, PEPT and borescopy data were further analyzed to obtain solid mass and momentum flux for identical operating conditions. All three techniques provided broadly similar time-average flux profiles. The experimental results obtained in this study provide a unique hydrodynamic benchmark database for validation of CFD codes and other models.
Fully Flexible Views: Theory and Practice
Creators: name: Meucci, Attilio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Portfolio Management (q-fin.PM)
subject: FOS: Economics and business

description: We propose a unified methodology to input non-linear views from any number of users in fully general non-normal markets, and perform, among others, stress-testing, scenario analysis, and ranking allocation. We walk the reader through the theory and we detail an extremely efficient algorithm to easily implement this methodology under fully general assumptions. As it turns out, no repricing is ever necessary, hence the methodology can be readily applied to books with complex derivatives. We also present an analytical solution, useful for benchmarking, which per se generalizes notable previous results. Code illustrating this methodology in practice is available at http://www.mathworks.com/matlabcentral/fileexchange/21307
description: 2008
Fundamental study of the sedimentation of copper tailings with Kynch theory
Creators: name: Li, Yuan
Publisher: name: University of British Columbia
Year: 2015

description: The management of tailings is a significant issue within the mining industry worldwide. An understanding of sedimentation and consolidation of tailings provides a solid foundation for the management of tailings. Kynch theory, the first mathematical formulation of sedimentation theory, is widely used as a tool in the analysis of batch sedimentation. However, due to various idealized assumptions within Kynch theory, the application of this theory to describe and analyze tailings sedimentation in the laboratory setting has not been well developed. For the purpose of this research, a new apparatus was designed and constructed to carry out column settling tests and to remove and collect samples of water and suspensions in thin layers. Tests conducted with this apparatus aim at investigating the settling behavior and the internal changes in the suspension during the process of sedimentation. Solid content and particle size were selected as the main parameters. Benchmark tests were first conducted to determine the general range of the two parameters. Solid contents of 35% and 40% were selected for the column settling tests. Tests were carried out on total copper tailings as well as fine portions of copper tailings with a particle size smaller than 37 µm. The experimental data collected from these tests was analyzed with Kynch theory. Total copper tailings, with a large range of particle sizes could not satisfy the assumptions of Kynch theory on particle size, and failed to conform to Kynch theory. In the tests of fines from copper tailings, the influence of segregation decreased as the coarse particles in the copper tailings were removed. Based on Kynch theory and some laboratory data, a prediction curve was developed and compared with the results of the column settling tests. Changes in the internal attractive force, and the influence of compaction settling were found to be reasons why the prediction curve was unable to completely match the experimental data.
Cosmology meets cohomology
Creators: name: De, Shounak
name: Pokraka, Andrzej
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The cosmological polytope and bootstrap programs have revealed interesting connections between positive geometries, modern on-shell methods and bootstrap principles studied in the amplitudes community with the wavefunction of the Universe in toy models of FRW cosmologies. To compute these FRW correlators, one often faces integrals that are too difficult to evaluate by direct integration. Borrowing from the Feynman integral community, the method of (canonical) differential equations provides an efficient alternative for evaluating these integrals. Moreover, we further develop our geometric understanding of these integrals by describing the associated \emph{relative} twisted cohomology. Leveraging recent progress in our understanding of relative twisted cohomology in the Feynman integral community, we give an algorithm to predict the basis size and simplify the computation of the differential equations satisfied by FRW correlators.
description: 36+3 pages, 8 figures; included ancillary files; Journal version
Nernst effect in the cuprate superconductor YBCO: Broken rotational and translational symmetries
Creators: name: Chang, J.
name: Doiron-Leyraud, Nicolas
name: Laliberté, Francis
name: Daou, R.
name: LeBoeuf, David
name: Ramshaw, B. J.
name: Liang, Ruixing
name: Bonn, D. A.
name: Hardy, W. N.
name: Proust, Cyril
name: Sheikin, I.
name: Behnia, K.
name: Taillefer, Louis
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The Nernst coefficient of the cuprate superconductor YBa2Cu3Oy was recently shown to become strongly anisotropic within the basal plane when cooled below the pseudogap temperature T*, revealing that the pseudogap phase breaks the four-fold rotational symmetry of the CuO2 planes. Here we report on the evolution of this Nernst anisotropy at low temperature, once superconductivity is suppressed by a magnetic field. We find that the anisotropy drops rapidly below 80 K, to vanish in the T=0 limit. We show that this loss of anisotropy is due to the emergence of a small high-mobility electron-like pocket in the Fermi surface at low temperature, a reconstruction attributed to a low-temperature state that breaks the translational symmetry of the CuO2 planes. We discuss the sequence of broken symmetries - first rotational, then translational - in terms of an electronic nematic-to-smectic transition such as could arise when unidirectional spin or charge modulations order. We compare YBa2Cu3Oy with iron-pnictide superconductors where the process of (unidirectional) antiferromagnetic ordering gives rises to the same sequence of broken symmetries.
description: 7 pages, 5 figures
title: Defending Buddhism by Fighting Federalism; Ethnoreligious Nationalism of the Sinhala Sangha and Peacemaking in Sri Lanka: 1995-2010
Creators: name: Raghavan, Suren
Publisher: name: University of Kent
Year: 2021

description: The ethnic conflict between the Tamil minority and the state of Sri Lanka turned into one of the bloodiest and protracted civil wars in the modern history of South Asia. In its final stage from 1995 to 2009, the war went through a textbook cycle from ceasefire to peace talks, to the resumption of war, and to final military victory for the state. During this period, many observers including governments and international organizations promoted federalism as a possible solution to the conflict. However, the fede ral proposal for Lanka was not only defeated but also provoked violent resistance led by the highly influential Buddhist monks the Sangha. Federalism not only failed as an instrument of peace; the very proposal led to more violence and the intensification of the conflict. This thesis is an inquiry into the question of how federalism became the reason for violent resistance promoted by the SaiIgha, who are expected to adhere to ahimsa, nonaggression and the non-violent, renouncer path of life. The research adopted a case study method in order to reconstruct the life history and mindsets of three Sangha activists, who changed the manner in which federalism was received as an idea in Lanka. By analyzing the history of the resistance poli tics of the Sinhala Sangha, this research found that Sangha resistance is not merely a colonial byproduct or post-colonial innovation but rather a direct expression of the Sinhala 'cosmion', i.e. of a world of meaning in which Sinhala society appears as an analogue of the Buddhist cosmic order. Within th is cosmion. the Sangha playa crucial role as the mediators between the cosmic order and its earthly manifestation. Peacebuilding projects and federal proposals advanced by Western actors and their local supporters failed to appreciate this historical Sinhala self-understanding, because their Western frameworks considered federalism as an 'export-ready' political template while the religious actors in Lanka featured as mere 'spoilers' in the inevitable process of modernization. In conclusion, we argue that future peacebuilding in Lanka should consider two approaches. On the one hand, recognize and appreciate the cultural role played by key forces in Lankan society and, on the other, work with the self-understanding of these forces in order to help them transcend the singular uniqueness of the position, which they think they occupy in the world of Buddhism and beyond.
Quantum correlations in a cluster-like system
Creators: name: Chen, Yi-Xin
name: Li, Sheng-Wen
name: Yin, Zhi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss a cluster-like 1D system with triplet interaction. We study the topological properties of this system. We find that the degeneracy depends on the topology of the system, and well protected against external local perturbations. All these facts show that the system is topologically ordered. We also find a string order parameter to characterize the quantum phase transition. Besides, we investigate two-site correlations including entanglement, quantum discord and mutual information. We study the different divergency behaviour of the correlations. The quantum correlation decays exponentially in both topological and magnetic phases, and diverges in reversed power law at the critical point. And we find that in TQPT systems, the global difference of topology induced by dimension can be reflected in local quantum correlations.
description: 7 pages, 6 figures
Do Cosmological Perturbations Have Zero Mean?
Creators: name: Armendariz-Picon, C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A central assumption in our analysis of cosmic structure is that cosmological perturbations have zero ensemble mean. This property is one of the consequences of statistically homogeneity, the invariance of correlation functions under spatial translations. In this article we explore whether cosmological perturbations indeed have zero mean, and thus test one aspect of statistical homogeneity. We carry out a classical test of the zero mean hypothesis against a class of alternatives in which perturbations have non-vanishing means, but homogeneous and isotropic covariances. Apart from Gaussianity, our test does not make any additional assumptions about the nature of the perturbations and is thus rather generic and model-independent. The test statistic we employ is essentially Student's t statistic, applied to appropriately masked, foreground-cleaned cosmic microwave background anisotropy maps produced by the WMAP mission. We find evidence for a non-zero mean in a particular range of multipoles, but the evidence against the zero mean hypothesis goes away when we correct for multiple testing. We also place constraints on the mean of the temperature multipoles as a function of angular scale. On angular scales smaller than four degrees, a non-zero mean has to be at least an order of magnitude smaller than the standard deviation of the temperature anisotropies.
description: 31 pages, 4 tables, 6 figures
Live scanning ptychography with the LiberTEM software framework
Creators: name: Weber, Dieter
name: Strauch, Achim
name: Clausen, Alexander
name: Arya Bangun
name: Lesnichaia, Anastasiia
name: Müller-Caspary, Knut
Publisher: name: Zenodo
Year: 2021

description: Live 4D STEM data processing and plotting
 • Any combination of user-defined functions
 • Wide range of algorithms possible: Virtual detectors, differential phase
 contrast, ptychography, strain and orientation mapping, …
 • Both CPU and GPU
 • Example: Live single side band ptychography (SSB) and first moment analysis
 • Available as Open Source (GPL-3)
 • Gatan K2 IS support under development (prototype)
 • Parallel/distributed live processing soon More information, example notebooks, downloads
 • https://ptychography-4-0.github.io/ptychography/
 • https://libertem.github.io/LiberTEM/
 • https://libertem.github.io/LiberTEM-live/
 • arXiv:2106.13457
 • Contact: d.weber@fz-juelich.de
Thermal heat radiation, near-field energy density and near-field radiative heat transfer of coated materials
Creators: name: Biehs, Svend-Age
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the thermal radiation and thermal near-field energy density of a metal-coated semi-infinite body for different substrates. We show that the surface polariton coupling within the metal coating leads to an enhancement of the TM-mode part of the thermal near-field energy density when a polar substrate is used. In this case the result obtained for a free standing metal film is retrieved. In contrast, in the case of a metal substrate there is no enhancement in the TM-mode part, as can also be explained within the framework of surface plasmon coupling within the coating. Finally, we discuss the influence of the enhanced thermal energy density on the near-field radiative heat transfer between a simple semi-infinite and a coated semi-infinite body for different material combinations.
JIRAM Observations of Volcanic Flux on Io: Distribution and Comparison to Tidal Heat Flow Models
Creators: name: Pettine, M.
name: Imbeah, S.
name: Rathbun, J.
name: Hayes, A.
name: Lopes-Gautier, R.
name: Mura, A.
name: Tosi, F.
name: Zambon, F.
name: Bertolino, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Juno has allowed clear, high-resolution imaging of Io's polar volcanoes using the Jovian Infrared Auroral Mapper (JIRAM) instrument. We have used data from JIRAM's M-band (4.78 um) imager from eleven Juno orbits to construct a global map of volcanic flux. This map provides short-term insight into the spatial distribution of volcanoes and the ways in which high- and low-latitude volcanoes differ. Using spherical harmonic analysis, we quantitatively compare our volcanic flux map to the surface heat flow distribution expected from models of Io's tidal heat deposition (summarized in de Kleer et al. 2019). Our observations confirm previously detected systems of bright volcanoes at high latitudes. Our study finds that both poles are comparably active and that the observed flux distribution is inconsistent with an asthenospheric heating model, although the south pole is viewed too infrequently to establish reliable trends.
description: 11 pages, 3 figures
Electronic identification of the actual parental phase of KxFe2-ySe2 superconductor and its intrinsic mesoscopic phase separation
Creators: name: Chen, F.
name: Xu, M.
name: Ge, Q. Q.
name: Zhang, Y.
name: Ye, Z. R.
name: Yang, L. X.
name: Jiang, Juan
name: Xie, B. P.
name: Che, R. C.
name: Zhang, M.
name: Wang, A. F.
name: Chen, X. H.
name: Shen, D. W.
name: Xie, X. M.
name: Jiang, M. H.
name: Hu, J. P.
name: Feng, D. L.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: While the parent compounds of the cuprate high temperature superconductors (high-Tc's) are Mott insulators, the iron-pnictide high-Tc's are in the vicinity of a metallic spin density wave (SDW) state, which highlights the difference between these two families. However, insulating parent compounds were identified for the newly discovered KxFe2-ySe2. This raises an intriguing question as to whether the iron-based high-Tc's could be viewed as doped Mott insulators like the cuprates. Here we report angle-resolved photoemission spectroscopy (ARPES) evidence of two insulating and one semiconducting phases of KxFe2-ySe2, and the mesoscopic phase separation between the superconducting/semiconducting phase and the insulating phases. The insulating phases are characterized by the depletion of electronic states over a 0.5 eV window below the chemical potential, giving a compelling evidence for the presence of Mott-like physics. The charging effects and the absence of band folding in the superconducting/semiconducting phase further prove that the static magnetic and vacancy orders are not related to the superconductivity. Instead, the electronic structure of the superconducting phase is much closer to the semiconducting phase, indicating the superconductivity is likely developed by doping the semiconducting phase rather than the insulating phases.
description: 6 pages, 5 figures
Three-dimensional imaging of direct-written photonic structures
Creators: name: Marshall, Graham D.
name: Jesacher, Alexander
name: Thayil, Anisha
name: Withford, Michael J.
name: Booth, Martin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Third harmonic generation microscopy has been used to analyze the morphology of photonic structures created using the femtosecond laser direct-write technique. Three dimensional waveguide arrays and waveguide-Bragg gratings written in fused-silica and doped phosphate glass were investigated. A sensorless adaptive optical system was used to correct the optical aberrations occurring in the sample and microscope system, which had a lateral resolution of less than 500 nm. This non-destructive testing method creates volume reconstructions of photonic devices and reveals details invisible to other linear microscopy and index profilometry techniques.
description: 8 pages, 3 color figures, 2 hyper-linked animations
Generalized Geologic Map for Land-Use Planning: Larue County, Kentucky
Creators: name: Davidson, Bart
name: Carey, David I.
name: Pike, Adam
Publisher: name: Kentucky Geological Survey, University of Kentucky
Year: 2006

description: Abstract:
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.
A First Principle Approach to Rescale the Dynamics of Simulated Coarse-Grained Macromolecular Liquids
Creators: name: Lyubimov, I. Y.
name: Guenza, M. G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We present a detailed derivation and testing of our approach to rescale the dynamics of mesoscale simulations of coarse-grained polymer melts (I. Y. Lyubimov et al. J. Chem. Phys. \textbf{132}, 11876, 2010). Starting from the first-principle Liouville equation and applying the Mori-Zwanzig projection operator technique, we derive the Generalized Langevin Equations (GLE) for the coarse-grained representations of the liquid. The chosen slow variables in the projection operators define the length scale of coarse graining. Each polymer is represented at two levels of coarse-graining: monomeric as a bead-and-spring model and molecular as a soft-colloid. In the long-time regime where the center-of-mass follows Brownian motion and the internal dynamics is completely relaxed, the two descriptions must be equivalent. By enforcing this formal relation we derive from the GLEs the analytical rescaling factors to be applied to dynamical data in the coarse-grained representation to recover the monomeric description. Change in entropy and change in friction are the two corrections to be accounted for to compensate the effects of coarse-graining on the polymer dynamics. The solution of the memory functions in the coarse-grained representations provides the dynamical rescaling of the friction coefficient. The calculation of the internal degrees of freedom provides the correction of the change in entropy due to coarse-graining. The resulting rescaling formalism is a function of the coarse-grained model and thermodynamic parameters of the system simulated. The rescaled dynamics obtained from mesoscale simulations of polyethylene, represented as soft colloidal particles, by applying our rescaling approach shows a good agreement with data of translational diffusion measured experimentally and from simulations. The proposed method is used to predict self-diffusion coefficients of new polyethylene samples.
description: 21 pages, 6 figures, 6 tables. Submitted to Phys. Rev. E
Shifting disturbances in a warming environment : the western spruce budworm and Douglas-fir beetle in British Columbia
Creators: name: Marciniak, Amberly
Publisher: name: University of British Columbia
Year: 2015

description: Outbreaks of western spruce budworm (Choristoneura occidentalis Freeman), a native defoliator of Douglas-fir, appear to have been occurring further north in British Columbia (BC) compared to the early 1900s potentially as a result of climate change, but there is a lack of quantitative evidence to support this. I analysed the distribution of western spruce budworm infestation centers in forest health survey data for BC from 1967 to 2011 using a geographic information system (GIS) and linear regression. There was a significant (p<0.05) range shift towards higher latitudes and elevations. I also tested the prediction that this range shift was a result of a climate change-induced northward shift in optimal synchrony between springtime budworm larval emergence and Douglas-fir budburst, since the budworm must feed on newly flushed, highly nutritious needles for the best chance of survival. I simulated the dates of first larval emergence and budburst annually from 1901 to 2011 using phenology models and long-term climate data, then analysed them with GIS and linear regression. The mean difference in dates at higher latitudes and elevations has indeed significantly (p<0.05) converged towards optimal synchrony over the last century, while lower latitudes show divergence from optimal synchrony. Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins), a native bark beetle that infests Douglas-fir in BC, has been associated with stands recently defoliated by western spruce budworm, leading to increased mortality of large-diameter trees. I predicted that moderate defoliation intensity, which reduces tree defenses while leaving thick phloem for optimal Douglas-fir beetle breeding material, will be most closely associated with subsequent Douglas-fir beetle infestation. Evaluation of generalized additive models with long-term insect and biophysical variables showed that moderate cumulative severity of a defoliation event greatly improved model fit for predicting the presence of subsequent Douglas-fir beetle infestation. I concluded that interactions between biotic disturbance agents is an important consideration in future research and forest management because of additive or synergistic effects and how changes in the outbreak dynamics of one species under climate change will affect the other.
Independent individual addressing of multiple neutral atom qubits with a MEMS beam steering system
Creators: name: Knoernschild, Caleb
name: Zhang, Xianli L.
name: Isenhower, Larry
name: Gill, Alex T.
name: Lu, Felix P.
name: Saffman, Mark
name: Kim, Jungsang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We demonstrate a scalable approach to addressing multiple atomic qubits for use in quantum information processing. Individually trapped 87Rb atoms in a linear array are selectively manipulated with a single laser guided by a MEMS beam steering system. Single qubit oscillations are shown on multiple sites at frequencies of ~3.5 MHz with negligible crosstalk to neighboring sites. Switching times between the central atom and its closest neighbor were measured to be 6-7 us while moving between the central atom and an atom two trap sites away took 10-14 us.
description: 9 pages, 3 figures
title: The role of traditional rulers in protracted communal conflicts in Nigeria
Creators: name: Tonson John Damishi, Sango
Publisher: name: University of Kent
Year: 2021

description: This thesis questions the view that the contemporary role of traditional African rulers is pre-dominantly in mediating and resolving social conflicts within States. The thesis argues that while Chiefs and Emirs in Nigeria play a significant role in resolving conflicts within their ethnic communities, their role is less significant when communal conflicts escalate in intensity and scope. By analysing the interaction between (a) the actions and strategies of traditional rulers, and (b) the escalation, de-escalation and re-escalation of conflicts involving or affecting their ethnic communities, this thesis finds that the cultural role of traditional rulers contributes to re-escalating past conflicts, thereby making communal conflicts protracted. Edward Azar's Protracted Social Conflict (PSC) theory serves as a foundation on which this thesis develops an analytical framework for mapping the Ife-Modakeke conflict and the Jos-Plateau conflict in Nigeria. Both conflicts have a history of sporadic violence that spans three political eras; pre-colonial, colonial and post-colonial. The fact that some of the traditional rulers that govern the affected communities also existed from pre-colonial times, presents an opportunity to analyse their past and present actions/strategies in relation to the conflicts' protracted cycle, as well as the political and contextual dynamics that shaped these actions. Although PSC theory serves the purpose of explaining the role of historical and contextual factors in shaping the genesis of PSCs, it focuses more on the role of the State as the sole intervening actor that influences the process dynamics of PSCs. However, the role of traditional actors cannot be neglected when analysing protracted communal conflicts involving identity groups such as Ife and Modakeke, because of their centrality in the governance of ethnic communities in Nigeria. As such, this thesis modifies Azar's PSC theory to include traditional rulers as secondary intervening actors in protracted communal and social conflicts.
Eigen-Based Transceivers for the MIMO Broadcast Channel with Semi-Orthogonal User Selection
Creators: name: Sun, Liang
name: McKay, Matthew R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: This paper studies the sum rate performance of two low complexity eigenmode-based transmission techniques for the MIMO broadcast channel, employing greedy semi-orthogonal user selection (SUS). The first approach, termed ZFDPC-SUS, is based on zero-forcing dirty paper coding; the second approach, termed ZFBF-SUS, is based on zero-forcing beamforming. We first employ new analytical methods to prove that as the number of users K grows large, the ZFDPC-SUS approach can achieve the optimal sum rate scaling of the MIMO broadcast channel. We also prove that the average sum rates of both techniques converge to the average sum capacity of the MIMO broadcast channel for large K. In addition to the asymptotic analysis, we investigate the sum rates achieved by ZFDPC-SUS and ZFBF-SUS for finite K, and show that ZFDPC-SUS has significant performance advantages. Our results also provide key insights into the benefit of multiple receive antennas, and the effect of the SUS algorithm. In particular, we show that whilst multiple receive antennas only improves the asymptotic sum rate scaling via the second-order behavior of the multi-user diversity gain; for finite K, the benefit can be very significant. We also show the interesting result that the semi-orthogonality constraint imposed by SUS, whilst facilitating a very low complexity user selection procedure, asymptotically does not reduce the multi-user diversity gain in either first (log K) or second-order (loglog K) terms.
description: 35 pages, 3 figures, to appear in IEEE transactions on signal processing
Einstein-Podolsky-Rosen correlations in a hybrid system
Creators: name: Caban, Paweł
name: Rembieliński, Jakub
name: Witas, Piotr
name: Włodarczyk, Marta
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We calculate the relativistic correlation function for a hybrid system of a photon and a Dirac-particle. Such a system can be produced in decay of another spin-1/2 fermion. We show, that the relativistic correlation function, which depends on particle momenta, may have local extrema for fermion velocity of order 0.5 c. This influences the degree of violation of CHSH inequality.
description: 9 pages, 6 figures
Many-Body Contributions to Green's Functions and Casimir Energies
Creators: name: Shajesh, K. V.
name: Schaden, M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The multiple scattering formalism is used to extract irreducible N-body parts of Green's functions and Casimir energies describing the interaction of N objects that are not necessarily mutually disjoint. The irreducible N-body scattering matrix is expressed in terms of single-body transition matrices. The irreducible N-body Casimir energy is the trace of the corresponding irreducible N-body part of the Green's function. This formalism requires the solution of a set of linear integral equations. The irreducible three-body Green's function and the corresponding Casimir energy of a massless scalar field interacting with potentials are obtained and evaluated for three parallel semitransparent plates. When Dirichlet boundary conditions are imposed on a plate the Green's function and Casimir energy decouple into contributions from two disjoint regions. We also consider weakly interacting triangular--and parabolic-wedges placed atop a Dirichlet plate. The irreducible three-body Casimir energy of a triangular--and parabolic-wedge is minimal when the shorter side of the wedge is perpendicular to the Dirichlet plate. The irreducible three-body contribution to the vacuum energy is finite and positive in all the cases studied.
description: 22 pages, 8 figures
Intelligent Communication Planning for Constrained Environmental IoT Sensing with Reinforcement Learning
Creators: name: Hu, Yi
name: Zuo, Jinhang
name: Iannucci, Bob
name: Joe-Wong, Carlee
Publisher: name: arXiv
Year: 2023
Subjects: subject: Multiagent Systems (cs.MA)
subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Internet of Things (IoT) technologies have enabled numerous data-driven mobile applications and have the potential to significantly improve environmental monitoring and hazard warnings through the deployment of a network of IoT sensors. However, these IoT devices are often power-constrained and utilize wireless communication schemes with limited bandwidth. Such power constraints limit the amount of information each device can share across the network, while bandwidth limitations hinder sensors' coordination of their transmissions. In this work, we formulate the communication planning problem of IoT sensors that track the state of the environment. We seek to optimize sensors' decisions in collecting environmental data under stringent resource constraints. We propose a multi-agent reinforcement learning (MARL) method to find the optimal communication policies for each sensor that maximize the tracking accuracy subject to the power and bandwidth limitations. MARL learns and exploits the spatial-temporal correlation of the environmental data at each sensor's location to reduce the redundant reports from the sensors. Experiments on wildfire spread with LoRA wireless network simulators show that our MARL method can learn to balance the need to collect enough data to predict wildfire spread with unknown bandwidth limitations.
description: To be published in the 20th Annual IEEE International Conference on Sensing, Communication, and Networking (SECON 2023)