cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Novel donor-acceptor reagents in annulation sequences : total synthesis of oplopanane-type sesquiterpenoids
Creators: name: Gavai, Ashvinikumar Vasant
Publisher: name: University of British Columbia
Year: 2010

description: An investigation of the effects of soil organic matter on boron retention and release in soils was carried out on soils from British Columbia. The effect of soil humic acid on boron adsorption was studied in detail as a function of pH, boron concentration in equilibrium solution, ionic strength and different cations. Boron adsorption by Ca-precipitated humic acid was found highly pH-dependent, with the maximum adsorption at pH around 9.5, and remained little changed below pH around 6.5. Boron adsorption isotherms by various humic acids were studied at two pH levels and it was found that the increase of boron adsorption with an increase of boron in equilibrium solution at a higher pH level (8.5-9.0) was much more pronounced than that at a lower pH level (near neutral). The adsorption conformed quite well to the Freundlich empirical equation and was fairly well described by the Langmuir theory. The b and kb values calculated from the Langmuir equation increased with increasing pH whereas k values decreased with increase of pH with one exception. High ionic strength in solution favored boron adsorption by soil humic acid. By comparing the b values (high pH level), the amount of boron adsorbed by the two humic acids, WH-HA(a) and LA-HA(b), increased 21% and 12 %, respectively, with an increase of solution ionic strength from 0.03 to 0.3. However, at lower pH levels, the effect seemed insignificant. Results indicated that humic acids extracted from different soils or by different extraction methods adsorbed very different amounts of boron. The difference was attributed to the contribution of iron present in the humic acid samples, and it was confirmed experimentally that Al or Fe precipitated humic acid adsorbed much more boron than Ca-precipitated humic acid. No significant amount of boron adsorption by soil polysaccharides was observed at pH near neutral. However, studies on boron adsorption by organo-clay complexes indicated that coating of soil polysaccharides on illite, montmorillonite and kaolinite reduced boron adsorption by 31.6%, 44.5% and 76.7%, respectively, if compared with that by the pure clays. The effect of coating of the fulvic polyphenol on those clays seemed the least, especially on montmorillonite. From the results of these equilibrium studies, it is proposed that soil organic matter may play an important role on boron adsorption in soils with alkaline reaction, high in organic matter content, and high in extractable iron and aluminum contents. However, the effect would be negligible in soils with low organic matter content but high in clay or sesquioxide contents.
Optical neuromorphic processing at Tera-OP/s speeds based on Kerr soliton crystal microcombs
Creators: name: Tan, Mengxi
name: Xu, Xingyuan
name: Moss, David J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Emerging Technologies (cs.ET)
subject: Optics (physics.optics)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Convolutional neural networks (CNNs), inspired by biological visual cortex systems, are a powerful category of artificial neural networks that can extract the hierarchical features of raw data to greatly reduce the network parametric complexity and enhance the predicting accuracy. They are of significant interest for machine learning tasks such as computer vision, speech recognition, playing board games and medical diagnosis. Optical neural networks offer the promise of dramatically accelerating computing speed to overcome the inherent bandwidth bottleneck of electronics. Here, we demonstrate a universal optical vector convolutional accelerator operating beyond 10 TeraOPS (TOPS: operations per second), generating convolutions of images of 250,000 pixels with 8 bit resolution for 10 kernels simultaneously, enough for facial image recognition. We then use the same hardware to sequentially form a deep optical CNN with ten output neurons, achieving successful recognition of full 10 digits with 900 pixel handwritten digit images with 88% accuracy. Our results are based on simultaneously interleaving temporal, wavelength and spatial dimensions enabled by an integrated microcomb source. This approach is scalable and trainable to much more complex networks for demanding applications such as unmanned vehicle and real time video recognition.
description: 28 pages, 21 figures, 110 references. arXiv admin note: substantial text overlap with arXiv:2011.07393
Strain-controlled Domain Wall injection into nanowires for sensor applications
Creators: name: Masciocchi, Giovanni
name: Fattouhi, Mouad
name: Kehlberger, Andreas
name: Lopez-Diaz, Luis
name: Syskaki, Maria-Andromachi
name: Kläui, Mathias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We investigate experimentally the effects of externally applied strain on the injection of 180$^\circ$ domain walls (DW) from a nucleation pad into magnetic nanowires, as typically used for DW-based sensors. In our study the strain, generated by substrate bending, induces in the material a uniaxial anisotropy due to magnetoelastic coupling. To compare the strain effects, $Co_{40}Fe_{40}B_{20}$, $Ni$ and $Ni_{82}Fe_{18}$ samples with in-plane magnetization and different magnetoelastic coupling are deposited. In these samples, we measure the magnetic field required for the injection of a DW, by imaging differential contrast in a magneto-optical Kerr microscope. We find that strain increases the DW injection field, however, the switching mechanism depends strongly on the direction of the strain with respect to the wire axis. We observe that low magnetic anisotropy facilitates the creation of a domain wall at the junction between the pad and the wire, whereas a strain-induced magnetic easy axis significantly increases the coercive field of the nucleation pad. Additionally, we find that the effects of mechanical strain can be counteracted by a magnetic uniaxial anisotropy perpendicular to the strain-induced easy axis. In $Co_{40}Fe_{40}B_{20}$, we show that this anisotropy can be induced by annealing in a magnetic field. We perform micromagnetic simulations to support the interpretation of our experimental findings. Our simulations show that the above described observations can be explained by the effective anisotropy in the device. The anisotropy influences the switching mechanism in the nucleation pad as well as the pinning of the DW at the wire entrance. As the DW injection is a key operation for sensor performances, the observations show that strain is imposing a lower limit for the sensor field operating window.
Novel Higgs decay signals in R-parity violating models
Creators: name: Sierra, D. Aristizabal
name: Porod, W.
name: Restrepo, D.
name: Yaguna, Carlos E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In supersymmetric models the lightest Higgs boson may decay with a sizable branching ratio into a pair of light neutralinos. We analyze such decays within the context of the minimal supersymmetric standard model with R-parity violation, where the neutralino itself is unstable and decays into Standard Model fermions. We show that the R-parity violating couplings induce novel Higgs decay signals that might facilitate the discovery of the Higgs boson at colliders. At the LHC, the Higgs may be observed, for instance, through its decay -via two neutralinos- into final states containing missing energy and isolated charged leptons such as $l^\pm l^\mp, l^\pm l^\pm, 3l$, and $4l$. Another promising possibility is the search for the displaced vertices associated with the neutralino decay. We also point out that Higgs searches at the LHC might additionally provide the first evidence of R-parity violation.
description: 15 pages, 7 figures. Corrected affiliations
Il panopticon e la sua utopia: dalla logica del modello alla corrispondenza della realtà
Creators: name: Bellizzi, Rosanna
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2006

description: Il Panopticon è un’architettura che nasce alla fine del Settecento, in un’epoca di forti contrasti e trasformazioni sociali in cui i temi ed i modelli del passato sono diventati obsoleti e ci si sente attratti fortemente verso la ricerca e la sperimentazione. In questo fermento culturale si colloca l’opera di Jeremy Bentham che, in conformità alle idee utilitaristiche, ipotizza una soluzione architettonica dello spazio, funzionale e per ogni tipo di sorveglianza. Questo nuovo modello, progettato nel 1787, era il Panopticon, che letteralmente significa “l’occhio che tutto vede”, un’architettura circolare multipiano che, in uno spazio ristretto, permetteva ad un singolo uomo di avere una visione totale, a 360° su tutto l’intorno. Gli elementi principali di questa architettura erano la torre circolare, posta al centro del dispositivo e da cui si esercitava una sorveglianza continua, e una corona anulare, periferica, in cui erano sistemate le celle dei prigionieri, convergenti verso il centro dell’edificio. La logica dell’ispezione fu architettonicamente il principio organizzatore di questo modello, che trasformò la prigione da spazio inerte in dispositivo disciplinare.
Maude Sildel in Feathered Hat
Creators: name: Scherer
Publisher: name: Unknown
Year: 1870
Subjects: East Hampton
Photographs
Cabinet photographs
Portrait photographs
Portraits
Women

description: This image shows a portrait of Maude Sildel dressed in a feathered hat. This photograph is part of a collection of photographs found in the ceiling of 140A Main Street, now 138, in East Hampton in 1970. This collection was donated by Joan Osborne in April 1995.
Cosmological Evolution via Interacting/Non-Interacting Holographic Dark Energy Model for Curved FLRW Space-time in Rastall Gravity
Creators: name: Saleem, Rabia
name: Shahnila
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work, we explore the phenomenon of cosmic evolution using curved FLRW space-time bounded by apparent horizon with a specific holographic cut-off. To this end, we use the framework of Rastall gravity (RG) and universe is assumed to be consists of interacting/ non-interacting dark energy (DE) and dark matter (DM). In both scenarios, we evaluate exact solutions of the dynamical equations and constraint the holographic parameter $c^{2}(z)$ assuming a slowly varying function of red-shift during non-interacting model. For interacting model, we consider $c^{2}$ as a constant function of red-shift. Moreover, we analyze nature of the obtained results via deceleration parameter $(q)$, statefinder pair $(j,s)$ and $Om(z)$-diagnostic by constraining the involved model parameters using latest observational data. The graphical analysis showed that interacting model is very close to $Λ$ cold DM ($Λ$CDM) model as compared to non-interacting case. We conclude that this holographic proposal is enough to describe the cosmic evolution at an accelerating rate.
description: 27 pages, 11 figures
title: Die Lupe: Jahrgang 1, 1925, Nr. 12, 5. Mai 2025
Creators: name: :None
Publisher: name: Verlag Die Lupe
Year: 1925
Subjects: subject: Bestände des Stadtarchivs Braunschweig
subject: Brunsvicensien der Universitätsbibliothek Braunschweig
subject: Kunst- und Kulturgeschichte
subject: 7

description: Die Lupe: Braunschweigische Wochenschrift für Theater, Musik, Kunst, Literatur, Film und Kabarett, vol. 1, no. 12
Synchrotron Radiation in the Standard Model Extension
Creators: name: Frolov, I. E.
name: Zhukovsky, V. Ch.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We obtain a system of exact solutions of the Dirac equation for an electron moving in a constant homogeneous external magnetic field with account of its vacuum magnetic moment and assumed Lorentz invariance violation in the minimal CPT-odd form in the framework of the Standard Model Extension. Using these solutions, characteristics of the particle synchrotron radiation are calculated, and possible observable effects caused by the Lorentz non-invariant interaction are described. We demonstrate that the angular distribution of the radiation has specific asymmetry, which can be explained as a consequence of non-conservation of transversal electron polarization in the presence of a background Lorentz non-invariant condensate field.
description: 14 pages, 2 figures
PDE Models and Riemann-Stieltjes Integrals in Sustainability
Creators: name: Rao, Arni S. R. Srinivasa
name: Saride, Sireesh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 92D40, 35Q80, 26A42

description: Understanding sustainability through modeling involves one of the complex and interdisciplinary activities where mathematics plays a key role. We provide arguments favoring the need for developing global models for measuring the status of sustainability. A global model (applicable in broader perspective) and global sustainability indices are proposed which can be used with real-world data. The solutions of the proposed Partial Differential Equations (PDEs) are blended with the weight functions of Riemann Stieltjes integrals to capture the differential importance of sustainability associated factors. The ideas, methods, and models are new and are prepared for handling multi-dimensional and multi-variate data. A practically adaptable formula for measuring the sustainability index is developed with few key variables. We provide a real-world example arising in civil engineering applications with a numerical example to demonstrate our models.
description: 27 pages and 5 Figures
V-Waves: Spatio-temporally induced group-velocity dispersion in free space
Creators: name: Hall, Layton A.
name: Abouraddy, Ayman F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Introducing precise spatio-temporal structure into a pulsed optical field can lead to remarkable changes with its free propagation. `Space-time' (ST) wave packets, for example, propagate rigidly at a tunable group velocity in free space by inculcating a one-to-one relationship between the axial wave numbers and the temporal frequencies. Here we introduce a new class of ST wave packets that we call V-waves (so named because of their characteristically V-shaped spatio-temporal spectrum) in which a linear one-to-one relationship is introduced between the temporal frequencies and the transverse wave numbers (or spatial frequencies). We confirm experimentally that V-waves experience anomalous group velocity dispersion in free space, all the while maintaining the group velocity fixed at the speed of light in vacuum. Extremely large values of group velocity dispersion can be easily realized, which are not accessible with traditional optical materials or photonic structures. Moreover, V-waves are the unique optical wave packets whose diffraction and dispersion lengths are intrinsically equal by virtue of the spatio-temporal structure of the field itself. These results are of interest for optical signal processing and nonlinear optics.
Unified description of equation of state and transport properties of nuclear matter
Creators: name: Benhar, Omar
name: Farina, Nicola
name: Fiorilla, Salvatore
name: Valli, Marco
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Correlated basis function perturbation theory and the formalism of cluster expansions have been recently employed to obtain an effective interaction from a state-of-the-art nucleon nucleon potential model. The approach based on the effective interaction allows for a consistent description of the nuclear matter ground state and nucleon-nucleon scattering in the nuclear medium. This paper reports the the results of numerical calculations of different properties of nuclear and neutron matter, including the equation of state and the shear viscosity and thermal conductivity transport coefficients, carried out using the effective interaction.
description: Invited talk at the Sixth Conference on Perspectives in Hadronic Physics (ICTP, Trieste, May 2008). To be published in the proceedings (AIP)
Polyketide derived metabolites from the marine hydroid Garveia annulata
Creators: name: Fahy, Eoin
Publisher: name: University of British Columbia
Year: 2010

description: The marine hydroid Garveia annulata is a small, brightly colored coelenterate whose crude methanol extracts exhibit potent antibacterial and antifungal activity. The compounds responsible for this biological activity were purified and characterised as a series of related 1-[4H]-anthracenone derivatives. Twenty one metabolites have been isolated and their structures were elucidated by using a combination of spectral analysis, chemical interconversions, synthesis and single crystal X-ray diffraction analysis. The structure of garveatin A (77), the major metabolite, was determined via a series of NMR experiments and by an X-ray diffraction analysis of its enol triacetate 87. Garveatins B (88), C (93) and D (96) share a common carbon skeleton with 77. The garvin family represents a different polyketide folding pattern as seen in garvin A (124) and garvin B (126.) which contain an n-propyl group and a delta lactone functionality, respectively. Both the garveatins and the garvins contain oxidized analogs in the form of 2-hydroxy derivatives, 9,10 quinones and C2,2' dimers. NMR analysis and optical rotation experiments indicate that the C2 position of the 2-hydroxy compounds is racemic. Garvalones A (137) and B (141) represent the corresponding 2-(3-oxobutyl) derivatives of garvins A and B respectively. They occur as pairs of C2 epimers. Their structures were confirmed by spectral comparison with 2-(3-oxobutyl) garveatin A (140) which was synthesised from 77. Annulins A (144) and B (148) have degraded anthracene skeletons and they appear to be products of garveatin B metabolism. All four families of G. annulata secondary metabolites appear to be produced by straightforward polyketide biogenesis. Different folding patterns of a putative nonaketide precursor account for all the structures elaborated. These polyketides represent the first examples of this type of metabolism in coelenterates.
Substrate impact on the thickness dependence of vibrational and optical properties of large area $MoS_2$ produced by gold-assisted exfoliation
Creators: name: Panasci, S. E.
name: Schilirò, E.
name: Migliore, F.
name: Cannas, M.
name: Gelardi, F. M.
name: Roccaforte, F.
name: Giannazzo, F.
name: Agnello, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The gold-assisted exfoliation is a very effective method to produce large-area ($cm^2$-scale) membranes of molybdenum disulfide ($MoS_2$) for electronics. However, the strong $MoS_2/Au$ interaction, beneficial for the exfoliation process, has a strong impact on the vibrational and light emission properties of $MoS_2$. Here, we report an atomic force microscopy (AFM), micro-Raman ($μ-R$) and micro-Photoluminescence ($μ-PL$) investigation of $MoS_2$ with variable thickness exfoliated on Au and subsequently transferred on an $Al_2O_3/Si$ substrate. The $E_{2g}$ - $A_{1g}$ vibrational modes separation $Δμ$ (typically used to estimate $MoS_2$ thickness) exhibits an anomalous large value ($Δμ=21.2 cm^{-1}$) for monolayer (1L) $MoS_2$ on Au as compared to the typical one ($Δμ=18.5 cm^{-1}$) measured on 1L $MoS_2$ on $Al_2O_3/Si$. Such substrate-related differences, explained in terms of tensile strain and p-type doping arising from the $MoS_2/Au$ interaction, were found to gradually decrease while increasing the number of $MoS_2$ layers. Furthermore, $μ-PL$ spectra for 1L $MoS_2$ on Au exhibit a strong quenching and an overall red-shift of the main emission peak at 1.79 eV, compared to the 1.84 eV peak for 1L $MoS_2$ on $Al_2O_3$. After PL spectra deconvolution, such red shift was explained in terms of a higher trion/exciton intensity ratio, probably due to the higher polarizability of the metal substrate, as well as to the smaller equilibrium distance at $MoS_2/Au$ interface.
description: 14 pages, 4 figures
Basic Agricultural Resources of Kenya
Creators: name: Singleton, Carey B.
name: Singleton, Carey B.
Publisher: name: Unknown
Year: 1974
Subjects: subject: Agricultural and Food Policy
subject: Crop Production/Industries
subject: International Development
subject: International Relations/Trade
subject: Land Economics/Use
subject: Livestock Production/Industries
subject: Marketing
subject: FOS: Economics and business
subject: Kenya
subject: East African Community
subject: agricultural production
subject: agricultural trade
subject: resettlement
subject: smallholder
subject: coffee
subject: tea
subject: pyrethrum
subject: sisal
subject: cotton
subject: dairy products
subject: livestock

description: Since 1960, expansion of cash crops for export has been significant in Kenya's economic growth. Important agricultural exports include coffee, tea, pyrethrum, fruits and vegetables, meat and meat preparations, and sisal. Production of substantial quantities of corn, wheat, sorghum, millet, vegetables, other crops, and livestock products enables the country to be largely self-sufficient with respect to food. Major food imports include vegetable oils, sugar, tobacco, fruits and vegetables, cereals and cereal preparations, dairy products, and animal oils and fats. Agricultural imports from the United States include nonfat dry milk, corn, wheat, tobacco, tallow, and miscellaneous foods. With external assistance, Kenya has instituted economic development plans and projects aimed at developing the agricultural and agribusiness sectors through introduction of improved seeds, product diversification, expansion of irrigation, and improvement of marketing facilities and infrastructure. During the past decade, the smallholder has made significant contributions toward increasing Kenya's agricultural production and furthering the African farm sector's transition from a subsistence to a market economy.
Gluon Parton Distribution of the Pion from Lattice QCD
Creators: name: Fan, Zhouyou
name: Lin, Huey-Wen
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present the first determination of the $x$-dependent pion gluon distribution from lattice QCD using the pseudo-PDF approach. We use lattice ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration, at two lattice spacings $a\approx 0.12$ and 0.15~fm and three pion masses $M_π\approx 220$, 310 and 690 MeV. We use clover fermions for the valence action and momentum smearing to achieve pion boost momentum up to 2.29 GeV. We find that the dependence of the pion gluon parton distribution on lattice spacing and pion mass is mild. We compare our results from the lightest pion mass ensemble with the determination by JAM and xFitter global fits.
description: 10 pages, 6 figures
Possible influence of the two string events on the hadron formation in a nuclear environment
Creators: name: Akopov, N.
name: Grigoryan, L.
name: Akopov, Z.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: One of the basic assumptions of the string model is that as a result of a DIS in nucleus a single string arises, which then breaks into hadrons. However the pomeron exchange considered in this work, leads to the production of two strings in the one event. The hadrons produced in these events have smaller formation lengths, than those with the same energy produced in the single string events. As a consequence, they undergo more substantial absorption in the nuclear matter.
Step-up simultaneous tests for identifying active effects in orthogonal saturated designs
Creators: name: Wu, Samuel S.
name: Wang, Weizhen
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62F35, 62F25, 62K15 (Primary) 62J15. (Secondary)

description: A sequence of null hypotheses regarding the number of negligible effects (zero effects) in orthogonal saturated designs is formulated. Two step-up simultaneous testing procedures are proposed to identify active effects (nonzero effects) under the commonly used assumption of effect sparsity. It is shown that each procedure controls the experimentwise error rate at a given $α$ level in the strong sense.
description: Published at http://dx.doi.org/10.1214/009053606000001136 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Multi-Particle Quasi Exactly Solvable Difference Equations
Creators: name: Odake, Satoru
name: Sasaki, Ryu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Several explicit examples of multi-particle quasi exactly solvable `discrete' quantum mechanical Hamiltonians are derived by deforming the well-known exactly solvable multi-particle Hamiltonians, the Ruijsenaars-Schneider-van Diejen systems. These are difference analogues of the quasi exactly solvable multi-particle systems, the quantum Inozemtsev systems obtained by deforming the well-known exactly solvable Calogero-Sutherland systems. They have a finite number of exactly calculable eigenvalues and eigenfunctions. This paper is a multi-particle extension of the recent paper by one of the authors on deriving quasi exactly solvable difference equations of single degree of freedom.
description: LaTeX with amsfonts, amssymb, amsmath, no figure, 12 pages
A Review of Maser Polarization and Magnetic Fields
Creators: name: Vlemmings, W. H. T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Through polarization observations masers are unique probes of the magnetic field in a variety of different astronomical objects, with the different maser species tracing different physical conditions. In recent years maser polarization observations have provided insights in the magnetic field strength and morphology in, among others, the envelopes around evolved stars, Planetary Nebulae (PNe), massive star forming regions and supernova remnants. More recently, maser observations have even been used to determine the magnetic field in megamaser galaxies. This review will present an overview of maser polarization observations and magnetic field determinations of the last several years and discuss the implications of the magnetic field measurements for several important fields of study, such as aspherical PNe creation and massive star formation.
description: 10 pages, Review paper from IAU symposium 242 "Astrophysical Masers and their Environments"
Radial temperature profiles for a large sample of galaxy clusters observed with XMM-Newton
Creators: name: Leccardi, A.
name: Molendi, S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Aims. We measure, as far out as possible, radial temperature profiles for a sample of ~50 hot, intermediate redshift galaxy clusters, selected from the XMM-Newton archive, keeping systematic errors under control. Methods. Our work is characterized by two major improvements. Firstly, we use the background modeling, rather than the background subtraction, and the Cash statistic rather than the chi square; this method requires a careful characterization of all background components. Secondly, we assess in details systematic effects. We perform two groups of test: prior to the analysis, we make use of extensive simulations to quantify the impact of different spectral components on simulated spectra; after the analysis, we investigate how the measured temperature profile changes, when choosing different key parameters. Results. The mean temperature profile declines beyond 0.2 R_{180}; for the first time we provide an assessment of the source and the magnitude of systematic uncertainties. When comparing our profile with that obtained from hydrodynamic simulations, we find the slopes beyond ~0.2 R_{180} to be similar. Our mean profile is similar but somewhat flatter with respect to that obtained by previous observational works, possibly as a consequence of a different level of characterization of systematic effects. Conclusions. This work allows us not only to constrain with confidence cluster temperature profiles in outer regions, but also, from a more general point of view, to explore the limits of the current X-ray experiments (in particular XMM-Newton) with respect to the analysis of low surface brightness emission.
description: 18 pages, 26 figures, accepted for publication in A&A
Cavity Opto-Mechanics with a Bose-Einstein Condensate
Creators: name: Brennecke, Ferdinand
name: Ritter, Stephan
name: Donner, Tobias
name: Esslinger, Tilman
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Cavity opto-mechanics studies the coupling between a mechanical oscillator and a cavity field, with the aim to shed light on the border between classical and quantum physics. Here we report on a cavity opto-mechanical system in which a collective density excitation of a Bose-Einstein condensate is shown to serve as the mechanical oscillator coupled to the cavity field. We observe that a few photons inside the ultrahigh-finesse cavity trigger a strongly driven back-action dynamics, in quantitative agreement with a cavity opto-mechanical model. With this experiment we approach the strong coupling regime of cavity opto-mechanics, where a single excitation of the mechanical oscillator significantly influences the cavity field. The work opens up new directions to investigate mechanical oscillators in the quantum regime and quantum gases with non-local coupling.
description: F.B. and S.R. contributed equally to this work. 6 pages, 4 figures
Demonstration of one-parameter scaling at the Dirac point in graphene
Creators: name: Bardarson, J. H.
name: Tworzydło, J.
name: Brouwer, P. W.
name: Beenakker, C. W. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We numerically calculate the conductivity $σ$ of an undoped graphene sheet (size $L$) in the limit of vanishingly small lattice constant. We demonstrate one-parameter scaling for random impurity scattering and determine the scaling function $β(σ)=d\lnσ/d\ln L$. Contrary to a recent prediction, the scaling flow has no fixed point ($β>0$) for conductivities up to and beyond the symplectic metal-insulator transition. Instead, the data supports an alternative scaling flow for which the conductivity at the Dirac point increases logarithmically with sample size in the absence of intervalley scattering -- without reaching a scale-invariant limit.
description: 4 pages, 5 figures; v2: introduction expanded, data for Gaussian model extended to larger system sizes to further demonstrate single parameter scaling
X-ray Scattering Study of the spin-Peierls transition and soft phonon behavior in TiOCl
Creators: name: Abel, E. T.
name: Matan, K.
name: Chou, F. C.
name: Isaacs, E. D.
name: Moncton, D. E.
name: Sinn, H.
name: Alatas, A.
name: Lee, Y. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have studied the S=1/2 quasi-one-dimensional antiferromagnet TiOCl using single crystal x-ray diffraction and inelastic x-ray scattering techniques. The Ti ions form staggered spin chains which dimerize below Tc1 = 66 K and have an incommensurate lattice distortion between Tc1 and Tc2 = 92 K. Based on our measurements of the intensities, wave vectors, and harmonics of the incommensurate superlattice peaks, we construct a model for the incommensurate modulation. The results are in good agreement with a soliton lattice model, though some quantitative discrepancies exist near Tc2. The behavior of the phonons has been studied using inelastic x-ray scattering with ~2 meV energy resolution. For the first time, a zone boundary phonon which softens at the spin-Peierls temperature Tsp has been observed. Our results show reasonably good quantitative agreement with the Cross-Fisher theory for the phonon dynamics at wave vectors near the zone boundary and temperatures near Tsp. However, not all aspects of the data can be described, such as the strong overdamping of the soft mode above Tsp. Overall, our results show that TiOCl is a good realization of a spin-Peierls system, where the phonon softening allows us to identify the transition temperature as Tsp=Tc2=92 K
description: 14 pages, 14 figures
From genome to metabolism: Pan genome-scale metabolic model reconstruction of the extremophile genus Sulfolobus
Creators: name: Rimón, María José
name: Zehetner, Leopold
name: Zanghellini, Jürgen
Publisher: name: Zenodo
Year: 2025
Subjects: subject: Genome-scale metabolic model
subject: GEM
subject: Sulfolobus
subject: Extremophiles

description: This poster was presented during the Panel B PhD retreat of the Vienna Doctoral School in Chemistry (DoSChem) of University of Vienna on 2nd April 2025.
title: Studienpfad zum Beruf als kommunale*r Klimamanager*in
title: Projektposter StudiKommKlima
titleType: AlternativeTitle
Creators: name: Hörisch, Jacob
name: Möller, Sebastian
name: Redenius, Pia
Publisher: name: Medien- und Informationszentrum, Leuphana Universität Lüneburg
Year: 2024
Subjects: subject: Klimaanpassung
subject: Klimawandel
subject: Kommune
subject: Kommunalverwaltung
classificationCode: 333
subject: 333 Boden- und Energiewirtschaft
classificationCode: 352
subject: 352 Allgemeines zur öffentlichen Verwaltung

description: Das Poster fasst Ziele und Maßnahmen des Drittmittelprojektes "Studienpfad für den Beruf als kommunale*r Klimamanager*in" (StudiKommKlima) zusammen, in dem inter- und transdisziplinäre Seminare zur kommunalen Klimawandelfolgenanpassung konzipiert, durchgeführt und evaluiert werden.
Reieluukaela murdude ravi Eestis läbi aegade
Creators: name: Kööp, Arne-Lembit
Publisher: name: Eesti Arst
Year: 2019

description: Reieluukaela murd on raske vigastus, mille ravimata jätmise või puuduliku arstiabi korral haige invaliidistub või sureb lähiajal. Sajandeid tegeleti nende murdude konservatiivse raviga, kuid murru kokkukasvamiseni viis see harva. Operatiivse raviga alustati XIX sajandi keskpaiku ja tulemused olid siis tagasihoidlikud. Operatiivne ravi muutus tulemuslikumaks Marius Nygaard Smith-Peterseni kolmelamellilise naela kasutuselevõtu järel 1931. aastal. Esimesena Eestis hakkas selle naelaga üksikuid operatsioone tegema Ulrih Karell 1934. aastal. XX sajandi 60.–70. aastatel sai tänu parematele naela juhtsüsteemidele võimalikuks enamiku haigete opereerimine. Praegu on tänu implantaatide ja operatsiooni abivahendite täiustamisele ja endoproteeside kasutamisele võimalik üle 90% haigetest opereerida, paljudele neist saab tagada liikumisvõime ja osale neist ka võimaluse pöörduda tagasi endisesse ellu.
description: Eesti Arst, 2019: Mai
Secondary metabolites from selected marine organisms
Creators: name: Pathirana, Induruwa Charles
Publisher: name: University of British Columbia
Year: 2010

description: Marine organisms are known to produce secondary metabolites which have novel structures and are often biologically active. Chemical studies of biologically active metabolites from three different marine organisms led to the discovery of six new compounds and six previously known compounds. The brown alga Dictyota binghamiae is fairly abundant in British Columbia coastal waters. A chemical study of this alga yielded ten diterpenoids of which four are new compounds. All the new compounds, dictyoxide A (66), dictyol G acetate (68), dictyotriol A diacetate (69), and epidictyol B acetate (70) contain a perhydroazulene carbon skeleton first encountered in the algal metabolite pachydictyol A (29). Dictyoxide A (66) appears to be an artifact of isolation. The acetates 68, 69, 70 were found to be antibacterial and antifungal. Six previously known compounds pachydictyol A (29), dictyol C (32), dictyoxide (35), acetyldictyolal (49) and the acetals 61a and 61b were also isolated from this alga. Chemical studies on an Agelas sp. of sponge collected in Sri Lanka yielded the antimicrobial metabolite desbromooroidin (79). An interesting interaction between the starfish Dermasterias imbricata and the sea anemone Stompia coccinea was observed a long time ago. When contacted by the starfish, the anemone displays an unusual "swimming" response which was, according to other subsequent studies, caused by a single chemical substance in the starfish. A study conducted to elucidate the structure of this starfish metabolite led to the isolation of imbricatine (91), a unique benzyltetrahydroisoquinoline alkaloid. Imbricatine (91) induced S. coccinea swimming response at a very low concentration and also exhibited antitumor activity. Structures of all the new metabolites were determined by spectral analysis, and chemical degradations and chemical interconversions.
Precision shooting: Sampling long transition pathways
Creators: name: Grünwald, M.
name: Geissler, P. L.
name: Dellago, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The kinetics of collective rearrangements in solution, such as protein folding and nanocrystal phase transitions, often involve free energy barriers that are both long and rough. Applying methods of transition path sampling to harvest simulated trajectories that exemplify such processes is typically made difficult by a very low acceptance rate for newly generated trajectories. We address this problem by introducing a new generation algorithm based on the linear short-time behavior of small disturbances in phase space. Using this ``precision shooting'' technique, arbitrarily small disturbances can be propagated in time, and any desired acceptance ratio of shooting moves can be obtained. We demonstrate the method for a simple but computationally problematic isomerization process in a dense liquid of soft spheres. We also discuss its applicability to barrier crossing events involving metastable intermediate states.
description: 9 pages, 12 figures, submitted to J. Chem. Phys
Gamma camera imaging in an undergraduate physics course
Creators: name: Lowe, Mary
name: Spiro, Alex
name: Kutt, Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: Gamma camera imaging is an important technique in nuclear medicine. It is capable of diagnostic imaging of metabolically active areas and organ function, and it can be used to evaluate blood flow in the heart muscle, measure bone growth, detect tumors, and perform many other medical studies. It is a real world application that integrates concepts in medicine, nuclear physics, geometric optics, data processing, calibration, and image formation. This paper provides an overview of gamma camera imaging intended for an intermediate-level undergraduate physics course for students majoring in STEM disciplines. Because working with radioactive materials is not practical in our setting, we use an approach involving paper-and-pencil exercises, visible light apparatus, and computer work.
description: 30 pages including 10 figures. To appear in the Am. J. Physics around Jan. 2022. Supplementary materials will appear in AJP but have not been submitted to arXiv
37 GHz observations of a large sample of BL Lacertae objects
Creators: name: Nieppola, E.
name: Tornikoski, M.
name: Lähteenmäki, A.
name: Valtaoja, E.
name: Hakala, T.
name: Hovatta, T.
name: Kotiranta, M.
name: Nummila, S.
name: Ojala, T.
name: Parviainen, M.
name: Ranta, M.
name: Saloranta, P. -M.
name: Torniainen, I.
name: Tröller, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present 37 GHz data obtained at Metsahovi Radio Observatory in 2001 December - 2005 April for a large sample of BL Lacertae objects. We also report the mean variability indices and radio spectral indices in frequency intervals 5 - 37 GHz and 37 - 90 GHz. Approximately 34 % of the sample was detected at 37 GHz, 136 BL Lacertae objects in all. A large majority of the detected sources were low-energy BL Lacs (LBLs). The variability index values of the sample were diverse, the mean fractional variability of the sample being ΔS_2 = 0.31. The spectral indices also varied widely, but the average radio spectrum of the sample sources is flat. Our observations show that many of the high-energy BL Lacs (HBL), which are usually considered radio-quiet, can at times be detected at 37 GHz.
description: 12 pages, 5 figures + 5 tables. Published in Astronomical Journal
Continuous-Time Quantum Monte Carlo Method for the Coqblin-Schrieffer Model
Creators: name: Otsuki, J.
name: Kusunose, H.
name: Werner, P.
name: Kuramoto, Y.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An impurity solver based on a continuous-time quantum Monte Carlo method is developed for the Coqblin-Schrieffer model. The Monte Carlo simulation does not encounter a sign problem for antiferromagnetic interactions, and accurately reproduces the Kondo effect. Our algorithm can deal with an arbitrary number N of local degrees of freedom, becomes more efficient for larger values of N, and is hence suitable for models with orbital degeneracy. The dynamical susceptibility and the impurity t-matrix are derived with the aid of the Padé approximation for various values of N, and good agreement is found with other methods and available exact results. We point out that the Korringa-Shiba relation needs correction for a finite value of the exchange interaction.
description: 12 pages, 15 figures
Quasi-additivity of Tsallis entropies and correlated subsystems
Creators: name: Asgarani, Somayeh
name: Mirza, Behrouz
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We use Beck's quasi-additivity of Tsallis entropies for $n$ independent subsystems to show that like the case of $n=2$, the entropic index $q$ approaches 1 by increasing system size. Then, we will generalize that concept to correlated subsystems to find that in the case of correlated subsystems, when system size increases, $q$ also approaches a value corresponding to the additive case.
description: 12 pages
Jerry Huntting, Father of Flora Edwards
Creators: name: (:Unas)
Publisher: name: Unknown
Year: 1870
Subjects: East Hampton
Photographs
Cabinet photographs
Portrait photographs
Portraits
Men

description: This image shows a portrait of Gerry Huntting, who was the father of Flora Edwards. This photograph is part of a collection of photographs found in the ceiling of 140A Main Street, now 138, in East Hampton in 1970. This collection was donated by Joan Osborne in April 1995.
Convertible Bond Arbitrage
Creators: name: Xiao, Tim
Publisher: name: Zenodo
Year: 2020
Subjects: convertible bond, bond, convertibles, convertible bond arbitrage

description: A convertible bonds can be thought of as a normal corporate bond with embedded options, which enable the holder to exchange the bond for the issuer's stock Having properties of both stocks and bonds, convertibles can be an attractive choice for investors and have tended to have lower risk
description: https://ia803402.us.archive.org/6/items/eq-convertible-4/EqConvertible-archive.pdf
kuibit: Analyzing Einstein Toolkit simulations with Python
Creators: name: Bozzola, Gabriele
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In the era of gravitational-wave astronomy, general-relativistic simulations of compact objects play a role of paramount importance. These calculations can be performed with the Einstein Toolkit, an open-source and community-supported software for numerical-relativity and relativistic astrophysics. The code comes with multiple solvers for Einstein's equations and for the equations of general-relativistic magneto-hydrodynamics, along with a series of useful diagnostics. However, analyzing the output of the Einstein Toolkit can be a challenging task. Usually, the process involves a series of technical obstacles, like combining data from different restarts or working with HDF5 files. Here, we present kuibit, a Python library that takes care of all these low-level details (and many other more) and that provides high-level, intuitive, representations of the data. Kuibit ships with a wide range of features that include full support for 1-3D ASCII and HDF5 grid data, time and frequency series, gravitational waves, and apparent horizons. With kuibit, users can inspect most of the content of a simulation with just a few lines of code. Importantly, kuibit is designed to be a code for the community: it is user-friendly and does not require any proprietary software to run, it has documentation and examples, and it is openly developed with emphasis on extensibility and maintainability.
description: Published in JOSS, code homepage: https://sbozzolo.github.io/kuibit/
Equity Future and Forward
Creators: name: Xiao, David
Publisher: name: Zenodo
Year: 2020
Subjects: Equity futures, equity forward, forward price, exchange, mark to market

description: An equity future or forward contract is an agreement between two parties to buy a specific number of equity stocks, stock index or basket at a given price (called strike price) at a given date. A future takes place on an organized exchange where the all of the contract's terms and conditions, except price, are formalized. The future's standardization helps to create liquidity in the marketplace enabling participants to close out positions before expiration. Equity forward contract is traded over the counter (OTC). They are customized to meet the user's special needs. Forwards have credit risk, but futures do not because a clearing house guarantees against default risk.
description: https://ia903405.us.archive.org/8/items/eq-future-5/EqFuture-archive.pdf
A Description of Stock Option Product and Valuation
Creators: name: Xiao, David
Publisher: name: Zenodo
Year: 2020
Subjects: equity option, stock option, European option, American option, call option, put option, option valuation

description: Equity options, which are the most common type of equity derivatives, give an investor the right but not the obligation to buy a call or sell a put at a set strike price prior to the contract’s expiry date. Equity options or stock options provide investors a way to hedge risk or speculate. Also option trading can limit an investor’s risk and leverage investing potential.
description: https://ia903400.us.archive.org/27/items/eq-option-6/EqOption-archive.pdf