cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Archaeological Baltic amber: degradation mechanisms and conservation measures
Creators: name: Pastorelli, Gianluca <1975>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: CHIM/12 Chimica dell'ambiente e dei beni culturali

description: The aim of this project was to achieve a deep understanding of the mechanisms by
which Baltic amber degrades, in order to develop techniques for preventive
conservation of archaeological amber objects belonging to the National Museum of
Denmark’s collections.
To examine deterioration of Baltic amber, a starting point was to identify and monitor
surface and bulk properties which are affected during degradation.
The way to operate consisted of the use of accelerated ageing to initiate degradation
of raw Baltic amber samples in different conditions of relative humidity, oxygen
exposure or pH and, successively, of the use of non/micro-destructive techniques to
identify and quantify changes in visual, chemical and structural properties.
A large piece of raw Baltic amber was used to prepare several test samples for two
different kinds of accelerated ageing: thermal-ageing and photo-ageing.
During the ageing, amber samples were regularly examined through several analytical
techniques related to different information: appearance/colour change by visual
examination, photography and colorimetry; chemical change by infrared
spectroscopy, Raman spectroscopy and elemental analysis; rate of oxidation by
oxygen measurement; qualitative analysis of released volatiles by gas
chromatography – mass spectrometry.
The obtained results were analysed through both critical evaluation and statistical
study.
After the interpretation of the achieved data, the main relations between amber and
environmental factors during the degradation process became clearer and it was
possible to identify the major pathways by which amber degrades, such as hydrolysis
of esters into alcohols and carboxylic acids, thermal-oxidation and photo-oxidation of
terpenoid components, depolymerisation and decomposition of the chemical structure.
At the end it was possible to suggest a preventive conservation strategy based on the
control of climatic, atmospheric and lighting parameters in the environment where
Baltic amber objects are stored and displayed.
Selection and cloning of optical patterns with a cold Rydberg atomic gas
Creators: name: Shi, Zeyun
name: Huang, Guoxiang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Chaotic Dynamics (nlin.CD)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We show that optical patterns formed in a cold Rydberg atomic gas working at the condition of electromagnetically induced transparency (EIT) can be selected by using a weakly modulated control laser field. We also show that the (hexagonal, stripe, square, etc.) patterns prepared in one probe laser field can be cloned onto another one with a high fidelity via a double EIT.
description: 5 pages; 4 figures
First- and second-order phase transitions in Ising models on small world networks, simulations and comparison with an effective field theory
Creators: name: Ferreira, A. L.
name: Mendes, J. F. F.
name: Ostilli, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We perform simulations of random Ising models defined over small-world networks and we check the validity and the level of approximation of a recently proposed effective field theory. Simulations confirm a rich scenario with the presence of multicritical points with first- or second-order phase transitions. In particular, for second-order phase transitions, independent of the dimension d_0 of the underlying lattice, the exact predictions of the theory in the paramagnetic regions, such as the location of critical surfaces and correlation functions, are verified. Quite interestingly, we verify that the Edwards-Anderson model with d_0=2 is not thermodynamically stable under graph noise.
description: 12 pages, 12 figures, 1 table
Photoinduced electronic transitions and leakage correlation to defects/dislocations in GaN heterostructures
Creators: name: Pandey, Saurabh <1987>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: FIS/03 Fisica della materia

description: III-nitride materials are very promising for high speed electronics/optical applications but still suffer in performance due to problems during high quality epitaxial growth, evolution of dislocation and defects, less understanding of fundamental physics of materials/processing of devices etc. This thesis mainly focus on GaN based heterostructures to understand the metal-semiconductor interface properties, 2DE(H)G influence on electrical and optical properties, and deep level states in GaN and InAlN, InGaN materials.  
The detailed electrical characterizations have been employed on Schottky diodes at GaN and InAl(Ga)N/GaN heterostructures in order to understand the metal-semiconductor interface related properties in these materials. I have observed the occurrence of Schottky barrier inhomogenity, role of dislocations in terms of leakage and creating electrically active defect states within energy gap of materials. Deep level transient spectroscopy method is employed on GaN, InAlN and InGaN materials and several defect levels have been observed related to majority and minority carriers. In fact, some defects have been found common in characteristics in ternary layers and GaN layer which indicates that those defect levels are from similar origin, most probably due to Ga/N vacancy in GaN/heterostructures. The role of structural defects, roughness has been extensively understood in terms of enhancing the reverse leakage current, suppressing the mobility in InAlN/AlN/GaN based high electron mobility transistor (HEMT) structures which are identified as key issues for GaN technology. 
Optical spectroscopy methods have been employed to understand materials quality, sub band and defect related transitions and compared with electrical characterizations. The observation of 2DEG sub band related absorption/emission in optical spectra have been identified and proposed for first time in nitride based polar heterostructures, which is well supported with simulation results. In addition, metal-semiconductor-metal (MSM)-InAl(Ga)N/GaN based photodetector structures have been fabricated and proposed for achieving high efficient optoelectronics devices in future.
Office of Everett A. Carpenter to Nathaniel T. Edwards, March 2, 1880
Creators: name: Carpenter, Everett A.
Publisher: name: Unknown
Year: 1880
Subjects: Edwards Family
East Hampton
Law & legal affairs
Montauk

description: Letter from the Office of Everett A. Carpenter to Nathaniel T. Edwards, March 2, 1880, in regards to land in Montauk purchased by Arthur W. Benson. This item is part of the Isaac Edwards Deed Collection, donated by Bess Rattray in December 2020.
Data-driven quest for two-dimensional non-van der Waals materials
Creators: name: Friedrich, Rico
name: Ghorbani-Asl, Mahdi
name: Curtarolo, Stefano
name: Krasheninnikov, Arkady V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Two-dimensional (2D) materials are frequently associated with the sheets which form bulk layered compounds bonded by van der Waals (vdW) forces. The anisotropy and weak interaction between the sheets have also been the main criteria in the computational search for new 2D systems, which predicted about 2000 exfoliable compounds. However, several representatives of a new type of non-vdW 2D systems, such as hematene or ilmenene, which have no layered 3D analogues, and which, unlike, e.g. silicene, do not need to strongly interact with the substrate to be stable, were recently manufactured. The family of non-vdW 2D materials is an attractive playground for data-driven high-throughput approaches as computational design principles are still missing. Here, we outline a new set of 8 binary and 20 ternary candidates by filtering the AFLOW-ICSD database according to the structural prototype of the first two template systems realized in experiment. All materials show a strong structural relaxation upon confinement to 2D which is essential to correctly estimate the bonding strength between facets. The oxidation state of the cations at the surface of the sheets is demonstrated to regulate the inter-facet binding energy with low oxidation states leading to weak bonding. We anticipate this descriptor to be highly useful to obtain novel 2D materials, providing clear guidelines for experiments. Our calculations further indicate that the materials exhibit a vast range of appealing electronic, optical and magnetic properties, which is expected to also make them attractive for potential applications particularly in spintronics.
description: 26 pages, 6 figures
Ferromagnetism in the Hubbard model with Topological/Non-Topological Flat Bands
Creators: name: Katsura, Hosho
name: Maruyama, Isao
name: Tanaka, Akinori
name: Tasaki, Hal
Publisher: name: arXiv
Year: 2009
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We introduce and study two classes of Hubbard models with magnetic flux or with spin-orbit coupling, which have a flat lowest band separated from other bands by a nonzero gap. We study the Chern number of the flat bands, and find that it is zero for the first class but can be nontrivial in the second. We also prove that the introduction of on-site Coulomb repulsion leads to ferromagnetism in both the classes.
description: 6 pages, 5 figures
An evaluation of health promotion workshops for nurses
Creators: name: Edwards, Joy
Publisher: name: University of British Columbia
Year: 2010

description: The purpose of this research project was to investigate the effectiveness of the two-hour and the one-day Health Promotion Workshops offered to nurses in British Columbia as part of a four month pilot project. The Registered Nurses' Association of British Columbia (RNABC) employed a nurse as special project director to develop and present Health Promotion Workshops to nurses. The goals of the workshop were: 1. To sensitize nurses to their own needs to optimize their own health. 2. To sensitize nurses to their role of sensitizing other to their need to optimize their own health. 3. To motivate nurses to make changes in their personal health behaviours. 4. To motivate nurses to make changes in their role as health promoters. The workshops were offered to all RNABC chapters throughout the province. Seventeen chapters chose the two-hour workshop and 5 chose the one-day workshop. Eight of the two-hour and three of the one-day workshop groups were used for the evaluation. The workshops were evaluated by observation, discussion with some participants, and with responses obtained through questionnaires. The questionnaires were designed to obtain information regarding knowledge, awareness, perceptions of the workshop, and behaviours of the nurses related to physical activity. Control groups were chosen by randomly selecting from the RNABC chapters, nurses who had not attended the workshop. Using analysis of variance, the control groups were found to be equivalent to the workshop groups prior to each session when comparing the questionnaire responses. Multivariate analysis of variance was done to determine differences between the workshop groups and their appropriate control groups six weeks following the workshops. The results indicated that: 1. There was a significant increase in reported exercise behaviours for both the two-hour and one-hour workshop groups. 2. There were no significant differences in reported habits relating to physical activity. 3. There were no significant differences in reported behaviours as a health promoter. Analysis of variance was done to determine significant differences among means for the knowledge test scores of each group. The results indicated that both workshop groups had a significantly higher mean score when compared to their control groups. Seventy-five percent of the participants reported that they identified changes they would like to make in their own fitness and forty-five percent indicated they were able to accomplish changes in this area. Seventy percent indicated they had an increased awareness of their role as health promoters in their work. It was concluded that the Health Promotion Workshops were effective in 1) sensitizing nurses to their own needs to optimize their own health, 2) motivating nurses to make changes in their health behaviours, and 3) sensitizing nurses to their role as health promoters.
Note on Chern-Simons Term Correction to Holographic Entanglement Entropy
Creators: name: Sun, Jia-Rui
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: From the perspective of AdS/CFT correspondence, we study the gravitational Chern-Simons term correction to the holographic entanglement entropy of CFT on the conformal boundary of asymptotically AdS$_3$ spacetime using the off-shell Euclidean path integral method. We show that, like the BTZ black hole entropy, the holographic entanglement entropy is indeed modified due to the gravitational Chern-Simons term although the bulk geometry does not change.
description: 20 pages, minor corrections made, comments added
Separability of N-particle Fermionic States for Arbitrary Partitions
Creators: name: Ichikawa, Tsubasa
name: Sasaki, Toshihiko
name: Tsutsui, Izumi
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a criterion of separability for arbitrary s partitions of N-particle fermionic pure states. We show that, despite the superficial non-factorizability due to the antisymmetry required by the indistinguishability of the particles, the states which meet our criterion have factorizable correlations for a class of observables which are specified consistently with the states. The separable states and the associated class of observables share an orthogonal structure, whose non-uniqueness is found to be intrinsic to the multi-partite separability and leads to the non-transitivity in the factorizability in general. Our result generalizes the previous result obtained by Ghirardi et. al. [J. Stat. Phys. 108 (2002) 49] for the s = 2 and s = N case.
description: 21 pages, 2 figures
Abelian covers of surfaces and the homology of the level L mapping class group
Creators: name: Putman, Andrew
Publisher: name: arXiv
Year: 2009
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We calculate the first homology group of the mapping class group with coefficients in the first rational homology group of the universal abelian $\Z / L \Z$-cover of the surface. If the surface has one marked point, then the answer is $\Q^{τ(L)}$, where $τ(L)$ is the number of positive divisors of $L$. If the surface instead has one boundary component, then the answer is $\Q$. We also perform the same calculation for the level $L$ subgroup of the mapping class group. Set $H_L = H_1(Σ_g;\Z/L\Z)$. If the surface has one marked point, then the answer is $\Q[H_L]$, the rational group ring of $H_L$. If the surface instead has one boundary component, then the answer is $\Q$.
description: 32 pages, 10 figures; numerous corrections and simplifications; to appear in J. Topol. Anal
Performance engineering of semiconductor spin qubit systems
Creators: name: Abolfath, Ramin M.
name: Brabec, Thomas
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The performance of a quantum computation system is investigated, with qubits represented by magnetic impurities in coupled quantum dots filled with two electrons. Magnetic impurities are electrically manipulated by electrons. The dominant noise source is the electron mediated indirect coupling between magnetic impurities and host spin bath. As a result of the electron mediated coupling, both noise properties and the time needed for elementary gate operations, depend on controllable system parameters, such as size and geometry of the quantum dot, and external electric and magnetic fields. We find that the maximum number of quantum operations per coherence time for magnetic impurities increases as electron spin singlet triplet energy gap decreases. The advantage of magnetic impurities over electrons for weak coupling and large magnetic fields will be illustrated.
description: 5 page, 2 figure
Seawater pH and Anthropogenic Carbon Dioxide
Creators: name: Marsh, Gerald E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In 2005, the Royal Society published a report titled "Ocean acidification due to increasing atmospheric carbon dioxide". The report's principal conclusion-that average ocean pH could decrease by 0.5 units by 2100-is demonstrated here to be consistent with a linear extrapolation of very limited data. It is also shown that current understanding of ocean mixing, and of the relationship between pH and atmospheric carbon dioxide concentration, cannot justify such an extrapolation.
description: Corrected misprints in Eqs. (1) and (A10). 14 pages, 4 figures (better quality available at gemarsh.com)
Die praktische Komponente deutscher Verständigungspolitik: Leopold von Hoesch in Paris
The technical elements of German reconciliation policy: Leopold von Hoesch in Paris
Creators: name: Koppen, Paul <1982>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: M-STO/04 Storia contemporanea

description: Diese Arbeit versucht, die Bedingungen und Umstände des deutsch-französischen Verständigungsprozesses zwischen Ruhrbesetzung und Locarno-Vertrag zu erklären, und geht dabei besonders auf den deutschen Gesandten in Paris, Leopold von Hoesch, und seinen Einfluss ein.
description: This paper tries to examine the conditions and circumstances of Franco-German reconciliation process between Ruhr occupation 1923 and Locarno-Treaty 1925 and focuses especially on the impact that German ambassador, Leopold von Hoesch, had on that process.
Effect of Oscillating Landau Bandwidth on the Integer Quantum Hall Effect in a Unidirectional Lateral Superlattice
Creators: name: Endo, Akira
name: Iye, Yasuhiro
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We have measured activation gaps for odd-integer quantum Hall states in a unidirectional lateral superlattice (ULSL) -- a two-dimensional electron gas (2DEG) subjected to a unidirectional periodic modulation of the electrostatic potential. By comparing the activation gaps with those simultaneously measured in the adjacent section of the same 2DEG sample without modulation, we find that the gaps are reduced in the ULSL by an amount corresponding to the width acquired by the Landau levels through the introduction of the modulation. The decrement of the activation gap varies with the magnetic field following the variation of the Landau bandwidth due to the commensurability effect. Notably, the decrement vanishes at the flat band conditions.
description: 7 pages, 6 figures, minor revision
Multiple dynamic regimes in concentrated microgel systems
Creators: name: Sessoms, David A.
name: Bischofberger, Irmgard
name: Cipelletti, Luca
name: Trappe, Véronique
Publisher: name: arXiv
Year: 2009
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We investigate dynamical heterogeneities in the collective relaxation of a concentrated microgel system, for which the packing fraction can be conveniently varied by changing the temperature. The packing fraction dependent mechanical properties are characterised by a fluid-solid transition, where the system properties switch from a viscous to an elastic low-frequency behaviour. Approaching this transition from below, we find that the range of spatial correlations in the dynamics increases. Beyond this transition, the spatial correlation range reaches a maximum, extending over the entire observable system size of approximately 5 mm. Increasing the packing fraction even further leads to a second transition, which is characterised by the development of large zones of lower and higher dynamical activity that are well separated from each other; the range of correlation decreases at this point. This striking non-monotonic dependence of the spatial correlation length on volume fraction is reminiscent of the behaviour recently observed at the jamming/rigidity transition in granular systems (Lechenault et al. 2008). We identify this second transition as the transition to 'squeezed' states, where the constituents of the system start to exert direct contact forces on each other, such that the dynamics becomes increasingly determined by imbalanced stresses. Evidence of this transition is also found in the frequency dependence of the storage and loss moduli, which become increasingly coupled as direct friction between the particles starts to contribute to the dissipative losses within the system. To our knowledge, our data provide the first observation of a qualitative change in dynamical heterogeneity as the dynamics switch from purely thermally-driven to stress-driven.
description: 19 pages, 8 figures. Latest version corrects errors in the indication of the concentration of microgel systems and the equation for the temperature dependence of the particle radius
Smooth approximation of Lipschitz projections
Creators: name: Li, Hanfeng
Publisher: name: arXiv
Year: 2008
Subjects: subject: Operator Algebras (math.OA)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics

description: We show that any Lipschitz projection-valued function p on a connected closed Riemannian manifold can be approximated uniformly by smooth projection-valued functions q with Lipschitz constant close to that of p. This answers a question of Rieffel.
description: 6 pages
Constructing classical field for a Bose-Einstein condensate in arbitrary trapping potential; quadrupole oscillations at nonzero temperatures
Creators: name: Karpiuk, Tomasz
name: Brewczyk, Miroslaw
name: Gajda, Mariusz
name: Rzazewski, Kazimierz
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We optimize the classical field approximation of the version described in J. Phys. B 40, R1 (2007) for the oscillations of a Bose gas trapped in a harmonic potential at nonzero temperatures, as experimentally investigated by Jin et al. [Phys. Rev. Lett. 78, 764 (1997)]. Similarly to experiment, the system response to external perturbations strongly depends on the initial temperature and on the symmetry of perturbation. While for lower temperatures the thermal cloud follows the condensed part, for higher temperatures the thermal atoms oscillate rather with their natural frequency, whereas the condensate exhibits a frequency shift toward the thermal cloud frequency (m=0 mode), or in the opposite direction (m=2 mode). In the latter case, for temperatures approaching critical, we find that the condensate begins to oscillate with the frequency of the thermal atoms, as in the m=0 mode. A broad range of frequencies of the perturbing potential is considered.
description: 10 pages, 9 figures, added references, changed content, improved English
Tuning exchange interactions in antiferromagnetic Fe/W(001) by 4d transition-metal overlayers
Creators: name: Petersen, Nanning
name: Meyer, Sebastian
name: Heinze, Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We use first-principles calculations based on density functional theory to study how the magnetic properties of an Fe monolayer on a W(001) surface -- exhibiting a $c(2 \times 2)$ antiferromagnetic ground state -- can be modified by an additional 4d transition-metal overlayer. To obtain an overview of how the 4d-band filling influences the exchange interactions in the Fe layer we have calculated the energy dispersion of spin spirals for 4d/Fe/2W unsupported quadlayers, in which the W(001)substrate is represented by only two atomic layers. Hybridization with the overlayer leads to a reduced ferromagnetic nearest-neighbor exchange interaction and the next-nearest neighbor exchange gains in strength. Surprisingly, we find that the $c(2 \times 2)$ antiferromagnetic state is unfavorable for all systems with a 4d overlayer. For 4d overlayers from the beginning (Nb) or end (Pd) of the series we find a ferromagnetic ground state. As one moves to the center of the series there is a transition via a spin spiral (Mo, Rh) to a $p (2 \times 1)$ antiferromagnetic ground state (Tc, Ru). We have studied the Mo, Ru, and Pd overlayer on Fe/W(001) representing the surface by a sufficiently large number of W layers to obtain bulk like properties in its center. The energy dispersion of spin spirals show qualitatively the same results as those from the 4\textit{d}/Fe/2W quadlayers. The Dzyaloshinskii-Moriya interaction calculated upon including spin-orbit coupling shows significant strength and considerable frustration effects. The calculated magnetocrystalline anisotropy energy is large as well. All 4d/Fe/W(001) films are potential candidates for complex non-collinear spin structures.
Special functions associated to a certain fourth order differential equation
Creators: name: Hilgert, Joachim
name: Kobayashi, Toshiyuki
name: Mano, Gen
name: Möllers, Jan
Publisher: name: arXiv
Year: 2009
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 33C45, 22E46, 34A05, 42C15

description: We develop a theory of "special functions" associated to a certain fourth order differential operator $\mathcal{D}_{μ,ν}$ on $\mathbb{R}$ depending on two parameters $μ,ν$. For integers $μ,ν\geq-1$ with $μ+ν\in2\mathbb{N}_0$ this operator extends to a self-adjoint operator on $L^2(\mathbb{R}_+,x^{μ+ν+1}dx)$ with discrete spectrum. We find a closed formula for the generating functions of the eigenfunctions, from which we derive basic properties of the eigenfunctions such as orthogonality, completeness, $L^2$-norms, integral representations and various recurrence relations. This fourth order differential operator $\mathcal{D}_{μ,ν}$ arises as the radial part of the Casimir action in the Schrödinger model of the minimal representation of the group $O(p,q)$, and our "special functions" give $K$-finite vectors.
Elliptical Trajectories in Nonsequential Double Ionization
Creators: name: Wang, Xu
name: Eberly, J. H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Using a classical ensemble method, nonsequential double ionization is predicted to exist with elliptical and circular polarization. Recollision is found to be the underlying mechanism and it is only possible via elliptical trajectories.
description: Submitted to New Journal of Physics
Fefferman-Stein inequalities for the \mathbb{Z}_2^d Dunkl maximal operator
Creators: name: Deleaval, Luc
Publisher: name: arXiv
Year: 2008
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: In this article, we establish the Fefferman-Stein inequalities for the Dunkl maximal operator associated with a finite reflection group generated by the sign changes. Similar results are also given for a large class of operators related to Dunkl's analysis.
description: This is the version accepted in JMAA
Interplanetary Magnetic Field Control of PolarIonospheric Equivalent Current System Modes
Creators: name: Shore, R. M.
name: Freeman, M. P.
name: Gjerloev, J. W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We analyze the response of different ionospheric equivalent current modes to variations in the interplanetary magnetic field (IMF) components By and Bz. Each mode comprises a fixed spatial pattern whose amplitude varies in time, identified by a month-by-month empirical orthogonal function separation of surface measured magnetic field variance. Here we focus on four sets of modes that have been previously identified as DPY, DP2, NBZ, and DP1. We derive the cross-correlation function of each mode set with either IMF (B$_{y}$) or (B$_{z}$) for lags ranging from -10 to +600 mins with respect to the IMF state at the bow shock nose. For all four sets of modes, the average correlation can be reproduced by a sum of up to three linear responses to the IMF component, each centered on a different lag. These are interpreted as the statistical ionospheric responses to magnetopause merging (15- to 20-min lag) and magnetotail reconnection (60-min lag) and to IMF persistence. Of the mode sets, NBZ and DPY are the most predictable from a given IMF component, with DP1 (the substorm component) the least predictable. The proportion of mode variability explained by the IMF increases for the longer lags, thought to indicate conductivity feedbacks from substorms. In summary, we confirm the postulated physical basis of these modes and quantify their multiple reconfiguration timescales.
Weighted-Lasso for Structured Network Inference from Time Course Data
Creators: name: Charbonnier, Camille
name: Chiquet, Julien
name: Ambroise, Christophe
Publisher: name: arXiv
Year: 2009
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: We present a weighted-Lasso method to infer the parameters of a first-order vector auto-regressive model that describes time course expression data generated by directed gene-to-gene regulation networks. These networks are assumed to own a prior internal structure of connectivity which drives the inference method. This prior structure can be either derived from prior biological knowledge or inferred by the method itself. We illustrate the performance of this structure-based penalization both on synthetic data and on two canonical regulatory networks, first yeast cell cycle regulation network by analyzing Spellman et al's dataset and second E. coli S.O.S. DNA repair network by analysing U. Alon's lab data.
Extracting the parton distribution functions evolution equations using the stochastic modeling in the non-equilibrium statistical mechanics
Creators: name: Olanj, N.
name: Moradi, E.
name: Modarres, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In this paper, using the stochastic modeling of the non-equilibrium statistical mechanics in the momentum space, the evolution equations of the parton distribution functions (PDF) usually used in the hadrons phenomenology are generated. These stochastic modeling PDF evolution equations are the same as those of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) ones, but they can be obtained by a more simplistic mathematical procedure based on the non-equilibrium statistical mechanics and the theory of Markov processes.
Role of a Phase Factor in the Boundary Condition of a One-Dimensional Junction
Creators: name: Furuhashi, Yoshiyuki
name: Hirokawa, Masao
name: Nakahara, Kazumitsu
name: Shikano, Yutaka
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Mathematical Physics (math-ph)
subject: Functional Analysis (math.FA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: One-dimensional quantum systems can be experimentally studied in recent nano-technology like the carbon nanotube and the nanowire. We have considered the mathematical model of the one-dimensional Schrödinger particle with a junction and have analyzed the phase factor in the boundary condition of the junction. We have shown that the phase factor in the tunneling case appears in the situation of the non-adiabatic transition with the three energy levels in the exact WKB analysis.
description: 19 pages, to appear in Journal of Physics A: Mathematical and Theoretical, Special issues: Quantum Phases: 50 Years of the Aharonov-Bohm Effect and 25 Years of the Berry Phase
Orthogonal polynomials associated to a certain fourth order differential equation
Creators: name: Hilgert, Joachim
name: Kobayashi, Toshiyuki
name: Mano, Gen
name: Möllers, Jan
Publisher: name: arXiv
Year: 2009
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 33C45, 22E46, 34A05, 42C15

description: We introduce orthogonal polynomials $M_j^{μ,\ell}(x)$ as eigenfunctions of a certain self-adjoint fourth order differential operator depending on two parameters $μ\in\mathbb{C}$ and $\ell\in\mathbb{N}_0$. These polynomials arise as $K$-finite vectors in the $L^2$-model of the minimal unitary representations of indefinite orthogonal groups, and reduce to the classical Laguerre polynomials $L_j^μ(x)$ for $\ell=0$. We establish various recurrence relations and integral representations for our polynomials, as well as a closed formula for the $L^2$-norm. Further we show that they are uniquely determined as polynomial eigenfunctions.
Killing Vector Fields in Three Dimensions: A Method to Solve Massive Gravity Field Equations
Creators: name: Gurses, Metin
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Killing vector fields in three dimensions play important role in the construction of the related spacetime geometry. In this work we show that when a three dimensional geometry admits a Killing vector field then the Ricci tensor of the geometry is determined in terms of the Killing vector field and its scalars. In this way we can generate all products and covariant derivatives at any order of the ricci tensor. Using this property we give ways of solving the field equations of Topologically Massive Gravity (TMG) and New Massive Gravity (NMG) introduced recently. In particular when the scalars of the Killing vector field (timelike, spacelike and null cases) are constants then all three dimensional symmetric tensors of the geometry, the ricci and einstein tensors, their covariant derivatives at all orders, their products of all orders are completely determined by the Killing vector field and the metric. Hence the corresponding three dimensional metrics are strong candidates of solving all higher derivative gravitational field equations in three dimensions.
description: 25 pages, some changes made and some references added, to be published in Classical and Quantum Gravity
Quasi-Chemical and Structural Analysis of Polarizable Anion Hydration
Creators: name: Rogers, David M.
name: Beck, Thomas L.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Quasi-chemical theory is utilized to analyze the roles of solute polarization and size in determining the structure and thermodynamics of bulk anion hydration for the Hofmeister series Cl$^-$, Br$^-$, and I$^-$. Excellent agreement with experiment is obtained for whole salt hydration free energies using the polarizable AMOEBA force field. The quasi-chemical approach exactly partitions the solvation free energy into inner-shell, outer-shell packing, and outer-shell long-ranged contributions by means of a hard-sphere condition. Small conditioning radii, even well inside the first maximum of the ion-water(oxygen) radial distribution function, result in Gaussian behavior for the long-ranged contribution that dominates the ion hydration free energy. The spatial partitioning allows for a mean-field treatment of the long-ranged contribution, leading to a natural division into first-order electrostatic, induction, and van der Waals terms. The induction piece exhibits the strongest ion polarizability dependence, while the larger-magnitude first-order electrostatic piece yields an opposing but weaker polarizability dependence. In addition, a structural analysis is performed to examine the solvation anisotropy around the anions. As opposed to the hydration free energies, the solvation anisotropy depends more on ion polarizability than on ion size: increased polarizability leads to increased anisotropy. The water dipole moments near the ion are similar in magnitude to bulk water, while the ion dipole moments are found to be significantly larger than those observed in quantum mechanical studies. Possible impacts of the observed over-polarization of the ions on simulated anion surface segregation are discussed.
description: slight revision, in press at J. Chem. Phys
The preparation and isolation of ¹⁴C-labelled egg white lysozyme and its utilization by in vitro cultured macrophage
Creators: name: Blommers, Hendrik Willem
Publisher: name: University of British Columbia
Year: 2010

description: A preparative electrophoretic method was developed to isolate egg white lysozyme. The electrophoretic unit consisted of a slightly modified glass funnel in which a slab of polyacrylamide gel was suspended. The A₂₈₀ absorbing material extracted from the polyacrylamide gel travelled as a single staining band on quantitative polyacrylamide disc gels. Up to 25 mg. of apparently pure lysozyme was prepared by this method. Radioactive lysozyme was prepared by injecting young laying hens with a ¹⁴C ammo acid hydrolysate. By injecting the hydrolysate 5 hrs. postoviposition, lysozyme with a specific activity of 2 .6 x 10¹⁰ dpm/mole was prepared. Injection of the radioactive amino acids at intervals less than 5 hrs. postoviposition resulted in lower activity lysozyme. A theory has been suggested which could explain the generation of antibody diversity. In this theory (25, 26), the RNA portion of the RNA—antigen complex formed during an immune response, acts in an informational capacity. In order to investigate one aspect of the formation of these complexes, a radioactive antigen was required. The radioactive lysozyme isolated as described above was used. Nucleic acid extractions of macrophage incubated with radioactive lysozyme found little activity in the nucleic acid fractions. A thorough discussion in light of these results is presented along with some suggestions for further work.
On a theorem of Carlitz
Creators: name: Zieve, Michael E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Number Theory (math.NT)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 11T06, 20B30

description: Carlitz proved that, for any prime power q other than 2, the group of all permutations of the finite field F_q is generated by the permutations induced by degree-one polynomials and x^{q-2}. His proof relies on a remarkable polynomial which appears to have been found by magic. We show here that no magic is required: there is a straightforward way to produce a simple polynomial which has the same remarkable properties as the complicated polynomial in Carlitz's proof. We also identify the crucial subtlety which allows such simple polynomials to exist, and discuss some consequences.
description: 2 pages
Bit Copying - The Ultimate Computational Simplicity
Creators: name: Mazonka, Oleg
Publisher: name: arXiv
Year: 2009
Subjects: subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: A computational abstract machine based on two operations: referencing and bit copying is presented. These operations are sufficient for carrying out any computation. They can be used as the primitives for a Turing-complete programming language. The interesting point is that the computation can be done without logic operations such as AND or OR. The compiler and emulator of this language with sample programs are available on the Internet.
Subspace hypercyclicity
Creators: name: Madore, Blair
name: Avendaño, Rubén A. Martínez
Publisher: name: arXiv
Year: 2010
Subjects: subject: Functional Analysis (math.FA)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 47A16

description: A bounded linear operator T on Hilbert space is subspace-hypercyclic for a subspace M if there exists a vector whose orbit under T intersects the subspace in a relatively dense set. We construct examples to show that subspace-hypercyclicity is interesting, including a nontrivial subspace-hypercyclic operator that is not hypercyclic. There is a Kitai-like criterion that implies subspace-hypercyclicity and although the spectrum of a subspace-hypercyclic operator must intersect the unit circle, not every component of the spectrum will do so. We show that, like hypercyclicity, subspace-hypercyclicity is a strictly infinite-dimensional phenomenon. Additionally, compact or hyponormal operators can never be subspace-hypercyclic.
description: 15 pages
Dark quadratic localized states and collapsed snaking in doubly resonant dispersive cavity enhanced second harmonic generation
Creators: name: Parra-Rivas, P.
name: Arabí, C. Mas
name: Leo, F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We theoretically investigate the dynamics, bifurcation structure and stability of quadratic dark localized dissipative states arising in cavity enhanced second-harmonic generation. These states, formed through the locking of plane front waves, undergo collapsed homoclinic snaking and may exhibit oscillatory dynamics.
Extremal Bases, Geometrically Separated Domains and Applications
Creators: name: Charpentier, Philippe
name: Dupain, Yves
Publisher: name: arXiv
Year: 2008
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: We introduce the notion of extremal basis of tangent vector fields at a boundary point of finite type of a pseudo-convex domain in $\mathbb{C}^n$. Then we define the class of geometrically separated domains at a boundary point, and give a description of their complex geometry. Examples of such domains are given, for instance, by locally lineally convex domains, domains with locally diagonalizable Levi form, and domains for which the Levi form have comparable eigenvalues at a point. Moreover we show that these domains are localizable. Then we define the notion of "adapted pluri-subharmonic function" to these domains, and we give sufficient conditions for his existence. Then we show that all the sharp estimates for the Bergman ans Szegö projections are valid in this case. Finally we apply these results to the examples to get global and local sharp estimates, improving, for examlple, a result of Fefferman, Kohn and Machedon on the Szegö projection.
description: 37 pages. Final version to appear in St. Petersburg Math. J
Multi-pollutants impact on modern cement built heritage
Creators: name: Ozga, Izabela Joanna <1982>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: CHIM/12 Chimica dell'ambiente e dei beni culturali

description: It is well known that the deposition of gaseous pollutants and aerosols plays a major role in
causing the deterioration of monuments and built cultural heritage in European cities. Despite
of many studies dedicated to the environmental damage of cultural heritage, in case of cement
mortars, commonly used in the 20th century architecture, the deterioration due to air multipollutants
impact, especially the formation of black crusts, is still not well explored making
this issue a challenging area of research.
This work centers on cement mortars – environment interactions, focusing on the diagnosis of
the damage on the modern built heritage due to air multi-pollutants. For this purpose three
sites, exposed to different urban areas in Europe, were selected for sampling and subsequent
laboratory analyses: Centennial Hall, Wroclaw (Poland), Chiesa dell'Autostrada del Sole,
Florence (Italy), Casa Galleria Vichi, Florence (Italy). The sampling sessions were performed
taking into account the height from the ground level and protection from rain run off
(sheltered, partly sheltered and exposed areas). The complete characterization of collected
damage layer and underlying materials was performed using a range of analytical techniques:
optical and scanning electron microscopy, X ray diffractometry, differential and gravimetric
thermal analysis, ion chromatography, flash combustion/gas chromatographic analysis,
inductively coupled plasma-optical emission spectrometer. The data were elaborated using
statistical methods (i.e. principal components analyses) and enrichment factor for cement
mortars was calculated for the first time.
The results obtained from the experimental activity performed on the damage layers indicate
that gypsum, due to the deposition of atmospheric sulphur compounds, is the main damage
product at surfaces sheltered from rain run-off at Centennial Hall and Casa Galleria Vichi. By
contrast, gypsum has not been identified in the samples collected at Chiesa dell'Autostrada del
Sole. This is connected to the restoration works, particularly surface cleaning, regularly
performed for the maintenance of the building.
Moreover, the results obtained demonstrated the correlation between the location of the
building and the composition of the damage layer: Centennial Hall is mainly undergoing to
the impact of pollutants emitted from the close coal power stations, whilst Casa Galleria Vichi
is principally affected by pollutants from vehicular exhaust in front of the building.
Captia
Creators: By- og Landskabsstyrelsen
Center for koncernforvaltning
Danmarks Miljøportal
Danmarks Miljøundersøgelser (DMU)
Miljøministeriets departement
Institut for Miljøvurdering
Kort & Matrikelstyrelsen
Skov- og Naturstyrelsen
Nationale Geologiske undersøgelse for Danmark og Grønland (GEUS)
Skov- og Naturstyrelsen
Naturklagenævnet
Miljøklagenævnet
Miljøcenter Nykøbing
Miljøcenter Odense
Miljøcenter Ribe
Miljøcenter Ringkøbing
Miljøcenter Roskilde
Miljøcenter Aalborg
Miljøcenter Aarhus
Publisher: name: Rigsarkivet
Year: 2022

description: Styring af opgaver på Miljøministeriets område
Thermal contraction in silicon nanowires at low temperatures
Creators: name: Jiang, Jin-Wu
name: Wang, Jian-Sheng
name: Li, Baowen
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The thermal expansion effect of silicon nanowires (SiNW) in [100], [110] and [111] directions with different sizes is theoretically investigated. At low temperatures, all SiNW studied exhibit thermal contraction effect due to the lowest energy of the bending vibration mode which has negative effect on the coefficient of thermal expansion (CTE). The CTE in [110] direction is distinctly larger than the other two growth directions because of the anisotropy of the bending mode in SiNW. Our study reveals that CTE decreases with an increase of the structure ratio $γ=length/diameter$, and is negative in whole temperature range with $γ=1.3$.
description: accepted by Nanoscale
آثار عدم اكتساب الشركات المدنية للشخصية الاعتبارية في ضوء نظام المعاملات المدنية السعودي
Creators: name: Mustapha, Alfurke
Publisher: name: figshare
Year: 2025
Subjects: classificationCode: 480102
subject: Commercial law

description: آثار عدم اكتساب الشركات المدنية للشخصية الاعتبارية في ضوء نظام المعاملات المدنية السعوديThe Effects of the Failure to Acquire Legal Personality for Civil Companies in Light of Saudi Civil Transactions Lawالباحثة : ساره سعود الرحيليطالبة ماجستير، قسم القانون الخاص كلية الحقوق، جامعة الملك عبدالعزيزإشراف: الدكتورة : دينا إسماعيل أبو زيدأستاذ مشارك في القانون المدني، قسم القانون الخاص كلية الحقوق، جامعة الملك عبدالعزيز