cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Application of solid state physics characterization techniques for the study of vertebrate fossils recovered from excavation sites in Greece
Creators: name: Ζούγρου, Ιωάννα Μαρία Γ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2017
Subjects: Απολιθώματα
Τεχνικές χαρακτηρισμού Φυσικής Στερεάς Κατάστασης
Ταφονομία
Ακτινοβολία σύγχροτρον
Fossils
Soils State Physics characterization techniques
Taphonomy
Synchrotron radiation

description: The aim of the present thesis was the study of fossil vertebrate skeletal remains unearthed from excavation sites of Northern Greece. The fossil skeletal and sedimentary specimens were examined by means of Optical Microscopy, Scanning Electron Microscopy, X-Ray Fluorescence spectroscopy, X-Ray Photoelectron spectroscopy, X-Ray Absorption Fine Structure spectroscopy, Raman spectroscopy and natural radioactivity measurements in order to obtain information about the taphonomic and diagenetic processes occurring during fossilization as well as for the investigation of the chemical and structural changes of fossilized apatite using Solid State Physics characterization techniques.
description: Στην παρούσα διατριβή μελετήθηκαν παλαιοντολογικά δείγματα οστών, οδόντων και χαυλιοδόντων καθώς και δείγματα ιζήματων προερχόμενων από παλαιοντολογικές ανασκαφές της Βόρειας Ελλάδας. Οι τεχνικές χαρακτηρισμού που χρησιμοποιήθηκαν περιλαμβάνουν οπτική (ΟΜ) και ηλεκτρονική μικροσκοπία σάρωσης (SEM), φασματοσκοπία φθορισμού ακτίνων-Χ (XRF), φασματοσκοπία φωτοηλεκτρονίων ακτίνων-Χ (XPS), φασματοσκοπία απορρόφησης ακτίνων-Χ λεπτής υφής (XAFS), φασματοσκοπία Raman καθώς και μετρήσεις φυσικής ραδιενέργειας. Σκοπός της εργασίας είναι η μελέτη των ταφονομικών και διαγενετικών διαδικασιών που έλαβαν χώρα κατά την απολίθωση καθώς και η διερεύνηση των δυνατοτήτων τεχνικών χαρακτηρισμού Φυσικής Στερεάς Κατάστασης για την μελέτη των χημικών και δομικών μεταβολών του απολιθωμένου απατίτη.
The synthesis, magnetic and mossbauer spectral properties of poly-[mu]-bis (di-n-octylphosphinato) iron(II) and its zinc(II)-doped analogues
Creators: name: Peers, James Richard Douglas
Publisher: name: University of British Columbia
Year: 2010

description: The inorganic coordination polymer, poly-μ-bis(di-n-octylphosphinato)iron(II), (Fe[(n-C₈H₁₇)₂PO₂])[sub n] , was prepared and characterized. The physical properties of this compound were analyzed using differential scanning calorimetry, vibrational, electronic and Mossbauer spectroscopy and temperature dependent magnetic susceptibility studies. Evidence for polymorphism in this compound was found, leading to the postulation of the existence of two forms of this material, labelled I and II. Evidence was seen suggesting that a Form I to Form II transition occurs upon the application of pressure. Differential scanning calorimetry results suggested that this transition was not thermally induced over the temperature range 35 to 300°C. Both forms were suggested to be four-coordinate and to possess a highly compressed tetrahedral metal-oxygen chromophore. Mossbauer spectral studies suggested that the iron(II) centres in this material were in the rare triplet ground state, giving an intermediate spin S=1 system. Mossbauer spectroscopy also showed a substantial positive contribution to the splitting of the S=1 quadrupole doublet, possibly as a result of σ-donation properties of the ligands. The magnetic susceptibility vs. temperature data, collected in the range of 2-80 K and analyzed according to a linear chain Heisenberg S=1 model, showed the iron centres to be antiferromagnetically coupled and also to have unexpectedly large Lande splitting factor, g. The high g value was presumed to be the result of large orbital angular momentum contributions. Based on these results, electronic structure schemes were proposed for Forms I and II. In addition, zinc(II)-doped samples of this compound, {Fe[sub 1-x] Zn [ (n-C₈H₁₇)₂ PO₂ ]₂}[sub n] , were prepared with x=0.05, 0.1 and 0.2. These compounds were analyzed by differential scanning calorimetry, vibrational and Mossbauer spectroscopy and temperature dependent magnetic susceptibility studies and also appeared to occur in the polymorphic forms I and II. Mossbauer spectroscopy again suggested the presence of iron (II) S=1 centres, but also showed the presence of S=2 iron (II). This led to the proposal that the effect of doping zinc(II) into this system is to distort the geometries of the iron centres adjacent to the zinc centres to a more tetrahedral configuration. A large quadrupole splitting was observed for the S=2 lines, again perhaps a result of substantial σ-donation from the ligands. Magnetic susceptibility vs. temperature data were also collected over the range 2-80 K for these samples; the details of these results are discussed in a qualitative manner.
Sudakov resummation from the BFKL evolution
Creators: name: Nefedov, Maxim
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Leding-Logarithmic (LL) gluon Sudakov formfactor is derived from rapidity-ordered BFKL evolution with longitudinal-momentum conservation. This derivation further clarifies the relation between High-Energy and TMD-factorizations and can be extended beyond LL-approximation as well.
description: 16 pages, 4 figures, significantly extended version, submitted to PRD
Cytogenotoxic evaluation of the acetonitrile extract, citrinin and dicitrinin-A from Penicillium citrinum
Creators: name: de Oliveira Filho, José Williams Gomes
name: de Jesus Aguiar dos Santos Andrade, Teresinha
name: de Lima, Rosália Maria Tôrres
name: Silva, Dulce Helena Siqueira
name: Reis, Antonielly Campinho dos
name: de Oliveira Santos, José Victor
name: de Meneses, Ag-Anne Pereira Melo
name: de Carvalho, Ricardo Melo
name: da Mata, Ana Maria Oliveira
name: de Alencar, Marcus Vinícius Oliveira Barros
name: Dias, Ana Carolina Soares
name: da Silva, Felipe Cavalcanti Carneiro
name: Islam, Muhammad Torequl
name: Clark, Cain C. T.
name: de Castro e Sousa, João Marcelo
name: de Carvalho Melo-Cavalcante, Ana Amélia
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Evolutionary Biology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: Cancer
subject: Plant Biology

description: Endophytic fungi are promising sources of bioactive substances; however, their secondary metabolites are toxic to plants, animals, and humans. This study aimed toevaluate the toxic, cytotoxic, mutagenic and oxidant/antioxidant activities of acetonitrile extract (AEPc), citrinin (CIT) and dicitrinin-A (DIC-A) of Penicillium citrinum. For this, the test substances at 0.5; 1.0; 1.5 and 2 μg/mLwere exposed for 24 and 48 h in Artemia salina, and 48 h in Allium cepa test systems. The oxidant/antioxidant test was evaluated in pre-, co- and post-treatment with the stressor hydrogen peroxide (H2O2) in Saccharomyces cerevisiae. The results suggest that the AEPc, CIT and DIC-A at 0.5; 1.0; 1.5 and 2 μg/mL showed toxicity in A. saline, with LC50 (24 h) of 2.03 μg/mL, 1.71 μg/mL and 2.29 μg/mL, and LC50 (48 h) of 0.51 μg/mL, 0.54 μg/mL and 0.54 μg/mL, respectively.In A. cepa, the test substances also exerted cytotoxic and mutagenic effects. The AEPc, CIT and DIC-A at lower concentrations modulated the damage induced by H2O2 in the proficient and mutant strains of S. cerevisiae for cytoplasmic and mitochondrial superoxide dismutase. Moreover, the AEPc at 2 μg/mL and CIT at the two highest concentrations did not affect the H2O2-induced DNA damage in the test strains. In conclusion, AEPc, CIT and DIC-A of P. citrinum may exert their toxic, cytotoxic and mutagenic effects in the test systems possibly through oxidative stress induction pathway.
Fermi arcs in cuprate superconductors: tracking the pseudogap below Tc and above T*
Creators: name: Storey, J. G.
name: Tallon, J. L.
name: Williams, G. V. M.
name: Loram, J. W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Using an energy-momentum dispersion for Bi2Sr2CaCu2O8 obtained from angle-resolved photoelectron spectroscopy we show that the shrinking Fermi arc model of the pseudogap is inconsistent with Raman scattering below Tc and specific heat near T*. By simulating the quasiparticle energy dispersion curves we show that Fermi arcs are an artifact of a T-dependent scattering rate.
description: 5 pages, 6 figures, accepted for publication as a Rapid Communication in Physical Review B
25I-NBOMe, a phenethylamine derivative, induces adverse cardiovascular effects in rodents: possible involvement of p21 (CDC42/RAC)-activated kinase 1
Creators: name: Yoon, Kyung Sik
name: Gu, Sun Mi
name: Cha, Hye Jin
name: Kim, Young-Hoon
name: Yun, Jaesuk
name: Lee, Jin-Moo
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biochemistry
subject: Cell Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Cancer
subject: 60506 Virology

description: Abuse of new psychoactive substances is an emerging social problem. Several phenethylamines are internationally controlled substances as they are likely to be abused and have adverse effects. Phenethylamine analog 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25I-NBOMe) has been reported as one of the most commonly abused psychoactive substance. However, the cardiotoxicity of this compound has not been extensively evaluated. Thus, in this study, we investigated the adverse cardiovascular effects of 25I-NBOMe, related to p21 (CDC42/RAC)-activated kinase 1 (PAK1). The cardiotoxicity of 25I-NBOMe was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, live/dead cytotoxicity assay, PAK1/CDC42 kinase assay, and in vivo electrocardiography (ECG). Also, we analyzed the expression level of PAK1, which is known to play key roles in the cardiovascular system. In the MTT assay, cell viability of 25I-NBOMe-treated H9c2 cells or primary cardiomyocytes of ICR mice decreased in a concentration-dependent manner. Results from the in vitro cytotoxicity assay in cardiomyocytes showed that 25I-NBOMe decreased the viability of H9c2 rat cardiomyocytes, and TC50 of 25I-NBOMe was found to be 70.4 μM. We also observed that 25I-NBOMe reduced PAK1 activity in vitro. Surface ECG measurement revealed that intravenous injection of 25I-NBOMe (doses of 1.0 and 3.0 mg/kg, corresponding to serum concentrations of 18.1 and 28.6 ng/mL, respectively) prolonged the QTc interval in SD rats. Furthermore, treatment with 25I-NBOMe downregulated the expression of PAK1 in the hearts of SD rats and H9c2 cells. In summary, our findings indicate that PAK1-related adverse effects of 25I-NBOMe can cause toxicity to cardiomyocytes and induce an abnormal ECG pattern in animals.
Tiling models for metadislocations in AlPdMn approximants
Creators: name: Engel, Michael
name: Trebin, Hans-Rainer
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The AlPdMn quasicrystal approximants xi, xi', and xi'_n of the 1.6 nm decagonal phase and R, T, and T_n of the 1.2 nm decagonal phase can be viewed as arrangements of cluster columns on two-dimensional tilings. We substitute the tiles by Penrose rhombs and show, that alternative tilings can be constructed by a simple cut and projection formalism in three dimensional hyperspace. It follows that in the approximants there is a phasonic degree of freedom, whose excitation results in the reshuffling of the clusters. We apply the tiling model for metadislocations, which are special textures of partial dislocations.
description: 7 pages, 2 figures, Proceedings of International Conference on Quasicrystals 9
Roughness and Correlations in the Transition from Island to Film Growth: Simulations and Application to CdTe Deposition
Creators: name: To, Tung B. T.
name: Almeida, Renan A. L.
name: Ferreira, Sukarno O.
name: Reis, Fábio D. A. Aarão
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using kinetic Monte Carlo simulations, we develop a framework to relate morphological properties and microscopic dynamics during island growth, coalescence, and initial formation of continuous heteroepitaxial films. The average island width is controlled by adatom mobility on the substrate. Subsequent evolution strongly depends on the Ehrlich-Schwöebel energy barrier $E_{ES}$ of the deposited material. As $E_{ES}$ decreases, islands becomes taller and their coalescence is delayed. For small islands and large $E_{ES}$, the global roughness increases as $W\sim{\text{thickness}}^{1/2}$ and the local roughness increases at short scales (apparent anomalous scaling) before and after island coalescence. If the islands are wide, $W$ may have a plateau for large $E_{ES}$ and has a maximum for small $E_{ES}$ when the islands coalesce. This framework is applied to atomic-force microscopy data of the initial stages of CdTe deposition on Kapton: a maximum of $W$ during island coalescence indicates negligible ES barrier, consistently with scaling properties of much thicker films, and the diffusion coefficient ${10}^{-7}{\text{--}}{10}^{-5}{\text{cm}}^2/{\text s}$ on the Kapton surface at $150\,^{\circ}\mathrm{C}$ is estimated. Applications of the framework to other materials are suggested, in which the expected roles of ES barriers are highlighted.
Heisenberg antiferromagnet with anisotropic exchange on the Kagome lattice: Description of the magnetic properties of volborthite
Creators: name: Yavors'kii, T.
name: Apel, W.
name: Everts, H. -U.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the properties of the Heisenberg antiferromagnet with spatially anisotropic nearest-neighbour exchange couplings on the kagome net, i.e. with coupling J in one lattice direction and couplings J' along the other two directions. For J/J' > 1, this model is believed to describe the magnetic properties of the mineral volborthite. In the classical limit, it exhibits two kinds of ground states: a ferrimagnetic state for J/J' < 1/2 and a large manifold of canted spin states for J/J' > 1/2. To include quantum effects self-consistently, we investigate the Sp(N) symmetric generalisation of the original SU(2) symmetric model in the large-N limit. In addition to the dependence on the anisotropy, the Sp(N) symmetric model depends on a parameter kappa that measures the importance of quantum effects. Our numerical calculations reveal that in the kappa-J/J' plane, the system shows a rich phase diagram containing a ferrimagnetic phase, an incommensurate phase, and a decoupled chain phase, the latter two with short- and long-range order. We corroborate these results by showing that the boundaries between the various phases and several other features of the Sp(N) phase diagram can be determined by analytical calculations. Finally, the application of a block-spin perturbation expansion to the trimerised version of the original spin-1/2 model leads us to suggest that in the limit of strong anisotropy, J/J' >> 1, the ground state of the original model is a collinearly ordered antiferromagnet, which is separated from the incommensurate state by a quantum phase transition.
description: 21 pages, 22 figures. Final version, PRB in press
Regulatory Dynamics on Random Networks: Asymptotic Periodicity and Modularity
Creators: name: Cros, Anne
name: Morante, Antonio
name: Ugalde, Edgardo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37L60, 37N25

description: We study the dynamics of discrete-time regulatory networks on random digraphs. For this we define ensembles of deterministic orbits of random regulatory networks, and introduce some statistical indicators related to the long-term dynamics of the system. We prove that, in a random regulatory network, initial conditions converge almost surely to a periodic attractor. We study the subnetworks, which we call modules, where the periodic asymptotic oscillations are concentrated. We proof that those modules are dynamically equivalent to independent regulatory networks.
description: 23 pages, 3 figures
GHZ-like states in the Qubit-Qudit Rabi Model
Creators: name: Shen, Yuan
name: Marchegiani, Giampiero
name: Catelani, Gianluigi
name: Amico, Luigi
name: Liu, Ai Qun
name: Fan, Weijun
name: Kwek, Leong-Chuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study a Rabi type Hamiltonian system in which a qubit and a d-level quantum system (qudit) are coupled through a common resonator. In the weak and strong coupling limits the spectrum is analysed through suitable perturbative schemes. The analysis show that the presence of the multilevels of the qudit effectively enhance the qubit-qudit interaction. The ground state of the strongly coupled system is a found of Greenberger-Horne-Zeilinger (GHZ) type. Therefore, despite the qubit-qudit strong coupling, the nature of the specific tripartite entanglement of the GHZ state suppress the bipartite entanglement. We analyze the system dynamics under quenching and adiabatic switching of the qubit-resonator and qudit-resonator couplings. In the quench case, we found that the non-adiabatic generations of photons in the resonator is enhanced by the number of levels in the qudit. The adiabatic control represents a possible route for preparation of GHZ states. Our analysis provides relevant information for future studies on coherent state transfer in qubit-qudit systems.
description: 15 pages, 7 figures, Submission to SciPost
On the Nature of Ultra-Luminous X-ray Sources from Optical/IR Measurements
Creators: name: Cropper, Mark
name: Copperwheat, Christopher
name: Wu, Kinwah
name: Soria, Roberto
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a model for the prediction of the optical/infra-red emission from ULXs. In the model, ULXs are binary systems with accretion taking place through Roche lobe overflow. We show that irradiation effects and presence of an accretion disk significantly modify the optical/infrared flux compared to single stars, and also that the system orientation is important. We include additional constraints from the mass transfer rate to constrain the parameters of the donor star, and to a lesser extent the mass of the BH. We apply the model to fit photometric data for several ULX counterparts. We find that most donor stars are of spectral type B and are older and less massive than reported elsewhere, but that no late-type donors are admissable. The degeneracy of the acceptable parameter space will be significantly reduced with observations over a wider spectral range, and if time-resolved data become available.
Polynomials with a common composite
Creators: name: Beals, Robert M.
name: Wetherell, Joseph L.
name: Zieve, Michael E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 14H25 (Primary), 12E30, 11C08 (Secondary)

description: Let f and g be nonconstant polynomials over an arbitrary field K. In this paper we study the intersection of the polynomial rings K[f] and K[g], and in particular we ask whether this intersection is larger than K. We completely resolve this question when K has characteristic zero, and in positive characteristic we present various results, examples, and algorithms.
description: 20 pages; various minor changes, and some alternate proofs suggested by the referee
Congestion control in high-speed networks using the probabilistic estimation approach
Creators: name: Jamali, Shahram
name: Talebi, Mir Mahmoud
name: Fotohi, Reza
Publisher: name: arXiv
Year: 2021
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Nowadays, the bulk of Internet traffic uses TCP protocol for reliable transmission. But the standard TCP's performance is very poor in High Speed Networks (HSN) and hence the core gigabytes links are usually underutilization. This problem has roots in conservative nature of TCP, especially in its Additive Increase Multiplicative Decrease (AIMD) phase. In other words, since TCP can't figure out precisely the congestion status of the network, it follows a conservative strategy to keep the network from overwhelming. We believe that precisely congestion estimation in the network can solve this problem by avoiding unnecessary conservation. To this end, this paper proposes an algorithm which considers packet loss and delay information jointly and employs a probabilistic approach to accurately estimation of congestion status in the network. To examine the proposed scheme performance, extensive simulations have been performed in the NS-2 environment. Simulation results reveal that the proposed algorithm has better performance than existing algorithms in terms of bottleneck utilization, stability, throughput and fairness.
description: 19 pages, 14 Figures, 2 Tables, Int J Commun Syst
Restoring isotropy in a three-dimensional lattice model: The Ising universality class
Creators: name: Hasenbusch, Martin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We study a generalized Blume-Capel model on the simple cubic lattice. In addition to the nearest neighbor coupling there is a next to next to nearest neighbor coupling. In order to quantify spatial anisotropy, we determine the correlation length in the high temperature phase of the model for three different directions. It turns out that the spatial anisotropy depends very little on the dilution parameter $D$ of the model and is essentially determined by the ratio of the nearest neighbor and the next to next to nearest neighbor coupling. This ratio is tuned such that the leading contribution to the spatial anisotropy is eliminated. Next we perform a finite size scaling (FSS) study to tune $D$ such that also the leading correction to scaling is eliminated. Based on this FSS study, we determine the critical exponents $ν=0.62998(5)$ and $η=0.036284(40)$, which are in nice agreement with the more accurate results obtained by using the conformal bootstrap method. Furthermore we provide accurate results for fixed point values of dimensionless quantities such as the Binder cumulant and for the critical couplings. These results provide the groundwork for broader studies of universal properties of the three-dimensional Ising universality class.
description: 45 pages, 15 figures; Changes: Estimate of $\eta$ corrected to 0.036284(40) [Before 0.036244(40) due to trivial but annoying mistake]. Text rewritten at several places. New appendix B, several Figures changed. Core results unchanged
Nonlinear Dirac Equations
Creators: name: Ng, Wei-Khim
name: Parwani, Rajesh R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We construct nonlinear extensions of Dirac's relativistic electron equation that preserve its other desirable properties such as locality, separability, conservation of probability and Poincaré invariance. We determine the constraints that the nonlinear term must obey and classify the resultant non-polynomial nonlinearities in a double expansion in the degree of nonlinearity and number of derivatives. We give explicit examples of such nonlinear equations, studying their discrete symmetries and other properties. Motivated by some previously suggested applications we then consider nonlinear terms that simultaneously violate Lorentz covariance and again study various explicit examples. We contrast our equations and construction procedure with others in the literature and also show that our equations are not gauge equivalent to the linear Dirac equation. Finally we outline various physical applications for these equations.
The conformationally controlled alkylation of 15-hexadecanolide
Creators: name: Graham, Ronald Joseph
Publisher: name: University of British Columbia
Year: 2010

description: The 16-membered lactone 17was synthesized and alkylated to yield a 4:1 ratio of 20 and 19 respectively. The product ratio was rationalized by molecular mechanics calculations on 18. A new polar map convention was developed for conformational analysis of cyclohexadecane.[See Thesis for Diagram]
A Robust Extrinsic Calibration Framework for Vehicles with Unscaled Sensors
Creators: name: Walters, Celyn
name: Mendez, Oscar
name: Hadfield, Simon
name: Bowden, Richard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Accurate extrinsic sensor calibration is essential for both autonomous vehicles and robots. Traditionally this is an involved process requiring calibration targets, known fiducial markers and is generally performed in a lab. Moreover, even a small change in the sensor layout requires recalibration. With the anticipated arrival of consumer autonomous vehicles, there is demand for a system which can do this automatically, after deployment and without specialist human expertise. To solve these limitations, we propose a flexible framework which can estimate extrinsic parameters without an explicit calibration stage, even for sensors with unknown scale. Our first contribution builds upon standard hand-eye calibration by jointly recovering scale. Our second contribution is that our system is made robust to imperfect and degenerate sensor data, by collecting independent sets of poses and automatically selecting those which are most ideal. We show that our approach's robustness is essential for the target scenario. Unlike previous approaches, ours runs in real time and constantly estimates the extrinsic transform. For both an ideal experimental setup and a real use case, comparison against these approaches shows that we outperform the state-of-the-art. Furthermore, we demonstrate that the recovered scale may be applied to the full trajectory, circumventing the need for scale estimation via sensor fusion.
Fracture of complex metallic alloys: An atomistic study of model systems
Creators: name: Rösch, F.
name: Trebin, H. -R.
name: Gumbsch, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Molecular dynamics simulations of crack propagation are performed for two extreme cases of complex metallic alloys (CMAs): In a model quasicrystal the structure is determined by clusters of atoms, whereas the model C15 Laves phase is a simple periodic stacking of a unit cell. The simulations reveal that the basic building units of the structures also govern their fracture behaviour. Atoms in the Laves phase play a comparable role to the clusters in the quasicrystal. Although the latter are not rigid units, they have to be regarded as significant physical entities.
description: 6 pages, 4 figures, for associated avi file, see http://www.itap.physik.uni-stuttgart.de/~frohmut/MOVIES/C15.LJ.011.100.avi
Inferring Multi-Period Optimal Portfolios via Detrending Moving Average Cluster Entropy
Creators: name: Murialdo, P.
name: Ponta, L.
name: Carbone, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Portfolio Management (q-fin.PM)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Economics and business
subject: FOS: Physical sciences

description: Despite half a century of research, there is still no general agreement about the optimal approach to build a robust multi-period portfolio. We address this question by proposing the detrended cluster entropy approach to estimate the portfolio weights of high-frequency market indices. The information measure produces reliable estimates of the portfolio weights gathered from the real-world market data at varying temporal horizons. The portfolio exhibits a high level of diversity, robustness and stability as it is not affected by the drawbacks of traditional mean-variance approaches.
description: 7 pages, 5 figures
Exact Integration of the High Energy Scale in Doped Mott Insulators
Creators: name: Choy, Ting-Pong
name: Leigh, Robert G.
name: Phillips, Philip
name: Powell, Philip D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We expand on our earlier work (cond-mat/0612130, Phys. Rev. Lett. {\bf 99}, 46404 (2007)) in which we constructed the exact low-energy theory of a doped Mott insulator by explicitly integrating (rather than projecting) out the degrees of freedom far away from the chemical potential. The exact low-energy theory contains degrees of freedom that cannot be obtained from projective schemes. In particular a new charge $\pm 2e$ bosonic field emerges at low energies that is not made out of elemental excitations. Such a field accounts for dynamical spectral weight transfer across the Mott gap. At half-filling, we show that two such excitations emerge which play a crucial role in preserving the Luttinger surface along which the single-particle Green function vanishes. In addition, the interactions with the bosonic fields defeat the artificial local SU(2) symmetry that is present in the Heisenberg model. We also apply this method to the Anderson-U impurity and show that in addition to the Kondo interaction, bosonic degrees of freedom appear as well. Finally, we show that as a result of the bosonic degree of freedom, the electron at low energies is in a linear superposition of two excitations--one arising from the standard projection into the low-energy sector and the other from the binding of a hole and the boson.
description: Published verison
Physisorption of Nucleobases on Graphene
Creators: name: Gowtham, S.
name: Scheicher, Ralph H.
name: Ahuja, Rajeev
name: Pandey, Ravindra
name: Karna, Shashi P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report the results of our first-principles investigation on the interaction of the nucleobases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) with graphene, carried out within the density functional theory framework, with additional calculations utilizing Hartree--Fock plus second-order Moeller-Plesset perturbation theory. The calculated binding energy of the nucleobases shows the following hierarchy: G > T ~ C ~ A > U, with the equilibrium configuration being very similar for all five of them. Our results clearly demonstrate that the nucleobases exhibit significantly different interaction strengths when physisorbed on graphene. The stabilizing factor in the interaction between the base molecule and graphene sheet is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study represents a significant step towards a first-principles understanding of how the base sequence of DNA can affect its interaction with carbon nanotubes, as observed experimentally.
description: 7 pages, 3 figures
The VANDELS Survey: New constraints on the high-mass X-ray binary populations in normal star-forming galaxies at 3 < z < 5.5
Creators: name: Saxena, A.
name: Ellis, R. S.
name: Forster, P. U.
name: Calabro, A.
name: Pentericci, L.
name: Carnall, A. C.
name: Castellano, M.
name: Cullen, F.
name: Fontana, A.
name: Franco, M.
name: Fynbo, J. P. U.
name: Gargiulo, A.
name: Garilli, B.
name: Hathi, N. P.
name: McLeod, D. J.
name: Amorin, R.
name: Zamorani, G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use VANDELS spectroscopic data overlapping with the $\simeq$7 Ms Chandra Deep Field South survey to extend studies of high-mass X-ray binary systems (XRBs) in 301 normal star-forming galaxies in the redshift range $3 < z < 5.5$. Our analysis evaluates correlations between X-ray luminosities ($L_X$), star formation rates (SFR) and stellar metallicities ($Z_\star$) to higher redshifts and over a wider range in galaxy properties than hitherto. Using a stacking analysis performed in bins of both redshift and SFR for sources with robust spectroscopic redshifts without AGN signatures, we find convincing evolutionary trends in the ratio $L_X$/SFR to the highest redshifts probed, with a stronger trend for galaxies with lower SFRs. Combining our data with published samples at lower redshift, the evolution of $L_X$/SFR to $z\simeq5$ proceeds as $(1 + z)^{1.03 \pm 0.02}$. Using stellar metallicities derived from photospheric absorption features in our spectroscopic data, we confirm indications at lower redshifts that $L_X$/SFR is stronger for metal-poor galaxies. We use semi-analytic models to show that metallicity dependence of $L_X$/SFR alone may not be sufficient to fully explain the observed redshift evolution of X-ray emission from high-mass XRBs, particularly for galaxies with SFR $<30$ $M_\odot$ yr$^{-1}$. We speculate that the discrepancy may arise due to reduced overall stellar ages in the early Universe leading to higher $L_X$/SFR for the same metallicity. We use our data to define the redshift-dependent contribution of XRBs to the integrated X-ray luminosity density and, in comparison with models, find that the contribution of high-mass XRBs to the cosmic X-ray background at $z>6$ may be $\gtrsim 0.25$ dex higher than previously estimated.
description: 16 pages, 10 figures, Published in MNRAS
Changeover from Glassy ferromagnetism of the orbital domain state to long range ferromagnetic ordering in La{_{0.9}}Sr_{0.1}MnO{_3}
Creators: name: Mukherjee, K.
name: Banerjee, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: An attempt is made to resolve the controversy related to the low temperature phase (ground state) of the low-doped ferromagnetic (FM)- insulator(I) manganite through bulk magnetic measurements on La${_{0.9}}$Sr$_{0.1}$MnO${_3}$ sample. It is shown that the FM phase, formed out of well defined transition in the low-doped system, becomes inhomogeneous with decrease in temperature. This inhomogeniety is considered to be an outcome of the formation of orbital domain state of e$_g$-electrons having hole rich (metallic) walls separating the hole deficient (insulating) regions. The resulting complexity brings in metastability and glassy behaviour within the FM phase at low temperature, however, with no resemblance to spin glass, cluster glass or reentrant phases. It shows ageing effect without memory but magnetic relaxation shows signatures of inter-cluster interaction. The energy landscape picture of this glassy phase is described in terms of hierarchical model. Further, it is shown that this inhomogeneity disappear in La${_{0.9}}$Sr$_{0.1}$MnO$_{3.08}$ where, the orbital domain state is destroyed by self doping resulting in reduction of Mn$^{3+}$ and hence e$_g$-electrons. The ferromagnetic phase of the non-stoichiometric sample, does not show glassy behaviour. It neither follows 'hierarchical model' nor 'droplet model' generally used to explain glassy or inhomogeneous systems. Its magnetic response can be explained simply from the domain wall dynamics of otherwise homogeneous ferromagnet.
title: ‘Nach und nach müssen wir alles ablehnen’: Hyperbolische Negativität bei Thomas Bernhard
Creators: name: Knobloch, Jan
Publisher: name: Universität Kassel
Year: 2021
Subjects: subject: 800
subject: Bernhard, Thomas
subject: Bernhard, Thomas. Der Keller
subject: Bernhard, Thomas. Auslöschung
subject: Negativität

description: Gefördert im Rahmen des Projekts DEAL
eduPIC: an introductory particle based code for radio-frequency plasma simulation
Creators: name: Donko, Zoltan
name: Derzsi, Aranka
name: Vass, Mate
name: Horvath, Benedek
name: Wilczek, Sebastian
name: Hartmann, Botond
name: Hartmann, Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: For the self-consistent description of various plasma sources operated in the low-pressure (nonlocal, kinetic) regime, the Particle-In-Cell simulation approach, combined with the Monte Carlo treatment of collision processes (PIC/MCC), has become an important tool during the past decades. PIC/MCC simulation codes have been developed and maintained by many research groups, some of these codes are available to the community as freeware resources. While this computational approach has already been present for a number of decades, the rapid evolution of the computing infrastructure makes it increasingly more popular and accessible, as simulations of simple systems can be executed now on personal computers or laptops. During the past few years we have experienced an increasing interest in lectures and courses dealing with the basics of particle simulations, including the PIC/MCC technique. In a response to this, this paper (i) provides a tutorial on the physical basis and the algorithms of the PIC/MCC technique and (ii) presents a basic (spatially one-dimensional) electrostatic PIC/MCC simulation code for Capacitively Coupled Plasmas, whose source is made freely available in various programming languages. We share the code in C/C++ versions, as well as in a version written in Rust, which is a rapidly emerging computational language. Our code intends to be a "starting tool" for those who are interested in learning the details of the PIC/MCC technique and would like to develop the "skeleton" code further, for their research purposes.
How Magnetic is the Neutrino?
Creators: name: Bell, Nicole F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment bounds are weaker than present experimental limits if $μ_ν$ is generated by new physics at ~ 1 TeV, and surpass current experimental sensitivity only for new physics scales > 10 -- 100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.
description: 9 pages, 6 figures. Talk given at Festschrift in honour of B. H. J McKellar and G. C. Joshi
Can Gravity Probe B usefully constrain torsion gravity theories?
Creators: name: Flanagan, Eanna E.
name: Rosenthal, Eran
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In most theories of gravity involving torsion, the source for torsion is the intrinsic spin of matter. Since the spins of fermions are normally randomly oriented in macroscopic bodies, the torsion generated is normally negligible. However, in a recent paper, Mao et al. point out that there is a class of theories in which the angular momentum of macroscopic spinning bodies generates a significant amount of torsion. They argue that by the principle of action equals reaction, one would expect the angular momentum of test bodies to couple to a background torsion field, and therefore the precession of the GPB gyroscopes should be affected in these theories by the torsion generated by the Earth. We show that in fact the principle of action equals reaction does not apply to these theories. We examine in detail a generalization of the Hayashi-Shirafuji theory suggested by Mao et al. called Einstein-Hayashi-Shirafuji theory. There are a variety of different versions of this theory, depending on the precise form of the coupling to matter chosen for the torsion. We show that for any coupling to matter that is compatible with the spin transport equation postulated by Mao et al., the theory has either ghosts or an ill-posed initial value formulation. These theoretical problems can be avoided by specializing the parameters of the theory and in addition choosing the standard minimal coupling to matter of the torsion tensor. This yields a consistent theory, but one in which the action equals reaction principle is violated, and in which the angular momentum of the gyroscopes does not couple to the Earth's torsion field. Thus, the Einstein-Hayashi-Shirafuji theory does not predict a detectable torsion signal for Gravity Probe B. There may be other torsion theories which do.
description: 13 pages, a small change to the terminology
Rethinking Search: Making Domain Experts out of Dilettantes
Creators: name: Metzler, Donald
name: Tay, Yi
name: Bahri, Dara
name: Najork, Marc
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Retrieval (cs.IR)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: When experiencing an information need, users want to engage with a domain expert, but often turn to an information retrieval system, such as a search engine, instead. Classical information retrieval systems do not answer information needs directly, but instead provide references to (hopefully authoritative) answers. Successful question answering systems offer a limited corpus created on-demand by human experts, which is neither timely nor scalable. Pre-trained language models, by contrast, are capable of directly generating prose that may be responsive to an information need, but at present they are dilettantes rather than domain experts -- they do not have a true understanding of the world, they are prone to hallucinating, and crucially they are incapable of justifying their utterances by referring to supporting documents in the corpus they were trained over. This paper examines how ideas from classical information retrieval and pre-trained language models can be synthesized and evolved into systems that truly deliver on the promise of domain expert advice.
Rosa Luxemburgs Kritik an Lenins ultrazentralistischem Parteikonzept und an der bolschewistischen Revolutionspolitik in Russland
Creators: name: Luban, Ottokar
Publisher: name: Moving the Social
Year: 2015

description: This is the contribution "Rosa Luxemburgs Kritik an Lenins ultrazentralistischem Parteikonzept und an der bolschewistischen Revolutionspolitik in Russland" of MTS 36 (3006).
description: Moving the Social, Vol 36 (2006): Forschungen und Forschungsberichte
Vergangenheit und Zukunft des Arbeitskampfes
Creators: name: Müller-Jentsch, Walther
Publisher: name: Moving the Social
Year: 2015

description: Michael Kittner: Arbeitskampf. Geschichte – Recht – Gegenwart. München: C. H. Beck, 20058, 738 S., 39,00


Peter Renneberg: Die Arbeitskämpfe von morgen? Arbeitsbedingungen und Konflikte im Dienstleistungsbereich. Hamburg: VSA-Verlag, 2005, 301 S., 18 €
description: Moving the Social, Vol 36 (2006): Forschungen und Forschungsberichte
Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres
Creators: name: Segura, A.
name: Meadows, V. S.
name: Kasting, J. F.
name: Crisp, D.
name: Cohen, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Previous research has indicated that high amounts of ozone (O3) and oxygen (O2) may be produced abiotically in atmospheres with high concentrations of CO2. The abiotic production of these two gases, which are also characteristic of photosynthetic life processes, could pose a potential "false-positive" for remote-sensing detection of life on planets around other stars.We show here that such false positives are unlikely on any planet that possesses abundant liquid water, as rainout of oxidized species onto a reduced planetary surface should ensure that atmospheric H2 concentrations remain relatively high, and that O2 and O3 remain low. Our aim is to determine the amount of O3 and O2 formed in a high CO2 atmosphere for a habitable planet without life. We use a photochemical model that considers hydrogen (H2) escape and a detailed hydrogen balance to calculate the O2 and O3 formed on planets with 0.2 of CO2 around the Sun, and 0.02, 0.2 and 2 bars of CO2 around a young Sun-like star with higher UV radiation. The concentrations obtained by the photochemical model were used as input in a radiative transfer model that calculated the spectra of the modeled planets. The O3 and O2 concentrations in the simulated planets are extremely small, and unlikely to produce a detectable signature in the spectra of those planets. We conclude that with a balanced hydrogen budget, and for planets with an active hydrological cycle, abiotic formation of O2 and O3 is unlikely to create a possible false positive for life detection in either the visible/near-infrared or mid-infrared wavelength regimes.
description: 27 pages, 15 figures, Astronomy & Astrophysics accepted
Für Stalins deutsche Opfer ein Denkmal aus Moskau. Alexander Vatlin: „Was für ein Teufelspack“ Die Deutsche Operation des NKWD in Moskau und im Moskauer Gebiet 1936 bis 1941, Berlin: Metropol Verlag 2013
Creators: name: Mensing, Wilhelm
Publisher: name: Moving the Social
Year: 2015

description: Alexander Vatlin: „Was für ein Teufelspack“ Die Deutsche Operation des NKWD in Moskau und im Moskauer Gebiet 1936 bis 1941, Berlin: Metropol Verlag 2013.
description: Moving the Social, Vol 47 (2012): Essays on social history and the history of social movements
การเปรียบเทียบคุณสมบัติทางชีววิทยาและลำดับนิวคลีโอไทด์ของยีนโปรตีนห่อหุ้มของเชื้อ Cucumber green mottle mosaic virus (CGMMV) ที่แยกได้จากเมลอนและนํ้าเต้า
Creators: name: พัสราภรณ์ ยี่สารพัฒน์
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2556
Subjects: Cucumber green mottle mosaic virus (CGMMV), โรคใบด่างเขียวในพืชวงศ์แตง, ยีนโปรตีนห่อหุ้ม

description: 6, 32, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
Reduction of one-loop integrals with higher poles by unitarity cut method
Creators: name: Feng, Bo
name: Wang, Hongbin
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Unitarity cut method has been proved to be very useful in the computation of one-loop integrals. In this paper, we generalize the method to the situation where the powers of propagators in the denominator are larger than one in general. We show how to use the trick of differentiation over masses to translate the problem to the integrals where all powers are just one. Then by using the unitarity cut method, we can find the wanted reduction coefficients of all basis except the tadpole. Using this method, we calculate the reduction of scalar bubble, scalar triangle, scalar box and scalar pentagon with general power of propagators.
description: 31 pages
การประยุกต์ใช้เมนูวงกลมบนคอมพิวเตอร์แท็บเล็ต
Creators: name: รัสรินทร์ พัฒน์ธนกฤษศิริ
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2556
Subjects: รูปแบบเมนูวงกลม, เมนูบนคอมพิวเตอร์แท็บเล็ต

description: 6, 32, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม