cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Nonlinear oscillator with parametric colored noise: some analytical results
Creators: name: Mallick, Kirone
name: Marcq, Philippe
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The asymptotic behavior of a nonlinear oscillator subject to a multiplicative Ornstein-Uhlenbeck noise is investigated. When the dynamics is expressed in terms of energy-angle coordinates, it is observed that the angle is a fast variable as compared to the energy. Thus, an effective stochastic dynamics for the energy can be derived if the angular variable is averaged out. However, the standard elimination procedure, performed earlier for a Gaussian white noise, fails when the noise is colored because of correlations between the noise and the fast angular variable. We develop here a specific averaging scheme that retains these correlations. This allows us to calculate the probability distribution function (P.D.F.) of the system and to derive the behavior of physical observables in the long time limit.
Covariant entropy bound beyond general relativity
Creators: name: Matsuda, Taisuke
name: Mukohyama, Shinji
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose a covariant entropy bound in gravitational theories beyond general relativity (GR), using Wald-Jacobson-Myers entropy instead of Bekenstein-Hawking entropy. We first extend the proof of the bound known in 4-dimensional GR to D-dimensional GR, f(R) gravity and canonical scalar-tensor theory. We then consider Einstein-Gauss-Bonnet (EGB) gravity as a more non-trivial example and, under a set of reasonable assumptions, prove the bound in the GR branch of spherically symmetric configurations. As a corollary, it is shown that under the null and dominant energy conditions, the generalized second law holds in the GR branch of spherically symmetric configurations of EGB gravity at the fully nonlinear level.
description: 11 pages
EFFECT OF PISTIA STRATIOTES AN AQUATIC WEED ON DIGESTIVE ENZYMES OF TARAI REGION CARPS IN UTTARAKHAND
Creators: name: Joshi, Amit
name: Dubey, Ashutosh
name: Anup Sachan
name: Bhuwan Chandra Joshi
Publisher: name: figshare
Year: 2020
Subjects: subject: 60107 Enzymes
subject: FOS: Biological sciences
subject: 60806 Animal Physiological Ecology

description: Study was carried out to analyse the effect of tannin isolated from Pistia stratiotes on the digestive enzymes of carps. The crucial layout of the work introduced effect of phenolics like tannin got from freshwater weed Pistia and so forth, on digestive enzymes of carps particularly Protease, Amylase and Lipase. Quantification of tannin extracted was seen as 25.8 milligrams/gram in type of against dietary factor to be tried for its effect on enzymatic activity of digestive proteomic catalysts found in selected carps in particular: silver carp (Hypophthalmichthys molitrix), rohu (Labeo rohita), and common carp (Cyprinus carpio). Extracted tannin was introduced in diet, selectable range of 12.5-200 micrograms and the responses were observed. Alterations in the enthralled action of standard digestive enzymes found in three carps were found to exhibit diminishing rate in activities. Tannin affects the enzymatic activities in many fishes. Reduced activity of enzymes was investigated out in carp species. So in feed formulations and designing it should be considered as primary necessity.
Spectroscopic properties of the dwarf nova-type cataclysmic variables observed by LAMOST
Creators: name: Zhongtao, Han
name: Soonthornthum, Boonrucksar
name: Shengbang, Qian
name: Xiaohui, Fang
name: Qishan, Wang
name: Liying, Zhu
name: Aijun, Dong
name: Qijun, Zhi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Spectra of 76 known dwarf novae from the LAMOST survey were presented. Most of the objects were observed in quiescence, and about 16 systems have typical outburst spectra. 36 of these systems were observed by SDSS, and most of their spectra are similar to the SDSS spectra. 2 objects, V367 Peg and V537 Peg, are the first to observe their spectra. The spectrum of V367 Peg shows a contribution from a M-type donor and its spectral type could be estimated as M3-5 by combining its orbital period. The signature of white dwarf spectrum can be seen clearly in four low-accretion-rate WZ Sge stars. Other special spectral features worthy of further observations are also noted and discussed. We present a LAMOST spectral atlas of outbursting dwarf novae. 6 objects have the first outburst spectra, and the others were also compared with the published outburst spectra. We argue that these data will be useful for further investigation of the accretion disc properties. The HeII $λ$4686 emission line can be found in the outburst spectra of seven dwarf novae. These objects are excellent candidates for probing the spiral asymmetries of accretion disc.
description: 29 pages, 11 figures
Spin Hall angle fluctuations in a disorder device
Creators: name: Santana, F. A. F.
name: da Silva, J. M.
name: Vasconcelos, T. C.
name: Ramos, J. G. G. S.
name: Barbosa, A. L. R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate a disorderly mesoscopic device that supports spin-orbit interaction. The systemis connected to four semi-infinite leads embedded in the Landauer-Buttiker setup for quantumtransport and, according to our analysis, exhibits spin Hall angle fluctuations. We show analyticallyand numerically the fingerprint of the universal fluctuation of the polarization mediated by theconversion of charge current into spin current. Our investigation shows the complete compatibilityof our analytical and numerical results with the most recent experiments. Furthermore, we shownonzero and universal features of spin Hall effect in Rashba 2DEG with disorder. All the resultsshow the relevance of microscopic parameters for electronic transport with charge-spin conversionand, in many cases, inevitably lead to universal numbers.
description: Accepted for publication as a Rapid Communication in Physical Review B
Exciton lifetime in InAs/GaAs quantum dot molecules
Creators: name: Bardot, C.
name: Schwab, M.
name: Bayer, M.
name: Fafard, S.
name: Wasilewski, Z.
name: Hawrylak, P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The exciton lifetimes $T_1$ in arrays of InAs/GaAs vertically coupled quantum dot pairs have been measured by time-resolved photoluminescence. A considerable reduction of $T_1$ by up to a factor of $\sim$ 2 has been observed as compared to a quantum dots reference, reflecting the inter-dot coherence. Increase of the molecular coupling strength leads to a systematic decrease of $T_1$ with decreasing barrier width, as for wide barriers a fraction of structures shows reduced coupling while for narrow barriers all molecules appear to be well coupled. The coherent excitons in the molecules gain the oscillator strength of the excitons in the two separate quantum dots halving the exciton lifetime. This superradiance effect contributes to the previously observed increase of the homogeneous exciton linewidth, but is weaker than the reduction of $T_2$. This shows that as compared to the quantum dots reference pure dephasing becomes increasingly important for the molecules.
[De Maritime Skoler, Trondheim. Prosjekt 84, Statens kjølemaskinistskole]
Creators: name: Stein, Asbjørn
name: Stein, Ingri
Publisher: name: Unknown
Year: 1963

description: Kj. 103, Statens kjølemaskinistskole, innredning av rom 12 og 13
Untitled Item
Creators: name: Joshi, Amit
name: Dubey, Ashutosh
name: Anup Sachan
name: Bhuwan Chandra Joshi
Publisher: name: figshare
Year: 2020
Subjects: subject: 60107 Enzymes
subject: FOS: Biological sciences
subject: 60806 Animal Physiological Ecology

description: Study was carried out to analyse the effect of tannin isolated from Pistia stratiotes on the digestive enzymes of carps. The crucial layout of the work introduced effect of phenolics like tannin got from freshwater weed Pistia and so forth, on digestive enzymes of carps particularly Protease, Amylase and Lipase. Quantification of tannin extracted was seen as 25.8 milligrams/gram in type of against dietary factor to be tried for its effect on enzymatic activity of digestive proteomic catalysts found in selected carps in particular: silver carp (Hypophthalmichthys molitrix), rohu (Labeo rohita), and common carp (Cyprinus carpio). Extracted tannin was introduced in diet, selectable range of 12.5-200 micrograms and the responses were observed. Alterations in the enthralled action of standard digestive enzymes found in three carps were found to exhibit diminishing rate in activities. Tannin affects the enzymatic activities in many fishes. Reduced activity of enzymes was investigated out in carp species. So in feed formulations and designing it should be considered as primary necessity.
Biot-Savart law in quantum matter
Creators: name: Yang, X. M.
name: Song, Z.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the topological nature of a class of lattice systems, whose Bloch vector can be expressed as the difference of two independent periodic vector functions (knots) in an auxiliary space. We show exactly that each loop as a degeneracy line generates a polarization field, obeying the Biot-Savart law: The degeneracy line acts as a current-carrying wire, while the polarization field corresponds to the generated magnetic field. Applying the Ampere's circuital law on a nontrivial topological system, we find that two Bloch knots entangle with each other, forming a link with the linking number being the value of Chern number of the energy band. In addition, two lattice models, an extended QWZ model and a quasi-1D model with magnetic flux, are proposed to exemplify the application of our approach. In the aid of the Biot-Savart law, the pumping charge as a dynamic measure of Chern number is obtained numerically from quasi-adiabatic processes.
description: 9 pages, 4 figures
title: Nanotechnology, ethics and policy education: research and pedagogy
Creators: name: Mitcham, Carl
name: Packard, Corinne E.
name: Heller, Laura
name: Hudson, Derrick
name: Holles, Cortney
name: Nan, Wang
name: Qin, Zhu
name: Delborne, Jason
name: Schneider, Jennifer J.
name: Woodson, Sandra
Publisher: name: Mountain Scholar
Year: 2013
Subjects: nanotechnology
APPE
curriculum development
faculty professional development
panel presentation
Nanotechnology Undergraduate Education (NUE)

description: This panel discussion on the creation of interdisciplinary modules about the social, ethical, environmental, and economic impact of nanotechnology was presented in three parts: the background of federal support for nanotechnology research; the pedagogy, practice and outcomes of the course modules and faculty workshop; and a review of the literature on social justice and ethics in nanotechnology with respect to belief systems and underrepresented groups. The presentation was delivered at the 2013 Association for Practical and Professional Ethics (APPE) conference.
[De Maritime Skoler, Trondheim. Prosjekt 84, Statens kjølemaskinistskole]
Creators: name: Stein, Asbjørn
name: Stein, Ingri
Publisher: name: Unknown
Year: 1963

description: Kj. 104, Statens kjølemaskinistskole, innredning av rom 15 og 16
Forecasting the daily and cumulative number of cases for the COVID-19 pandemic in India
Creators: name: Khajanchi, Subhas
name: Sarkar, Kankan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The ongoing novel coronavirus epidemic has been announced a pandemic by the World Health Organization on March 11, 2020, and the Govt. of India has declared a nationwide lockdown from March 25, 2020, to prevent community transmission of COVID-19. Due to absence of specific antivirals or vaccine, mathematical modeling play an important role to better understand the disease dynamics and designing strategies to control rapidly spreading infectious diseases. In our study, we developed a new compartmental model that explains the transmission dynamics of COVID-19. We calibrated our proposed model with daily COVID-19 data for the four Indian provinces, namely Jharkhand, Gujarat, Andhra Pradesh, and Chandigarh. We study the qualitative properties of the model including feasible equilibria and their stability with respect to the basic reproduction number $\mathcal{R}_0$. The disease-free equilibrium becomes stable and the endemic equilibrium becomes unstable when the recovery rate of infected individuals increased but if the disease transmission rate remains higher then the endemic equilibrium always remain stable. For the estimated model parameters, $\mathcal{R}_0 >1$ for all the four provinces, which suggests the significant outbreak of COVID-19. Short-time prediction shows the increasing trend of daily and cumulative cases of COVID-19 for the four provinces of India.
description: 18 Pages, 7 Figures
Four-body problem and BEC-BCS crossover in a quasi-one-dimensional cold fermion gas
Creators: name: Mora, C.
name: Komnik, A.
name: Egger, R.
name: Gogolin, A. O.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Superconductivity (cond-mat.supr-con)
subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The four-body problem for an interacting two-species Fermi gas is solved analytically in a confined quasi-one-dimensional geometry, where the two-body atom-atom scattering length $a_{aa}$ displays a confinement-induced resonance. We compute the dimer-dimer scattering length $a_{dd}$, and show that this quantity completely determines the many-body solution of the associated BEC-BCS crossover phenomenon in terms of bosonic dimers.
description: 5 pages, 1 figure, published in Phys. Rev. Lett., breathing mode calculation added
[De Maritime Skoler, Trondheim. Prosjekt 84, Statens kjølemaskinistskole]
Creators: name: Stein, Asbjørn
name: Stein, Ingri
Publisher: name: Unknown
Year: 1963

description: Kj. 105, Statens kjølemaskinistskole, skjema delvegger til rom 17 og 18
[De Maritime Skoler, Trondheim. Prosjekt 84, Statens kjølemaskinistskole]
Creators: name: Stein, Asbjørn
name: Stein, Ingri
Publisher: name: Unknown
Year: 1963

description: Kj. 106, Statens kjølemaskinistskole, detaljer delvegger til rom 17 og 18
Entanglement entropy of fermions in any dimension and the Widom conjecture
Creators: name: Gioev, Dimitri
name: Klich, Israel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Functional Analysis (math.FA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We show that entanglement entropy of free fermions scales faster then area law, as opposed to the scaling $L^{d-1}$ for the harmonic lattice, for example. We also suggest and provide evidence in support of an explicit formula for the entanglement entropy of free fermions in any dimension $d$, $S\sim c(\partialΓ,\partialΩ)\cdot L^{d-1}\log L$ as the size of a subsystem $L\to\infty$, where $\partialΓ$ is the Fermi surface and $\partialΩ$ is the boundary of the region in real space. The expression for the constant $c(\partialΓ,\partialΩ)$ is based on a conjecture due to H. Widom. We prove that a similar expression holds for the particle number fluctuations and use it to prove a two sided estimates on the entropy $S$.
description: Final version
Greenhouse climate control Experimental data
Creators: name: Mattara, Subin
Publisher: name: figshare
Year: 2020
Subjects: subject: 70103 Agricultural Production Systems Simulation
subject: FOS: Other agricultural sciences
subject: 70104 Agricultural Spatial Analysis and Modelling
subject: 70399 Crop and Pasture Production not elsewhere classified
subject: FOS: Agriculture, forestry and fisheries
subject: 70107 Farming Systems Research

description: Design and Robustness Analysis of Intelligent Controllers for Commercial Greenhouse
An interim model to predict maximum wave heights of low speed displacement mono-hull ships
Creators: name: Sireli, Eyup Mete
Publisher: name: University of British Columbia
Year: 2009

description: Hull shapes of ships are highly complex. A formula giving ship-generated maximum wave heights should contain all the main characteristics of ship hulls. Nevertheless, having a universal formula for all ship types is practically not possible, therefore different maximum wave height formulas for particular ships or ship families have been derived by previous researchers. This requires tedious work for each ship family, and the result is usually a complex regression formula whose parameters can only be understood by a naval architect. To avoid these problems, an interim model is proposed in this thesis, whose results are to be corrected by a simple correction formula for a particular ship family. By this way, the number of parameters in the formula is reduced significantly, which also reduces the time and money to derive the formula and makes it understandable for users lacking naval architectural background. The interim model is based on the results of experiments of three barge-like models of 1 m in length, which are constructed in three different beam sizes and three different draft levels, which increases the number of models virtually to nine. The experiments were conducted at BC Research Ocean Engineering Centre's towing tank facility. The models were towed at three different ship length Froude numbers. Measurements from three wave probes positioned at different proximities were used to investigate the effect of distance from sailing line (towline). The effects of distance, speed and shape on wave height are defined in separate functions, which are then combined in the maximum wave height formula. To derive the functions, regression analysis is used. The results of the interim model are compared to the experimental data of three ferries in Nece et al.'s study (1986) with the formulas of Sorensen and Weggel (1984) and the Ship Wave Committee (1976). The interim model gives closer results to the measured data than the two formulas. Still, correction formulas are provided for three ferries. Then, the interim model is compared to the experimental data of a ship model of 1.146 m in length towed at BC Research Ocean Engineering Centre. Interestingly, the interim model did not require a correction formula for the ship model. In addition to the wave height analysis, the adequacy of the theoretical maximum wave period formula is also investigated as a secondary objective. It was observed that the theoretical wave period formula provides good results and requires no correction in practical applications.
Streptococcus bovis endocarditis after colonic polypectomy
Creators: name: Chongprasertpon, Napohn
name: Cusack, Ronan
name: Coughlan, JJ
name: Tung Chung, Wing
name: Ho Leung, Chun
name: Kiernan, Thomas J.
Publisher: name: University of Limerick
Year: 2024
Subjects: classificationCode: 42
subject: Health sciences
subject: FOS: Health sciences

description: We describe a case of Streptococcus lutetiensis infective endocarditis occurring in a patient following colonic polypectomy. The patient had multiple risk factors for infective endocarditis including pre-existing mitral valve prolapse and regurgitation. Transoesophageal echocardiography revealed a friable mass on the posterior mitral valve leaflet, confirming the diagnosis. The patient was treated with intravenous antibiotics, successfully underwent mitral valve surgery and was discharged home for outpatient follow-up. This report details an uncommon case presentation, highlights areas for improvement in clinical practice, and summarises the current knowledge available in the literature regarding Streptococcus bovis infective endocarditis.
An Algorithm for Constructing Polynomial Systems Whose Solution Space Characterizes Quantum Circuits
Creators: name: Gerdt, Vladimir P.
name: Severyanov, Vasily M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An algorithm and its first implementation in C# are presented for assembling arbitrary quantum circuits on the base of Hadamard and Toffoli gates and for constructing multivariate polynomial systems over the finite field Z_2 arising when applying the Feynman's sum-over-paths approach to quantum circuits. The matrix elements determined by a circuit can be computed by counting the number of common roots in Z_2 for the polynomial system associated with the circuit. To determine the number of solutions in Z_2 for the output polynomial system, one can use the Groebner bases method and the relevant algorithms for computing Groebner bases.
description: 10 pages, 9 Postscript figures, report presented on QI 2005
Inelastic scattering and cooling of photoexcited electrons through coupling with acoustic, optic and surface polar optic phonons in graphene
Creators: name: Khatoon, S. Arshia
name: Ansari, Meenhaz
name: Ashraf, S. S. Z.
name: Obaidurrahman, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The acoustic, optic, and surface polar optic phonons are the three important intrinsic and extrinsic phononic modes that increasingly populate graphene on a substrate with rising temperatures; the coupling of which with photoexcited hot carriers in the equipartition regime provides significant pathways for electron-phonon relaxation. In this paper, we theoretically investigate the relative significance of the three phononic modes in electron scattering and cooling phenomena in single layer graphene, including their comparison with supercollision driven power loss, and obtain analytical formulae on the energy dependence of electron-phonon scattering rate and cooling power in the Boltzmann transport formalism. The obtained analytical solutions not only closely reproduce the results for scattering rate and cooling power, as that obtained from the earlier reported numerically tractable integral forms, but also enable us to derive closed-form formulae of the cooling time and thermal conductance. The important role of Pauli blocking that prevents transition to filled energy states has also been elucidated in the estimation of the scattering rate and cooling power density for all the three modes. The obtained formulae provide a better insight into the dynamics of hot electron phenomena giving an explicit view on the interplay of the different variables that affect the transport quantities under investigation. The formulae can also be potentially useful for performance optimization of transport quantities in numerical optimization methods since the first and second-order derivatives are easily deducible from these formulae.
description: 32 pages, 10 Figures, Tables 2
"VIII. Internationaler Kongreß der Gesellschaft für das Recht der Ostkirchen" in Santiago de Compostela, 20.-27.9.1987
Creators: name: Kaufhold, Hubert
Publisher: name: Oriens christianus : Hefte für die Kunde des christlichen Orients
Year: 2024

description: Oriens christianus : Hefte für die Kunde des christlichen Orients, Bd. 72 (1988): Oriens christianus, Band 72
Discrete Solitons and Vortices on Anisotropic Lattices
Creators: name: Kevrekidis, P. G.
name: Frantzeskakis, D. J.
name: Carretero-Gonzalez, R.
name: Malomed, B. A.
name: Bishop, A. R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We consider effects of anisotropy on solitons of various types in two-dimensional nonlinear lattices, using the discrete nonlinear Schr{ö}dinger equation as a paradigm model. For fundamental solitons, we develop a variational approximation, which predicts that broad quasi-continuum solitons are unstable, while their strongly anisotropic counterparts are stable. By means of numerical methods, it is found that, in the general case, the fundamental solitons and simplest on-site-centered vortex solitons ("vortex crosses") feature enhanced or reduced stability areas, depending on the strength of the anisotropy. More surprising is the effect of anisotropy on the so-called "super-symmetric" intersite-centered vortices ("vortex squares"), with the topological charge $S$ equal to the square's size $M$: we predict in an analytical form by means of the Lyapunov-Schmidt theory, and confirm by numerical results, that arbitrarily weak anisotropy results in dramatic changes in the stability and dynamics in comparison with the \emph{degenerate}, in this case, isotropic limit.
description: 10 pages + 7 figures
Biological Microscopy with Undetected Photons
Creators: name: Buzas, Andras
name: Wolff, Elmar K.
name: Benedict, Mihaly G.
name: Ormos, Pal
name: Der, Andras
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Novel imaging techniques utilizing nondegenerate, correlated photon pairs sparked intense interest during the last couple of years among scientists of the quantum optics community and beyond. It is a key property of such "ghost imaging" or "quantum interference" methods that they use those photons of the correlated pairs for imaging that never interacted with the sample, allowing detection in a spectral range different from that of the illumination of the object. Extensive applications of these techniques in spectroscopy and microscopy are envisioned, however, their limited spatial resolution to date has not yet supported real-life microscopic investigations of tiny biological objects. Here we report a modification of the method based on quantum interference by using a seeding laser and confocal scanning, that allows the improvement of the resolution of imaging with undetected photons by more than an order of magnitude, and we also present examples of application in the microscopy of biological samples.
description: This article has been accepted for publication in IEEE Access, but has not been fully edited
[De Maritime Skoler, Trondheim. Prosjekt 84, Statens kjølemaskinistskole]
Creators: name: Stein, Asbjørn
name: Stein, Ingri
Publisher: name: Unknown
Year: 1963

description: Kj. 109, Statens kjølemaskinistskole, skjema, kateter, demonstrasjonsdisk, klasser
Relationship between the non linear dynamic behaviour of an oscillating tip-microlever system and the contrast at the atomic scale
Creators: name: Aimé, Jean-Pierre
name: Couturier, Gérard
name: Boisgard, Rodolphe
name: Nony, Laurent
Publisher: name: arXiv
Year: 2005
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: In this paper, the dynamic behaviour of an oscillating tip-microlever system at the proximity of a surface is discussed. The attractive tip-surface interaction is simply described with a Van der Waals dispersive term and a sphere-plane geometry. We show that the non linear behaviour of the oscillator is able to explain the observed shifts of the resonance frequency as a function of the tip-surface distance without the need of introducing a particular short range force.
Principales determinantes de la productividad total de los factores en el sector agrario espanol
Creators: name: Diaz, Pilar Exposito
name: Gonzalez, Xose Anton Rodriguez
name: Diaz, Pilar Exposito
name: Gonzalez, Xose Anton Rodriguez
Publisher: name: Unknown
Year: 2001
Subjects: Productivity Analysis

description: RESUMEN - En este trabajo se analizan, de forma conjunta y para el periodo 1970-1995, los factores que a priori deben ser muy relevantes para explicar el comportamiento de la productividad total en el sector agrario español. En el estudio se utilizan dos procedimientos principales de modelización: lo que podemos considerar como metodología econométrica "tradicional" y la metodología de cointegración. Se acepta la influencia sobre la productividad, coincidiendo con los resultados que se obtienen mayoritariamente en otros estudios sobre el tema, de variables como el capital humano o los gastos en I+D agrario, pero se resalta adicionalmente la gran influencia de otras variables como las condiciones climáticas, los cambios en la propia estructura productiva del sector y el capital público. SUMMARY - In this paper we analyse, as a whole and for the period 1970-95, the outstanding factors that explain the behaviour of total productivity in the Spanish agrarian sector. In the study, two main methods of modeling had been used: those we consider like "traditional" econometric methodology and the methodology of cointegration. We accepted the influence on the productivity, with the same results that the majority of authors which obtain equal results about this subject, and about variables like, human capital, or the expenditures in agrarian research and development; but in addition we stick out the big influence of others variables like weather conditions, the change in the own structure of productivity by the sector and the public capital.
Supplementary materials from How disease constrains the evolution of social systems
Creators: name: Oyita Udiani
name: Fefferman, Nina H.
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Ecology
subject: Health Care
subject: Diseases
subject: 111706 Epidemiology
subject: FOS: Health sciences

description: This document contains supporting information for our study. There are six sections in total. Appendix A provides details of the model's implementation. Appendix B provides a description of Monte Carlo experiments used to test our hypotheses. Appendix C provides results of sensitivity analysis for the full space of model parameters. This analysis is restricted to functional forms chosen to capture the utility of work under mortality risk. Appendix D provides additional outputs of Monte Carlo simulations with disease risk. This section outlines a remarkable effect of age-based social organization under infectious exposure that suggests enhanced demographic robustness. Appendix E provides a theoretical rationale for the results found with age-based social systems. Appendix F discusses examples form specific eusocial insect systems (honeybees and termites) that matches with our theoretical findings.
Frozen local hole approximation
Creators: name: Pahl, Elke
name: Birkenheuer, Uwe
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The frozen local hole approximation (FLHA) is an adiabatic approximation which is aimed to simplify the correlation calculations of valence and conduction bands of solids and polymers. Within this approximation correlated local hole states (CLHSs) are explicitely generated by correlating local Hartree-Fock (HF) hole states. The hole orbital and its occupancy is kept frozen during these correlation calculations. Effective Hamilton matrix elements are then evaluated with the above CLHSs; diagonalization finally yields the desired correlation corrections for the cationic hole states. We compare and analyze the results of the FLHA with the results of a full MRCI(SD) (multi-reference configuration interaction with single and double excitations) calculation for two prototype model systems, (H2)n ladders and H-(Be)n-H chains. Excellent numerical agreement between the two approaches is found. Comparing the FLHA with a full correlation treatment in the framework of quasi-degenerate variational perturbation theory reveals that the leading contributions in the two approaches are identical. Thus, the FLHA is well-justified and provides a very promising and efficient alternative to fully correlated wavefunction-based treatments of the valence and conduction bands in extended systems.
description: RevTeX, 9 pages, 7 figures (6 ps files)
Especificaciones y consideraciones muestrales en la estimacion de la demanda de un espacio natural singular: las Illa Cies en Galicia
Creators: name: Gomez, Manuel Gonzalez
name: Polome, Philippe
name: Blanco, Albino Prada
name: Gomez, Manuel Gonzalez
name: Polome, Philippe
name: Blanco, Albino Prada
Publisher: name: Unknown
Year: 2001
Subjects: Resource /Energy Economics and Policy

description: RESUMEN - En este trabajo se presentan estimaciones de diferentes especificaciones de demanda para un espacio recreativo singular a partir de la información de entrevis-tas a visitantes y no visitantes. Tenemos en cuenta los problemas de forma funcional, de medición del coste y demanda, de elección de una técnica de muestreo y de trata-miento de la muestra. La consideración de estas alternativas permite elegir una especi-ficación en mejores condiciones y nos aleja de supuestos iniciales restrictivos. Los resultados en términos de predicción de la demanda y estimación del excedente son bastante divergentes, resaltando la importancia de comparar diferentes especificacio-nes que incluyan el espectro de opciones potenciales. SUMMARY - In this paper, we present estimates of several specifications of demand for a singular natural area using data from surveys on visitors and non-visitors. The estimates take into account the problems of functional form, measurement of the cost and of the demand, choosing sampling scheme, and handling the sample. Considering these alternatives allows us to select a specification of demand under improved condi-tions and frees us from initial restrictive hypothesis. The results in terms of prediction of demand and consumer surplus estimates are quite dissimilar, stressing the impor-tance of comparing various specifications that encompass a range of possible options.
Potential of Ensemble Copula Coupling for Wind Power Forecasting
Creators: name: Phipps, Kaleb
name: Ludwig, Nicole
name: Hagenmeyer, Veit
name: Mikut, Ralf
Publisher: name: KIT Scientific Publishing
Year: 2020

description: With the share of renewable energy sources in the energy system increasing,accurate wind power forecasts are required to ensure a balanced supply anddemand. Wind power is, however, highly dependent on the chaotic weathersystem and other stochastic features. Therefore, probabilistic wind powerforecasts are essential to capture uncertainty in the model parameters and inputfeatures. The weather and wind power forecasts are generally post-processedto eliminate some of the systematic biases in the model and calibrate it topast observations. While this is successfully done for wind power forecasts,the approaches used often ignore the inherent correlations among the weathervariables. The present paper, therefore, extends the previous post-processingstrategies by including Ensemble Copula Coupling (ECC) to restore the de-pendency structures between variables and investigates, whether including thedependency structures changes the optimal post-processing strategy. We findthat the optimal post-processing strategy does not change when including ECCand ECC does not improve the forecast accuracy when the dependency struc-tures are weak. We, therefore, suggest investigating the dependency structuresbefore choosing a post-processing strategy.
Incident rational curves
Creators: name: Ran, Ziv
Publisher: name: arXiv
Year: 2020
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14n05

description: We study families of rational curves on an algebraic variety satisfying incidence conditions. We prove an analogue of bend-and-break: that is, we show that under suitable conditions, such a family must contain reducibles. In the case of curves in $¶^n$ incident to certain complete intersections, we prove the family is irreducible.
Analisis del efecto de los mercados de agua sobre el beneficio de las explotaciones, la contaminacion por nitratos y el empleo eventual agrario
Creators: name: Calatrava-Leyva, Javier
name: Colmenero, Alberto Garrido
name: Calatrava-Leyva, Javier
name: Colmenero, Alberto Garrido
Publisher: name: Unknown
Year: 2001
Subjects: Resource /Energy Economics and Policy

description: RESUMEN - La evidencia disponible sobre los efectos externos de los mercados de agua actualmente en funcionamiento es contradictoria. Algunos trabajos demuestran que el intercambio de agua reduce la contaminación derivada de los sistemas productivos del regadío, mientras que otros concluyen lo contrario. El uso combinado de tasas sobre el input contaminante y la implantación de un mercado de agua plantea incentivos a los productores con resultados ambiguos, entre otras razones porque agua y fertilización no son sustitutivos. El objetivo de este trabajo es analizar el efecto conjunto del establecimiento de un hipotético mercado de agua entre agricultores y un impuesto sobre el nitrógeno sobre la rentabilidad de las explotaciones, la contaminación por nitratos y la demanda de mano de obra eventual. Para ello se plantean y desarrollan dos modelos de programación no lineal que simulan la conducta de los regantes y el funcionamiento de un mercado de aguas entre comunidades de regantes de la Cuenca del Guadalquivir. Los resultados muestran que los intercambios de agua suponen un mayor uso de mano de obra y un incremento del excedente económico, si bien a costa de un cierto incremento en la contaminación por nitratos. La reducción de contaminación que produce el gravamen al nitrógeno se atenúa cuando los regantes pueden intercambiar el agua, al tiempo que se mitiga también el efecto renta negativo causado por la tasa al nitrógeno. No existe ambigüedad alguna sobre el aumento del empleo estacional derivado del intercambio de agua. SUMMARY - The evidence available about the external effects of functioning water markets is ambiguous. While some authors have shown that water exchanges diminishes the polluting effects of irrigated agriculture, others conclude otherwise. The joint use of contaminant input taxes and the establishment of water markets gives rise to ambiguous results, because water and fertilisers are not substitutes. The objective of this paper is to examine the joint effects of establishing an hypothetical spot water market among farmers and a nitrogen tax on irrigators' benefits, nitrogen pollution and hired external labour. Two non-linear models are formulated and developed that simulate irrigators' behaviour and the functioning of inter-district water markets in the Guadalquivir basin. Results show that water markets would increase hired farm labour and irrigators' surplus, though at the cost of increasing nitrates pollution. The reduction of nitrates contamination achieved by the tax is attenuated as a result of water exchanges, which in turn contribute to reduce the negative income effects caused by the nitrates tax. Water markets increase unambiguously the social benefits resulting from increasing hired labour.
XENON1T Anomaly: A Light $Z^\prime$
Creators: name: Lindner, Manfred
name: Mambrini, Yann
name: de Melo, Tessio B.
name: Queiroz, Farinaldo S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We have witnessed the beginning of an era where dark matter and neutrino detectors can probe similar new physics phenomena. Motivated by the low-energy electron recoil spectrum observed by the dark matter experiment, XENON1T, at Gran Sasso laboratory, we interpret the observed signal not in terms of a dark matter particle, but rather in the context of a new light $Z^\prime$ gauge boson. We discuss how such a light $Z^\prime$ rises in a Two Higgs Doublet Model augmented by an abelian gauge symmetry where neutrino masses and the flavor problem are addressed, in agreement with neutrino-electron scattering data.
description: 6 pages, 1 figure
Black hole formation through fragmentation of toroidal polytropes
Creators: name: Zink, Burkhard
name: Stergioulas, Nikolaos
name: Hawke, Ian
name: Ott, Christian D.
name: Schnetter, Erik
name: Mueller, Ewald
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We investigate new paths to black hole formation by considering the general relativistic evolution of a differentially rotating polytrope with toroidal shape. We find that this polytrope is unstable to nonaxisymmetric modes, which leads to a fragmentation into self-gravitating, collapsing components. In the case of one such fragment, we apply a simplified adaptive mesh refinement technique to follow the evolution to the formation of an apparent horizon centered on the fragment. This is the first study of the one-armed instability in full general relativity.
description: 4 pages, 3 figures
"First International Conference on Manichaeism" in Lund (Schwe- den), 5.-9. August 1987
Creators: name: Böhlig, Alexander
Publisher: name: Oriens christianus : Hefte für die Kunde des christlichen Orients
Year: 2024

description: Oriens christianus : Hefte für die Kunde des christlichen Orients, Bd. 72 (1988): Oriens christianus, Band 72
On the impossibility of frozen nuclei
Creators: name: Grohmann, Thomas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Many molecular "quantum" theories, like "quantum chemistry", conceal that they are actually quantum-classical approaches---they treat one set of molecular degrees of freedom classically while the remaining degrees of freedom follow the laws of quantum mechanics. We show that the prominent "frozen-nuclei approximation", which is often used in molecular control communities, is a further example for such theory reduction: It treats the nuclei of the molecule as classical particles. Here, we demonstrate that the ignorance about the quantum nature of nuclei has far-reaching consequences for the theoretical description of molecules. We analyse the symmetry of oriented and aligned rigid molecules with feasible permutations of identical nuclei and show: The presumption of fixed nuclei corresponds to a localized state that is impossible to create if the existence of stable nuclear spin isomers is a justifiable assumption for the controlled molecule. The results of studies on molecules containing identical nuclei have to be re-evaluated and properly anti-symmetrised, because for such molecules the premise of frozen nuclei is inherently wrong: Molecular wave functions have to obey the spin-statistics theorem twice.
Partially drained response of sands
Creators: name: Gananathan, Nadarajah
Publisher: name: University of British Columbia
Year: 2009

description: This study was carried out to improve our understanding of the behaviour of sands under different drainage conditions, especially the partially drained condition. The influence of aging on the stress-strain response of sands was also considered. The study was performed on two different sands, a Fraser River sand and a North Sea sand. As such, objectives of this study are (a) the effects of drainage conditions, (b) the partially drained response and (c) the influence of aging on the stress-strain response of sands. Identical soil specimens were aged under constant stresses for 1, 100 and 1,000 minutes and then sheared under undrained or partially drained conditions. Effects of the aging period on the stress-strain response were studied at k0 conditions and at different values of confining stress. A constant period of aging of 100 minutes was selected for the main laboratory program of tests. The shear response of aged (100 mins) sands, under drained and undrained conditions, was examined. Although aging positively influences the shear response of sands, in that shear strength increases, the general behaviour regarding the effect of confining stress and stress ratio is found to be the same. The effect of small imposed volumetric strains on the shear response of aged (100 mins) sands was studied. Imposed expansive volumetric strains negatively influence the shear response whereas the contractive strains influence positively. Certain imposed expansive volumetric strains results in continuous strain softening. Even though sands continuously strain soften for certain imposed expansive volumetric strains, the effect of confining stress and stress ratio are seen at small strain levels. The material with higher stress ratio and lower confining stress start to strain soften at smaller strain levels.
Risk-Averse MPC via Visual-Inertial Input and Recurrent Networks for Online Collision Avoidance
Creators: name: Schperberg, Alexander
name: Chen, Kenny
name: Tsuei, Stephanie
name: Jewett, Michael
name: Hooks, Joshua
name: Soatto, Stefano
name: Mehta, Ankur
name: Hong, Dennis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, we propose an online path planning architecture that extends the model predictive control (MPC) formulation to consider future location uncertainties for safer navigation through cluttered environments. Our algorithm combines an object detection pipeline with a recurrent neural network (RNN) which infers the covariance of state estimates through each step of our MPC's finite time horizon. The RNN model is trained on a dataset that comprises of robot and landmark poses generated from camera images and inertial measurement unit (IMU) readings via a state-of-the-art visual-inertial odometry framework. To detect and extract object locations for avoidance, we use a custom-trained convolutional neural network model in conjunction with a feature extractor to retrieve 3D centroid and radii boundaries of nearby obstacles. The robustness of our methods is validated on complex quadruped robot dynamics and can be generally applied to most robotic platforms, demonstrating autonomous behaviors that can plan fast and collision-free paths towards a goal point.
description: Accepted to the 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Las Vegas, USA. First two authors contributed equally. For supplementary video, see https://www.youtube.com/watch?v=td4K55Tj-U8