Search results for "Names"
showing 10 items of 6843 documents
Ultraprecise Rydberg atomic localization using optical vortices
2020
We propose a robust localization of the highly-excited Rydberg atoms, interacting with doughnut-shaped optical vortices. Compared with the earlier standing-wave (SW)-based localization methods, a vortex beam can provide an ultrahigh-precision two-dimensional localization solely in the zero-intensity center, within a confined excitation region down to the nanometer scale. We show that the presence of the Rydberg-Rydberg interaction permits counter-intuitively much stronger confinement towards a high spatial resolution when it is partially compensated by a suitable detuning. In addition, applying an auxiliary SW modulation to the two-photon detuning allows a three-dimensional confinement of R…
Quantum-chemical calculation of Born–Oppenheimer breakdown parameters to rotational constants
2010
The paper describes how Born–Oppenheimer breakdown parameters for the rotational constants of diatomic molecules can be determined via quantum-chemical computations. The deviations from the Born–Oppenheimer equilibrium values are accounted for by considering the adiabatic correction to the equilibrium bond distances, the electronic contribution to the rotational constant via the rotational g tensor, and the so-called Dunham correction, which can be computed directly from a polynomial expansion of the potential curve around the equilibrium distance. Calculations for HCl, SiS, and HF demonstrate the accuracy that can be achieved in the theoretical treatment of the considered Born–Oppenheimer …
Elastic Wave Near-Cloaking
2020
Cloaking elastic waves has, in contrast to the cloaking of electromagnetic waves, remained a fundamental challenge: the latter successfully uses the invariance of Maxwell's equations, from which the field of transformational optics has emerged, whereas the elastic Navier equations are not invariant under coordinate transformations. Our aim is to overcome this challenge, at least in practical terms, and thereby unlock applications in mechanics, ultrasound, vibration mitigation, non-destructive evaluation and elastic wave control. We achieve near-cloaking by recognising that, despite the lack of invariance, a decoupling into a system of form invariant potential equations together with a quant…
PLA based biocomposites reinforced with Posidonia oceanica leaves
2018
Abstract Biocomposites can valorize some natural products related to natural processes or crop and waste industries. In this work, leaves of Posidonia oceanica (PO), dominant sea grass in the Mediterranean Sea, were used to prepare PLA based biocomposites. Materials were prepared by melt mixing PLA with PO as filler. The morphology as well as the mechanical and thermal properties of PLA/PO composites were evaluated and related with the influence of the content and size of PO. Moreover, the experimental elastic moduli of the biocomposites was modelled employing the Halpin–Tsai (HT) model. Furthermore, in order to take into consideration the high porosity of PO leaves, the HT parameters relat…
Materialism and the Bright and Dark Sides of the Financial Dream in Spain: The Positive Role of Money Attitudes-The Matthew Effect
2012
Research suggests that materialism leads to the dark side of the financial dream. In this study, we treat love of money as a mediator and test a theoretical model's direct path (Materialism to Financial Satisfaction) and indirect path (Materialism to Love of Money to Financial Satisfaction) simultaneously using the whole sample and across several demographic variables based on 1,011 citizens in Spain. Results for the whole sample showed that the positive indirect effect suppressed the negative direct effect creating an overall small positive effect. Furthermore, we found a significant negative direct path for rural dwellers, the 30–44-year-old age group, and married people, but a positive i…
Nonrenewable Energy Prices and Stock Prices of EU Financial Companies: A Short Versus Long-Term Analysis
2021
This paper investigates the relationship between financial companies’ stock prices and nonrenewable energy sources prices (crude oil and coal price) using a sample of major financial companies headquartered in the EU. The link between stock prices and nonrenewable energy sources prices risk is modeled using a set of macroeconomic variables, such as Brent crude oil price, coal price, local stock market indices, the EUR/USD exchange rate, long-term interest rates and a global volatility measure (VIX). We apply panel data as the base econometric model and an ARDL extension that sheds light on the long versus short-run exposure of EU financial companies to nonrenewable energy prices volatility.…
The effect of vertical ground movement on masonry walls simulated through an elastic–plastic interphase meso-model: a case study
2019
The present paper proposes an interphase model for the simulation of damage propagation in masonry walls in the framework of a mesoscopic approach. The model is thermodynamically consistent, with constitutive relations derived from a Helmholtz free potential energy. With respect to classic interface elements, the internal stress contribute is added to the contact stresses. It is considered that damage, in the form of loss of adhesion or cohesion, can potentially take place at each of the two blocks–mortar physical interfaces. Flow rules are obtained in the framework of the Theory of Plasticity, considering bilinear domains of ‘Coulomb with tension cut-off’ type. The model aims to be a first…
On the convergence of a finite volume method for the Navier–Stokes–Fourier system
2020
Abstract The goal of the paper is to study the convergence of finite volume approximations of the Navier–Stokes–Fourier system describing the motion of compressible, viscous and heat-conducting fluids. The numerical flux uses upwinding with an additional numerical diffusion of order $\mathcal O(h^{ \varepsilon +1})$, $0<\varepsilon <1$. The approximate solutions are piecewise constant functions with respect to the underlying polygonal mesh. We show that the numerical solutions converge strongly to the classical solution as long as the latter exists. On the other hand, any uniformly bounded sequence of numerical solutions converges unconditionally to the classical solution of t…
Poincaré inequalities and Steiner symmetrization
1996
A complete geometric characterization for a general Steiner symmetric domain Ω ⊂ Rn to satisfy the Poincare inequality with exponent p > n−1 is obtained and it is shown that this range of exponents is best possible. In the case where the Steiner symmetric domain is determined by revolving the graph of a Lipschitz continuous function, it is shown that the preceding characterization works for all p > 1 and furthermore for such domains a geometric characterization for a more general Sobolev–Poincare inequality to hold is given. Although the operation of Steiner symmetrization need not always preserve a Poincare inequality, a general class of domains is given for which Poincare inequalities are…
A Novel Multi-step Finite-State Automaton for Arbitrarily Deterministic Tsetlin Machine Learning
2020
Due to the high energy consumption and scalability challenges of deep learning, there is a critical need to shift research focus towards dealing with energy consumption constraints. Tsetlin Machines (TMs) are a recent approach to machine learning that has demonstrated significantly reduced energy usage compared to neural networks alike, while performing competitively accuracy-wise on several benchmarks. However, TMs rely heavily on energy-costly random number generation to stochastically guide a team of Tsetlin Automata (TA) to a Nash Equilibrium of the TM game. In this paper, we propose a novel finite-state learning automaton that can replace the TA in TM learning, for increased determinis…