Search results for "Theories"
showing 10 items of 302 documents
Tunable invisibility cloaking by using isolated graphene-coated nanowires and dimers
2017
AbstractWe investigate, both theoretically and numerically, a graphene-coated nano-cylinder illuminated by a plane electromagnetic wave in the far-infrared range of frequencies. We have derived an analytical formula that enables fast evaluation of the spectral window with a substantial reduction in scattering efficiency for a sufficiently thin cylinder. This polarization-dependent effect leads to tunable resonant invisibility that can be achieved via modification of graphene chemical potential monitored by the gate voltage. A multi-frequency cloaking mechanism based on dimer coated nanowires is also discussed in detail.
Splitting of the surface phonon modes in wurtzite nanowires
2013
We analyze the surface optical modes of GaN nanowires (NW) and perform a comparative study with the characteristics expected for other polar NWs. The theoretical analysis of the modes is performed within the context of the effective medium theory that takes into account the dipolar interaction between neighboring NWs (Maxwell-Garnett approximation). It is shown that deviations of the exciting light from the NWs axis, which coincides with the wurtzite c-axis, result in the anticrossing of two distinct surface phonon branches, leading to their splitting in axial and planar components and the appearance of two peaks in the Raman spectra. Additional calculations are performed that determine th…
Le relazioni tra utente ed informazioni. Principi e metodi di analisi
2016
Presentación de los estudios sobre comportamiento informacional desde el punto de vista de: a) conceptos y evolución histórica, b) fundamentos teóricos y c) fundamentos metodológicos. Overview of studies on information behavior from the point of view of: a) concepts and historical evolution, b) theorical and c) methodological foundations.
IMPLICIT THEORIES OF INTELLIGENCE AND ACADEMIC ACHIEVEMENT: REVIEW OF TWO STUDIES IN LATVIA
2020
Growth mindset has become popular in the field of psychology and education all around the world. In the Baltic States this concept is relatively new. This research compiles results of two different studies that, for the first time in the Baltic States, analyse the concept of “implicit theories of intelligence” (ITI) and its factors – growth and fixed mindset, and investigate the relations between ITI and academic achievement of students. Data of two different samples of secondary school adolescents is used. Sample 1 consisted of students (N1=258) aged between 14 and 18, 134 females (M=15.13; SD=1.29) and 124 males (M=15.40; SD=1.20) studying in 7th-12th grade in two Latvian schools. Sample …
La Méthode como hermenéutica musical Homenaje a Edgar Morin por su 100º cumpleaños
2021
The present work addresses the principles and properties of the complex thought formulated by the French thinker Edgar Morin and the way in which he was able me to articulate his conception of organizational complexity with one of the most important theories of musical analysis, which emerged at the beginning of the 20th century: the schenkerian analysis. It is a review and extension of a few pages of my doctoral thesis, which are intended to pay tribute to who has been, in addition to my teacher, Honorary President of Itamar since its first issue. His teachings and support has always been the engine for my quest for musical organization. On July 21, 2021, Morin celebrated his 100th birthda…
New Physics adventures in the LHC age
2017
La física de partículas está viviendo actualmente una era de exploración que comenzó con la observación en el LHC del bosón de Higgs, proporcionando así al Modelo Estándar de la Física de Partículas la elusiva pieza final que lo completa. Si bien esta teoría es extremadamente exitosa, se acepta comúnmente que no es la teoría final ya que no puede responder a todas las preguntas teóricas ni a ciertas observaciones experimentales. Por lo tanto, se espera que Nueva Física que extienda al Modelo Estándar aparezca pronto, aunque esto bien podría ser sólo una esperanza. Esta tesis recoge algunas de las aventuras en la búsqueda de Nueva Física. Se organiza en tres partes: la Parte I introduce, en …
Integration of an LP Solver into Interval Constraint Propagation
2011
This paper describes the integration of an LP solver into iSAT, a Satisfiability Modulo Theories solver that can solve Boolean combinations of linear and nonlinear constraints. iSAT is a tight integration of the well-known DPLL algorithm and interval constraint propagation allowing it to reason about linear and nonlinear constraints. As interval arithmetic is known to be less efficient on solving linear programs, we will demonstrate how the integration of an LP solver can improve the overall solving performance of iSAT.
NONLOCAL LAYER-WISE ADVANCED THEORIES FOR LAMINATED PLATES
2019
Eringen nonlocal layer-wise models for the analysis of multilayered plates are formulated in the framework of the Carrera Unified Formulation and the Reissner Mixed Variational Theorem (RMVT). The use of the layer-wise approach and RMVT ensures the fulfilment of the transverse stress equilibrium at the layers’ interfaces and allows the analysis of plates with layers exhibiting different characteristic lengths in their nonlocal behaviour. A Navier solution has been implemented and tested for the static bending of rectangular simply-supported plates. The obtained results favourably compare against available three-dimensional analytic results and demonstrate the features of the proposed theori…
Time evolution of linearized gauge field fluctuations on a real-time lattice
2016
Classical real-time lattice simulations play an important role in understanding non-equilibrium phenomena in gauge theories and are used in particular to model the prethermal evolution of heavy-ion collisions. Due to instabilities, small quantum fluctuations on top of the classical background may significantly affect the dynamics of the system. In this paper we argue for the need for a numerical calculation of a system of classical gauge fields and small linearized fluctuations in a way that keeps the separation between the two manifest. We derive and test an explicit algorithm to solve these equations on the lattice, maintaining gauge invariance and Gauss's law.
Consistent Searches for SMEFT Effects in Non-Resonant Dilepton Events
2019
Employing the framework of the Standard Model Effective Field Theory, we perform a detailed reinterpretation of measurements of the Weinberg angle in dilepton production as a search for new-physics effects. We truncate our signal prediction at order $1/\Lambda^2$, where $\Lambda$ denotes the new-physics mass scale, and introduce a theory error to account for unknown contributions of order $1/\Lambda^4$. Two linear combinations of four-fermion operators with distinct angular behavior contribute to dilepton production with growing impact at high energies. We define suitable angular observables and derive bounds on those two linear combinations using data from the Tevatron and the LHC. We find…