Formalism
Mostrando 13-24 de 375 artigos, teses e dissertações.
-
13. Adsorción y oxidación de monóxido de carbono en una lamina de ß-grafino: Estudio teórico
ABSTRACT This work presents a study, based on the Density functional theory (DFT), of the adsorption and oxidation of CO on a free platinum catalyst constituted from a sheet of Graphyne. Graphyne is a new allotrope of carbon, its structure is two-dimensional and is constituted by a monolayer of carbon atoms with sp-sp2 hybridization. Depending on the differe
Matéria (Rio J.). Publicado em: 19/07/2018
-
14. Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients
Ever-rising energy demand, fossil fuel dependence, and climate issues have harmful consequences to the society. Exploring clean and renewable energy to diversify the world energy matrix has become an urgent matter. Less explored or unexplored renewable energy sources like the salinity and proton gradient energy are an attractive alternative with great energy
J. Braz. Chem. Soc.. Publicado em: 2018-05
-
15. Error variance of short duration sieving
Abstract In this study, the variance of ordinary sieving test error was determined concerning the specification limit of sized iron ore product by subtracting the fundamental error (described by the Gy's formalism for sampling), from the global error (recoverable from database of historical values). The results allowed the calculation of the confidence inter
REM, Int. Eng. J.. Publicado em: 2018-04
-
16. Electromagnetism as a world view: implications for the teaching of energy
There are considerable differences in the ways mechanics and electromagnetism conceptualize energy. In the former, energy is defined in terms of force and work in a process-like reasoning that remits us to the ”past” of a given body or system. Moreover, in the mechanical framework energy is ascribed to matter, i.e., one speaks of the energy of a system o
Rev. Bras. Ensino Fís.. Publicado em: 22/06/2017
-
17. Autocatalysis, Entropic Aspects and the Martensite Transformation Curve in Iron-Base Alloys
This study advances a methodology that consolidates the description of time-dependent (isothermal) as well as time-independent (athermal) martensitic transformation curves. Our model is applied in an extended 3-space, thus permitting inclusion of the effects of autocatalysis on nucleation to be distinguished from the initiation of the transformation, as infl
Mat. Res.. Publicado em: 09/01/2017
-
18. BIOMASS PYROLYSIS KINETICS: A REVIEW OF MOLECULAR-SCALE MODELING CONTRIBUTIONS
Abstract Decades of classical research on pyrolysis of lignocellulosic biomass has not yet produced a generalized formalism for design and prediction of reactor performance. Plagued by the limitations of experimental techniques such as thermogravimetric analysis (TGA) and extremely fast heating rates and low residence times to achieve high conversion to usef
Braz. J. Chem. Eng.. Publicado em: 2017-01
-
19. Mathematical Description of a Flexible Connection of Links and its Applications in Modeling the Joints of Spatial Linkage Mechanisms
Abstract The general mathematical model of a flexible connection of links by means of spring-damping elements is presented in the paper. The formalism of homogeneous transformation matrices is used to derive formulas for the energy of spring deformation and the Rayleigh dissipation function of the spring-damping elements. The formulas have convenient forms t
Lat. Am. j. solids struct.. Publicado em: 2016-12
-
20. El teorema del Trabajo y la Energía en marcos de referencias rotacionales
In standard textbooks of college physics, Theorem of Work and Energy is generally presented for inertial reference systems in which it is clear that the kinetic energy is conserved when there is not net work of the forces of interaction. But what happens when energy and work are calculated on a non-inertial reference frame? In general, in basic physics textb
Rev. Bras. Ensino Fís.. Publicado em: 03/06/2016
-
21. Extracting Metamaterial Properties of Negative-Index and Plasmonic scatterers from the Mie Coefficients
Abstract An alternative theoretical approach is presented for improving the understanding of the scattering properties of simple negative-index and plasmonic spheres. The Mie scattering coefficients are broken up into two terms, the first representing the expected fields of a corresponding positive-index sphere, the second emerging from the intrinsic metamat
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-06
-
22. Inversion Method for Obtaining Electrical Parameters for Soil in the Rural Region in Brazil
AbstractThis paper presents an inversion methodology through weighted least squares to obtain the electrical parameters for the soil of a typical mid-western region in Brazil using the model based in the formalism of the parabolic equations to calculate the electric field intensity received. To validate this methodology, the results of the radio signal measu
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
-
23. Mecánica cuántica fundamental, una propuesta didáctica
Fundamental quantum mechanics (FQM) is a commented presentation of fundamental experiments and concepts of quantum mechanics, the physical theory of the quantum phenomena domain: superposition principle and quantum entanglement become the cornestone of the theoretical foundation of the quantum description. The formalism of these basic notions, for two-level
Rev. Bras. Ensino Fís.. Publicado em: 2014-03
-
24. Simulação de sinais de RMN através das equações de Bloch
The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonance signals using the Bloch equations. These phenomenological equations describe the classical behavior of macroscopic magnetization and are easily simulated using rotation matrices. Many NMR pulse sequences can be simulated with this formalism, allowing a quantit
Quím. Nova. Publicado em: 2014