360 research outputs found
AN ALTERNATIVE AND SIMPLE MANNER TO CALCULATE THE THERMAL EFFICIENCY OF COMBUSTION ENGINES
This papers aims to present techniques and methods to develop an alternative equation to determine the thermal efficiency of internal combustion engines. Towards interpolation of data, obtained from thermodynamic tables, it presents a function that allows a faster calculation of efficiency for combustion engines
Least squares finite element method for 3D unsteady diffusion and reaction-diffusion problems
In this paper a study to application of Least Squares Finite Element Method (LSFEM) is made and with auxiliary equations (temperature derivatives) in the solution of Transient Three-dimensional Diffusion-Reaction. In order to do so, two applications are presented and discussed, one of them Pure Diffusion and another DiffusionReaction, both solved towards the constructive meshes with hexahedron of 8 and 27 nodes. This analysis uses the standard L∞ (maximum error in all meshes) and L2 (average error in all the meshes) to verify the numerical error committed in the solution9196209CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP500382/2011-52014/06679-
Interplate versus intraplate strike-slip deformed belts: examples from SW Iberia
A complete transition in tectonic style between pure thrust belts and pure strike-slip beltscan be envisaged, both in interplate and intraplate settings, by a combination of thrust and strike-slipcomponents of displacement. The accommodation of shortening components in strike-slip deforma-tion belts has been discussed recently on the basis of two alternative perspectives: (1) the “sub-horizon-tal attachment model”, where discrete strike-slip faulting of rigid blocks in the schiszosphere evolves tocontinuous movement in plastosphere through a bottom-up driving mechanism controlled by verticalcoupling across the lithosphere, and (2) the “accommodation model” that considers decoupling with-in a heterogeneous and anisotropic plastosphere. Two examples of variable shortening componentaccommodation in strike-slip deformation belts of the SW Iberia Variscides are reported and discussed.In the Tomar-Badajoz-Córdoba shear zone, an important shortening component is accommodated inflat-lying bends around the horizontal axis within a WNW-ESE flower-structure with sinistral strike-slip component; the geodynamic evolution points to an intraplate setting for this structure. In the N-S, Porto-Tomar-Ferreira do Alentejo, dextral shear zone, the shortening component is restricted torestraining bends around the vertical axis; the geodynamic evolution allows inferring a transformnature for this structure, thus indicating an interplate setting. For these examples, the “accommodationmodel” is preferred to the “sub-horizontal attachment model”info:eu-repo/semantics/publishedVersio
ERROR ANALYSIS IN THE NUMERICAL SOLUTION OF 3D CONVECTION-DIFFUSION EQUATION BY FINITE DIFFERENCE METHODS
In this work an error analysis for numerical solution of 3D convectiondiffusionequation by finite difference methods has been done. The backward, the forward and the central difference schemes are applied for three applications: a case with diffusion dominant corresponding to high diffusion coefficients and two cases with convection dominant or with low diffusion coefficients. In the second application the convective coefficients are function only of the diffusion coefficient that in dimensionless form is named Reynolds numbers. In the third application the convective coefficients are function of both the Reynolds number and of the space. The three applications have analytical solutions to facilitate numerical comparisons of the solutions
HEAT TRANSFER IN MULTI-CONNECTED AND IRREGULAR DOMAINS WITH NON-UNIFORM MESHES
In this work is presented a numerical solution for temperature profile in two-dimensional diffusion inside irregular multi-connected geometry. The special discretization has been done by two variants of the finite Element Method: Galerkin Finite Element Method (GFEM) and Least Squares Finite Element Method (LSFEM). Three applications are presented. The first for a regular double connected domain; the second for a regular multi-connected domain and the third application for an irregular multi-connected domain. In all applications are considered Dirichlet boundary conditions. The results obtained in the present work are compared with results from Ansys® simulations. The results of each method are presented and discussed and the characteristics and advantages of the methods are also discussed
Slow Schroedinger dynamics of gauged vortices
Multivortex dynamics in Manton's Schroedinger--Chern--Simons variant of the
Landau-Ginzburg model of thin superconductors is studied within a moduli space
approximation. It is shown that the reduced flow on M_N, the N vortex moduli
space, is hamiltonian with respect to \omega_{L^2}, the L^2 Kaehler form on
\M_N. A purely hamiltonian discussion of the conserved momenta associated with
the euclidean symmetry of the model is given, and it is shown that the
euclidean action on (M_N,\omega_{L^2}) is not hamiltonian. It is argued that
the N=3 flow is integrable in the sense of Liouville. Asymptotic formulae for
\omega_{L^2} and the reduced Hamiltonian for large intervortex separation are
conjectured. Using these, a qualitative analysis of internal 3-vortex dynamics
is given and a spectral stability analysis of certain rotating vortex polygons
is performed. Comparison is made with the dynamics of classical fluid point
vortices and geostrophic vortices.Comment: 22 pages, 2 figure
GFEM AND LSFEM IN THE SOLUTION OF THE TRANSIENT BIDIMENSIONAL CONVECTION-DIFFUSION EQUATION
Convection dominated flows result in a hyperbolic system of equations which leads to ill-conditioned matrices and oscillatory approximations when using the classical Galerkin Finite Element Method (GFEM). In this paper, the Least Square Finite Method (LSFEM) is introduced in the study of transient bidimensional convection-diffusion problems. The differentiated equation of second order which describes the convective-diffusive phenomenon is transformed into an equivalent system of partial differentiated equations of first order which is discretized by the formulation of the LSFEM resulting in a defined algebraic, symmetrical and positive system. The performance of the method is verified by the solution of a test- problem
MEMBRO FANTASMA EM AMPUTADOS DE GUERRA
O membro fantasma é a experiência de possuir um membro ausente que se comporta similarmente ao membro real, englobando a sensação e dor.
Os objectivos deste trabalho foi avaliar a prevalência da dor pós-amputação em amputados de guerra, em Portugal, e a sua caracterização. A prevalência da sensação fantasma e dor no coto e as suas implicações
na dor fantasma constituem objectivos secundários, assim como o impacto da dor no quotidiano destes doentes e seu bem-estar físico e social
Effects of web-based electrocardiography simulation on strategies and learning styles
Objective: To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. Method: A descriptive and correlational design with a one-group pretest– posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. Results: No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. Conclusion: The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students
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