Uma Aplicação do Teorema dos Resíduos

O movimento rotativo de um rotor numa região confinada determina o escoamento do fluído envolvente e o desenvolvimento de forças de interacção fluído-estrutura, cujo conhecimento é essencial na previsão do comportamento dinâmico deste sistema. A determinação explícita das forças referidas a partir das equações de Navier-Stokes conduz à necessidade de resolução de integrais definidos do tipo [equação]. A aplicação de uma forma particular do teorema dos resíduos da análise complexa constitui a solução natural do problema anterior, concretizada recorrendo ao auxílio de um manipulador simbólico para fazer face à extensão das manipulações algébricas necessárias

Metafora Dalam Pasambahan Maanta Marapaulai Di Nagari Tanjung Kecamatan Koto VII Kabupaten Sijunjung

The purpose of the research is to decribe (1) the metaphor forms in pasambahan maanta marapulai at Nagari Tanjung subsdistrict of Koto VII Sijunjung regency, (2) the meaning of metaphor in pasambahan maanta marapulai at Nagari Tanjung subdistrcit of Koto VII Sijunjung regency, as well as (3) the context of metaphor use in pasambahan maanta marapulai at Nagari Tanjung subdistrict of Koto VII Sijunjung regency. Data of the research is the words in pasambahan maanta marapulai used by citizien at Nagari Tanjung subdistrict of Koto VII Sijunjung regency. The resource of data is pasambahan maanta marapulai from the beginning till pasambahan minta pulang. Data is gained using listening and conversation method, While techniques used is record technique and note technique. Based on the finding, there are fouty four metaphor consisted of 9 metaphor antropomorfis, 12 animal metaphor, 21 metaphor from conrete to abstract as well as 2 metaphor sinaestetik. The meaning of metaphor is based on literal meaning and meaning from the interviwee. While, the context of metaphor use consists of situation and culture context

Optimization of baffle configurations to prevent aeroacoustic instabilities in heat exchangers - preliminary experiments

It is well known that gas heat exchangers are prone to aeroacoustic instabilities, which often lead to severe noise levels, structural vibrations and fatigue. These are unacceptable, as they threaten the component integrity and expose the plant workers to excessive noise levels. Such phenomenon is due to a cooperative interplay between the Karman vortices generated by the cross-flow and the heat exchanger acoustical modes (mainly those transverse to the tube banks). Energy exchanges are then such that, for certain operating velocities, self-excitation of one or more acoustical modes arises. Actually, this problem is solved by placing rigid baffles inside the container, which modify the acoustic modal fields and eventually inhibit the instability. However, an effective location of such baffles is more or less difficult depending on the system complexity and on the range of flow velocities of interest. For realistic industrial components - using a restricted number of acoustical baffles - their optimal location is a challenging problem, as trial and error experimentation is often a costly and frustrating procedure. In this paper we improve a recently proposed strategy for the optimal location of a given number of baffles, in order to inhibit instability of the acoustical modes in a given frequency range. Our approach is based on a stochastic global optimization technique. Some preliminary experiments are also performed and compared with the simulation results

High-Resolution Mid-Infrared Morphology of Cygnus A

We present subarcsecond resolution mid-infrared images at 10.8 and 18.2 microns of Cygnus A. These images were obtained with the University of Florida mid-IR camera/spectrometer OSCIR at the Keck II 10-m telescope. Our data show extended mid-IR emission primarily to the east of the nucleus with a possible western extension detected after image deconvolution. This extended emission is closely aligned with the bi-conical structure observed at optical and near-IR wavelengths by the HST. This emission is consistent with dust heated from the central engine of Cygnus A. We also marginally detect large-scale low level emission extending > 1.5 kpc from the nucleus which may be caused by in-situ star formation, line emission, and/or PAH contamination within the bandpass of our wide N-band filter.Comment: 20 pages, 8 figures, accepted for publication in the Astrophysical Journa

Surgical correction of scoliosis: Numerical analysis and optimization of the procedure

A previously developed model is used to numerically simulate real clinical cases of the surgical correction of scoliosis. This model consists of one-dimensional finite elements with spatial deformation in which (i) the column is represented by its axis; (ii) the vertebrae are assumed to be rigid; and (iii) the deformability of the column is concentrated in springs that connect the successive rigid elements. The metallic rods used for the surgical correction are modeled by beam elements with linear elastic behavior. To obtain the forces at the connections between the metallic rods and the vertebrae geometrically, non-linear finite element analyses are performed. The tightening sequence determines the magnitude of the forces applied to the patient column, and it is desirable to keep those forces as small as possible. In this study, a Genetic Algorithm optimization is applied to this model in order to determine the sequence that minimizes the corrective forces applied during the surgery. This amounts to find the optimal permutation of integers 1, ... , n, n being the number of vertebrae involved. As such, we are faced with a combinatorial optimization problem isomorph to the Traveling Salesman Problem. The fitness evaluation requires one computing intensive Finite Element Analysis per candidate solution and, thus, a parallel implementation of the Genetic Algorithm is developed

Effect of the saliva biomolecules on the interface zirconia/Ti6Al4V triboactivity

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Product assurance technology for custom LSI/VLSI electronics

The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification

Land cover classification using high‐resolution aerial photography in Adventdalen, Svalbard

A methodology was tested for high‐resolution mapping of vegetation and detailed geoecological patterns in the Arctic Tundra, based on aerial imagery from an unmanned aerial vehicle (visible wavelength – RGB, 6 cm pixel resolution) and from an aircraft (visible and near infrared, 20 cm pixel resolution). The scenes were fused at 10 and 20 cm to evaluate their applicability for vegetation mapping in an alluvial fan in dventdalen, Svalbard. Ground‐truthing was used to create training and accuracy evaluation sets. Supervised classification tests were conducted with different band sets, including the original and derived ones, such as and principal component analysis bands. The fusion of all original bands at 10 cm resolution provided the best accuracies. The best classifier was systematically the maximum neighbourhood algorithm, with overall accuracies up to 84%. Mapped vegetation patterns reflect geoecological conditioning factors. The main limitation in the classification was differentiating between the classes graminea, moss and Salix, and moss, graminea and Salix, which showed spectral signature mixing. Silty‐clay surfaces are probably overestimated in the south part of the study area due to microscale shadowing effects. The results distinguished vegetation zones according to a general gradient of ecological limiting factors and show that + high‐resolution imagery are excellent tools for identifying the main vegetation groups within the lowland fan study site of dventdalen, but do not allow for detailed discrimination between species.info:eu-repo/semantics/publishedVersio