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Wyszukujesz frazę "Pereira, T. M." wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
Analysis and monitoring of electrical grounding grid encapsulated with concrete: case study using simulation in finite element method
Autorzy:
Pereira, T. M.
Lima, R.
Gomes, V. M.
Calixto, W. P.
Alves, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/136184.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
grounding systems
finite elements method
Opis:
This work study the influence of concrete, plaster, clay and others buried structures in grounding systems. Comparison of soil characteristics between dry and rainy seasons on different grounding systems. The study includes comparison of six different grounding system on dry season and wet season. Simulations in finite element method was performed for tree layer stratified soil and the electrostatic equipotential surfaces were mapped into the region of interest.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 2; 31-36
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of the influence of slot geometry on the magnetic flux density of the air gap
Autorzy:
Lima, R. A. de
Coimbra, A. C. P.
Almeida, T.
Gomes, V. M.
Pereira, T. M.
Alves, A. J.
Calixto, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/136264.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
Carter's factor
finite element method
rotating machines
Opis:
The objective of this work is to investigate the influence of slotted air gap constructive parameters on magnetic flux density of rotating machines. For this purpose, different approaches were used to solve the air gap field diagram using finite element method and the magnetic field distribution uniformity was evaluated by Carter's factor calculation on two-dimensional and three-dimensional models. Sensitivity analysis of slot constructive parameters was performed and results show that slot geometry modifies the magnetic flux on air gap and shifts the air gap magnetic equipotential midline of double slotted machines. Finally, minimization of Carter’s factor on two-dimensional model presents an optimized slot geometry with a near uniform magnetic flux density distribution.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 1; 81-89
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of crystals based on cesium iodide for measurements of gamma radiation and alpha particles
Autorzy:
Pereira, M. C. C.
Filho, T. M.
Hamada, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/148098.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
scintillator
crystals
gamma radiation
alpha particles
luminescence
Opis:
During the past 50 years, scintillators have been among the most important nuclear radiation detectors. Inorganic scintillators are widely used in experimental nuclear physics, high energy physics, nuclear medicine, nuclear tomography, environmental studies and many other fields of use. Scintillation crystals based on cesium iodide (CsI) are matters of relatively low hygroscopy, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, the growth of pure CsI crystals, CsI:Br and CsI:Pb, using the Bridgman technique, is described. Ions of divalent lead (Pb2+) doped in the crystal structures are efficient emission centers and their application as scintillators is still the reason for intensive studies. Recently, promising results have been found for crystals of CsI doped by bromine (Br) for their use as radiation detectors. The concentration of the bromine doping element (Br) was studied in the range from 1.5 × 10–1 M to 10–2 M and the lead (Pb) in the range from 10–2 M to 5 × 10–4 M. To evaluate the scintillators developed, systematic measurements were carried out for luminescence emission and luminescence decay time for gamma radiation, Vickers microhardness assays, and analysis of crystals response to the gamma radiation, in the energy range from 350 keV to 1330 keV, and alpha particles from a 241Am source, with energy of 5.54 MeV. The obtained values for luminescence decay time for CsI:Br and CsI:Pb crystals, were from 13 to 19 ns.
Źródło:
Nukleonika; 2009, 54, 3; 151-155
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A concept of in-process measurement system for spline forming
Autorzy:
Wieczorowski, M.
Eichner, T.
Lindner, I.
Pereira, A.
Powiązania:
https://bibliotekanauki.pl/articles/407260.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gear
spline
forming
coordinate metrology
in-process inspection
Opis:
In the paper a possibility of in-process inspection of gear and spline shafts during forming was discussed. Different methods of forming toothed elements were discussed as well as the other technologies were mentioned. Coordinate measurement technique as a way of post process inspection was presented. However, it is not possible to use it for checking features during forming process. To do it different sensors were used and their combinations were described.
Źródło:
Management and Production Engineering Review; 2015, 6, 2; 73-81
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of edge ion temperature and poloidal rotation velocity from carbon III triplet measurements on the COMPASS tokamak
Autorzy:
Tomeš, M.
Weinzettl, V.
Pereira, T.
Imríšek, M.
Seidl, J.
Powiązania:
https://bibliotekanauki.pl/articles/148182.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
high-resolution spectroscopy
spectra processing
peak detection
line detection
line fitting
poloidal plasma rotation
ion temperature
Opis:
A high-resolution spectroscopic system for the measurements of the CIII triplet at 465 nm was installed at the COMPASS tokamak. The Doppler broadening and shift of the measured spectral lines are used to calculate the edge ion temperature and poloidal plasma rotation. At first, the spectroscopic system based on two-grating spectrometer and the calibration procedure is described. The signal processing including detection and removal of spiky features in the signal caused by hard X-rays based on the difference in the behaviour of Savitzky-Golay and median filters is explained. The detection and position estimation of individual spectral lines based on the continuous wavelet transform is shown. The method of fitting of Gaussians using the orthogonal distance regression and estimation of the error of estimation of the rotation velocity and ion temperature is described. At the end, conclusions about the performance of the spectroscopic system and its shortcomings based on summary of results calculated from 2033 processed spectral lines measured in 61 shots are drawn and the possible enhancements are suggested.
Źródło:
Nukleonika; 2016, 61, 4; 443-451
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship between performance, dry-land power and kinematics in master swimmers
Autorzy:
Espada, M. C.
Costa, M. J.
Costa, A. M.
Silva, A. J.
Barbosa, T. M.
Pereira, A. F.
Powiązania:
https://bibliotekanauki.pl/articles/307228.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pływanie
kinematyka
energia
master swimmers
kinematic
dry-land power
performance
Opis:
The purpose of the study was to analyze the relationships between sprint swimming performance, dry-land power, and kinematics in master swimmers. Twenty-two male master swimmers were separated in two groups based on their chronological age: (i) 30–39 years and; (ii) 40–49 years. Maximum dry-land power was determined through counter movement jump and 3 kg medicine ball throwing (Hmax and Tmax, respectively). Kinematic determinants of performance were measured during a maximal bout of 15, 25 and 50 m front crawl (T15, T25, T50). Stroke frequency (SF), stroke length (SL) and stroke index (SI) were calculated as kinematical aspects of the stroke. In the 30-39 group, SI25 was correlated to T25 (r = –0.76, p < 0.01, η2 = 0.96), the same was observed between SI50 and T50 (r = –0.83, p < 0.01, η2 = 0.96). Only SI50 was significantly correlated to T50 (r = –0.86, p < 0.01, η2 = 0.97) in the 40–49 years age cohort. In dryland power variables, Hmax and Tmax were only correlated in the younger master swimmers group (r = –0.87, p < 0.01, η2 = 0.97). There were no significant differences (p < 0.05) between younger (30–39 years) and older (40–49 years) swimmers groups in dry-land tests (Hmax 28.5 ± 5.9 vs. 26.5 ± 3.9 cm and Tmax 4.2 ± 1.0 vs. 4.2 ± 1.1 m). Our results suggest that swimming performance in younger master swimmers (30–39 years) seem more dependent on kinematic swimming variables than on strength parameters, which were most related to swimming performance in the older master swimmers (40–49 years).
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 2; 145-151
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stratigraphy, palynology and organic geochemistry of the Devonian-Mississippian metasedimentary Albergaria-a-Velha Unit (Porto-Tomar shear zone, W Portugal)
Autorzy:
Machado, G.
Francu, E.
Vavrdová, M.
Flores, D.
Fonseca, P. E.
Rocha, F. T.
Pereira, L. C. G.
Gomes, A.
Fonseca, M.
Chaminé, H.
Powiązania:
https://bibliotekanauki.pl/articles/2059150.pdf
Data publikacji:
2011
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Mississippian
Late Devonian
Ossa-Morena Zone
Porto-Tomar shear zone
palynology
organic geochemistry
Opis:
The Albergaria-a-Velha Unit is one of several tectonostratigraphic out-of-sequence units of the metamorphic belt associated with the Porto-Tomar shear zone (Ossa-Morena Zone, W Portugal). It is composed of considerably deformed - very low grade - metasediments, namely shales, siltstones and rare fine sandstones. In this work we present new sedimentological and biostratigraphical data that suggest the Albergaria-a-Velha Unit was deposited from the (?)early Frasnian to the Serpukhovian in a distal marine environment, where turbiditic and basinal sedimentation prevailed. Palynofacies analysis and lithological data point to a gradual increase of terrestrial input, suggesting a prograding system. Detrital framework data is indicative of a stable cratonic sediment source area composed of low grade metamorphic rocks. The timing of the onset of the Porto-Tomar shear zone activity and consequently its influence on the sedimentation of this unit is discussed. Organic petrology and geochemistry data indicate that the Albergaria-a-Velha Unit is within the dry gas window in terms of hydrocarbon generation ranges.
Źródło:
Geological Quarterly; 2011, 55, 2; 139-164
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray computed tomography SCANNERS for applications in multiphase system COLUMNs
Autorzy:
Calvo, W. A. P.
Hamada, M. M.
Sprenger, F. E.
Vasquez, P. A. S.
Rela, P. R.
Martins, J. F. T.
de Matos Pereira, J. C. S.
Omi, N.
de Mesquita, C. H.
Powiązania:
https://bibliotekanauki.pl/articles/148082.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
industrial computed tomography
multiphase flow systems
non-destructive testing
gas absorption column
industrial process optimization
packed distillation columns
scanning systems
Opis:
Gamma-ray tomography experiments have been carried out to detect spatial patterns in the porosity, in a 0.27 m diameter packed steel column using a first generation computed tomography (CT) system. The CT scanner consists of a NaI(Tl) detector 5.08 cm in diameter, and an encapsulated 137Cs (3.7 GBq) radioactive source, located opposite to the center of the detector. The detector and the source, mounted on a fixed support and the column, can rotated and dislocate by two stepping motors controlled through a microprocessor. Different sizes of stainless steel Raschig rings (12.6, 37.9 and 76 mm) have been examined. The primary objective of this work is to detect spatial patterns and statistical information on porosity variation in packed distillation columns. Horizontal scans, at different vertical positions of the packed bed were made for each size of Raschig rings. Radial porosity variation within the packed bed has been determined. This study has demonstrated that the porosity and its spatial distribution in a metallic packed column can be measured with adequate spatial resolution using the gamma-ray tomography technique. After validation of this first generation CT, the turntable design to rotate and dislocate the 60Co or 137Cs sealed gamma-ray sources and multidetector array for the third generation industrial computed tomography was also developed.
Źródło:
Nukleonika; 2009, 54, 2; 129-133
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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