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Wyszukujesz frazę "Silva, A." wg kryterium: Wszystkie pola


Tytuł:
A Simple Localized-Itinerant Model for PrAl$\text{}_{3}$: Crystal Field and Exchange Effects
Autorzy:
Von Ranke, P. J.
Palermo, L.
Da Silva, X. A.
Powiązania:
https://bibliotekanauki.pl/articles/1891680.pdf
Data publikacji:
1991-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Dg
75.30.Cr
Opis:
We present a simple magnetic model for PrAl$\text{}_{3}$. The effects of crystal field are treated using a reduced set of levels and the corresponding wave functions are extracted from the actual crystal field levels of Pr$\text{}^{+3}$ in a hexagonal symmetry. The exchange between 4f- and conduction-electrons are dealt within a molecular field approximation. An analytical magnetic state equation is derived and the magnetic behaviour discussed. The parameters of the model are estimated from a fitting of the inverse susceptibility of PrAl$\text{}_{3}$ given in the literature.
Źródło:
Acta Physica Polonica A; 1991, 80, 4; 583-590
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infinite ergodic index $ℤ^d$ -actions in infinite measure
Autorzy:
Muehlegger, E.
Raich, A.
Silva, C.
Touloumtzis, M.
Narasimhan, B.
Zhao, W.
Powiązania:
https://bibliotekanauki.pl/articles/1396029.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
We construct infinite measure preserving and nonsingular rank one $ℤ^d$-actions. The first example is ergodic infinite measure preserving but with nonergodic, infinite conservative index, basis transformations; in this case we exhibit sets of increasing finite and infinite measure which are properly exhaustive and weakly wandering. The next examples are staircase rank one infinite measure preserving $ℤ^d$-actions; for these we show that the individual basis transformations have conservative ergodic Cartesian products of all orders, hence infinite ergodic index. We generalize this example to obtain a stronger condition called power weakly mixing. The last examples are nonsingular $ℤ^d$-actions for each Krieger ratio set type with individual basis transformations with similar properties.
Źródło:
Colloquium Mathematicum; 1999, 82, 2; 167-190
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined Analyses of Ion Beam Synthesized Layers in Porous Silicon
Autorzy:
Ramos, A. R.
Pászti, F.
Horváth, Z. E.
Vázsonyi, É.
Conde, O.
da Silva, M. F.
da Silva, M. R.
Soares, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/2028988.pdf
Data publikacji:
2001-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.-i
61.18.Bn
61.43.Gt
68.55.Ln
Opis:
High dose ion implantation was used to form polycrystalline silicide films on porous silicon with different native concentrations of light impurities (C and O). Porous silicon layers severalμm thick were implanted with 170 keV Cr$\text{}^{+}$ ions to fluences of 3×10$\text{}^{17}$ ions/cm$\text{}^{2}$ both at room temperature and 450ºC. Similar samples were implanted with 100 keV Co$\text{}^{+}$ ions to fluences of 2×10$\text{}^{17}$ ions/cm$\text{}^{2}$ at room temperature, 350ºC, and 450ºC. The formed silicide compounds were studied by Rutherford backscattering spectrometry, elastic recoil detection, glancing incidence X-ray diffraction, and four point-probe sheet resistance measurements. Selected Co implanted samples were analysed by cross-section transmission electron microscopy. Results show that the light impurities were partially expelled from the forming silicide layer. Combining cross-section transmission electron microscopy with ion beam methods it was possible to show that, in the implanted region, the porous structure collapses and densifies during implantation, but the underlying porous silicon remains intact. The layer structure, as well as the quality and type of the formed silicide, were found to depend on the original impurity level, implantation temperature, and annealing.
Źródło:
Acta Physica Polonica A; 2001, 100, 5; 773-780
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loads on walls and inserts in a mass-flow silos
Autorzy:
Ding, S.
Wójcik, M.
Jecmenica, M.
Silva de, S. R.
Powiązania:
https://bibliotekanauki.pl/articles/1955779.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
silo flow/loads
insert
Lagrangian-Eulerian
adaptive
fillet
Opis:
A finite element analysis has been carried out to investigate flow patterns and loads on silos either with a ralatively steep hopper, or with a shallow hopper but in the presence of an insert. A Lagrangian-Eulerian approach was first adopted to simulate the material flow pattern, with the precondition that mass flow was obtained. It was then attempted to predict the loads exerted by granular materials on the walls of such silos. The load on the insert was also simulated. Techniques such as the adoption of adaptive meshes and filleting along sharp corners were applied in the analysis to overcome the difficulties usually encountered with large deformations in the FEM and the mathematic singularity presented by the abruptness of geometry. Filleting proved to be necessary to bring down the pressure peak at the transition level. The insert took over a significant part of the loads. Comparison with the classic theories have confirmed that the loads predicted on the wall agree quite well with the theoretical results in the silo's cylinder section, but that differences exist in the hopper section; the difference is greater when the hopper is shallower. It has also shown the limitations of predicting flow patterns of granular materials with the traditional elastic-plastic model; a more advanced model is needed.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 4; 525-538
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical modelling for whole body motion using natural coordinates
Biomechaniczne modelowanie trójwymiarowych ruchów człowieka w środowisku współrzędnych naturalnych
Autorzy:
Czaplicki, A.
Silva, M. T.
Ambrosio, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/281844.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
biomechanical model
multibody dynamics
inverse dynamics
internal forces
Opis:
The study of spatial human movements requires the development and use of a three-dimensional model. The model proposed here has 44 degrees-of-freedom and it is described using natural coordinates, which do not require an explicit definition of rotation coordinates. The biomechanical model consists of 16 anatomical segments composed of 33 rigid bodies. Joint actuators are introduced into equations of motion of the multibody model by means of kinematic driver constrains in order to reflect the effect of the muscle forces about each anatomical joint. After associating a Lagrange multiplier to each joint actuator, the torques that represent muscle forces become coupled with the biomechanical model through the Jacobian matrix of the underlying multibody system. The developed model is applied to identify net torques and reaction forces at the anatomical joints in application cases that include the take-off to aerial trajectories and standing backwards somersault.
W pracy zaprezentowano pełną metodologię do badania ruchów człowieka. Podstawowym elementem tej metodologii jest trójwymiarowy biomechaniczny model ciała ludzkiego. Położenia członów modelu opisano za pomocą współrzędnych naturalnych, co wyeliminowało konieczność użycia współrzędnych kątowych. Model składa się z 33 ciał sztywnych połączonych przegubami (stawami) i posiada 44 stopnie swobody. Wypadkowe momenty sterujące w poszczególnych stawach pochodzące od sił mięśniowych wprowadzono do dynamicznych równań ruchu modelu za pomocą stosownych więzów kinematycznych pomiędzy sąsiadującymi członami w danym stawie. Wartości tych momentów wyznaczono wykorzystując formalizm mnożników Lagrange'a. Model wykorzystano do identyfikacji wypadkowych momentów mięśniowych i reakcji wewnętrznych w głównych stawach kończyny dolnej człowieka podczas odbicia do skoku w dal oraz w trakcie wykonywania salta w tył z miejsca.
Źródło:
Journal of Theoretical and Applied Mechanics; 2004, 42, 4; 927-944
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
From palaeosols to carbonate mounds: facies and environments of the middle Frasnian platform in Belgium
Autorzy:
Silva da, A. C.
Boulvain, F.
Powiązania:
https://bibliotekanauki.pl/articles/2058840.pdf
Data publikacji:
2004
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Belgium
middle Frasnian
carbonate platform
palaeogeography
facies
carbonate mounds
Opis:
This paper provides a synthetic sedimentological overview of themiddle Frasnian carbonate platform of Belgium and associated carbonate mounds. Carbonate mounds started usually in a relatively deep, quiet subphotic environment with a crinoid-coral-sponge assemblage, then reached the fair-weather wave base and the euphotic zone with an algal-microbial facies. The upper parts of themounds are characterised by lateral facies differentiation with the algal-microbial facies protecting a central sedimentation area with a dendroid stromatoporoids facies and fenestral limestone. The lateral facies reflect different kinds of input of reworked mound material in the proximal area, from transported fine-grained sediment to coarse-grained fossil debris. On the platform, environments range from the outer zone (crinoidal facies) to stromatoporoid-dominated biostromes and to the lagoonal area of the inner zones (subtidal facies with Amphipora floatstone, algal packstone, intertidal mudstone and laminated peloidal packstone and palaeosols). These facies are stacked in metre-scale shallowing-upward cycles. The larger scale sequential organisation corresponds to transgressions and regressions, whose cycles are responsible for differentiating a lower open-marine biostrome dominated unit from an upper lagoonal unit. The last regression- transgression cycle, responsible for the platform-scale development of lagoonal facies, can be correlated with an atoll-stage evolution of the carbonate mounds belonging to the Lion Member.
Źródło:
Geological Quarterly; 2004, 48, 3; 253--266
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mulheres policiais : presença feminina na Polícia Militar do Rio de Janeiro
Autorzy:
Musumeci - Soares, Barbara.
Musumeci, Leonarda.
Patrício, Luciane.
De Faria - Silva, Angelica.
Data publikacji:
2005
Wydawca:
Rio de Janeiro : Civilização Brasileira : CESeC, Centro de Estudos de Segurança e Cidadania
Tematy:
Służba wojskowa kobiet socjologia Brazylia
Kobiety (żołnierze) socjologia Brazylia
Kobieta a wojsko Brazylia
Opis:
Bibliogr. s. [291]-307.
Dostawca treści:
Bibliografia CBW
Książka
Tytuł:
Least squares estimator consistency: a geometric approach
Autorzy:
Mexia, João
da Silva, João
Powiązania:
https://bibliotekanauki.pl/articles/729688.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
linear models
least squares estimator
consistency
radial symmetry
generalized polar coordinates
Opis:
Consistency of LSE estimator in linear models is studied assuming that the error vector has radial symmetry. Generalized polar coordinates and algebraic assumptions on the design matrix are considered in the results that are established.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2006, 26, 1; 19-45
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensorless Control of Surface Mounted Permanent Magnet Synchronous Motors Using Matrix Converters
Autorzy:
Saltiveri, D.
Arias, A.
Asher, G.
Sumner, M.
Wheeler, P.
Empringham, L.
Silva, C.
Powiązania:
https://bibliotekanauki.pl/articles/262580.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
sensorless control
permanent magnet synchronous motor
matrix converters
Opis:
This paper investigates the influence of the power converter on the performance of Surface Mounted Permanent Magnet Synchronous Motor drives, which employ High Frequency voltage injection to achieve low and zero speed control. Experimental results demonstrate the remarkable performance of the sensor less speed and position control employing the Matrix Converter and the contributions of the Space Modulation Profiling technique. The Matrix Converter has almost zero dead time, which means that behaves almost like an ideal power converter and achieves better results than the conventional Voltage Source Inverter. A comparison of the sensor less technique proposed using both converters is made.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 1; 59-67
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on the computation of ordered supported non-dominated solutions in the bi-criteria minimum spanning tree problems
Autorzy:
Silva, C. G.
Cli'maco, J. C. N.
Powiązania:
https://bibliotekanauki.pl/articles/308580.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
minimum spanning tree
supported non-dominated solutions
combinatorial problems
Opis:
This paper presents a new procedure for computing the set of supported non dominated solutions of bi-criteria minimum spanning tree problems in ordered manner. The procedure is based on the systematic detection of edges which must be replaced in one efficient solution to obtain the adjacent one, in the criteria space. This new approach avoids solving unnecessary problems and makes use of previous computations.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 4; 11-15
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Os autos indianistas de José de Anchieta e a iniciação do teatro luso-brasileiro
Autorzy:
Kalewska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2079118.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Warszawski. Wydział Neofilologii
Tematy:
teatro luso-brasileiro
Prémio de Dramaturgia António José da Silva
rituais indígenas
teatro jesuítico
antropologia do teatro
Opis:
O artigo coloca uma pergunta sobre o início do teatro luso-brasileiro, institucionalizado recentemente pela atribuição do Prémio de Dramaturgia de A. J. da Silva a J. M. Vieira Mendes. Ninguém questiona a paternidade de Gil Vicente em relação ao teatro português. Seria que o teatro brasileiro começasse mesmo com António José (1838) de D. J. Gonçalves de Magalhães? Ou mais cedo, ainda no séc. XVI, com os autos indianistas de Anchieta, i.e. com as peças centrados no índio do Brasil? a autora defende que a segunda interpretação é plausível, considerando Padre José de Anchieta o Apóstolo do Teatro Brasileiro. Anna Kalewska justifica esta tese, analisando as três peças indianistas anchietanas (O Auto da Pregação Universal, o Auto de São Lurenço, Na Aldeia de Guaraparim) em termos da antropología do teatro e da história do processo literário. Os rituais indígenas – ecológicos e sociais – foram mais importantes para o primeiro teatro brasileiro do que a dramatização da liturgia cristã, haurida do teatro vicentino e jesuítico. Os autos indianistas de Anchieta são bom exemplo da aculturação dramatúrgica, em que a velha gramática do teatro se conjugou com o novo idiolecto cénico.
Źródło:
Itinerarios; 2007, 6; 175-193
1507-7241
Pojawia się w:
Itinerarios
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and production of radioactive sources used for cancer treatment in Brazil
Autorzy:
Rostelato, M. E. C. M.
Rela, P. R.
Zeituni, C. A.
Feher, A.
Manzoli, J. E.
Moura, J. A.
Moura, E. S.
Silva, C. P. G.
Powiązania:
https://bibliotekanauki.pl/articles/148305.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radioactive sources production
iodine-125 seeds
iridium-192 wires
brachytherapy
cancer treatment
Opis:
The number of cancer patients in Brazil is increasing and part of the patients are submitted to brachytherapy treatment using iridium-192 wire and iodine-125 radioactive seeds. The Nuclear Energy Research Institute established a programme to produce iridium-192 wire and iodine-125 radioactive seeds. With the purpose of settling a laboratory for iridium-192 sources production, a wire activation method was developed and a hot cell for the wire manipulation, quality assurance and packaging was built. The iodine-125 seeds consist of a welded titanium capsule containing iodine-125 adsorbed onto a silver rod. Concerning the setup of the local production, the following activities were carried out: superficial treatment of the silver rod, development of a process to absorb the iodine in the silver rod, welding methodology to seal the seeds, leakage and contamination test and source activity measurement.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 99-103
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent studies of irradiated mangoes in Brazil : a trend towards commercial approach
Autorzy:
Sabato, S. F.
Silva, J. M.
Cruz, J. N.
Broisler, P. O.
Rela, P. R.
Salmieri, S.
Lacroix, M.
Powiązania:
https://bibliotekanauki.pl/articles/148822.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma radiation
mangoes
physicochemical properties
sensory evaluation
Opis:
Mango is an important commodity to our country as Brazil is a great producer and exporter of tropical fruits. Nowadays, Mexico and India are the main exporters of mango in the world and Brazil occupies the third position in this ranking. As these countries have adopted gamma radiation as a phytosanitary treatment and signed a bilateral agreement with the United States for exporting mango to this country, Brazil has to be up-to-dated with this trend. The Institute of Nuclear and Energy Researches together with field producers in the northeastern region and partners like the International Atomic Energy Agency, the Canadian Irradiation Center and Empresa Brasileira de Agropecuária joined to demonstrate this technology, its application and its commercial feasibility. The whole project was structured in two parts that involved around 1300 mangoes. The first step consisted mainly in studying the quality of irradiated mangoes within our territory, using a multipurpose semi-commercial cobalt facility, and comparing two harvesting points of the fruits. The second one was an international consignment of irradiated fruits from Brazil to Canada, where the control sample consisted of fruits treated with a hot water dip. The financial part of the feasibility study covers the scope of the investment, including the net working capital and production costs. In a summarized way to express, the results from physicochemical analysis and sensory evaluation were favorable, indicating that gamma radiation is a potential quarantine treatment.
Źródło:
Nukleonika; 2008, 53, suppl. 2; 77-79
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on the strong consistency of least squares estimates
Autorzy:
da Silva, Joǎo
Powiązania:
https://bibliotekanauki.pl/articles/729980.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
least squares estimates
linear models
strong consistency
Opis:
The strong consistency of least squares estimates in multiples regression models with i.i.d. errors is obtained under assumptions on the design matrix and moment restrictions on the errors.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2009, 29, 2; 223-231
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an irradiation system for a small size continuous run multipurpose gamma irradiator
Autorzy:
Calvo, W. A. P.
Rela, P. R.
Napolitano, C. M.
Kodama, Y.
Omi, N. M.
da Costa, F.
de Andrade e Silva, L. G.
Powiązania:
https://bibliotekanauki.pl/articles/148041.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
multipurpose irradiator
gamma irradiator
compact irradiator
cobalt-60 irradiator
gamma facility
Opis:
The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is a product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 PBq. The performed qualification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process qualification. The initial load of the multipurpose irradiator was 3.4 PBq with 13 cobalt-60 sources model C-188, supplied by MDS Nordion – Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The polymethylmetacrylate (PMMA) dosimeter system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning with dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma irradiators available on the market.
Źródło:
Nukleonika; 2009, 54, 2; 93-97
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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