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Wyszukujesz frazę "Costa, M." wg kryterium: Autor


Tytuł:
Formation and Annealing of Micropores in Hematite
Autorzy:
Dauwe, C.
Da Costa, G. M.
Van Hoecke, T.
Segers, D.
Powiązania:
https://bibliotekanauki.pl/articles/1933484.pdf
Data publikacji:
1995-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.Bj
Opis:
In iron oxide powders positrons are trapped in the surface layers and the value of the S-parameter is an indicator of the total specific surface, including external surface and internal surfaces of micropores. The evolution of micropores is followed when α-FeOOH is thermally decomposed into α-Fe$\text{}_{2}$O$\text{}_{3}$. It is shown that the micropore formation is not linked to the decomposition process, but that they also form in hematite synthesized from a ferrihydrite precursor in aqueous solution.
Źródło:
Acta Physica Polonica A; 1995, 88, 1; 119-123
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Expert System Coupled With a Hierarchical Structure of Fuzzy Neural Networks for Fault Diagnosis
Autorzy:
Calado, J. M. F.
Costa, I. S.
Powiązania:
https://bibliotekanauki.pl/articles/908283.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
rozpoznanie błędu
wykrywanie błędu
system ekspertowy
sieć neuronowa rozmyta
fault diagnosis
fault detection
fault isolation
shallow knowledge
deep knowledge
expert system
fuzzy neural network
abrupt faults
incipient faults
Opis:
An on-line fault diagnosis system, designed to be robust to the normal transient behaviour of the process, is described. The overall system consists of an expert system cascade with a hierarchical structure of fuzzy neural networks, corresponding to a multi-stage fault detection and isolation system. The fault detection is performed through the expert system by means of fault detection heuristic rules, generated from deep and shallow knowledge of the process under consideration. If a fault is detected, the hierarchical structure of fuzzy neural networks starts and it performs the fault isolation task. The structure of this diagnosis system was designed to allow for the diagnosis of single and multiple simultaneous abrupt and incipient faults from only single abrupt fault symptoms. Also, it combines the advantages of both fuzzy reasoning and neural networks learning capacity. A continuous binary distillation column has been used as a test bed of the current approach. Single, double and triple simultaneous abrupt faults, as well as incipient faults, have been considered. The preliminary results obtained show a good accuracy, even in the case of multiple faults.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 3; 667-687
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear elastic brittle damage: numerical solution by means of operator split methods
Autorzy:
Pires-Domingues, S.M.
Costa-Mattos, H.
Rochinha, F.A.
Powiązania:
https://bibliotekanauki.pl/articles/279553.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage mechanics
finite elements
splitting technique
Opis:
The avoid the loss of well-posedness in the post localization range, some continuum damage theories for elastic materials introduce higher order gradients of the damage variable into constitutive model. Although such theories allow for mathematically correct modelling of the strain localization phenomena, they are usually considered to be very complex to handle from the numerical point of view. The present work deals with the numerical implementation of a gradient-enhanced damage theory for elastic materials. A simple numerical technique, based on the finite element method, is proposed to approximate the solution to the resulting nonlinear mathematical problems. The coupling between damage and strain variables is circumvented by means of a splitting technique.
Celem poprawności sformułowania problemu w pewnych teoriach zniszczenia do modelu konstytutywnego materiałów sprężystych wprowadza się wyższe gradienty zmiennych opisujących zniszczenie. Chociaż teorie takie umożliwiają matematycznie poprawne modelowanie zjawisk lokalizacji odkształceń, to z punktu widzenia numeryki stosowanie ich uważa się zwykle za bardzo skomplikowane. W niniejszej wersji przedstawiono zastosowanie numeryczne teorii zniszczenia z wyższymi gradientami do materiałów sprężystych. Do przybliżonego rozwiązania otrzymanych nieliniowych zadań matematycznych zaproponowano prostą metodę numeryczną opartą na metodzie elementów skończonych. Użycie metody operatorowej pozwoliło uniknąć sprężenia między zmiennymi opisującymi zniszczenie i odkształcenie.
Źródło:
Journal of Theoretical and Applied Mechanics; 1999, 4; 847-861
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
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
Tytuł:
Development of an automation system for iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding
Autorzy:
Somessari, S. L.
Feher, A.
Sprenger, F. E.
Rostelato, M. E. C. M.
da Costa, F. E.
Calvo, W. A. P.
Powiązania:
https://bibliotekanauki.pl/articles/147664.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iodine-125 seeds
prostate cancer
brachytherapy
Nd:YAG laser welding
Opis:
The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Săo Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95 per cent.
Źródło:
Nukleonika; 2011, 56, 4; 369-374
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative study on the performance of radiation detectors from the HgI2 crystals grown by different techniques
Autorzy:
Martins, J. F. T.
Costa, F. E.
dos Santos, R. A.
de Mesquita, C. H.
Hamada, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/146916.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
crystal growth
iodide mercury crystal
physical vapor transport (PVT)
radiation detector
semiconductor crystal
Opis:
In this work, the establishment of a technology for HgI2 purification and crystal growth is described, aiming at a future application of this crystal as a room temperature radiation semiconductor detector. Two methods of crystal growth were studied in the development of this work: (1) physical vapor transport (PVT) and (2) saturated solution from dimethylsulphoxide (DMSO) complexes. In order to evaluate the crystals obtained using each of these methods, systematic measurements were carried out for determining the stoichiometry, structure, orientation, surface morphology and impurity of the crystal. The influence of these physicochemical properties of the crystals developed was evaluated in terms of their performance as a radiation detector. The best response to radiation was found for the crystals grown by the PVT technique. Significant improvement in the performance of HgI2 radiation detector was found, purifying the crystal by means of two successive growths by the PVT technique.
Źródło:
Nukleonika; 2012, 57, 4; 555-562
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Air-assistance in spray booms which have different spray volumes and nozzle types for chemically controlling Spodoptera frugiperda on corn
Autorzy:
Gimenes, M.J
Raetano, C.G.
Ferreira, M.H
Pereira-Prado, E.
Souza-Christovam, R.
Tourino-Rezende, D.
Almeida-Costa, S.I.
Powiązania:
https://bibliotekanauki.pl/articles/66410.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The study aimed to evaluate the performance of air assistance in spray booms using different types of nozzles and spray volumes. We took into account spray deposits, fall armyworm control and crop corn performance in a narrow row cropping system. The experiment was carried out at the experimental area of Sao Paulo State University, Botucatu/SP, Brazil, during the 2008/2009 agricultural season, in randomized blocks with a factorial scheme (2×2+1) and four replications. Two spray nozzles (flat fan nozzle and hollow cone nozzle) were tested, combined with two air assistance levels in the spray boom (with and without air assistance) and a treatment control. In the experimental spraying, Spinosad insecticide was sprayed in amounts of 48 g active substance (a.s.)/ha. The air assistance in the spray boom increased the spray deposits in the V4 growth stage of the corn plants. Moreover, the application of this technology showed higher efficiency on fall armyworm control, reaching a 100% level 15 days after spraying, in the V10 growth stage of the plants. The hollow cone nozzle increased the spray deposit level on the corn plants compared with the flat fan nozzle, at growth stage V4. However, the flat fan nozzle, combined with air assistance technology, was more effective for controlling fall armyworm in the same growth stage (V4), although the hollow cone nozzle increased the deposit levels on the plants. All the technologies tested in the study promoted a reduction of plant damage from fall armyworm attack. Corn productivity is directly related to the control efficiency of fall armyworm.
Źródło:
Journal of Plant Protection Research; 2012, 52, 2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shape memory process in resorbable polymers: effect on surface properties and cell adhesion
Autorzy:
Costa, A. M.
Ferreira, A. S.
Posadowska, U.
Krok, M.
Smola, A.
Dobrzyński, P.
Pamuła, E.
Powiązania:
https://bibliotekanauki.pl/articles/286068.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
shape memory
PLGA
tissue regeneration
foil
Opis:
The objectives of this study were to confirm the shape memory behavior of two new bioresorbable terpolymers (L-lactide, glycolide, and trimethylene carbonate: L-PLGTMC and B-PLGTMC), to follow the influence of the shape memory process on their surface properties and to test their cytocompatibility using osteoblast-like cells. For this purpose, foils of both terpolymers were prepared. The terpolymers' ability to recover up to 92-93% of the memorized shape within 10 seconds was obtained. The influence of shape memory process on the surface properties was assessed by water contact angle (WCA) measurement and atomic force microscopy (AFM) and the results suggested that both terpolymers preserved the hydrophilicity after recovery and also that B-PLGTMC polymer was rougher than L-PLGTMC (about 9 folds more). The AFM pictures showed the presence of spherical shape hills on the B-PLGTMC foil surface which after the stretching procedure became oriented toward the direction of the applied load. The terpolymers were seeded on both sides (Top and Bottom faces) with human MG63 osteoblast-like cells. Cell viability was assessed after 1, 3 and 7 days, using MTT assay. Results revealed an increasing number of metabolically active cells with the incubation time, suggesting, together with nitric oxide (NO) level determination, the cytocompatibility of both terpolymers. Cell spreading and morphology were investigated by H&E staining and obtained results corresponded well with ones of MTT and NO.
Źródło:
Engineering of Biomaterials; 2012, 15, 114; 8-11
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Winter Cover Crop Biomass on Summer Weed Emergence and Biomass Production
Autorzy:
Bittencourt, H.H.
Lovato, P.E.
Comin, J.J.
Lana, M.A.
Altieri, M.A.
Costa, M.D.
Gomes, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/65024.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
A greenhouse assay was carried out to evaluate the effect of winter cover crop residues on spontaneous plants that commonly occur on summer annual fields in Southern Brazil. Dry shoot residues of rye (Secale cereale), vetch (Vicia villosa), fodder radish (Raphanus sativus), and a mix of the three species, were applied over pots that had been seeded with alexandergrass (Brachiaria plantaginea), hairy beggarticks (Bidens pilosa), wild poinsettia (Euphorbia heterophylla), and morning glory (Ipomoea grandifolia) at four different depths (0, 1, 2, or 4 cm). Plant emergence and biomass production were measured. Residues of rye reduced the emergence of B. plantaginea, while vetch diminished I. grandifolia and B. plantaginea emergence. Fodder radish reduced emergence of I. grandifolia. The mix of cover crops reduced emergence of I. grandifolia, B. plantaginea, and B. pilosa. None of the cover crops differed from the control on E. heterophylla emergence. The lowest yields in spontaneous plant shoot biomass were obtained from the cover with rye + vetch + fodder radish. The lowest values of root biomass occurred under cover with rye, fodder radish or the mix. Use of vetch residues decreased emergence of B. plantaginea and I. grandifolia, but enhanced biomass accumulation by the latter.
Źródło:
Journal of Plant Protection Research; 2013, 53, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Involvement of carbohydrates and antioxidant enzymes in the oxidative balance during drought and recovery: the eucalyptus case
Autorzy:
Correia, B.
Silva, S.
Jesus, C.
Valledor, L.
Dias, M.
Costa, A.
Santos, C.
Pinto, G.
Powiązania:
https://bibliotekanauki.pl/articles/79853.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
carbohydrate
antioxidative enzyme
oxidative balance
drought
recovery
cellular function
abiotic stress
reactive oxygen species
eucalyptus
Eucalyptus globulus
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limits in the use of cPTIO as nitric oxide scavenger and EPR probe in plant cells and seedlings
Autorzy:
D'Alessandro, S.
Posocco, B.
Costa, A.
Zahariou, G.
Lo Schiavo, F.
Carbonera, D.
Zottini, M.
Powiązania:
https://bibliotekanauki.pl/articles/80661.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
nitric oxide
scavenger
plant cell
seedling
2-4-carboxyphenyl-4,4,5,5-tetramethyl imidazoline-1-oxyl-3-oxide
fluorescent dye
EPR probe
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust control of depth of anesthesia based on H∞ design
Autorzy:
Caiado, D. V.
Lemos, J. M.
Costa, B. A.
Powiązania:
https://bibliotekanauki.pl/articles/229439.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
depth of anesthesia
model uncertainty
robust control feedback
H∞ design
μ-synthesis
Opis:
This paper presents a case study on the design of a robust controller for the depth of anesthesia (DoA) induced by the drug propofol. This process is represented by a linear model together with a non-parametric uncertainty description that is evaluated using a patient model bank with 20 patients undergoing sedation. By using H∞ methods, the controller is aimed to comply with robust stability and performance specifications for the class of patient models considered. A minimization problem of sensitivity and complementary sensitivity is made to design the controller. The controller that results from this procedure is approximated by a controller with a lower order, that in turn is redesigned in discrete time for computer control application. The resulting controller is evaluated in simulations using a realistic nonlinear model of DoA.
Źródło:
Archives of Control Sciences; 2013, 23, 1; 41-59
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tracking young talented swimmers : follow-up of performance and its biomechanical determinant factors
Autorzy:
Morais, J. E.
Saavedra, J. M.
Costa, M. J.
Silva, A. J.
Marinho, D. A.
Barbosa, T. M.
Powiązania:
https://bibliotekanauki.pl/articles/951824.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
prepubescent swimmers
longitudinal assessment
kinematics
drag force
anthropometrics
efficiency
kinematyka
efektywność
pływak
biomechanika
Opis:
The aim of the study was to follow-up the stability of young talented swimmers’ performance and its biomechanical determinant factors (i.e., anthropometrics, kinematics, hydrodynamics and efficiency) during a competitive season. Thirty three (15 boys and 18 girls) young swimmers (overall: 11.81 ± 0.75 years old and Tanner stages 1–2 by self-evaluation) were evaluated. Performance, anthropometrics, hydrodynamics, kinematics and efficiency variables were assessed at three moments during a competitive season. Performance had a significant improvement (with minimum effect size) and a moderate-very high stability throughout the season. In the anthropometrics domain all variables increased significantly (ranging from without to minimum effect size) between moments and had a moderate-very high stability. Hydrodynamics presented no variations between all moments and had a low-very high stability throughout the season. In the kinematics domain, there were no variations between moment one and three, except for an increase in stroke frequency (without size effect). Speed fluctuation remained constant, with no significant variations. All kinematic variables had a low-very high stability. Efficiency variables did not present variations between moment one and three and had a low-moderate stability. Overall, young swimmers showed a minimum improvement in performance and in anthropometric factors; and a moderate stability of performance and its determinant factors (i.e., anthropometrics, hydrodynamics, kinematics and efficiency) during the competitive season.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 129-138
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study about the measurement method of the homogeneity of radioactivity along an iridium-192 wire used in brachytherapy
Autorzy:
Costa, O. L.
Calvo, W. A. P.
Zeituni, C. A.
Rostelato, M. E. C. M.
Moura, J. A.
Feher, A.
Souza, C. D.
Somessari, S. L.
Powiązania:
https://bibliotekanauki.pl/articles/148238.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iridium-192
iridium wire
low dose rate brachytherapy
quality control
cancer treatment
radioactive sources production
Opis:
The Nuclear and Energy Research Institute has produced, since 1998, iridium-192 wires used in low dose rate brachytherapy. In the paper the authors studied the influence of wire profile on the homogeneity distribution of radioactivity of iridium-192 along the wire. The authors propose the improvements in the quality control procedure that will provide more accurate measurement data and suggest changes in control devices.
Źródło:
Nukleonika; 2014, 59, 1; 37-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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