Low Energies
Mostrando 13-24 de 170 artigos, teses e dissertações.
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13. Low-velocity Impact Response of a Nanocomposite Beam Using an Analytical Model
AbstractLow-velocity impact of a nanocomposite beam made of glass/epoxy reinforced with multi-wall carbon nanotubes and clay nanoparticles is investigated in this study. Exerting modified rule of mixture (MROM), the mechanical properties of nanocomposite including matrix, nanoparticles or multi-wall carbon nanotubes (MWCNT), and fiber are attained. In order
Lat. Am. j. solids struct.. Publicado em: 2015-04
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14. Análise dos procedimentos e critérios de implantação de feixes de raios X de referência ISO 4037 em baixas energias
According to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done wi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/08/2012
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15. Manufacturing polycrystalline pellets of natural quartz for applications in thermoluminescence dosimetry
This paper describes the manufacturing process of quartz-pellets and shows their potential use as thermoluminescence dosimeters (TLD) for those applications where low-levels of ionising radiation are present. Two batches of cold-pressed pellets were produced and their resistance were evaluated by vibration tests and weight-loss measurements. The batch manufa
Materials Research. Publicado em: 10/07/2012
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16. What can we learn from confusing Olivella columellaris and O. semistriata (Olivellidae, Gastropoda), two key species in panamic sandy beach ecosystems?
Olivella columellaris (Sowerby 1825) and O. semistriata (Gray 1839) are suspension-feeding, swash-surfing snails on tropical sandy beaches of the east Pacific. While they often are the numerically dominant macrofaunal element in their habitats, their biology is poorly understood; the two species actually have been confused in all of the few publications that
Biota Neotrop.. Publicado em: 2012-06
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17. Comparative study of BxNyCz nanojunctions fragments
Theoretical analysis of formation energy and geometry was done to compare the relative stabilities of modified carbon nanostructures representative fragments. Structure and energies of formation were calculated at semiempirical level of theory. Depending of B-N pair localization on the molecular structures the formation enthalpy decreases. B-N substitution i
Materials Research. Publicado em: 12/08/2011
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18. Adsorção de corantes em turfa de origem Magalhânica / Absorption dyes om Magallanic peat
The aim of this work was to study the removal of dyes Naphthol Blue Black (NBB) and Maxilon Blue 5G (MB) in the aqueous phase by adsorption on Magellan peat. According to the peat physicochemical characterization, the carboxylic, phenolic, hydroxyl and methyl amines were identified as the main functional groups, that giving it a preferably negative charge an
Publicado em: 2011
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19. UV dominant optical emission newly detected from radioisotopes and XRF sources
The current paper reports first and definite experimental evidence for γ-, X-, or β radiation causing UV dominant optical radiation from (1) radiochemicals such as 131I; (2) XRF sources such as Rb XRF source present as salts; and (3) metal sources such as 57Co, and Cu XRF sources. Due to low quantum yield a need arose to develop two techniques with narrow
Brazilian Journal of Physics. Publicado em: 2010-03
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20. PROPRIEDADES VIBRACIONAIS E DIELÉTRICAS DA MULITA Bi2Mn4O10 / VIBRATIONAL PROPERTIES AND DIELECTRIC OF MULITA Bi2Mn4O10
In this work we investigated the vibrational properties of ceramics Bi2Mn4O10 (BMO) at room temperature by the Raman and Infrared spectroscopies, the phonons were classified by FG matrix method of Wilson. The dielectric properties of the material, in turn, were studied using the impedance spectroscopy in a range of 22 C to 275 C. Furthermore, static atomisti
Publicado em: 2010
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21. Estudo da adsorção do líquido iônico [BMIM]+[BF4]sobre γ-Al2O3 por cálculos ab initio
Ionic liquids are, by definition, salts formed by an organic cation and an inorganic anion, with a low melting point. An important application of ionic liquids is that they can replace conventional solvents. Recently, they were also used as cocatalysts (in the form of solvents) for metallic clusters, in the process of removal of aromatics from petroleum. The
Publicado em: 2010
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22. Estudo exploratÃrio de parÃmetros de soldagem de revestimentos com ligas de NÃquel empregando o processo TIG com alimentaÃÃo de arame frio / Exploratory study of coating welding parameters with nickel alloys using GTAW with cold wire feeding
The aim of this work was to carry out a systematic study of GTAW welding parameters with feeding of cold wire for covering application of nickel alloys (UNS N06625, UNS N06686 and UNS N10276) in substract of steel C-Mn considering the analysis of geometric, economic and operational characteristics of layers, form to adjust these coverings for the industries
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/01/2009
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23. Low-energy electron collisions with ethane
We employed the Schwinger multichannel method to compute elastic cross sections for low-energy electron collisions with ethane (C2H6). The calculations were carried out in the static-exchange and static-exchange plus polarization approximations for energies up to 12 eV. Our integral cross section shows good agreement with experimental data and with theoretic
Brazilian Journal of Physics. Publicado em: 2009-03
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24. Estudo sistemático do freamento de íons pesados em sólidos no regime de baixas velocidades / Systematic study of heavy ions stopping in solids at the low velocity regime
The energy loss of ions in materials is an important issue not only because of its direct applications on material analysis techniques, but also for the understanding of the interactions. Accurate knowledge of heavy ion stopping power at low energies is necessary in materials science as well as in basic physics, e. g. in the Doppler Shift Attenuation Method
Publicado em: 2009