Linear Absorption Coefficient
Mostrando 13-24 de 33 artigos, teses e dissertações.
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13. High sensitivity Thermal Lens spectroscopy / Espectroscopia de lente térmica de alta sensibilidade
The efficiency of conventional transmission methods used to measure absorption of hightransparent materials is usually limited by light scattering and reflection. On the other hand, Thermal Lens spectroscopy is insensible to such phenomena and has been widely applied to determinate low optical absorptions. In this thesis, we have studied a recently developed
Publicado em: 2008
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14. DESENVOLVIMENTO E VALIDAÇÃO DE MÉTODO PARA DETERMINAÇÃO DE ETILENOTIOURÉIA EM URINA EMPREGANDO HPLCUV / DEVELOPMENT AND VALIDATION METHOD FOR THE DETERMINATION OF ETHYLENETHIOUREA IN URINE BY HPLC-UV
In order to supply the world-wilde demand for food, it is essential to use the pesticides to protect the crops against pests and diseases. But the indiscriminate and injudicious use of these compounds have resulted in widespread contamination in food commodities and environment in all fields, increasing, this way, the preoccupation with chemical products use
Publicado em: 2008
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15. "Caracterização estrutural e óptica de elastômeros dopados com ferrofluidos" / Optical and Structural Characterization of Elastomers Dopeds with Ferrofluids
This work aims the structural, mechanical and optical characterization of urethane/urea elastomers (PU/PBDO), based on polypropylene oxide and polybutadiene diol, pure, after swelling in toluene and doped with ferrofluid. The ratios in weight % of PU and PBDO used are 40/60, 50/50, 60/40 and 80/20. The structural analysis were made through of polarized light
Publicado em: 2007
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16. Propriedades Magneto-Ópticas do Pb(x)Eu(1-X)Te COM 0 ≤ x ≤ 0.2 / MAGNETO-OPTICAL PROPERTIES OF Pb(x)Eu(1-X)Te WITH 0 ≤ x ≤ 0.2
The optical properties of epitaxial samples of PbxEu1-xTe with 0 ≤ x ≤ 0.2 have been investigated by photoluminescence measurements at various temperatures and magnetic fields and through transmittance and reflectance measurements at room temperature. The samples were grown by molecular beam epitaxy in a Riber 32p MBE system at LAS-INPE o
Publicado em: 2007
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17. Evaluation via multivariate techniques of scale factor variability in the rietveld method applied to quantitative phase analysis with X ray powder diffraction
The present work uses multivariate statistical analysis as a form of establishing the main sources of error in the Quantitative Phase Analysis (QPA) using the Rietveld method. The quantitative determination of crystalline phases using x ray powder diffraction is a complex measurement process whose results are influenced by several factors. Ternary mixtures o
Materials Research. Publicado em: 2006-12
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18. Variation in either the physical and mechanical properties and the quality of the bean (Phaseolus vulgaris L.) during the drying process and storage / Variação das propriedades físicas e mecânicas e da qualidade do feijão (Phaseolus vulgaris L.) durante a secagem e o armazenamento
There is a lack of information in the available literature on the changes that may occur in the bean during the drying process and storage time. Thus, the accomplishment of studies that would generate theoretical and practical information about a better conservation of the product are really relevant. So, this work was carried out to analyze several characte
Publicado em: 2006
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19. Doses de Cd, Pb, Cu, Zn e Ni em latossolos: efeitos no solo e em plantas de alface e feijão / Doses of Cd, Pb, Cu, Zn and Ni in Oxissols: efects in soil and in plants of lettuce and common beans
Two experiments were carried out in greenhouse, aiming to study the absorption of cadmium, lead, copper, zinc and nickel and their distribution in plants of lettuce and common beans. The comercial cultivars of alface (Regina de Verão) and common beans (Carnaval) were grown under increasing doses of cadmium (0, 1, 2, 4, 8 and 16 mg/dm3), lead (0, 23, 46, 92,
Publicado em: 2006
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20. Flow analysis by using solenoid valves for As(III) determination in natural waters by an on-line separation and pre-concentration system coupled to a tungsten coil atomizer
A flow system coupled to a tungsten coil atomizer in an atomic absorption spectrometer (TCA-AAS) was developed for As(III) determination in waters, by extraction with sodium diethyldithiocarbamate (NaDDTC) as complexing agent, and by sorption of the As(III)-DDTC complex in a micro-column filled with 5 mg C18 reversed phase (10 µL dry sorbent), followed by e
Química Nova. Publicado em: 2005-03
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21. Efeito anomalo nas medidas de lente termica em vidros com pontos quanticos de CdTe / Anomalous effect in thermal lens measurements in CdTe quantum dot doped glasses
Semiconductor doped glasses are of great interest because of their non-linear optical properties and short response time due to quantum confinement. In this work, we used the thermal lens technique to determine the thermal diffusivity (a ) and the behavior of the temperature coefficient of the refractive index (dn/dT ) in CdTe doped borosilicate glasses trea
Publicado em: 2005
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22. FabricaÃÃo e caracterizaÃÃo elÃtrica de heterojunÃÃes de polianilina-silÃcio para aplicaÃÃo em dosimetria de radiaÃÃo gama
In this work a technique has been developed to fabricate high quality polyanilinesilicon heterojunction diodes for use as gas and/or ionizing radiation sensors. Polyaniline thin films (40 nm thick) produced by spin-coating on silicon substrates, were the active part of the junction structure. The devices presented excellent reproducibility of their electrica
Publicado em: 2004
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23. Ferrugem e mancha angular do feijoeiro: efeito de fungicidas no desenvolvimento do hospedeiro e no progresso das doenças. / Bean rust and angular leaf spot of bean: effect of foliar fungicides on the host vegetative development of host and on the progress of the diseases.
Four trials were carried out on dry beans (Phaseolus vulgaris), variety Carioca with goal to verify the possibility of implementation of an integrated management system for rust and angular spot after the application with of oxycarboxin (Hokko Plantvax 750 - 700 g/ha) and trifenil stannic hydroxide (Mertin â - 660 ml/ha) fungicides, applied in different tim
Publicado em: 2002
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24. Estudo de propriedades ópticas não-lineares de cristal líquido dopado com corante em função da temperatura. / Studies of non-linear optical properties of dye doped liquid crystal in function of the temperature.
With the objective of studying the effects due to the addition of a dye in a thermotropic liquid crystal (LC), we investigated in this work the influence of the temperature in the reorientation of the molecules of this compound, as well as the refraction index and the non linear absorption, in the presence of a electromagnetic field. The studied LC presents
Publicado em: 2000