Encontrados 197 documentos, a visualizar página 1 de 20
Use of ß-glucanases and ß-1,4-xylanases to supplement diets containing alfalfa ...
Mourão, J.L.; Ponte, P.I.P; Prates, J.A.M.; Centeno, M.S.J.; Ferreira, L.M.A.; Chaveiro-Soares, M.A.; Fontes, C.M.G.It is well established that the use of alfalfa in diets for monogastric animals is limited by its high fiber content. However, alfalfa is a natural source of xanthophylls and gives poultry products a desirably yellow color. In addition, alfalfa saponins may contribute to reduce the levels of cholesterol in the meat and egg yolk. We have investigated the potential utilization of β-glucanases and β-1,4-xylanases ...
Doença Pulmonar Obstrutiva Crónica em Portugal: estudoPneumobil (1995) e estudo...
Cardoso, J; Ferreira, JR; Almeida, J; Santos, JM; Rodrigues, F; Matos, MJ; Gaspar, MBACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) has been a leading cause of morbidity and mortality worldwide, over the years. In 1995, the implementation of a respiratory function survey seemed to be an adequate way to draw attention to neglected respiratory symptoms and increase the awareness of spirometry surveys. By 2002 there were new consensual guidelines in place and the awareness that prevalenc...
Extracção Óptica de Relógio para Redes de Elevado Débito
Orlando Frazão; Pedro Tavares; António F. Cunha; L. Botelho Ribeiro; J. Ferreira da RochaThis article reports a modelling and experimental work on all-optical clock extraction for high bit-rate systems using self-pulsation mechanisms in semiconductor lasers at 1300 nm. External cavity DFB semiconductor lasers have been used, of both bulk and multiple quantum-well (MQW) types. ; Este artigo descreve um trabalho de modelização e realização pr...
Automatização de Laboratórios de Medida de Componentes Ópticos e Electrónicos a...
P. J. Silva; P. Mendes; J. Ferreira da Rocha; J. C. Pedro; P. Tavares; P. S. André; N. B. CarvalhoThis paper describes the work developed in the final project of the degree in Electronics and Telecommunications Engineering, at Aveiro University in the domain of laboratory automation. Here are shown some final applications developed with the programming tool of National InstrumentsTM – LabVIEW, such as Pin/Pout, I/V and I/P for device characterisation. ; Nesta comunica&cc...
Auto-pulsação em Lasers de Semicondutor por Bloqueio de Modos e por Injecção
Pedro Tavares; J. Ferreira da Rocha; L. Botelho Ribeiro; Orlando Frazão; António F. CunhaThis article describes two techniques for operating a semiconductor laser in a pulsed regime, namely the mode locking and injection locking mechanisms. For each one we present the operational principle, the theory and simulation results. We also describe the self Q-switching mechanism in multi-sections DFB lasers. ; Este artigo descreve duas técnicas de operar um laser de s...
Auto-pulsação em Lasers de Semicondutor por Comutação do Ganho e do Factor de Q...
Pedro Tavares; J. Ferreira da Rocha; L. Botelho RibeiroThis article describes two techniques for operating a semiconductor laser in a pulsed regime, namely the gain switching and Q-switching mechanisms. For each one we present the operational principle, the theory and simulation results. ; Este artigo descreve duas técnicas de operar um laser de semicondutor em regime pulsado, nomeadamente o mecanismo de comutação...
Técnicas de Extracção Óptica de Relógio
Pedro Tavares; J. Ferreira da Rocha; L. Botelho RibeiroWith the increasing traffic and consequent demand for higher bitrates, optical telecommunications networks include new systems operating exclusively in the optical domain, thus avoiding the optical to electrical conversion. Modules implementing the procedure of alloptical clock recovery are of extreme importance because the produced signal has all the synchronisation information&nb...
How does heat-shock affect the influence of titanium dioxide nanoparticles in g...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, IsabelNanomaterials include all substances that contain nanoscale structures sized between 1 and 100 nm. At this size, the characteristics of materials change: their strength, conductivity, and reactivity, which differ substantially from macro- or micron- sized materials, shifting the rules of physics and chemistry to the sidelines. Although, the geological origin and the ubiquitous occurrence of nanoparticles in the...
Enzyme activity profile of peroxidases and polifenoloxidases of Malus domestica...
Agostinho, J; Ferreira, Rui; Alves-Pereira, IsabelThe region of Beira Alta, Portugal distinguishes itself as a favorable area for apple growing that produces fruits with great economic importance. The polyphenoloxidase (EC 1.14.18.1, PPO) a copper-enzyme located in plastids, catalyzes the oxidation of phenols to quinones present in the vacuoles, generating brown coloration products. In general, the enzymatic browning occurs when phenolic compounds are released...
Titanium dioxide nanoparticles inhibits Saccharomyces cerevisiae BY4741 prolife...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, Isabelphysicochemical properties are poorly known. In the case of metal nanoparticles, their dimension is often important, since their surface area increases as molecular size decreases, causing alterations in their magnetic and thermodynamic properties. Consequently, the influence they exert on life is an attractive topic of research in biochemical toxicology by the novelty of their behavior. Although titanium diox...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||