3 resultados para Gold nanocrystals

em Repositório Científico do Instituto Politécnico de Lisboa - Portugal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Gold(III) complexes of type [AuCl2{eta(2)-RC(R'pz)(3)}]Cl [R = R' = H (1), R = CH2OH, R' = H (2) and R = H, R' = 3,5-Me-2(3), pz = pyrazol-1-yl] were supported on carbon materials (activated carbon, carbon xerogel and carbon nanotubes) and used for the oxidation of cyclohexane to cyclohexanol and cyclohexanone, with aqueous H2O2, under mild conditions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A Europa assiste ao envelhecimento da população, onde a doença respiratória assume relevância. Com o aumento da idade, da exposição à poluição ambiental e do tabagismo, a prevalência da Doença Pulmonar Obstrutiva Crónica (DPOC) tende a ser elevada, nomeadamente na população idosa. A idade avançada poderá associar-se com uma menor percepção de sintomas, pelo que a espirometria será útil nesta faixa etária. Objetivo do estudo - Descrever o resultado da espirometria com prova de broncodilatação, de acordo com os critérios GOLD e prevalência de sintomas respiratórios dos idosos residentes num lar de Lisboa.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cellulose and its derivatives, such as hydroxypropylcellulose (HPC) have been studied for a long time but they are still not well understood particularly in liquid crystalline solutions. These systems can be at the origin of networks with properties similar to liquid crystalline (LC) elastomers. The films produced from LC solutions can be manipulated by the action of moisture allowing for instance the development of a soft motor (Geng et al., 2013) driven by humidity. Cellulose nanocrystals (CNC), which combine cellulose properties with the specific characteristics of nanoscale materials, have been mainly studied for their potential as a reinforcing agent. Suspensions of CNC can also self-order originating a liquid-crystalline chiral nematic phases. Considering the liquid crystalline features that both LC-HPC and CNC can acquire, we prepared LC-HPC/CNC solutions with different CNC contents (1,2 and 5 wt.%). The effect of the CNC into the LC-HPC matrix was determined by coupling rheology and NMR spectroscopy - Rheo-NMR a technique tailored to analyse orientational order in sheared systems. (C) 2015 Elsevier Ltd. All rights reserved.