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Mar Pollut Bull ; 80(1-2): 302-11, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24433999


Coastal zones and the biosphere as a whole show signs of cumulative degradation due to the use and disposal of plastics. To better understand the manifestation of plastic pollution in the Atlantic Ocean, we partnered with local communities to determine the concentrations of micro-plastics in 125 beaches on three islands in the Canary Current: Lanzarote, La Graciosa, and Fuerteventura. We found that, in spite of being located in highly-protected natural areas, all beaches in our study area are exceedingly vulnerable to micro-plastic pollution, with pollution levels reaching concentrations greater than 100 g of plastic in 1l of sediment. This paper contributes to ongoing efforts to develop solutions to plastic pollution by addressing the questions: (i) Where does this pollution come from?; (ii) How much plastic pollution is in the world's oceans and coastal zones?; (iii) What are the consequences for the biosphere?; and (iv) What are possible solutions?

Conservação dos Recursos Naturais , Plásticos/análise , Resíduos/análise , Poluentes Químicos da Água/análise , Oceano Atlântico , Praias/estatística & dados numéricos , Monitoramento Ambiental , Espanha , Resíduos/estatística & dados numéricos , Poluição Química da Água/estatística & dados numéricos
Opt Express ; 20(23): 25596-602, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-23187378


We demonstrate a dual-wavelength Nd:YSAG ceramic laser in which the gain volume is structurated into two different regions providing gain at the wavelength of 1061 nm and 1064 nm respectively. We discuss the role of the nonuniform distribution of the temperature in structurating the gain region via the Boltzmann effect. We show that the two laser wavelengths can be switched by adjusting the size of the pump beam or by slightly modifying the geometrical parameters of the laser cavity, either the length of the cavity or the orientation of a mirror. Additionally, we demonstrate that the transverse modes at the two wavelengths are shaped according to the effect of gain filtering caused by the structuration of the gain region.

Opt Express ; 20(2): 1202-12, 2012 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-22274464


We present a novel broadband laser source based on a dual cavity in which a subnanosecond passively Q-switched microchip laser is coupled with a long cavity including an acousto-optic modulator (AOM) and a microstructured optical fiber working as a non linear medium. This active-passive Q-switched laser source emits pulses as short as those emitted by the free running microchip laser (~600 ps). The time pulse emission is governed by the AOM allowing tunable repetition rate from 0 to more than 4 kHz with a temporal jitter reduced to less than 50 ns, i.e. a 600-fold reduction compared to that of the free running microchip. Furthermore, thanks to spectral broadening in the microstructured fiber, this source emits a supercontinuum from 700 nm to 1700 nm.

Citometria de Fluxo/instrumentação , Dispositivos Lab-On-A-Chip , Lasers , Óptica e Fotônica/instrumentação , Acústica/instrumentação , Desenho de Equipamento , Manufaturas , Miniaturização , Modelos Teóricos