5 documents found, page 1 of 1
Portable and low-cost fluorometer for phytoplankton monitoring
Sá, Leonardo Rafael Correia; Pinto, Vânia Cristina Gonçalves; Sousa, Paulo Jorge Teixeira; Magalhães, Vitor H.; Carvalho, Denise Andreia MotaPhytoplankton monitoring using fluorescence spectroscopy techniques has been frequently used over time. This monitoring is based on the detection of the main photosynthetic pigment, chlorophyll-a, as its concentration is widely used as a proxy of phytoplankton biomass in the water column. However, the fluorometers available for their measurement and use in the field are still quite expensive and bulky, which li...
A microfluidic device for size-based microplastics and microalgae separation
Magalhães, Vitor H.; Pinto, Vânia Cristina Gonçalves; Sousa, Paulo Jorge Teixeira; Gonçalves, L. M.; Fernández, Emilio; Minas, GraçaPhytoplankton are microscopic marine algae that constitute the foundation of the aquatic food web. They are essential to drive life in the oceans but can also be harmful in the form of algae blooms, either by producing phytoplankton toxins or massive biomass proliferation. Microalgae cell size is a relevant morphologic trait that can help identifying species responsible for these blooms at early stages. Sorting...
Methodology for phytoplankton taxonomic group identification towards the develo...
Carvalho, Denise Andreia Mota; Pinto, Vânia Cristina Gonçalves; Sousa, Paulo Jorge Teixeira; Magalhães, Vitor H.; Fernández, Emilio; Gomes, Pedro A.This paper presents the absorbance and fluorescence optical properties of various phytoplankton species, looking to achieve an accurate method to detect and identify a number of phytoplankton taxonomic groups. The methodology to select the excitation and detection wavelengths that results in superior identification of phytoplankton is reported. The macroscopic analyses and the implemented methodology are the ba...
Factors influencing methane-derived authigenic carbonate formation at cold seep...
Wang, Shuhong; Yan, Wen; Magalhães, Vitor H.; Chen, Zhong; Pinheiro, Luis M.; Gussone, NikolausThis paper carried out mineral and geochemical studies on a profile through a diagenetic methane-derived authigenic carbonate sample that was collected from southwestern Dongsha area of the northern South China Sea. Five samples locating in the cross-sectional middle mainly consist of dolomite and quartz, and two samples close to the surface have a small amount of Mg-calcite. The d13C values of the samples vary ...
Formation processes of methane-derived authigenic carbonates from the Gulf of C...
Magalhães, Vitor H.; Pinheiro, Luis M.; Ivanov, Michael K.; Kozlova, Elena; Blinova, Valentina; Kolganova, J.; Vasconcelos, CrisogonoThe Gulf of Cadiz, NE Atlantic, represents an area of extensive formation of methane-derived authigenic carbonates (MDAC), indicative of fluid seepage. These MDAC, that reach extraordinary length and thickness, were geophysically mapped and sampled and the recovered carbonate-cemented material has δ13C values as low as − 56.2‰ VPDB, indicating methane as the major carbon source. The MDAC form two main lithologi...