1,041 research outputs found
Vortex-Antivortex Lattice in Ultra-Cold Fermi Gases
We discuss ultra-cold Fermi gases in two dimensions, which could be realized
in a strongly confining one-dimensional optical lattice. We obtain the
temperature versus effective interaction phase diagram for an s-wave superfluid
and show that, below a certain critical temperature T_c, spontaneous
vortex-antivortex pairs appear for all coupling strengths. In addition, we show
that the evolution from weak to strong coupling is smooth, and that the system
forms a square vortex-antivortex lattice at a lower critical temperature T_M.Comment: Submitted to Physical Review Letter
Effect of weathering conditions on the degradation behaviour of ABS
Fundação para a Ciência e a Tecnologia (FCT) - Bolsa de Doutoramento SFRH/BDE/15657/2007Poliversal – Plásticos e Tecnologia, S.A
Preparation of biodegradable materials by reactive extrusion
This work aimed to prepare biodegradable polymeric materials based on blends of a
synthetic high density polyethylene (HDPE) and biodegradable polymers such as polylactic acid
(PCL) and poly(caprolactone) (PLA), in a co-rotating twin-screw extruder. A polyethylene
modified with maleic anhydride was used as compatibiliser. The mechanical results showed that the
addition of PLA improves the blends stiffness while the addition of PCL leads to materials with a
greater elongation at break and a lower Young modulus. This feature is related with the mechanical
properties of each material as well as the adhesion between them. Concerning the biodegradability
tests, it was found that HDPE/PCL blend presents the highest degree of biodegradability
Magnetoelectric CoFe2O4/polyvinylidene fluoride electrospun nanofibres.
Magnetoelectric 0-1 composites comprising CoFe2O4 (CFO) nanoparticles in a polyvinylidene fluoride (PVDF) polymer-fibre matrix have been prepared by electrospinning. The average diameter of the electrospun composite fibres is ∼325 nm, independent of the nanoparticle content, and the amount of the crystalline polar β phase is strongly enhanced when compared to pure PVDF polymer fibres. The piezoelectric response of these electroactive nanofibres is modified by an applied magnetic field, thus evidencing the magnetoelectric character of the CFO/PVDF 0-1 composites.This work was supported by FEDER through the COMPETE Program and
by the Portuguese Foundation for Science and Technology (FCT) in the
framework of the Strategic Project PEST C/FIS/UI607/2014 and
PTDC/CTM NAN/112574/2009. R. G., P. M., V. S., G. B. and S. L. M.
acknowledge support from “Matepro – Optimizing Materials and
Processes” (ref. NORTE-07-0124-FEDER-000037), co funded by
“Programa Operacional Regional do Norte” (ON.2 – O Novo Norte,
QREN, FEDER). P. M. and R. Gonçalves acknowledges also support from
FCT (SFRH/BPD/96227/2013 and SFRH/BD/88397/2012 grants
respectively). X. M. acknowledges support from the Ramón y Cajal (RYC)
Programme (Spanish MEC) and the Royal Society.This is the accepted manuscript. The final version is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/NR/c5nr00453e#!divAbstract
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