We determine the spin-lifetime anisotropy of spin-polarized carriers in graphene. In contrast to prior approaches, our method does not require large out-of-plane magnetic fields and thus it is reliable for both low- and high-carrier densities. We first determine the in-plane spin lifetime by conventional spin precession measurements with magnetic fields perpendicular to the graphene plane. Then, to evaluate the out-of-plane spin lifetime, we implement spin precession measurements under oblique magnetic fields that generate an out-of-plane spin population. We find that the spin-lifetime anisotropy of graphene on silicon oxide is independent of carrier density and temperature down to 150 K, and much weaker than previously reported. Indeed, within the experimental uncertainty, the spin relaxation is isotropic. Altogether with the gate dependence of the spin lifetime, this indicates that the spin relaxation is driven by magnetic impurities or random spin-orbit or gauge fields.

The low magnetic field vortex patterns nucleation and evolution in a high-quality two-gap superconductor MgB 2 single crystal have been investigated by low-temperature scanning Hall probe microscopy. Large areas have been imaged with single-vortex resolution while changing systematically the thermodynamic parameters for field and temperature. The obtained patterns have been studied and compared with those of a reference 2H-NbSe 2 single crystal. We found that the observed vortex patterns in MgB 2 (e.g., stripes, clusters) appear due to competing vortex-vortex interactions as suggested by the theory of type-1.5 superconductivity.

In recent years, new spin-dependent thermal effects have been discovered in ferromagnets, stimulating a growing interest in spin caloritronics, a field that exploits the interaction between spin and heat currents . Amongst the most intriguing phenomena is the spin Seebeck effect , in which a thermal gradient gives rise to spin currents that are detected through the inverse spin Hall effect . Non-magnetic materials such as graphene are also relevant for spin caloritronics, thanks to efficient spin transport , energy-dependent carrier mobility and unique density of states . Here, we propose and demonstrate that a carrier thermal gradient in a graphene lateral spin valve can lead to a large increase of the spin voltage near to the graphene charge neutrality point. Such an increase results from a thermoelectric spin voltage, which is analogous to the voltage in a thermocouple and that can be enhanced by the presence of hot carriers generated by an applied current . These results could prove crucial to drive graphene spintronic devices and, in particular, to sustain pure spin signals with thermal gradients and to tune the remote spin accumulation by varying the spin-injection bias.

Aminobacter sp. MSH1 immobilized in an alginate matrix in porous stones was tested in a pilot system as an alternative inoculation strategy to the use of free suspended cells for biological removal of micropollutant concentrations of 2,6-dichlorobenzamide (BAM) in drinking water treatment plants (DWTPs). BAM removal rates and MSH1 cell numbers were recorded during operation and assessed with specific BAM degradation rates obtained in lab conditions using either freshly grown cells or starved cells to explain reactor performance. Both reactors inoculated with either suspended or immobilized cells showed immediate BAM removal under the threshold of 0.1 μg/L, but the duration of sufficient BAM removal was 2-fold (44 days) longer for immobilized cells. The longer sufficient BAM removal in case of immobilized cells compared to suspended cells was mainly explained by a lower initial loss of MSH1 cells at operational start due to volume replacement and shear. Overall loss of activity in the reactors though was due to starvation, and final removal rates did not differ between reactors inoculated with immobilized and suspended cells. Management of assimilable organic carbon, in addition to cell immobilization, appears crucial for guaranteeing long-term BAM degradation activity of MSH1 in DWTP units.

Aminobacter sp. MSH1 uses the groundwater micropollutant 2,6-dichlorobenzamide (BAM) as sole source of carbon and energy. In the first step, MSH1 converts BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) by means of the BbdA amidase encoded on the IncP-1β plasmid pBAM1. Information about the genes and degradation steps involved in 2,6-DCBA metabolism in MSH1 or any other organism is currently lacking. Here, we show that the genes for 2,6-DCBA degradation in strain MSH1 reside on a second catabolic plasmid in MSH1, designated as pBAM2. The complete sequence of pBAM2 was determined revealing that it is a 53.9 kb repABC family plasmid. The 2,6-DCBA catabolic genes on pBAM2 are organized in two main clusters bordered by IS elements and integrase genes and encode putative functions like Rieske mono-/dioxygenase, meta-cleavage dioxygenase, and reductive dehalogenases. The putative mono-oxygenase encoded by the bbdD gene was shown to convert 2,6-DCBA to 3-hydroxy-2,6-dichlorobenzoate (3-OH-2,6-DCBA). 3-OH-DCBA was degraded by wild-type MSH1 and not by a pBAM2-free MSH1 variant indicating that it is a likely intermediate in the pBAM2-encoded DCBA catabolic pathway. Based on the activity of BbdD and the putative functions of the other catabolic genes on pBAM2, a metabolic pathway for BAM/2,6-DCBA in strain MSH1 was suggested.