Electron-hole coexistence in disordered graphene probed by high-field magneto-transport

We report on magneto-transport measurement in disordered graphene under pulsed magnetic field of up to 57T. For large electron or hole doping, the system displays the expected anomalous Integer Quantum Hall Effect (IQHE) specific to graphene up to filling factor $\nu=2$. In the close vicinity of the charge neutrality point, the system breaks up into co-existing puddles of holes and electrons, leading to a vanishing Hall and finite longitudinal resistance with no hint of divergence at very high magnetic field. Large resistance fluctuations are observed near the Dirac point. They are interpreted as the the natural consequence of the presence of electron and hole puddles. The magnetic field at which the amplitude of the fluctuations are the largest is directly linked to the mean size of the puddles

Optimización y revalidación del análisis de nitrógeno por el método

En el presente artículo, se ha optimizado y se ha revalidado el procedimiento de análisis de nitrógeno en muestras de taurina mediante el método Kjeldahl. La Asociación Española de Farmacéuticos de la Industria (AEFI) propone un modelo de cálculo que permite determinar el número de replicados a realizar, en función del coeficiente de variación de la repetibilidad del procedimiento (C.V.%) y el valor límite aceptado, que en el caso de la determinación de la pureza, corresponde al valor máximo o mínimo de las especificaciones de la muestra. Al aplicar dicho modelo, considerando la incertidumbre de calibración del equipo, como el mínimo valor posible para el C.V.%, y teniendo en cuenta las especificaciones establecidas para la taurina en la U.S. Pharmacopeia 30, se obtiene que el número de replicados a realizar es de cinco o seis, según las condiciones de trabajo

On a strong form of Oliver’s p-group conjecture.

We introduce a stronger and more tractable form of Olivers p-group conjecture, and derive a reformulation in terms of the modular representation theory of a quotient group. The Sylow p-subgroups of the symmetric group Sn and of the general linear group satisfy both the strong conjecture and its reformulation

A 'Minifesta' and the Promise of Collective Voice

This polyvocal paper describes the collective writing of a manifesto for urban equality by an international and interdisciplinary team of researchers who met in Kampala, Uganda, in November 2019. It explains the methodologies that inspired the process of writing, reflects on the contradictions that permeate the generation of collective voices, and discusses the relationship between collective voice and situated knowledge. In doing so, it proposes a move from grand manifestos to situated minifestas, arguing for minor literature in the generation of feminist, subaltern knowledge

Hall effect in the heavy-fermion compound CePtSi

We present Hall-effect measurements on the heavy-fermion compound CePtSi. Above the temperature of antiferromagnetic ordering T_N, the Hall effect of CePtSi exhibits the behavior generally observed in heavy-fermion systems and ascribed to skew scattering. Below T_N the Hall effect is enhanced and its field dependence is strongly nonlinear. We show that this behavior arises from skew scattering or anomalous velocity effects rather than from a change of the ordinary Hall effect induced by a reconstruction of the Fermi surface