Vortex phase transition and superconducting properties of organic quasi-two-dimensional k-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br

International audienceWe report investigations of the low temperature dc susceptibility and the magnetization on the layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br near 80K and the effect of disorder on the superconducting transition temperature Tc. The shielding effect (S) and the critical current density Jc were studied (with H parallel to the c axis of the crystal). Jc can be estimated by analysis of magnetic hysteresis measurement using the Bean model. For each temperature value, we observed two regimes in the critical current density Jc(H). This result implies that there exists a first-order phase transition in the vortex system in this organic superconductor. Our results show that the magnetic properties of these compounds depend strongly on the cooling rate. The structural transformation which occurs at the vicinity of 80K very strongly influences the physics of vortex lattice and the associated magnetic behavior

LEÓN, JOSÉ CLAUDIO DE Y SRA. [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

Some physicochemical and morphological characterizations of three varieties of Algerian common dates

The date palm is a typical plant of the arid and semi arid areas. Unfortunately in fact they are not all the varieties that profits from an economic interest except for Deglet-Nour. Thus, it represents a danger to the genetic inheritance and the biodiversity. The three varieties studied in this work are: Mech-Degla, Degla-Beida and Frezza, which are common varieties cultivated in the south of Algeria. They are characterized by a good availability and an interesting aptitude for the conservation. In this work (included in our project consisting in the valorization of the common local dates) were presented only the obtained first results. The morphological characteristics (weight of whole date, pea of pulp (pulpit), weight of the seed, length and width of whole date and the seed, pulp/seed ratio, pulp/date ratio, seed/date ration) are given. The physicochemical parameters studied are: pH, ashes, flavonoid, minerals and antioxidant activity. All three varieties are particularly rich in minerals (K, Ca, Na, Zn, Fe, Cu and Mn), in flavonoïd. Concerning the antioxidant activity, different cultivars is endowed with an extraordinary capacity (61.82, 61.56 and 61.61% respectively for Mech-Degla, Degla-Beida and Frezza). © EuroJournals Publishing, Inc. 200

Apparatus for measurement of the electric dipole moment of the neutron using a cohabiting atomic-mercury magnetometer

A description is presented of apparatus used to carry out an experimental search for an electric dipole moment of the neutron, at the Institut Laue-Langevin (ILL), Grenoble. The experiment incorporated a cohabiting atomic-mercury magnetometer in order to reduce spurious signals from magnetic field fluctuations. The result has been published in an earlier letter; here, the methods and equipment used are discussed in detail