Mapping quantum Hall edge states in graphene by scanning tunneling microscopy

Quantum Hall edge states are the paradigmatic example of the bulk-boundary correspondence. They are prone to intricate reconstructions calling for their detailed investigation at high spatial resolution. Here, we map quantum Hall edge states of monolayer graphene at a magnetic field of 7 T with scanning tunneling microscopy. The graphene sample features a gate-tunable lateral interface between areas of different filling factor. We compare the results with detailed tight-binding calculations quantitatively accounting for the perturbation by the tip-induced quantum dot. We find that the edge state pattern is mapped with little perturbation by adequate choice of gate voltage. We observe extended compressible regions, the antinodal structure of edge states and their meandering along the lateral interface.Comment: 23 pages, 23 figure

EU Agro Biogas Project

EU-AGRO-BIOGAS is a European Biogas initiative to improve the yield of agricultural biogas plants in Europe, to optimise biogas technology and processes and to improve the efficiency in all parts of the production chain from feedstock to biogas utilisation. Leading European research institutions and universities are cooperating with key industry partners in order to work towards a sustainable Europe. Fourteen partners from eight European countries are involved. EU-AGRO-BIOGAS aims at the development and optimisation of the entire value chain – to range from the production of raw materials, the production and refining of biogas to the utilisation of heat and electricity

Human native kappa opioid receptor functions not predicted by recombinant receptors: Implications for drug design

International audienc

Traenkverfahren und Vorrichtung zur Ueberwachung der Durchtraenkung eines Traegermaterials

DE 19745404 A UPAB: 19990603 NOVELTY - For the impregnation of a carrier material, by immersion, the dielectric constant of the material changes during impregnation. A value (C) is measured, related to the dielectric constant, which gives the impregnating penetration (D) of the carrier material. DETAILED DESCRIPTION - In an INDEPENDENT CLAIM the monitoring system has a conductor (3) so that the carrier material acts as a dielectric to affect the electrical capacity of the conductor (3), which is measured. The conductor can be an electrically conductive strip, around the carrier material, with the electrical lead of the conductor rod. To measure the value (C), the electrical capacity is used of an electrical conductor, with the carrier material acting as a dielectric. The timed run (C(t)) of the measurement gives the timed run (D(t)) of the impregnation. A functional relationship (DR(C)) between a reference impregnation (DR) and the measured value gives the functional relationship of the impregnation. The timed run (D(t)) of the impregnation (D) is expressed as D(t)=DR(C(t)), where D is the impregnation, DR the reference impregnation, C the measured value and especially capacity, and t is the time. The amount of impregnation is defined as the ratio of impregnated and non-impregnated vols. of the carrier material. To determine the stages of impregnation, according to given parameters, each stage has a reference impregnation provided by a simulation model with a spaced distribution in the carrier material with at least one zone which is not impregnated and one zone which is impregnated. At least one dry zone (4) has an initial dielectric constant and at least one damp zone (5) has another dielectric constant. Each reference impregnation (DR), together with the dielectric constants, is associated with a measured value (C) to give the required functional relationship (CD(C)). Using a porous carrier material, the spaced distribution of the reference impregnation (DR) uses the Darcy law for a current of a Newton impregnation medium or by using a suitable modification of the Darcy law for a non-Newton impregnation medium. From the impregnation (D), the penetration depth is derived of the impregnation medium in the carrier material, in a timed run of the penetration and at least one factor of the filtration coefficient, flow resistance, permeability and relative porosity, which also gives the viscosity of the impregnating medium. The material can be the fibers, to be impregnated and form the compound material, or the carrier material is an electrical insulation. USE - The system is for the impregnation of a carrier for use in resin transfer molding, using a compound material of fibers impregnated with a resin. It can be used for applications such as for the insulation of a conductor rod at the stator of a generator and especially a turbo generator, or the impregnation of the coil of the stator of a generator, and especially a turbo generator, in a total immersion impregnation, and the impregnation indicates if there is an impregnation fault. ADVANTAGE - The system gives an effective impregnation of the carrier material, with positive indications of a fault in the process

A method for the analysis and control of mica tape impregnation processes

The impregnation of mica tape insulations usually is monitored with dielectric capacitance measurements. In this work, a method is developed that translates measured capacitance and loss into an average drag coefficient that characterizes flow resistance, which is the critical parameter of the process. In a first step, the impregnation depth is determined based on an appropriate model of the dielectric measurement. The impregnation depth curve and its derivative are then used to compute the average drag coefficient, which is defined in the framework of a standard porous media flow model. The method has been developed and tested for cylindrical insulators. Appropriate extensions to rectangular insulators are indicated

Reactive oxygen species (ROS) generation is stimulated by opioid receptor activation through phosphorylated c-Jun N-terminal kinase and inhibited by p38 mitogen-activated protein kinase (MAPK) activation

Activation of the mitogen-activated protein kinase (MAPK) c-Jun N-terminal kinase (JNK) by the Gi/o protein-coupled opioid receptor (KOR), \u3bc opioid, and D2 dopamine receptors stimulates peroxiredoxin 6 (PRDX6)-mediated production of reactive oxygen species (ROS). ROS production by KOR-inactivating antagonists norbinaltorphimine (norBNI) and JDTic blocks Gi protein activation, but the signaling mechanisms and consequences of JNK activation by KOR agonists remain uncharacterized. Binding of arrestins to KOR causes desensitization of G protein signaling and acts as a scaffold to initiate MAPK activation. Here, we found that the KOR agonists U50,488 and dynorphin B stimulated biphasic JNK activation with an early arrestin-independent phase, requiring the small G protein RAC family small GTPase 1 (RAC1) and protein kinase C (PKC), and a later arrestinscaffolded phase, requiring RAC1 and Ras homolog family member(RHO) kinase.JNK activation byU50,488 anddynorphinB also stimulated PRDX6-dependent ROS production but with an inverted U-shaped dose-response relationship. KOR agonist-induced ROS generation resulted from the early arrestin-independent phase ofJNK activation, andthis ROS response was suppressed by arrestin-dependent activation of the MAPK p38. The apparent balance between p38 MAPK and JNK/ROS signaling has important physiological implications for understanding of dynorphin activities during the stress response. To visualize these activities, we monitored KOR agonist-mediated activation of ROS in transfected live cells by two fluorescent sensors, CellROX Green and HyPerRed. These findings establish an important aspect of opioid receptor signaling and suggest that ROS induction may be part of the physiological response to KOR activation