Search results for "Electrode"
showing 10 items of 950 documents
Tunneling into epitaxial UPd2Al3 thin films
1999
Abstract UPd2Al3–AlOx–Pb Giaever-type tunneling junctions were prepared employing an in vacuo process. The high junction quality is evident by the observation of the well-known superconducting density of states of the Pb counter electrode. For HPbc2
Patterning of Suitable Structures for the Investigation of the Josephson Effect in YBa2Cu3O7/PrBa2Cu3O7 Superlattices
1996
The aim of our work is to investigate the Josephson effect in YBa 2 Cu 3 O 7-δ /PrBa 2 Cu 3 O 7-δ superlattices. In the case of current flow along c axis direction the superlattice forms an array of artificial Josephson junctions where the YBa 2 Cu 3 O 7-δ layers are the superconducting electrodes which are separated but Josephson coupled by the PrBa 2 Cu 3 O 7-δ sheets. In this paper we report on the preparation, characterisation and patterning of the superlattices into suitable structures via standard photolithograpy and lift-off technique.
Microrefrigeration by NIS tunnel junctions
1996
By using a normal metal-insulator-superconductor (NIS) tunnel junction one can manipulate the Fermi-Dirac distribution of the electrons in the normal electrode. If the junction is biased close to the superconducting gap, Δ, only “hot electrons” above Fermi level can tunnel from the normal electrode to the superconductor. Thus, due to the decoupling of the conduction electrons from the lattice at low temperatures, there exists a possibility to decrease the electronic temperature by this method. Because of the symmetry with bias voltage, two NIS tunnel junctions in series can form an efficient microrefrigerator. Temperature can be measured with two additional junctions by considering the vari…
Microrefrigeration by normal-metal/ insulator/superconductor tunnel junctions
1997
Abstract A normal-metal/insulator/superconductor (NIS) tunnel junction can be applied to cool electrons by biasing the junction suitably with external voltage. Because of the symmetry with bias voltage, two NIS junctions in series can form an efficient microrefrigerator. So far our SINIS microrefrigerator has been capable of reaching electronic temperatures of about 100 mK starting from 300 mK. To achieve appreciable refrigeration of the underlying lattice, microrefrigerator must be thermally decoupled from the bulk substrate. We have demonstrated experimentally the reduction of lattice temperature of a few mK at 200 mK by extending the normal electrode on a thin dielectric membrane. Method…
Refrigeration of a dielectric membrane by superconductor/insulator/normalmetal/insulator/superconductor tunneling
1997
We have applied tunneling of electrons between a normal metal and a superconductor to refrigerate a thin dielectric membrane attached to the normal electrode of a superconductor/ insulator/normal-metal/insulator/superconductor (SINIS) structure. Starting from T≈200 mK, a decrease in temperature of several mK was observed, measured by a separate thermometer on the membrane. It should be straightforward to improve the refrigerator performance to the level of the recently demonstrated SINIS electron cooling method, such that the drop in the lattice temperature would be more than an order of magnitude larger.
NIS chip refrigeration
1999
A normal-metal/insulator/superconductor (NIS) tunnel junction can be applied to cool electrons by biasing the junction suitably with external voltage. Two NIS junctions in series can form an efficient microrefrigerator because of the symmetry with bias voltage. Our SINIS microrefrigerator has been capable of reaching electronic temperatures of about 100 mK starting from 300 mK. To achieve appreciable refrigeration of the underlying lattice, the microrefrigerator must be thermally decoupled from the bulk substrate. We have demonstrated experimentally the reduction of lattice temperature by 23 mK at 180 mK by extending the normal electrode on a thin dielectric membrane with four suspended bri…
Electrochemical Conversion of Dichloroacetic Acid to Chloroacetic Acid in Conventional Cell and in Two Microfluidic Reactors
2013
The electrochemical conversion of dichloroacetic acid to chloracetic acid is investigated in conventional cells and in microreactors. Two different microreactors are used: the first is a filter press cell equipped with PTFE micrometric spacers, easy to assemble and disassemble and available for a large variety of electrodes and solvents; the second is made using an adhesive spacer, micromilling and press and could easily be developed on an industrial scale. The electrochemical synthesis is performed successfully in the microreactors equipped with a graphite cathode under proper operative conditions. The performance of the process strongly depends on the nature of the cathode and, for micror…
Electrochemical impedance spectroscopy of polyelectrolyte multilayer modified gold electrodes: influence of supporting electrolyte and temperature.
2005
Electrochemical impedance spectroscopy and cyclic voltammetry are employed to characterize poly(styrenesulfonate)/poly(allylamine hydrochloride) multilayers assembled onto cysteamine-modified gold surfaces. The influence of the supporting electrolyte and temperature on the impedance response is studied because of both its practical interest and the need to test further the capillary membrane model recently developed by Barreira et al. [J. Phys. Chem. B 2004, 108, 17973]. The results obtained are interpreted quite satisfactorily in terms of this model, thus providing additional support to its usefulness for the description of ionic transport through polyelectrolyte multilayers. It is observe…
Sympathetic nervous system synchrony: An exploratory study of its relationship with the therapeutic alliance and outcome in couple therapy.
2019
In previous research, we found that sympathetic nervous system synchrony, measured via electrodermal activity (EDA), occurs between participants at the start of couple therapy. The aim now was to test whether this synchrony changes during the therapy process, and how any changes may be related to clients' and therapists' evaluations of the working alliance, and the outcome of therapy. Twelve different couple therapy processes were analyzed (24 clients, plus 10 therapists, working in pairs; hence, 4 persons per session) using EDA concordance indices and questionnaires (Outcome Rating Scale, Session Rating Scale, and Clinical Outcomes in Routine Evaluation-Outcome Measure). EDA synchrony betw…
An analysis methodology to evaluate the contribution to electrical security given by bare buried conductors in a system of intertied earthing grids
2004
The paper presents an analysis methodology for a single-line-to-ground fault, occurring at a secondary MV/LV substation in a power network formed by a HV/MV station, feeding, through a MV tri-phase cable line, N MV/LV substations whose earth electrodes are interconnected by bare buried conductors. In the preliminary explanation of the methodology, earth buried conductors are studied in their double function of earth electrodes and connection elements between earthing grids, both in absence and in presence of other interfering conductors. Subsequently analyzed is, with a distributed parameters approach, the system constituted by an earth buried conductor and a MV tri-phase cable line. The eq…