Search results for "Current voltage"
showing 6 items of 6 documents
Calcium binding and ionic conduction in single conical nanopores with polyacid chains: model and experiments.
2012
Calcium binding to fixed charge groups confined over nanoscale regions is relevant to ion equilibrium and transport in the ionic channels of the cell membranes and artificial nanopores. We present an experimental and theoretical description of the dissociation equilibrium and transport in a single conical nanopore functionalized with pH-sensitive carboxylic acid groups and phosphonic acid chains. Different phenomena are simultaneously present in this basic problem of physical and biophysical chemistry: (i) the divalent nature of the phosphonic acid groups fixed to the pore walls and the influence of the pH and calcium on the reversible dissociation equilibrium of these groups; (ii) the asym…
Generation of nonlinear current-voltage characteristics. A general method
2002
International audience; A general method allowing to construct nonlinear resistors with arbitrary current-voltage (I-V) characteristics is proposed. The example of a cubic I-V characteristic is presented showing a perfect agreement between the theoretical desired resistor and its electronic realization based on analog multipliers.
Optical Gating of Photosensitive Synthetic Ion Channels
2011
4-oxo-4-(pyren-4-ylmethoxy) butanoic acid is used as a photolabile protecting group to show the optical gating of nanofluidic devices based on synthetic ion channels. The inner surface of the channels is decorated with monolayers of photolabile hydrophobic molecules that can be removed by irradiation, which leads to the generation of hydrophilic groups. This process can be exploited in the UV-light-triggered permselective transport of ionic species in aqueous solution through the channels. The optical gating of a single conical nanochannel and multichannel polymeric membranes is characterised experimentally and theoretically by means of current-voltage and selective permeation measurements,…
Inhibitoren der Korrosion 28 (1). 2-Aminopyrimidin (2-AP) als an Inhibitor der the Korrosion des Kupfers in Salzlösungen unter Sauerstoff
1982
2-Aminopyrimidin ist der z. Z. beste Inhibitor der Korrosion von Kupfer unter Standardbedingungen. Mit den aus der Oberflache der Kupferprobe austretenden oder gebildeten Cu1+-Ionen baut sich eine Schutzschicht auf. Die Ausbildung dieser Deckschicht wird studiert als Funktion: (a) der Konzentration an 2-AP und der Cu2+-Ionen, (b) der Stromungsgeschwindigkeit und (c) in Abhangigkeit von der Art der Anionen im korrosiven Medium. Ruhepotential-Zeit-Messungen, Strom-Spannungskurven, Polarisationswiderstandskurven und Halteversuche, ohne und mit 2-AP sowie ohne und mit Cu2+-Ionen vermitteln einen Einblick in den Aufbau der Deckschicht. Inhibiors of corrosion 28 (1). 2-Aminopyrimidine (2-AP) as a…
Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.
2012
We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…
Accelerated Light-Induced Defect Transformation Study of Elkem Solar Grade Silicon
2012
AbstractSolar cells made of silicon feedstock from a metallurgical route must qualify not only the initial efficiency, but must also be comparable to the solar cells made from reference polysilicon on the spectral response after light induced degradation. A detailed comparative study of light induced defects and its impact on cell performance is necessary for both materials. We have studied accelerated light induced degradation (ALID) defect transformation for Elkem Solar Silicon and polysilicon solar cells by selecting wafers from different positions from respective silicon bricks. Active boron-oxygen complexes and iron ions in multicrystalline silicon solar cells have been analyzed, and t…