Passive Conductivity Research Articles

A Wireless Passive Conductivity Detector for Fluidic Conductivity Analyzation in Microchannel

Electrical conductivity is one of the main parameters of an electrolyte solution. Fluidic conductivity detection and analyzation is very important in many academic research and industrial applications. In order to avoid the issues of the conventional sensing technique, this study utilizes the wireless passive conductivity detector for fluidic conductivity analyzation in the microchannel. The operation of the proposed structure is designed, simulated and then validated by experiments. The experimental results show that the resonance frequency of the sensor decreases from 64.7 MHz to 58.6 MHz according to the rise of KCl concentration in the fluidic channel from 10 mM to 1 M. The dependence of resonance frequency on the distance between inductors was also implemented and analyzed in this work. The integration of the LC passive sensing technique in microfluidic conductivity detector can be utilized in various academic research, industrial application, especially in biosensor applications.

Algorithm for Indirect Measurement of the Parameters of the Passive Complex Conductivity of a Two-Terminal Circuit in a Multipole Electrical Circuit

An algorithm is proposed for indirect measurement of the parameters of the passive complex conductivity as a separate two-terminal circuit and also as a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit without needing to separate it into separate two-terminal circuits. A structural diagram is presented for a microprocessor device to measure the parameters of the passive complex conductivity of a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit. The algorithm for the indirect method of measuring the parameters of the passive complex conductivity of the two-terminal circuit is based on the theory of matrices and nondirectional graphs. Equations are obtained for calculating the modulus and components of the passive complex conductivity of a two-terminal circuit located in a multipole triangle-type electrical circuit. The proposed algorithm avoids the methodological error owing to the influence of parasitic parameters. Results are presented from an experimental test of the algorithm for indirect measurement of the conductivity of a two-terminal circuit.

Algorithm for indirect measurement method of parameters of passive complex conductance of a two-pole in a multi-pole electrical circuit

An algorithm is proposed for indirectly measuring the parameters of the passive complex conductivity of a two-terminal circuit, both separate and located in one of the branches of a multi-pole passive electric circuit of the triangle-type. A block diagram of a microprocessor measurement unit is presented. The algorithm of the indirect method for measuring the parameters of the passive complex conductivity of a two-terminal circuit, the rationale of which is given on the basis of the theory of matrices and undirected graphs, is considered. Equations for calculating the modulus and components of the studied passive complex conductivity of a two-terminal device located in a multi-pole electric circuit of the triangle-type are obtained. The revealed features of the proposed algorithm exclude a methodological error due to the influence of spurious parameters. Parasitic parameters include: input complex conductivities and transmission coefficients of voltage converters; complex conductivity of a harmonic signal source; passive complex conductivity of two-terminal circuits located in other branches of the studied passive multipolar electric circuit. The results of an experimental verification of the developed algorithm of the indirect method for measuring the module of the complex conductivity of a two-terminal device are presented. The developed algorithm can be used to measure the parameters of passive complex conductivity of both an individual two-terminal circuit and a two-terminal circuit located in one of the branches of a multi-pole passive electric circuit of the triangle-type, without the need for its separation into separate two-terminal devices.

Microfabricated self-resonant structure as a passive wireless dielectric constant and conductivity sensor

This paper describes a low cost, passive wireless dielectric constant and conductivity sensor using a microfabricated inductor with interdigitated capacitors (IDC). A self-resonant-structure (SRS) is designed by incorporating IDC electrodes in the inter-winding space of the inductor. The distributed capacitance and conductance of the sensor is affected by dielectric constant (e) and conductivity (σ) of its environment or material under test (MUT). The e and σ can be used to provide information about the surrounding environment. This serves as an impedance transducer changing the resonant frequency and phase dip of the SRS. The SRS is interrogated using a non-contact inductively coupled reader coil. The change in resonance frequency and phase dip of the SRS is used to detect material properties of the environment/MUT. The relationship between sensor layout and coupling factor between sensor and reader is investigated. Optimizations of the coupling factor based on this relationship are discussed. IDC design trade-offs between the sensor’s sensitivity and coupling factor are also investigated. The sensor’s response to variety of liquid MUTs with a wide range of dielectric constant and conductivity is presented.

Studies on the mechanism of action of triphenyltin on proton conduction by the H+-ATPase of mitochondria.

A study is presented of the action of triphenyltin on the kinetics of the anaerobic relaxation of the proton gradient set up by respiration in various type of 'inside-out' inner membrane vesicles obtained by exposure of beef-heart mitochondria to ultrasonic energy. Triphenyltin is shown to act as a powerful inhibitor of the proton conductivity of the H+-ATPase. The inhibition persists after removal of the ATPase protein inhibitor, F1 and the oligomycin-sensitivity conferral protein (OSCP) from the particles. The inhibitory effect of triphenyltin is exerted, as in the case of oligomycin and N,N'-dicyclohexylcarbodiimide, on the F0 moiety of the ATPase complex. Comparison of the characteristics of the effect of triphenyltin on proton translocation in chloride and nitrate media shows that the inhibition of passive proton conductivity studied here is unrelated to the hydroxide/anion exchange induced by the organotin. Lack of additivity of the inhibition of H+ conduction by triphenyltin with that exerted by oligomycin and N,N'-dicyclohexylcarbodiimide and the kinetic pattern of the effect of triphenyltin show that the mechanism of action of the organotin is different from that of the other two inhibitors. The relevance of the results obtained with respect to the subunit location and chemical nature of the reaction site of triphenyltin in the H+-ATPase complex is discussed.

Passive conductivity detection for capillary electrophoresis.

A passive electrochemical detection principle that can be applied to capillary electrophoresis is presented. The separation electrical field is used to generate a potential difference between two electrodes located along the channel. For constant-current electrophoresis, the generated signal is proportional to the resistance of the solution passing between the two electrodes. Contrary to conductivity detectors that are ac driven and need to be decoupled from the separation field, the passive detection directly takes advantage of the separation field. The signal is simply measured by a high-impedance voltmeter. The detection concept has been validated by numerical simulations showing how the magnitude of the signal is related to the ratio between the electrode distance and the length of the sample plug. As a proof of the principle, this detection concept has been demonstrated by the electrophoretic separation of three alkali ions on a polymer microchip. Based on preliminary results, a detection limit of 20 microM and a dynamic range of up to 3 orders of magnitude have been achieved.

On the effective passive Conductivity of human Tissues at low Frequencies

On the effective passive Conductivity of human Tissues at low Frequencies

Einfluß von Indolylessigsäure und Gibberellinsäure auf passive und energieabhängige Ionentransporte in Maiskoleoptilenzellen

Summary Using glass microelectrodes the influence of enhanced external ion ( K+ or Na+) concentrations on membrane potential in dwarf corn coleoptile cells is measured. From that results a modified form of the Hodgkin-Horowicz-equation, containing both the relative ion conductivity Tj and the ionic strength of the medium, is derived. Making use of this modified equation the passive and energy-dependent parts of the Tj’s are estimated from experiments in presence or absence of 0.5 mM KCN, respectively. It is found, that indoleacetic acid affects an electrogenic ion transport system, probably a proton pump, whereas gibberellic acid strongly influences the passive ion conductivity.