242 results about "Electric conductance" patented technology

The invention relates to the technical field of intelligent operation and maintenance of power equipment, in particular to a cable system full life cycle health management method based on digital twinning, which comprises the following steps: step 1, constructing a cable digital twinning body fusing electric-thermal-mechanical-chemical multi-physical fields; 2, dynamically fusing multi-source monitoring data, and collecting a cable skin continuous temperature sequence, a partial discharge pulse waveform and soil environment parameters; 3, solving a coupling equation of conductivity-thermal conductivity-stress tensor-ion diffusivity through iteration to realize multi-physical field linkage simulation; 4, generating a self-adaptive maintenance decision, inputting the insulation aging factor into an LSTM predictor to output a residual life prediction value, and generating a maintenance work order when the residual life is lower than a threshold value; and 5, carrying out closed-loop correction on the model, and updating the insulation aging factor calculation model and the physical attributes of the three-dimensional grid according to actual maintenance data. The method improves the safety, reliability and operation and maintenance efficiency of the cable system, and has important industrial application prospects.

The invention discloses a metal flat plate thickness and conductivity eddy current measurement method and system. According to the method, an electromagnetic detection platform is built, and a coaxial excitation-receiving eddy current probe structure is designed. Establishing a coaxial eddy current detection analysis model, and deducing a dynamic calculation result of mutual inductance parameters of the sensor in a frequency sweeping mode; setting two PID (Proportion Integration Differentiation) controllers and initial control variables thereof, and inputting the control variables serving as a thickness value and a conductivity value into the analytical theoretical model to obtain a corresponding mutual inductance change result; calculating an instantaneous error term and an accumulative error term of the current iteration period in real time, and when the error exceeds a preset convergence threshold value, inputting the error into a PID controller and updating the two control quantities until the maximum iteration frequency is reached; otherwise, outputting a control variable value, wherein the two control variables output by the controller are the thickness and the conductivity of the metal plate respectively. According to the invention, the thickness and conductivity of the metal plate can be accurately and simultaneously measured.

Systems and methods are provided for modeling and for providing a graphical representation of tissue heating and electric field distributions for medical treatment devices that apply electrical treatment energy through one or a plurality of electrodes. In embodiments, methods comprise: providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to tissue through a plurality of electrodes; modeling electric and heat distribution in the tissue based on the parameters; and displaying a graphical representation of the modeled electric and heat distribution. In another embodiment, a treatment planning module is adapted to generate an estimated target ablation zone based on a combination of one or more parameters for an irreversible electroporation protocol and one or more tissue-specific conductivity parameters.

The invention discloses a grounding grid electric heating power multi-field coupling modeling method and system considering soil nonlinear breakdown, and belongs to the technical field of power system grounding grids. The method comprises the following steps: establishing a three-dimensional geometric model containing a soil domain and a grounding grid conductor; defining non-linear conductivity characteristics of the soil; setting multi-physical field parameters and corresponding boundary conditions of the three-dimensional geometric model; and establishing a multi-physical field coupling control equation set including an electric field equation, a heat conduction equation and a thermal stress equation, and solving by adopting a finite element method to obtain three-dimensional space distribution data of the grounding grid under lightning current impact. According to the invention, on the basis of fully considering the nonlinear breakdown characteristic of the soil, the accurate simulation of the electric heating power multi-physical field behavior of the grounding grid under the impact current effect is realized, and the accuracy of impact impedance, potential distribution and temperature rise prediction is obviously improved.

The invention provides a brain deep electrical stimulation electrode parameter determination method and related equipment, and the method comprises the steps: building a head simulation model which comprises conductivity distribution; determining one or more target stimulation target spots and one or more non-target inhibition areas on the head simulation model; based on one or more target stimulation target spots and one or more non-target inhibition areas, multiple groups of electrode configuration schemes are determined through an electrode positioning method, each group of electrode configuration scheme is configured on the head simulation model, and multiple groups of stimulation simulation models are obtained; performing finite element solution based on the anatomical structure and the conductivity distribution of each group of stimulation simulation models, and optimizing the electric field intensity of one or more target stimulation target spots and the electric field intensity of one or more non-target suppression regions to obtain a plurality of electrode parameters; and determining a target electrode parameter in the plurality of electrode parameters, and taking an electrode configuration scheme corresponding to the target electrode parameter as a target electrode configuration scheme.

Systems and methods are provided for modeling and for providing a graphical representation of tissue heating and electric field distributions for medical treatment devices that apply electrical treatment energy through one or a plurality of electrodes. In embodiments, methods comprise: providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to tissue through a plurality of electrodes; modeling electric and heat distribution in the tissue based on the parameters; and displaying a graphical representation of the modeled electric and heat distribution. In another embodiment, a treatment planning module is adapted to generate an estimated target ablation zone based on a combination of one or more parameters for an irreversible electroporation protocol and one or more tissue-specific conductivity parameters.

The invention relates to the field of intelligent medical treatment, in particular to an electrical impedance imaging method and device based on mixed excitation and a program product. Comprising the steps that an initial current vector and an initial boundary voltage vector of mixed excitation are obtained, the mixed excitation comprises L kinds of excitation, and L is a natural number larger than 1; performing weighted fusion on the L excitation initial current vectors to obtain a mixed excitation current vector, and performing weighted fusion on the L excitation initial boundary voltages to obtain a mixed excitation voltage; performing electrical impedance imaging optimization function calculation based on the mixed excitation current vector and the mixed excitation voltage to obtain conductivity change; the optimization function is used for carrying out regularization calculation on regional potential distribution and conductivity variation based on the mixed excitation current vector and the mixed excitation voltage; an electrical impedance distribution image is generated based on the conductivity change. According to the invention, the resolution of EIT imaging is improved, and the method has good clinical value.

The invention discloses an electrical impedance tomography method, which integrates a physical model and deep learning to construct a deep learning framework with physical constraints so as to improve physical consistency and reconstruction precision. According to the method, a neural network based on an encoder-decoder structure is adopted, and measured boundary voltage is used as input to predict conductivity distribution of a target object; in order to improve the performance of the neural network, a physical Jacobian matrix is introduced, and the sensitivity of boundary voltage to conductivity is described; and constructing a physical regularization loss function, comparing a physically calculated Jacobi matrix with a neural network predicted Jacobi matrix, and combining a final total loss function with data error loss and physical consistency loss. According to the method, data driving model training is guided through physical constraints, combination of physical information and deep learning is achieved, the precision of electrical impedance reconstruction and the generalization ability of the model are remarkably improved, and a new solution thought is provided for the fields of medicine, flexible electronics, environment monitoring and the like.

The invention provides a converter station valve cooling system water abandoning strategy optimization model and method. According to the method, the scaling index and the corrosion rate are calculated in real time by collecting the conductivity, the pH value, the temperature and the flow data of the circulating cooling water, so that the system is monitored in real time. And a multi-objective intelligent optimization control method is designed by defining optimization objectives and constraints and establishing a dynamic performance index model. According to the method, a plurality of conflict targets in the wastewater treatment process can be balanced, for example, the water abandoning amount is reduced, the energy consumption is reduced to improve the cooling effect, so that intelligent optimization of the water abandoning strategy of the converter station valve cooling system is realized, the environmental protection performance is improved, the operation state of the converter station is optimized, and fine management and optimization of the water abandoning strategy are realized. The method is simple and easy to operate and has high practical value.

The invention relates to the technical field of soil physical parameter in-situ measurement, and discloses a soil layer natural water content portable intelligent measuring instrument based on multi-source sensing fusion, which comprises a composite probe assembly and an intelligent measurement and control host which are physically connected, the composite probe assembly is configured to be inserted into a soil layer to be tested to construct a multi-physical field test environment, and an electrical transceiving unit and an acoustic transceiving unit are integrated in the composite probe assembly. By constructing a cross physical field excitation and multiphase parameter collaborative decoupling mechanism, a multidimensional dynamic correlation model is established by using the thermosensitive drift characteristic of the sound velocity of a mixed medium during thermal disturbance and the transient step response of a dielectric constant under an acoustic radiation force field; the problems that the coupling influence of the water content and the volume weight cannot be distinguished and the conductivity of bound water and the conductivity of free water are difficult to separate in a traditional means are effectively solved, and four independent physical quantities including the volumetric water content, the in-situ dry volume weight, the bound water content and the actual conductivity of pore water are synchronously inverted through a single probe. And the decoupling precision of the equipment on complex multi-phase soil medium parameters is improved.

Provided herein are apparatuses and methods of releasing or converting a gas. In some embodiments, an apparatus may include a gas flow cell having an inlet and an outlet for flowing a gas through said gas flow cell; a structured material within said gas flow cell, wherein the structured material has an electrical conductivity selected from the range of 3×10−15 S / m to 6.3×107 S / m; and a plasma source integrated with said gas flow cell, the plasma source being configured to generate a plasma within a portion of the gas flow cell, the plasma source comprising: a first electrode and a second electrode within said gas flow cell; and a power source configured to provide voltage to the first and second electrodes.

The invention discloses a cable material diameter detection method based on an eddy current impedance effect, and particularly relates to the field of cable nondestructive testing, which comprises the following steps: S1, synchronously acquiring the resistance and inductance of a coil under a low-frequency signal and the resistance and inductance of the coil under a high-frequency signal by adopting a double-frequency excitation eddy current sensor; the environment temperature and the lift-off distance between the sensor and the cable are measured; s2, denoising is carried out through a combinatorial algorithm, and temperature compensation is carried out on the resistance and inductance of a sensor coil and the conductivity of a cable core wire; s3, calculating a material sensitive factor under low frequency, calculating a line diameter sensitive factor under high frequency, and correcting when the lift-off distance deviates; s4, calculating a material deviation rate to judge the material, fitting a linear regression model, and combining with conductivity to correct the skin depth to calculate the line diameter; and S5, according to the material and the wire diameter, comprehensively determining progressive output, and triggering a corresponding alarm in case of abnormality. The problems of parameter coupling and incomplete temperature compensation are solved, and the detection precision and the environmental adaptability are improved.

The invention provides an EIT lung three-dimensional reconstruction method using a fractional diffusion model, and the method comprises the steps: enabling an EIT lung three-dimensional reconstruction problem to be linearized into a linear uncomfortable problem A [delta] x = [delta] y, enabling A to be a sensitivity matrix, [delta] y to be a boundary voltage change value of a detected field domain, and [delta] x to be a conductivity distribution change value in the detected field domain, which are called as a solution vector, a target solution is obtained by solving an optimization problem F (x) = min (A [delta] x-[delta] y2), prior distribution of conductivity real distribution x is learned by using a fraction-based diffusion model, and a reconstruction result is constrained by using a voltage measurement value in a diffusion model sampling stage: a disturbance voltage value yt of the voltage measurement value y at a corresponding moment t is obtained, and by minimizing the distance between the reconstruction target x and the reconstruction image xt under the time step t and minimizing the difference value between the A delta x and the disturbance voltage variation delta yt, obtaining a reconstruction result # imgabs0 # constrained by a voltage value at the moment t, and performing loop iteration until t is equal to 0 to obtain a final EIT lung three-dimensional reconstruction image.

The invention discloses a high-flexibility anti-interference fire-resistant cable for a robot and a preparation method thereof, and belongs to the technical field of wires and cables, the cable comprises an insulating wire core, the insulating wire core comprises a conductor, a shielding layer and an insulating layer, the conductor is formed by layering and twisting a plurality of anaerobic copper wires, tensile fibers are arranged in the middle of the conductor, the shielding layer is overlapped and lapped on the surface of the conductor, and the insulating layer is arranged in the shielding layer. A plurality of insulating wire cores and a filling layer are twisted into a cable, a composite belt is arranged on the outer side of the filling layer, the composite belt is made of glass fiber-aerogel, the overlapping rate is 15%-25%, and an inner shielding layer and an outer shielding layer are arranged on the outer side of the composite belt. And the outer side of the outer shielding layer is coated with a sheath layer. According to the invention, the composite belt can form a high-efficiency heat insulation layer in a fire hazard, and heat transfer to the wire core can be obviously delayed. The conductor is formed by stranding a plurality of oxygen-free copper wires in a layered manner, annealing is performed after stranding, and the aramid yarn is embedded in the conductor, so that the tensile stress to the metal conductor can be reduced, and the diameter of the conductor and the outer diameter of the whole cable are reduced while the conductivity and the transmission capability are maintained.

A current sensor may include: at least one magnetoelectric conversion unit; a current conductor through which a measurement current measured by the magnetoelectric conversion unit flows; and a conductor plate which at least partially overlaps the current conductor in plan view. A main body portion of the current conductor includes a first portion. A thickness of the conductor plate, magnetic permeabilities of the conductor plate and the current conductor, electrical conductivities of the conductor plate and the current conductor, a shortest distance between a magnetic sensing surface and the current conductor, a maximum width of the first portion, a shorter distance of a distance between the conductor plate and the current conductor and a distance between the conductor plate and the magnetic sensing surface of the magnetoelectric conversion unit, and a narrowest width in a portion, which crosses the magnetoelectric conversion unit, of the conductor plate satisfy a condition.

Examples include a functionalized compressible nonwoven material (CNM) cushion with a three-dimensional (3D) pressure-varying electrical conductance (PVEC) region. Integrated with the PVEC surface area is a conductive ink printed on thermoplastic film (CPT) single-sided conductance measurement coupling. The CPT single-sided conductance measurement coupling includes, on the thermoplastic film, N pairs of contact pads and N pairs of pad connection traces. The N pairs of contact pads are maintained, by thermoplastic adhesion, in direct electrical contact with the PVEC surface areas. The N pairs of connection traces extend from the N pairs of contact pads to trace terminals. A conductance measuring circuit selectively applies, via the N pairs of connection traces, voltage and a path to ground to the pairs of contact pads, and measures the resulting current.

The invention relates to the technical field of strip steel pickling, and discloses a method for reducing the use amount of rinsing water in a continuous strip steel pickling process section, a multi-stage rinsing process is adopted, a conductivity detector is arranged in a last-stage rinsing tank to detect the conductivity in real time, and the running state of a unit is interlocked with a rinsing water pump. Spraying and water replenishing are automatically started based on the running state of the unit, the minimum water replenishing amount is set based on the running speed of the unit, water replenishing is conducted with the minimum water replenishing amount in the running period, and when the conductivity detection value exceeds the conductivity threshold value, the maximum water replenishing amount is adjusted for rapid water replenishing. The invention further provides a system for implementing the method. By means of the method, on the premise that the strip steel rinsing quality is guaranteed, the rinsing water consumption can be greatly reduced, the average rinsing water consumption before improvement is 10.0 m < 3 > / h, the average rinsing water consumption after improvement is 5.0 m < 3 > / h, the production cost of a pickling unit is reduced, and therefore the benefits of enterprises are improved.

The invention relates to the field of grounding technology and electrical measurement, and discloses a grounding electrode current diffusion characteristic and environment correlation analysis method, which comprises the following steps: acquiring a ground electricity state vector representing soil electrochemical characteristics; constructing and calibrating a state phase space evolution model for describing time-space evolution of the vector; an adaptive dynamic analysis closed loop is executed, a state vector at the next moment and uncertainty are predicted through the model, an adaptive sensing protocol is generated based on the uncertainty to guide new data collection, a prediction result is corrected through new data, and a corrected state vector is obtained; and finally, based on the continuous corrected state vector, analyzing the causal association between the environment and the state, reconstructing three-dimensional complex conductivity distribution, and determining current diffusion characteristics such as grounding impedance through numerical calculation. According to the method, the limitation of static evaluation in the prior art is solved, and the dynamic prediction of the performance of the grounding system and the physical tracing of the abnormal cause are realized.

The invention discloses a dam anti-seepage body integrity detection method based on an artificial power supply. Comprising the following steps: injecting a broadband excitation current signal into a dam anti-seepage body through a multi-frequency program control constant current source; a modular distributed electrode array is adopted to collect and obtain voltage data of the surface of the dam anti-seepage body in real time; high signal-to-noise ratio voltage data is obtained by adopting filtering processing and a digital phase-locked amplification technology; carrying out three-dimensional inversion calculation by adopting an improved electrical impedance tomography algorithm, and reconstructing an internal conductivity distribution image of the dam anti-seepage body; analyzing, identifying and positioning defects through a deep learning model; and constructing an electro-seepage coupling inversion model, converting the internal conductivity distribution image based on the dam anti-seepage body into permeability coefficient distribution, and generating an integrity evaluation report of the dam anti-seepage body. Compared with a traditional detection method, the method is high in detection precision, wide in application range and high in detection efficiency, and a brand new technical means is provided for evaluating the health state of the dam seepage-proofing body.

The invention discloses a quench characterization method and device for multi-field coupling of a high-temperature superconducting coating conductor and a medium, and relates to the technical field of superconducting strips. The method comprises the following steps: establishing a force-electricity-heat multi-physics field coupling model; the force-electricity-heat multi-physics field coupling model comprises an electricity module, a mechanical module and a thermal module; in the electrical module and the thermal module, the material conductivity is a function of temperature, and Joule heat causes temperature change, so that electric-thermal bidirectional coupling is realized; in the thermal module and the mechanical module, temperature change enables the strip to generate thermal strain, a strain item exists in a non-classical Fourier heat conduction equation based on the generalized thermoelasticity principle, and force-heat bidirectional coupling is achieved. According to the method, a mixed dimension model is adopted, a superconducting layer is modeled into a two-dimensional plane, a silver layer and a buffer layer are geometrically ignored, interlayer contact resistance and thermal resistance are added through weak contribution, and the quench process of multi-field coupling of the high-temperature superconducting coating conductor is successfully simulated.

This invention relates to the field of machine learning technology, and particularly to a machine learning control method for LIG laser-induced high thermal conductivity and high electrical conductivity performance. The method includes calculating the contribution weights of processing parameters to dual performance characteristics, identifying key dominant and auxiliary parameters, and generating a training dataset for both performance characteristics. Two machine learning models are trained separately to obtain initial core hyperparameters for the two prediction models, and then the core hyperparameters are tuned. The two prediction models process candidate datasets respectively, outputting thermal conductivity and electrical conductivity prediction sets, and a comprehensive evaluation is performed to obtain recommended laser processing parameters. The contribution weights of key related laser processing parameters are updated based on a comparison between the target dual performance characteristics and the measured dual performance characteristics. The recommended laser processing parameters are then trained and updated again. By training the dual performance relationship model using the contribution weights of processing parameters and optimizing hyperparameters from multiple aspects, global collaborative optimization is achieved, enabling rapid and accurate prediction of the dual performance characteristics of LIG thermal conductivity and electrical conductivity.

The invention relates to the technical field of grounding grid fault diagnosis, and provides a grounding grid fault diagnosis method, which comprises the following steps: S1, building a corrosion fault diagnosis model according to an electric network theory method, iteratively solving the corrosion fault diagnosis model by adopting a seasonal optimization algorithm SOA, obtaining resistance change multiplied speed of each branch in a grounding grid, and determining a corroded branch or region; s2, based on the determined corroded branch circuit or region, injecting current through a grounding down lead of the power equipment, performing finite element analysis on the corroded branch circuit or region by utilizing an electrical impedance tomography (EIT) technology, and reversely deducing conductivity distribution to generate a two-dimensional chromatographic image; and S3, based on the resistance change multiplied speed of each branch and the generated two-dimensional chromatographic image, determining the specific position and corrosion degree of the corrosion fault of the grounding grid in the soil environment through a preset threshold value and a chromatographic gradient. The method aims to make full use of the advantages of respective technologies and make up for the defects of the technologies, so that the high efficiency and accuracy of grounding grid corrosion fault detection are realized.

The utility model relates to a device for preparing sodium hypochlorite by electrolyzing seawater and supporting polarity reversal. The sodium hypochlorite electrolytic bath is electrically connected with a polarity variable electrolysis power supply, the polarity variable electrolysis power supply comprises a rectifying circuit, the rectifying circuit is connected to alternating current mains supply, the rectifying circuit is connected with an inverter and provides direct current input for the inverter, the direct current input is converted into controllable alternating current through the inverter, and the controllable alternating current is connected with the polarity variable electrolysis power supply. The inverter is connected with two polarity-variable cascade direct current generation circuits, the output polarities of the polarity-variable cascade direct current generation circuits are opposite, the polarity-variable cascade direct current generation circuits are electrically connected with a controller, the controller is electrically connected with a second conductivity sensor arranged on the sodium hypochlorite electrolytic cell, and the controller collects the output voltage of a polarity-variable electrolytic power supply. And the controller is electrically connected with the electrolytic current sensor. Deposition condition detection is supported, and through polarity conversion, sediments such as calcium hydroxide and magnesium hydroxide on the original cathode act with hydrogen ions to generate water and corresponding cations, so that the sediments are eliminated.

This invention discloses a method for predicting the dynamic conductivity of biological tissues considering the pulse dispersion effect. The method includes: constructing a two-dimensional dual-needle electrode geometric finite element model, setting boundary conditions and initial treatment parameters; introducing a Debye function into the finite element model to characterize the change of tissue dielectric constant with frequency; performing frequency domain analysis on the applied pulse signal and converting the Debye function from the frequency domain to the time domain, allowing the polarization vector to couple with the electric field to participate in transient solutions, thereby obtaining a voltage and current dataset including the effect of pulse dispersion; constructing a tissue dynamic conductivity prediction model and training the prediction model using the voltage and current dataset; inputting the voltage and current response data of the tissue to be determined into the trained model to obtain the tissue dynamic conductivity prediction result. This invention can improve the consistency between the finite element current calculation results and the actual tissue electrical response, and improve the accuracy of tissue dynamic conductivity prediction. It is applicable to dynamic conductivity prediction in electroporation therapy, providing a reference for electroporation therapy.

Methods include functionalizing, into a compressible pressure varying electrical conductance device, a portion of a compressible nonwoven material (CNM) cushion. A process includes forming within a three-dimensional (3D) target region of the CNM cushion a columnar distribution of non-solidified conductive polymer, and converting the columnar distribution of non-solidified conductive polymer into a columnar compressible pressure varying electrical conductance structure. The columnar distribution of non-solidified conductive polymer extends along a column axis. Forming the columnar distribution includes injecting into at least a portion of the 3D target region a liquid carrying conductive polymer in suspension. The columnar compressible pressure varying electrical conductance structure includes mutually separated masses of solidified conductive polymer respectively supported by mutually separated flexible fibers of the compressible nonwoven material. Optionally, forming the columnar distribution of non-solidified conductive polymer includes a first injection followed by partial drying, and a second injection.

This invention belongs to the field of plant seedling technology, specifically relating to a method for improving the survival rate of Forsythia suspensa cuttings. Specifically, fruiting mother trees are selected, and semi-lignified branches of the current year are collected as cuttings, retaining plump buds. The cuttings are soaked in a rooting agent compound solution and then dried for later use. The treated cuttings are then inserted into a gradient substrate and thoroughly watered after planting. The stomatal conductance of the cutting leaves and the electrical conductivity at the base of the cuttings are monitored in real time. The substrate temperature, spraying frequency, shading rate, and ventilation are adaptively adjusted in a closed-loop manner according to the physiological thresholds of different rooting stages of Forsythia suspensa cuttings. Stress-resistant fertilizer is applied according to the physiological state of the cuttings, and disease control and daily management are carried out. This method improves the survival rate of Forsythia suspensa cuttings, reduces the rate of cutting rot, exhibits strong environmental adaptability, and high seedling stability.

The invention relates to the technical field of high-voltage direct-current cables, in particular to a load circulation system of a high-voltage direct-current cable system and an operation method, and the system comprises a temperature circulation module which comprises a PID temperature control unit and a conductor heating unit, and the conductor heating unit is electrically connected with the PID temperature control unit; the multi-polarity voltage loading unit is provided with a high-voltage source, and the high-voltage source can output voltage from the negative polarity to the positive polarity; and the distributed electric field sensor is embedded at the interface of the cable accessory stress cone and the insulation, and the distributed electric field sensor is in contact with the surface of the cable accessory stress cone. The method has the beneficial effects that the tangential electric field distribution at the cable accessory stress cone and the insulation interface is monitored in real time through the distributed electric field sensor, and the maximum electric field intensity is reduced in combination with the low ripple design of the multi-polarity voltage loading unit and the design of the interface conductivity matching layer, so that the electric field distortion and the surface discharge risk are effectively inhibited, and the reliability of the cable accessory is improved. And the operation stability of the high-voltage direct-current cable system under complex working conditions is improved.

A system and method of analyzing a micro-volume sample using two measurements of the sample's electrical conductivity to measure the sample's temperature is described herein. The system includes a first surface, a second surface, and an electronic processing unit. The second surface is positioned opposite the first surface for holding the sample between the first surface and the second surface by surface tension. The electronic processing unit is configured to apply at least one electrical signal across the sample via a first electrode and a second electrode, determine a first electrical conductivity of the sample at a first frequency associated with the at least one electrical signal and a second electrical conductivity of the sample at a second frequency associated with the at least one electrical signal based on the at least one electrical signal applied across the sample, and determine a temperature of the sample based on the first electrical conductivity and the second electrical conductivity.

An electrically drivable motor for use in an aircraft, the motor comprises a motor coil 110 with coil windings; elongate thermally conductive members 120 arranged to thermally communicate with the coil windings; and a thermally conductive portion arranged to thermally communicate with the elongate thermally conductive members. A portion of the elongate thermally conductive members abuts a portion of the coil windings. Each of the elongate thermally conductive members has an in use thermal conductivity of at least 100 Wm-1K-1 and an electrical conductivity of less than 10-14 Sm-l. This could be for example a sapphire, diamond, aluminum nitride, alumina or beryllium oxide. The elongate thermally conductive members may be connected to the coil windings via laser ablation or a sol-gel process. The thermally conductive members may be in the form of plates or cables. The elongate thermally conductive members may be interleaved with the coil windings. The motor may be used in an aircraft propulsion system which uses cryogen for energy generation as well as for providing heat exchange to the thermally conductive portion or elongate thermally conductive members, aiding cooling of the windings.

The invention provides an oxidation stability evaluation method, detection equipment and a detection method for agent-free transformer oil, and belongs to the technical field of power grid power transmission and transformation. According to the method, copper wires are added into the agent-free transformer oil, air is introduced into the agent-free transformer oil at a preset experimental temperature in a preset experimental period, oxidation of the agent-free transformer oil is accelerated, and the conductivity value of volatile acid in the oil oxidation process is continuously monitored; and evaluating the oxidation stability of the transformer oil without the additive according to the conductivity value of the volatile acid in the preset experimental period. According to the method, the oxidation stability evaluation efficiency of the agent-free transformer oil is improved, the working intensity and technical requirements of operators are reduced, and the cost is reduced.