Linear Resistance Research Articles

METHOD OF INCREASING EFFICIENCY, MEAN OF CONTROL AND TOOL OF ANALYSIS OF THE USE ENERGY OF POWER SOURCE PULSE LASER RANGE FINDER

The latest results of a series researches of the revealed paradox of energy balance disturb and its manifestations in electrical circuits are presented in order to increase the efficiency of the conversion of energy voltage direct current into pulsed energy of other forms, on the example of improving the use energy of the power source of pulsed solid-state laser range finder. It is show, that the efficiency of simultaneous conversion in a load with active linear or nonlinear resistance of the energy, which accumulated in the inductive and capacitive storage, can reach the efficiency of its accumulation. For this the first time offered the aperiodic mode of the transient process in the oscillating circuit use to combined the dual properties of inductive and capacitive energy storages and method of automatically switching their parallel connection during accumulation by them energy in series connection during conversion accumulated energy, particular, into optical pulses in the range finder. In total, proposed method of converting energy voltage direct current into pulsed energy of other forms, mean of objective control and tool of modeling and analyzing the use of energy primary power sources make up a set of measures for increasing energy efficiency separate nodes mobile devices of telecommunications, automation and robotics, what is especially actual in the existing conditions limited energy resources.

Some remarks on projectile motion with a linear resistance force

In this article, we revisit projectile motion assuming a retarding force proportional to the velocity, . We obtain an analytical expression for the set of maxima of the trajectories, in Cartesian coordinates, without using the Lambert W function. Also, we investigate the effect of parameter k on the radial distance of the projectile showing that the radial distance oscillates from a certain critical launch angle and find an approximate expression for it. In our analysis, we consider the impact of parameter k in the kinetic energy, the potential energy, the total energy, the rate of energy loss, and the phase space. Our results can be included in an intermediate-level classical mechanics course.

Performance analysis of nonlinear piezoelectric energy harvesting system under bidirectional excitations

In this paper, a cantilever beam piezoelectric energy harvester model of nonlinear partial differential equation based on Hamilton's Principle is established. A piezoelectric device using a bimorph cantilever beam with a fixed is subjected to horizontal and vertical excitation. Based on the Euler-Bernoulli thin beam model assumptions and inextensible deformation, the analysis further includes the effects of geometric nonlinearity and damping nonlinearity. The reduced-order nonlinear partial differential equations of motion with electro-mechanical coupling distributed parameter are derived by using Galerkin method. By using the method of multiple scales and solving the equations of motion, the energy harvester in its fundamental first-order resonance response is analyzed and the amplitudes of fundamental transverse deflection, output voltage and output power are determined. The major influence aspects of excitation amplitude, linear damping coefficient, nonlinear damping coefficient, impedance, nonlinear electro-mechanical coupling coefficient on transverse deflection, voltage and power are analyzed. The result shows that the linear damping coefficient and resistance affect the initial threshold of parametric excitation. The combination of parametric excitation and direct excitation gives full play to the advantages of parametric excitation and improve the energy conversion efficiency of the energy harvesting system.

Influence of yarn geometry on electrical properties of silver-coated nylon filaments for e-textiles: a fundamental study

Conductive fibrous assemblies and yarns play a crucial role in wearable electronic textiles (e-textiles), through their use in flexible sensors and interconnects. This study investigated the influence of yarn twist and geometrical parameters on the electrical properties of silver-coated nylon multifilament yarns, ranging from 1-ply to 4-ply, with twist levels of 30 twists per meter (TPM) and up to 600 TPM. Increase in twist level resulted in decreasing yarn linear resistance, with a plateau at 300 TPM, along with limiting values for yarn specific volume (1.6-1.9 cc/g), and fibre orientation angle (12-18°). The increase in yarn conductivity with higher twist was explained by greater contact between the fibrous assembly, that bridges electrically conductive pathways in the yarn structure. Twisted yarns (2-ply) were fabricated into electrode structures via embroidery, and a progressive increase in contact impedance was observed, followed by a stabilization and plateau within the range of measured impedance from 210 to 300 TPM. This observation was attributed to the decrease in the yarn specific volume, and subsequently the longitudinal diameter with increasing twist level, which decreased the contact area between the skin and electrode interface. The electrodes fabricated from varying yarn twist levels were used for electrocardiogram (ECG) measurement, and demonstrated comparable signal quality to standard gel electrodes. This experimental and theoretical work forms the basis in defining relationships between established yarn twist mechanics and geometrical properties with electrical properties. This can guide materials and design parameter selection of suitable conductive yarns for e-textiles used in biopotential monitoring applications.

Programmable hardening and softening cubic inductive shunts for piezoelectric structures: Harmonic balance analysis and experiments

It has been well explored in the literature that intentionally introduced (designed) nonlinearities offer significant advantages in vibration absorption and isolation problems. In the context of using piezoelectric shunt damping for vibration attenuation in flexible structures, synthetic impedance circuits with digital control enable precise tuning capabilities and eliminate the need for bulky analog circuit components when targeting low frequencies, and they have been studied mostly for linear circuits. In this work, we explore nonlinear synthetic impedance-based Duffing shunts with hardening and softening nonlinearities, connected to a cantilever under base excitation in its geometrically and materially linear regime. We demonstrate a shunt of nonlinear impedance equivalent to a positive or negative cubic inductor connected in parallel to a linear inductor and a linear resistor. This shunt, along with the inherent piezoelectric capacitance, provides digital analog of a hardening- or softening-type nonlinear stiffness, linear stiffness, linear damping, and mass, as a synthetic Duffing circuit. Electromechanical modeling of a piezoelectric cantilevered beam shunted to the Duffing oscillator with hardening or softening inductance is performed. Numerical simulations for single-term and multi-term harmonic balance solutions are performed for periodic response. These approximate analytical predictions are compared against time-domain numerical simulations and are experimentally validated for various mechanical excitation amplitudes and nonlinear coefficients. Overall, a very good agreement is obtained between the model simulations and experimental results, in addition to demonstrating the unique digital programming capabilities of this nonlinear shunt.

Catechyl lignin-reinforced mechanical performances of Poly(vinyl alcohol)-Based materials

Catechyl lignin, a unique naturally occurring biopolymer is hailed as an “idea lignin” archetype owing to its homogeneity, linearity, and acid resistance. In this study, we discover that the precipitation-induced C-lignin nanoparticles (NPs) display a crystallite structure with clear lattice spacings which has never been observed in conventional G/S-lignin NPs. Compositing C-lignin with poly (vinyl alcohol) (PVA) through casting-drying, freezing-thawing, and freezing-salting methods, results in a dazzling array of PVA-based films, soft hydrogels, and rigid hydrogels, respectively. Such compositing processes not only improve the mechanical properties by 2–6 times, but also make the resultant materials UV-blocking, fluorescence, thermostability, and water-resistance properties. This work introduces a novel sustainable building block for the fabrication of strong polymeric materials and discovers a new route for the valorization of waste biomass.

Modeling of Linear-Nonlinear Behavior in Electrical Contacts With Interaction Interference

The reliability of electrical contacts is important to the quality of signal transmission. In this letter, an equivalent circuit model is proposed to illustrate the linear-nonlinear interaction effect in coaxial connectors. The linear region is simplified to a cascade system composed of impedance matching and impedance mismatch networks, while the nonlinear region is equivalent to a contact impedance network coupling a module defined by nonlinear I-V relation. By tuning values of each component in the presented circuit, the effect of linear and nonlinear elements on scattering characteristics and passive intermodulation (PIM) are observed. The S-parameters are sensitive to linear network with equivalent inductance and capacitance, but the PIM behavior is affected by both nonlinear resistance and linear resistance which are temperature and frequency dependent. Connectors with designed contact resistance are tested separately in different frequency band and environmental temperature, verifying the proposed model in predicting scattering performance and PIM behavior.

Characterisation of SiC Varistor Quench Protection Operating at 4 Kelvin for Use With Superconducting Magnets

Silicon carbide (SiC) composite high-energy varistors have been demonstrated as a viable alternative to linear resistors as energy extraction devices during an abrupt loss of superconductivity in a magnet, called a quench. These have typically been installed external to the cryostat at ambient temperatures, but for some superconducting magnets it may be beneficial to mount the varistors within the cryostat in vacuum, a gaseous environment, or submerged in liquid cryogens. Varistors are semiconductors and therefore exhibit a temperature-dependent voltage–current relationship, so characterising their behaviour at low temperatures is important to predict their energy extraction behaviour. <p xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">In this paper we present characterisation data of SiC varistor devices from 4–300 K: voltage-current characteristics, thermal conductivity, specific heat capacity, thermal expansion, and flexural strength. These varistors are a candidate for protection at 1.9 K of the MCBY magnets, currently being built at Uppsala University for CERN.

Improving electric-energy transmission performance of LixNi1-xO linear ceramic resistors by Li+/Ni3+ ion occupation regulation for pulsed power technology

Linear ceramic resistor receives extensive attention for its great advantages of fast energy transmission in pulsed power technology. However, the research about improving the linear current-voltage characteristics and pulsed charge-discharge speed of LixNi1-xO solid solution is rarely reported. Herein, we fabricated the LixNi1-xO linear ceramic resistors through a solid-phase reaction method, and the effects of the Li+ ion on the microstructure, current-voltage characteristics and pulsed charge-discharge properties were studied. Specifically, the electron holes exchange between divalent and trivalent nickel ions is enhanced by Li substitution, which contributed to the significantly decreasing in nonlinear coefficient (α) and resistivity. On a separate note, the rising edge of pulse charge-discharge is influenced by the linearity of LixNi1-xO ceramic resistors. The closer the nonlinear coefficient is to 1, the shorter the pulsed charge-discharge time is. Meanwhile, the defect dipoles induced by Li substitution may also contribute to the reduction of discharge time of LixNi1-xO linear ceramic resistors. As a result, the Li0.03Ni0.97O linear ceramic resistor with an excellent nonlinear coefficient of 1.03 exhibits extraordinary fast discharge speed (t0.9 = 94.8 ns) at 1.0 kV. The investigation on LixNi1-xO linear ceramic resistors suggests the potential of this material to be applied in the pulsed power system.

Effect of carbon fiber and thermoplastic resin on laminates under lightning and dielectric strength tests

AbstractThe incorporation of carbon fiber (CF) and thermoplastic resin in wind turbine rotor‐blade represents a challenge for lightning events because CF conducts electricity and the behavior of thermoplastic resins is not well known. A comparative study with laminates with epoxy or thermoplastic resins was performed, using lightning and dielectric strength tests. Lightning tests revealed that resins behaved similarly; the current preferentially flowed in fiber direction and in zones with high contact between fibers (e.g., criss‐crossed fibers at panel edges); the level of through‐thickness damage was inversely related to panel thickness; current flow did not affect the tensile properties in fiber direction, but produced a drop in bending strength; the adequate integration of earth terminals in CF laminates was critical for a proper lightning discharge. In dielectric tests, it was concluded that panels with glass fiber covering CF laminates behaved as through‐thickness insulators; the thermoplastic reduced the laminate's dielectric strength, while the incorporation of CF, or laminate aging in a salt spray chamber showed no difference. Electrical resistance tests showed that the results were not dependent on the type of resin, but on the level of fiber‐to‐fiber and fiber‐to‐terminal contact. The lowest linear resistance was obtained in the longitudinal fiber direction, followed by the transverse and through‐thickness ones.

Power efficient ReLU design for neuromorphic computing using spin Hall effect

We demonstrate that a magnetic tunnel junction injected with a spin Hall current can exhibit linear rotation of the magnetization of the free-ferromagnet using only the spin current. Using the linear resistance change of the magnetic tunnel junction (MTJ), we devise a circuit for the rectified linear activation (ReLU) function of the artificial neuron. We explore the role of different spin Hall effect (SHE) heavy metal (HM) layers on the power consumption of the ReLU circuit. We benchmark the power consumption of the ReLU circuit with different SHE layers by defining a new parameter called the spin Hall power factor. It combines the spin Hall angle, resistivity, and thickness of the HM layer, which translates to the power consumption of the different SHE layers during spin-orbit switching/rotation of the free FM. We employ a hybrid spintronics-CMOS simulation framework that couples Keldysh non-equilibrium Green’s function formalism with Landau–Lifshitz–Gilbert–Slonzewski equations and the HSPICE circuit simulator to account for the diverse physics of spin-transport and the CMOS elements in our proposed ReLU design. We also demonstrate the robustness of the proposed ReLU circuit against thermal noise and a non-trivial power-error trade-off that enables the use of an unstable free-ferromagnet for energy-efficient design. Using the proposed circuit, we evaluate the performance of the convolutional neural network for MNIST datasets and demonstrate comparable classification accuracies to the ideal ReLU with an energy consumption of 75 pJ per sample.

Integrated and Robust Fabry–Perot Humidity Sensor Based on Metal–Organic Framework onto Fiber-Optic Facet

An integrated and robust fiber-optic Fabry-Perot (FP) humidity sensor based on the Metal-Organic Framework (MOF) material FIR-53 is presented and characterized for the first time, along with its implementation method. Noticeably, the FIR-53 crystal was chosen as the moisture-sensitive material, due to its large porosity and chemical tailorability. By connecting the single-mode fiber (SMF) with FIR-53 using Polydimethylsiloxane (PDMS) rationally, our sensor, whose FP cavity was formed by FIR-53, monitors the spectrum peak shift caused by humidity change. The experiments revealed that the proposed sensor had a sensitivity of 315 pm/ %RH in the range of 10% to 90% RH, while also the good linearity, reversibility, long-time stability, and anti-high temperature interference resistance. To summarize, the proposed sensor has the advantages of easy fabrication, low cost, and is highly sensitive to humidity, which is going to have significant potential in the field of humidity sensing and promote the research and application of new fiber-optic sensors for humidity.

Effect of Sc2O3 doping on the microstructure and electrical characteristics of ZnO linear resistors

Herein, to improve the electrical characteristics, ZnO linear resistors mixed with MgO, TiO2, Al2O3, and various concentrations of Sc2O3 (with 0, 0.35, 0.7, and 1.05 wt %) were obtained using the conventional solid-state sintering technique, while the influences of Sc2O3 doping on the micro-morphology and electrical characteristics was investigated in detail. The crystalline phases and microstructure were investigated by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The dielectric properties and electrical characteristics were evaluated using a precision inductance-capacitance-resistance meter and a high-voltage source meter. Results from SEM micrographs, XRD patterns, and EDS mappings illustrated that the doping of Sc2O3 hinders the growth of ZnO grains. Electric field-current density and resistivity-frequency measurements illustrated that the doping of Sc2O3 improves the linear performance of ZnO linear resistors and increases its grain resistivity and grain boundary resistivity. With Sc2O3 doping, the dielectric properties of the samples are significantly affected, while the resistance-temperature features reveal the negative temperature constant function. By appropriate Sc2O3 doping, the ZnO linear resistors exhibited excellent performance with grain boundary barrier height φb of 0.0106 eV, nonlinear coefficient α of 1.03, and resistance temperature constant αT of −2.88 × 10−3. It is beneficial to investigate the influence of Sc2O3 doping on the micro-morphology and electrical performances in detail for the preparation of zinc oxide linear resistors with superior performance.

Precise Modeling of Nonlinear Rectifier Loads in Wireless Power Transfer Systems

The load of the receiver coil in a wireless power transfer system can be considered as a sub-circuit, typically comprising a diode rectifier, a filter capacitor, and an equivalent resistor <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> . Such sub-circuit is nonlinear but is usually represented as an equivalent linear resistor model 8 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> /π <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> based on the fundamental approximation of Fourier Analysis. Such simplified approach is inaccurate particularly when the receiver current is distorted. This paper presents two novel models for the nonlinear rectifier load with full consideration of harmonics and parasitic components of the rectifier. One intermediate model is applicable for systems with continuous rectifier currents, while an advanced model is valid for systems with both continuous and discontinuous rectifier currents. The advanced model is proved to be accurate for any load conditions, including extreme-light load conditions with highly distorted receiver currents. It can be reduced to the intermediate model if the rectifier currents are continuous. The intermediate model can in turn be simplified to the classic linear model if harmonics are ignored. Both simulation and experimental results have verified the accuracies of the proposed models over the conventional linear resistor model for a wider range of load conditions.

Impedance models for single and two degree of freedom linings with an improved data base and local non-linearity

Previously developed predictive models for impedance of single-degree-of-freedom and two-degree-of-freedom acoustic linings driven by a broad band acoustic source are reexamined. Two issues are addressed, the first being improvement of the conventional perforate face sheet impedance model. Data correlations based on flow bench measurements of steady flow pressure drop are reevaluated with emphasis on low flow velocity to improve the consistency of the prediction of linear resistance. In addition, for two-degree-of-freedom linings, face sheet mass reactance is modified to account for the presence of the septum. The second issue addresses the implication that for a non-linear lining, with impedance a function of the local sound pressure level, the installed performance of the lining depends on the local impedance, as opposed to impedance based on the source sound pressure level. This is investigated in the benchmarking of the impedance models by comparison of the acoustic transfer function predicted by a propagation code with the imbedded impedance model and transfer function measurements made in a grazing flow duct test facility. The propagation code is extended to make the non-linear behavior of the lining model dependent on the local acoustic spectrum, introducing an additional level of non-linearity and an iterative application of the propagation code. A principal conclusion is that with no grazing flow both the lining model and grazing flow duct transfer function measurements show a significant effect of local variation of the acoustic spectrum. With increasing grazing flow Mach number, this effect is reduced and effectively disappears at the highest Mach number. With increasing grazing flow Mach number the grazing flow contribution to face sheet resistance dominates and tends to mask the non-linear behavior of the component of resistance not related to grazing flow.

Load model and parameter measurement method of DBD for power supply design

Plasma is widely used in sterilization and disinfection, environmental treatment, and material surface modification. At present, the DBD load equivalent circuit model used in the design of dielectric barrier discharge (DBD) low-temperature plasma generator power supply mainly includes the nonlinear clamping model and linear resistance capacitance model, which have advantages and disadvantages in the research and application of DBD load. This paper focuses on the modeling and parameter acquisition method of the RC parallel DBD load linear model, adds measurement capacitance to the discharge load loop, and obtains RC parallel equivalent model parameters by Q-V and I-V Lissajous-Figure analysis. After the experimental data is processed, the simulation circuit model is built by MATLAB/SIMULINK, and the experimental results are compared with the simulation calculation results. They verify the feasibility of the DBD load parameter measurement scheme and comprehensively demonstrate that the DBD load linear resistance capacitance model has important guiding significance in the design of the DBD power supply.

Comparing the effects of two resistance training models with Linear and Non- Linear Periodization on muscle strength, fatigue, and quality of life among women with multiple sclerosis

Background: Multiple sclerosis disease (MS) is progressing, especially in women. The present study aimed to determine the effect of eight weeks of resistance training with two types of linear and nonlinear periodized on muscle strength, fatigue, and quality of life in women with MS. Materials and Methods: A total of 19 patients with MS were selected and randomly assigned to three groups: nonlinear periodized (NLP) (n=6), linear periodized (LP) (n=5), and control (n=8). Both exercise groups performed resistance exercises three sessions a week for 30-45 minutes per session, with an intensity of 30%-70% of a maximum repetition for eight weeks. The linear group (LP) used a linear loading pattern per week. In contrast, the nonlinear group (NLP) experienced different intensities of training from the fourth week onwards. Two days before and after the training protocol, muscle strength was measured indirectly. Moreover, fatigue was evaluated with a 5-item Modified Fatigue Impact Scale (MFIS-5) and quality of life with a 36-Item Short Form Health Survey (SF-36). The results were analyzed in SPSS software (version 21) using the analysis of the covariance model and Fisher's least significant difference (LSD) post hoc test. Results: Based on the results, LP and NLP training led to a marked increase in muscular strength )P&lt;0.001) and a significant decrease in fatigue )P=0.020) in MS patients. Nonetheless, no significant difference was observed in the quality of life between research groups )P=0/092). There were no significant differences between LP and NLP in factors, except leg press )P&lt;0/001). Conclusion: As evidenced by the obtained results, both LP and NLP training models increased muscle strength and reduced fatigue. Nevertheless, linear resistance training led to greater improvement in the aforementioned factors.

Design space exploration of flow diverter hydraulic resistance parameters in sidewall intracranial aneurysms

Intracranial aneurysms are nowadays treated with endovascular flow diverter devices to avoid sac rupture. This study explores how different linear and quadratic hydrodynamic resistance parameters reduce the flow in the sac for five patient-specific sidewall aneurysms.The 125 performed blood flow simulations included the stents using a Darcy-Forcheimer porous layer approach based on real-life stent characteristics. Time- and space-averaged velocity magnitudes were strongly affected by the linear coefficient with a power-law relationship. Quadratic coefficients alter the flow in a minor way due to the low-velocity levels in the aneurysm sac and neck region.

Contribution of Gravity Data for Structural Characterization of the Ifni Inlier, Western Anti-Atlas, Morocco: Hydrogeological Implications

The Sidi Ifni region in southwest Morocco is mainly composed of crystalline rocks with limited groundwater storage capacity. These water resources drain in particular fault zones with high fracture permeability. The main objective of this study is to describe the geological structure of the region to optimize future drilling locations. The gravity data were processed using various techniques, such as total horizontal gradient, tilt derivative, and Euler deconvolution, in conjunction with the interpretation of the geological data, to create a new structural map. This map confirms the presence of many previously identified or inferred faults and identifies significant new faults with their respective trends and depths. Analysis of this map shows that major faults are oriented NNE-SSW and NE-SW, while minor faults are oriented E-W, NW-SE, and NNW-SSE. The superposition of the hydrogeological data and the structural map reveals that the high groundwater flow values in the boreholes are located in the vicinity of the major faults and talwegs. The structures deduced from the filtering and interpretation of the gravity data suggest that the hydrogeological system of the Ifni Inlier is controlled by its structures. To confirm this impact, a high-resolution electrical resistivity map (7200 Hz) was used, with penetration depths ranging from 84 to 187 m. Negative boreholes, located in high resistivity ranges corresponding to sound basement formations without fault crossings, showed high resistivity values. The positive holes, located in anomalies with low linear resistivity, revealed the impact of fault crossings, which drain water and tend to decrease the resistivity values of the formations. Therefore, these new structural maps will assist in planning future hydrogeological studies in this area.

Sewing and adhesive bonding technologies for smart clothing production

PurposeThis paper aims to present investigations of the influence of sewing and adhesive bonding technology on the aesthetic, mechanical and conductive properties of the e-textile package. Commercially available conductive textiles are tested for the production of e-textile package by most common cut-and-sewn clothing production technologies.Design/methodology/approachSewing, adhesive bonding and seam sealing technologies used to obtain e-textile packages with woven and knitted conductive textiles. Produced e-textile packages described in terms of thickness, bending rigidity and general appearance. Exploitation properties of prepared samples tested by cycle tensile experiment and discussed on the basis of variation of linear electrical resistance property.FindingsResearch has shown that a reliable e-textile package can be obtained by applying cut-and-sew technology for conductive tracks of silver coated woven and knitted material. Seam sealing by thermoplastic polymer layer has an impact on the electrical and deformation properties of the samples. To create attractive smart clothing design, the appropriate joining method and its technological parameters must be chosen to ensure the durability and safety of e-textile packages.Originality/valueThe findings of the research are of substantial value for the production of e-textiles by cut-and-sewn technologies. The required shape of the conductive textile element for various applications can be cut and joined to the garment parts using traditional sewing or adhesive bonding techniques.