Measured Resonance Curves Research Articles

Textile UHF-RFID Antenna Embroidered on Surgical Masks for Future Textile Sensing Applications

Ultrahigh frequency (UHF, 865–868 MHz) radio frequency identification (RFID) devices are expected to be implemented in many health-caring areas. In this article, we present three progressive designs of textile UHF-RFID antennas on surgical masks using a function-extensible integrated circuit (IC) chip (Rocky 100). The simulated and measured resonance curves of the designs all match well ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$|S_{11}| &lt; -20$ </tex-math></inline-formula> dB at 868 MHz) and the maximum realized gain are improved progressively in order to overcome the difficulty of the chip low sensitivity and increase the maximum read range. The best type (Design 3) is selected and its read range measured by the RFID reader (M6E Kit) can reach 2.5 m in air. In addition, several reliability validation measurements are performed, such as bending and skin contact, and maximum read range can reach 1.1 m considering the on-body worn worst case. The proposed Design 3 allows common use as a tag for tracking or safe distance alert under an epidemic situation. Alternatively, for the used function-extensible chip, the design can be applied to many different types of sensors for various application scenarios.

Computational Guided Method Applied to LSPR‐Based Biosensor for Specific Detection of the Four‐Serotypes of Dengue Virus in Seropositive Patients (Part. Part. Syst. Charact. 3/2022)

In article number 2100157, Ramirez and coworkers propose an original computational approach to differentiate the various serotypes of dengue in the presence of other flaviviruses, after a detection process using localized surface plasmon resonance (LSPR)-based biosensors, with high sensitivity, selectivity, and precision. This study demonstrates genetic similarity between DENV3/DENV2, and DENV4/DENV1, implementing recurrence maps, largest Lyapunov exponent, among others, on the measured resonance curve.

Textile UHF-RFID antenna sensor for measurements of sucrose solutions in different levels of concentration

With the trend of textile antennas development, ultra high frequency (UHF, 865–868 MHz) radio frequency identification (RFID) devices using textile materials are expected to be developed in many areas for replacing or simplifying some complex RFID devices on a PCB. In this paper, we present a textile UHF-RFID tag with two sensing positions (‘radiation parts’ and ‘loop part’) for exploring the feasibility of sucrose solutions measurements and the relationship between variables of the proposed design and the sucrose solutions. The simulated and measured resonance curves of the designs both match well (−20 dB in the simulation and −15.8 dB in the measurement at 868 MHz) and the read range measured by the RFID reader (M6e kit) is 1.71 m in air. Before the tests by the solutions on the proposed designs, a test board is developed as a preparation work for confirming the relative dielectric constants of the sensing substrate area in the real measurements. Compare the results of the simulation and the real tests, the proposed design shows good feasibility by comparing the simulated and measured results in confirmed relative dielectric constants. Moreover, its two sensing positions have different sensing features. The sensing ‘radiation parts’ position shows a stable frequency operation performance but sensing range is from 1.71 m (dry) to 2.3 m, while the sensing ‘loop part’ position has a wide sensing range from 0.4 m to 1.71 m (dry) but a lower frequency operation performance.

Asymmetry Analysis of the Resonance Curve in Resonant Integrated Optical Gyroscopes.

The Resonant Integrated Optic Gyroscope (RIOG) is a type of high accuracy gyroscope based on the Sagnac effect. A symmetrical resonance curve is very important to the performance of the RIOG. To further investigate and design a RIOG with a waveguide ring resonator, an in-depth research of the asymmetric resonance curve and its influence on the RIOG is fully developed. Four possible optical noises inducing the resonance curve asymmetry are analyzed and their mathematic models are established. These four optical noises are the normal mode effect, the backscattering noise, the backreflection noise and the polarization noise. Any asymmetry of the resonance curve will not only induce a large output bias error into the gyro output, but also seriously decrease the frequency discrimination parameter of the demodulation curve. By using a tunable fiber laser, the high aspect ratio silicon nitride WRR and the silicon dioxide WRR were tested. The experiment measured resonance curves can be well fitted with the theoretical simulation results. The experimental results show that a high aspect ratio silicon nitride waveguide can effectively suppress the polarization noise in the RIOG.

Measurement of interfacial wave dynamics in orbitally shaken cylindrical containers using ultrasound pulse-echo techniques

We present a novel experiment on interfacial wave dynamics in orbitally shaken cylindrical vessels containing two and three fluid layers. The experiment was designed as a hydrodynamical model for liquid metal batteries. It is intended to shed new light into some aspects of the very similar rotational wave motion emerging due to the metal pad roll instability, as the viscous damping behavior or the contact line dynamics. Both issues can be important to better predict instability onsets for upcoming liquid metal batteries and lab-size experiments. Different options are presented to realize stable and measurable multi-layer stratifications. We introduce a new acoustic measurement procedure allowing to reconstruct wave amplitudes also in opaque liquids by tracking ultrasonic pulse echoes reflected at the interfaces. Measurements of resonance curves and phase shifts were conducted for varying interface positions. A strong influence of the top and bottom walls was observed, considerably reducing wave amplitudes and eigenfrequencies, when the interface is getting close. Finally, measured resonance curves were successfully compared with an existing forced wave theory that we extended to two-layer interfacial waves. The comparison stresses the importance to carefully control the boundary condition at the contact line.

Analysis of asymmetric resonance response of thermally excited silicon micro-cantilevers for mass-sensitive nanoparticle detection

In this paper, the asymmetric resonance frequency (f0) responses of thermally in-plane excited silicon cantilevers for a pocket-sized, cantilever-based airborne nanoparticle detector (Cantor) are analysed. By measuring the shift of f0 caused by the deposition of nanoparticles (NPs), the cantilevers are used as a microbalance. The cantilever sensors are low cost manufactured from silicon by bulk-micromachining techniques and contain an integrated p-type heating actuator and a sensing piezoresistive Wheatstone bridge. f0 is tracked by a homemade phase-locked loop (PPL) for real-time measurements. To optimize the sensor performance, a new cantilever geometry was designed, fabricated and characterized by its frequency responses. The most significant characterisation parameters of our application are f0 and the quality factor (Q), which have high influences on sensitivity and efficiency of the NP detector. Regarding the asymmetric resonance signal, a novel fitting function based on the Fano resonance replacing the conventionally used function of the simple harmonic oscillator and a method to calculate Q by its fitting parameters were developed for a quantitative evaluation. To obtain a better understanding of the resonance behaviours, we analysed the origin of the asymmetric line shapes. Therefore, we compared the frequency response of the on-chip thermal excitation with an external excitation using an in-plane piezo actuator. In correspondence to the Fano effect, we could reconstruct the measured resonance curves by coupling two signals with constant amplitude and the expected signal of the cantilever, respectively. Moreover, the phase of the measurement signal can be analysed by this method, which is important to understand the locking process of the PLL circuit. Besides the frequency analysis, experimental results and calibration measurements with different particle types are presented. Using the described analysis method, decent results to optimize a next generation of Cantor are expected.

Precise damping and stiffness extraction in acoustic driven cantilever in liquid

In this paper, we first explain how to extract accurately the driving force acting on the acoustic driven atomic force microscope cantilever in liquid from the measured resonance curve. We present a model that includes the driving force to extract precisely the damping and the stiffness of the tip sample interaction. The model is validated by an experimental test based on two independent methods to measure the hydrodynamic drag coefficient of a sphere moving perpendicular to flat surface.

Standing waves in an elastic layer loaded with a finite mass

Standing shear waves in a plane-parallel rubberlike layer fixed without slippage between two rigid plates with finite masses are investigated. The lower plate, which underlies the layer, oscillates in the direction parallel to its surface under an external harmonic force, whereas the upper plate freely overlies the layer. It is shown both theoretically and experimentally that such a system exhibits resonances at frequencies the values of which depend on the mass of the free plate and the shear modulus of the layer. The shapes of the resonance curves are calculated and measured for different values of parameters of the layer and different masses of the upper plate. From the measured resonance curves, it is possible to determine the dynamic shear modulus and the shear viscosity of the rubberlike material.

Characterizing nonlinear resonant structures

A method for the characterization of nonlinear resonant systems is proposed, which is based on the measurement of the transfer coefficient as a function of the frequency at constant amplitude of oscillations in the resonator. In this case, the amplitude-dependent characteristics of the nonlinear resonator, such as the level of losses and the resonance frequency, are the same for all points of the measured resonance curve. This situation can be realized by carrying out the measurements at a fixed output power. The resonance curve measured using this approach, in contrast to the standard amplitude-frequency characteristic obtained at a constant input power, has a Lorentz shape even for a strongly nonlinear system (irrespective of the operative mechanism of nonlinearity), which allows the Q value to be correctly defined (so that it will be constant for the entire measured resonance curve) and determined. The proposed method is illustrated by measuring the characteristics of a superconducting filter in a nonlinear regime.

Optical microring resonators in fluorineimplanted lithium niobate

We report on the production and characterisation of optical microring resonators and optical channel waveguides by using fluorine-ion implantation and planar structuring in lithium niobate. We demonstrate the production of single-mode planar waveguides by low fluence fluorine-ion implantation (?? = 2.5 x10(14) ions/cm(2)) into lithium niobate wafers. The waveguides are strongly confined by the amorphous 2-microm wide optical barrier induced by the implantation process. A refractive index contrast of Deltan(o) = 0.17 at the telecom wavelength lambda = 1.5 microm has been determined between the waveguide and the barrier. Planar structuring with ridge height of up to 1.2 microm has been achieved by laser lithography masking and Ar(+) sputtering. For TE waves, the channel waveguides exhibit propagation losses lower than 8 dB/cm. First ring resonators with 80-microm radius have been fabricated by planar structuring in fluorine-ion implanted lithium niobate. The measured resonance curves show an extinction ratio of 14 dB, a free spectral range of 2.0 nm and a finesse of 4.

Resonant response matching circuit for hearing aid

An apparatus for and method of employing an electronic hearing aid device to assist a hearing impaired patient. The resonance curve of the outer auditory canal of the patient is determined. A device in accordance with the present invention is tuned to a frequency response curve which matches the measured resonance curve. The device is tuned by adjusting the overshoot of a low pass filter stage which is interposed between the microphone input and a class D output stage.

Center-of-mass and breathing oscillations in small complex plasma disks

Center-of-mass and breathing oscillations of a complex (dusty) plasma disk are excited for n = 3 and 5 microspheres (approximately 10 microm diameter) with neutral argon pressures P approximately 1-4 Pa . The mode frequencies and damping rates are determined directly from measured resonance curves. Millikan's coefficient for the Epstein drag force, the Debye length, and the particle charge is found by comparison with theory. The damping rates are the same for both modes and for n = 3 and 5, as predicted. Millikan's coefficient is found to be delta = 1.55 +/- 0.16, in agreement with delta = 1.44 for diffuse reflection. A consistent value of the Debye length that decreases with pressure is measured. The average particle charge for n = 3 particles is found to be more negative than that for n = 5 particles for the same conditions, indicating that the effective ion collection area of the particles increases as their separation decreases.

Resonance frequency of four-terminal-pair air-dielectric capacitance standards and closing the metrological impedance triangle

A new technique for determining the resonance frequency (f0) of four-terminal-pair air-dielectric capacitance standards is discussed. The resonance frequency is determined by measuring four parameters of the capacitance standards over a range of frequencies near f0. These parameters are the two-terminal-pair impedance coefficients as defined in an impedance matrix. From a knowledge of the four-terminal-pair resonance frequency of the standards it is possible to calculate their frequency dependence for f ≪ f0 using a simple electrical model. For air-dielectric capacitance standards it is also possible to determine their dissipation factor from the −3 dB width of the measured resonance curve. Ultimately, the validity of the technique described here would need to be verified by establishing closure of a proposed ‘metrological impedance triangle’ (MIT). This would involve measuring the frequency dependence of a four-terminal-pair air-dielectric capacitance and a calculable resistance standard in a 10:1 bridge between a range of frequencies, for example 1.592 kHz and 1.592 MHz. The same standards are then compared in a quadrature bridge operating at the upper frequency of 1.592 MHz to enable closure of the MIT. Accurate closure of the MIT would be an important test for the validity of a number of high-frequency techniques and calculations for the first time.

A case of abnormal overvoltages in a Petersen grounded 132-kV system caused by broken conductor

This paper analyzes stationary overvoltages in Petersen grounded systems resulting from a broken phase conductor. The analysis is done with basis in a real case where the overvoltages caused extensive damages and outages. It is shown that a requirement for high overvoltages to result is the combination of the following: The fault occurs on a radial connection that has substantial generation on one side only, the total compensation is close to 100%, and the compensation of the two subnetworks defined by the fault is far from 100% (one subnetwork is undercompensated and the other is overcompensated). These conditions were all met for the network subject to investigation. Overvoltages calculated by a simple model compare favorably with recorded results. The overvoltages are shown to be strongly dependent on the compensation level, the compensation distribution, and the shunt conductance to ground, and the load. A least squares method has been developed for estimating the shunt conductance based on a measured resonance curve.

A Case of Abnormal Overvoltages in a Petersen Grounded 132 Kv System Caused by Broken Conductor

This paper analyzes stationary overvoltages in Petersen grounded systems resulting from a broken phase conductor. The analysis is done with basis in a real case where the overvoltages caused extensive damages and outages. It is shown that a requirement for high overvoltages to result is the combination of the following: The fault occurs on a radial connection that has substantial generation on one side only, the total compensation is close to 100%, and the compensation of the two subnetworks defined by the fault is far from 100% (one subnetwork is undercompensated and the other is overcompensated). These conditions were all met for the network subject to investigation. Overvoltages calculated by a simple model compare favorably with recorded results. The overvoltages are shown to be strongly dependent on the compensation level, the compensation distribution, and the shunt conductance to ground, and the load. A least squares method has been developed for estimating the shunt conductance based on a measured resonance curve.

Calibration of the cross section of the 18O(p, α) 15N nuclear reaction at Ep = 1700–1775 keV

The differential cross section of the 18O(p, α) 15N nuclear reaction has been calibrated at proton energies between 1700 and 1775 keV and at a detection angle of 155°. For the calibration, two silicon reference samples and a nickel sample were partially oxidized in enriched 18O. The absolute 18O-content in the grown oxide films is measured with RBS by direct comparison with a Bi-implanted silicon calibration standard. The measured resonance curve is fitted with a split Breit-Wigner function. The maximal cross section of the resonance at 1766 keV is found to be 135 ± 5 mb sr . Its width is 4.5 ± 0.3 keV.

The specific heat of dilute 3He- 4He mixtures measured with a second-sound Helmholtz resonator

An alternative way of measuring the specific heat of superfluid 4He and dilute 3He- 4He mixtures is described. Specific heat data are derived from the measured resonance curves for the temperature amplitude in a second-sound Helmholtz resonator. It is shown that the nature of the losses that govern the shape of these curves, need not to be known for the analysis. The applicability of the method is first demonstrated by a series of measurements on pure 4He in the temperature range between 1.4–2.0 K; the results are in good agreement with existing specific heat data. Next, some measurements performed in the range from 0.3 K to 0.7 K on two mixtures of molar concentrations X = 6.0 × 10 −3 and X = 8.5 × 10 −3 are presented. Although the thermal anchoring of the resonator to the mixing chamber of the Leyden dilution refrigerator did not appear to be optimal, so that the precision of the results was not high, the feasibility of the method also for the case of mixtures could be shown. It is further shown that the analysis of the data is somewhat more difficult for mixtures than for pure 4He; this is due to less direct coupling between the amplitudes of the energy and the temperature, caused by the accompanying oscillations in the concentration X.

Analysis of a second-sound resonator for velocity and viscosity measurements in liquid helium II

A Helmholtz-type resonator for second sound may serve as a reliable and accurate tool for the determination of the velocity of second sound and the viscosity of liquid helium II. In this paper the theory of the resonator is given, and an analytic scheme is developed which allows for the determination of these quantities from measured resonance curves. In a second paper this method will be applied to our measurements in dilute 3He- 4He mixtures in the temperature range between 100 mK and 650 mK.

Alfvén wave heating of a theta pinch

The process of shear Alfvén wave resonant absorption for plasma heating has been applied to a theta pinch. The m = 1 mode is excited by means of a helical launching structure with a given wavelength, at a number of different frequencies. When the frequency lies in the continuous Alfvén spectrum the kink energy is transferred to the Alfvén wave and then is rapidly thermalized. The heating power is measured by a diamagnetic probe. It is shown that the probe signal can be treated as a thermodynamic variable permitting an exact energy balance to be deduced. The measured resonance curve of the heating power is in agreement with the predicted behaviour. A 50% efficiency is achieved and the coupling between the plasma and the external circuit is strong, in spite of the high compression ratio.

A Study on Vibration Characteristics of Large Ships

This paper deals with a practical method for vibration analysis of large ships. The vibration characteristics for 230, 000 DWT oil tanker are also analyzed and compared with experimental results.The results obtained are as follows.1) In estimating the vibration characteristics of large ships, a response factor of acceleration is effectively used, which is determined by the mode shape matrix and the generalized mass.2) Although large ships usually have lots of eigen values, the vibration modes with large response factors are relatively few and localize upon some frequency regions.3) The higher modes with large response factors are remarkable at superstructure and afterbody of shiphull. The response factors of their modes may considerably vary with the load condition, by which little frequency changes are observed.4) The calculated and measured natural frequencies for the lower modes show good agreements. Although the data for the higher modes are not sufficient, it can be seen that the peak frequencies on the measured resonance curves correspond to those of the typical calculated vibration modes.5) The calculated resonance curves are similar to the measured ones over a frequency range of 500 to 600 cpm except some cases. In general, further investigation will be required about estimating the exciting force, such as surface force induced by propeller and axial force of shaft system due to main engine.