Measured Resonance Frequencies Research Articles

Digital guides to facilitate retained root removal and simultaneous implant placement

The aim of this study was to report the use of digital guides to locate impacted residual roots (IRR) (location guide) and to simultaneously insert dental implants (surgical guide). This case series included five patients. The IRR was first removed through a lateral window approach using the digital location guide, then the implant was placed simultaneously with the implant surgical guide. Definitive restorations were completed after a 6-month healing period. An average of 13.0 ± 3.1 minutes was required to locate the IRR. The implant stability quotient (ISQ) was obtained during surgery and before digital coping using a non-invasive resonance frequency measurement. The average ISQ during surgery for the five dental implants was 60.2 ± 6.3, and the value increased to 66.6 ± 4.8 before final restoration. The average deviations at the implant neck and root apex were 0.48 ± 0.25 mm and 0.74 ± 0.46 mm, respectively. The average angular deviation was 3.5 ± 1.4°. Bone resorption at the implant neck was a mean 0.072 ± 0.041 mm before final restoration. All implants functioned well at 1 year after final restoration. The application of surgical guides in the extraction of IRR enabled crestal bone preservation and simultaneous implant placement.

Thermoresponsive Gelatin/Chitosan Hydrogel Films for a Degradable Capacitor.

Ingestible electronic devices are tools for exploring the condition of the gastrointestinal tract and adjacent organs without a burden on the patients. Making them safe requires that they be fabricated with harmless materials. In this study, we developed a capacitor using food materials for a wireless sensing component. As a safer approach, gelatin, an ingredient responsive to external stimuli, was selected as a substrate for deforming the device at the desired time. Gelatin experiences sol-gel changes near body temperature; however, it is instantly dissolved and is not suitable for long-term use in the body. Thus, to maintain its thermal responsiveness, we used a tangle of gel networks created by mixing gelatin and chitosan without cross-linking agents. Our search for the appropriate gel mixing ratio provided insights into the criteria for achieving slow sol-gel changes and how to improve the thermal durability. We transferred a sputtered gold film onto the gel films to produce electrodes and then made a capacitor by sandwiching a naturally dried sodium polyacrylate film between the electrodes. The resonance frequency measurement of RLC circuits in combination with commercial plane coils showed that the capacitor worked in the megahertz band and that it collapsed when immersed in hot water. Gastric acid detection was also achieved with this capacitor. This electronic part will contribute to the development of implanted or ingestible medical devices and a wide range of environmental sensors composed of natural ingredients.

Thermal Modeling of Resonant Scatterers and Reflectometry Approach for Remote Temperature Sensing

Thermal modeling of different transmission lines (TLs) based on resonant scatterers is presented. The coplanar strip (CPS) and microstrip (MS) TLs are used to model resonators and to introduce the thermal dependence. A reflectometry approach is employed to validate the model by detecting the scatterers’ resonance frequency and comparing it with analytical expressions. The observable shift in the resonance frequency of the scatterers with temperature variations is due to the thermal expansion of metals and temperature dependence of the substrate permittivity. Since all the measurements are done remotely with no direct line of sight, it is shown how such a reflectometry approach can be used for remote temperature sensing using a passive label composed of resonators. Unlike previous works in this domain where the thermal dependence is considered empirically, the introduced model is used to take into account all thermal effects affecting the resonant scatterers allowing to link rigorously the variations of the measured resonance frequency with the temperature without any lookup table. Temperature sensing using very simple TLs based on resonant scatterers was demonstrated in a real environment. A temperature error of less than 3 °C is obtained. Once the temperature has been determined, it is possible to go back to the TL parameters, such as the effective permittivity and the physical length.

Design evaluation of microwave transmission properties of YBa2Cu3O7-based kinetic inductance detectors

We designed, fabricated, and characterized microwave transmission properties with rewound strip structures for YBa2Cu3O7 (YBCO)-based kinetic inductance detectors (KIDs). The superconducting rewound strip serves as a microwave resonator and as a broadband terahertz-wave antenna. To predict the microwave resonance characteristics before fabrication, the line-width (w) and space (s) dependence of the spiral resonators were analyzed using an electromagnetic simulator; the resonance frequency increased, and the quality factor decreased with increasing w and s from 10 to 40 μm. YBCO-based KID arrays with different w (10 and 40 μm) were fabricated on 10 mm-square MgO substrates, cooled to 3 K using a 4He refrigerator, and evaluated using a vector network analyzer to verify the result of the simulation experimentally. The measured resonance frequency ratio of 1.11 times (5.04 → 5.59 GHz) agreed with the simulated ones of 1.10 times (4.84 → 5.33 GHz) between w = 10 and 40 μm. The other resonance characteristics, such as transmission coefficient and quality factor, have a similar w dependence with the simulation.

A strategy for correcting errors in automated formant extraction

Sociophonetic vowel analysis relies heavily on measurements of resonant frequencies, particularly of the first and second formants. Automated formant estimation using linear predictive coding (LPC) algorithms in software like Praat greatly increases efficiency compared to hand measurements and allows researchers to analyze more data than was possible before this technological advancement. However, LPC analysis is prone to certain types of errors (e.g., Di Paolo et al., 2011; Harrison, 2013; Labov et al., 2006; Strelluf, 2019; Styler, 2017). In one common error, which I call “faulty low F2” (FLF2), LPC identifies a spectral peak between F1 and F2 as an F2 measurement. In automated extraction, the real F2 is then recorded as F3. Manually correcting these errors is time-consuming, potentially erasing the gains made by automated extraction. However, a systematic error suggests the possibility of a systematic solution. This presentation describes a method for identifying and correcting FLF2 errors using a script in R. The script identifies possible errors based on expected ranges and trajectories, determines whether the recorded F3 at the measurement point meets the criteria for a legitimate F2, and makes substitutions where appropriate. Results of tests with real data are presented. [Work supported by NSF #XXXXXXX.]

Enhanced resonant ultrasound spectroscopy for multi-material characterization

Resonant ultrasound spectroscopy (RUS) is a non-destructive technique to describe the elastic tensor of a material through inversion of a sample’s measured resonance frequencies. The original RUS approach is limited to simple geometries as it uses a semi-analytical method to simulate the vibrational response. We modified this approach by combining the finite-element method with genetic algorithm. The new approach is applicable to systems with composite materials, complex geometries, and misaligned material and geometry axes. We present recent work focused on the response of a graphite-TZM composite system. We find composite material properties only vary a few percent from results from single-material RUS. Results from varied geometries and materials suggest further optimizations to enhanced RUS.

Self-Temperature-Compensated Air-Filled Substrate Integrated Waveguide (AFSIW) Quasi-Elliptic Filters

Patented single-slab self-temperature-compensated air-filled substrate integrated waveguide (AFSIW) cavities and quasi-elliptic filters are proposed and demonstrated in this article. Such components are of high interest for the design of thermally stable circuits and systems on substrate meeting the size, weight, power, and cost (SWaP-C) reduction expected for future systems, especially for space applications. First, a theoretical multiphysics model is presented for the synthesis of single-slab self-temperature-compensated AFSIW cavities. It is demonstrated from theory that by properly choosing the dielectric slab material and dimensions, perfect temperature compensation can be achieved. This extended technique allows the implementation of temperature compensation in any type of cavity, filter, and multiplexer configuration. For demonstration purposes, a single-slab self-temperature-compensated in-line folded seventh-order quasi-elliptic AFSIW filter operating at 12 GHz with a 250-MHz (2.27%) −3-dB bandwidth is designed and fabricated. It achieves a measured unload <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -factor of 992 at ambient temperature (23 °C) and a measured resonance frequency thermal stability as low as 0.58 ppm/°C at −20 °C and 0.89 ppm/°C at 70 °C compared with its temperature-uncompensated counterpart achieving a thermal stability of −15.5 ppm/°C at −20 °C and −17.73 ppm/°C at 70 °C. Furthermore, it is demonstrated in this article that transmission zeros (TZs) created by cross-couplings in the in-line folded configuration of the self-temperature-compensated quasi-elliptic filter achieve a thermal stability of 2.55 ppm/°C and 2.3 ppm/°C (2.34 ppm/°C and 4.37 ppm/°C) at −20 °C (70 °C), in the lower and upper bands, respectively.

Real-Time Detection and Control of Microchannel Resonance Frequency in Acoustic Trapping Systems by Monitoring Amplifier Supply Currents.

The utilization of bulk acoustic waves from a piezoelectric transducer for selective particle trapping under flow in a microchannel is limited by the high sensitivity of the resonance frequency to tolerances in device geometry, drift during trapping, and variations in the local flow or sample conditions in each channel. This is addressed by detecting the resonance condition based on the impedance minimum obtained by monitoring the amplitude of the stimulation voltage across the piezo transducer and utilizing real-time feedback to control the stimulation frequency. However, this requires an overlap in the frequency bandwidth of the detection and the stimulation system and is also limited by the decline in the acoustic trapping power when the stimulation and resonance frequency measurement are conducted simultaneously. Instead, we present a novel circuit implementation for on-chip real-time resonance frequency measurement and feedback control based on monitoring the current drawn from the amplifier used to stimulate the piezo transducer, since the need for high measurement sensitivity in this mode does not lower the power available for stimulation of the transducer. The enhanced level of control of acoustic trapping utilizing this current mode is validated for various localized channel perturbations, including drift, wash steps, and buffer swaps, as well as for selective sperm cell trapping from a heterogeneous sample that includes lysed epithelial cells.

Fundamental limits and optimal estimation of the resonance frequency of a linear harmonic oscillator

All physical oscillators are subject to thermodynamic and quantum perturbations, fundamentally limiting measurement of their resonance frequency. Analyses assuming specific ways of estimating frequency can underestimate the available precision and overlook unconventional measurement regimes. Here we derive a general, estimation-method-independent Cramer Rao lower bound for a linear harmonic oscillator resonance frequency measurement uncertainty, seamlessly accounting for the quantum, thermodynamic and instrumental limitations, including Fisher information from quantum backaction- and thermodynamically driven fluctuations. We provide a universal and practical maximum-likelihood frequency estimator reaching the predicted limits in all regimes, and experimentally validate it on a thermodynamically limited nanomechanical oscillator. Low relative frequency uncertainty is obtained for both very high bandwidth measurements (≈10−5 for τ = 30 μs) and measurements using thermal fluctuations alone (<10−6). Beyond nanomechanics, these results advance frequency-based metrology across physical domains.

MEMS-Based Cantilever Sensor for Simultaneous Measurement of Mass and Magnetic Moment of Magnetic Particles

This study presents a measurement approach suitable for the simultaneous determination of both the mass mp and magnetic moment µp of magnetic particles deposited on a micro electro mechanical system (MEMS) resonant cantilever balance, which is operated in parallel to an external magnetic field-induced force gradient F′(z). Magnetic induction B(z) and its second spatial derivative δ2B/δz2 is realized, beforehand, through the finite element method magnetics (FEMM) simulation with a pair of neodymium permanent magnets configured in a face-to-face arrangement. Typically, the magnets are mounted in a magnet holder assembly designed and fabricated in-house. The resulting F′ lowers the calibrated intrinsic stiffness k0 of the cantilever to k0-F′, which can, thus, be obtained from a measured resonance frequency shift of the cantilever. The magnetic moment µp per deposited particle is determined by dividing F′ by δ2B/δz2 and the number of the attached monodisperse particles given by the mass-induced frequency shift of the cantilever. For the plain iron oxide particles (250 nm) and the magnetic polystyrene particles (2 µm), we yield µp of 0.8 to 1.5 fA m2 and 11 to 19 fA m2 compared to 2 fA m2 and 33 fA m2 nominal values, respectively.

Parametric Analysis of the Edge Capacitance of Uniform Slots and Application to Frequency-Variation Permittivity Sensors

This paper presents a parametric analysis relative to the effects of the dielectric constant of the substrate, substrate thickness and slot width on the edge capacitance of a slot-based resonator. The interest is to find the conditions (ranges of the previously cited parameters) compatible with the presence of a quasi-magnetic wall in the plane of the slot (or plane of the metallization). If such magnetic wall is present (or roughly present), the electric field in the plane of the slot is tangential (or quasi-tangential) to it and the edge capacitance can be considered to be the parallel combination of the capacitances at both sides of the slot. Moreover, variations in one of such capacitances, e.g., caused by a change in the material on top of the slot, or by a modification of the dielectric constant of the substrate do not affect the opposite capacitance. Under the magnetic wall approximation, the capacitance of certain electrically small slot-based resonators can be easily linked to the dielectric constant of the material present on top of it. The consequence is that such resonators can be used as sensing elements in a permittivity sensor and the dielectric constant of the so-called material under test (MUT) can be determined from the measured resonance frequency and a simple analytical expression. In this paper, the results of this parametric analysis are validated by considering several sensing structures based on dumbbell defect ground structure (DB-DGS) resonators of different dimensions.

Computation and experimental considerations on dynamic testing of cement mortar

Non-destructive tests to assess the dynamic characteristics of the materials are important for both in-situ and laboratory situations. Elastic modulus, rigidity modulus and Poisson ratio can be determined through dynamic testing, by employing resonant frequency measurements. The ASTM C-215 standard contains the necessary information for the experimental set-up and subsequent computation using the longitudinal, transversal and torsional frequencies, for both prismatic and cylindrical specimens. Nevertheless, some experimental particularities are not explained and their influence on the final results might prove important. In this paper, the experimental and computational insights on performing the dynamic Young modulus test for cement mortar prismatic samples, with emphasis on the importance of interpretation of the results are presented. The type of specimen support and the actual data manipulation, when extracting results, are taken into consideration. The results may prove important for the correct employment of dynamic testing.

RETRACTED] An Approach to Optimize the Design of Ultrasonic Transducer for Food Dehydration

==========================================================Available online: 30 June 2021This article has been retracted by International Journal on Advanced Science, Engineering and Information Technology Editorial team, following clear correspondence and confirmation with authors.The article contained redundant material, the editor investigated and found that the paper published in Computational Intelligence Methods for Green Technology and Sustainable Development. GTSD 2020. Advances in Intelligent Systems and Computing, vol 1284. Springer, Cham. DOI: https://doi.org/10.1007/978-3-030-62324-1_35, URL: https://link.springer.com/chapter/10.1007/978-3-030-62324-1_35, entitled "An Approach to Optimize the Design of Ultrasonic Transducer for Food Dehydration".The paper is retracted from 30 November 2021.==========================================================Ultrasound-assisted air-drying is considered a useful method to reduce drying time and ensure some agricultural food products' quality. In this study, a practical design method of an Ultrasonic Transducer (UT), which is in the form of a circular stepped-plate, was developed by using Particle Swarm Optimization (PSO) algorithm and Finite Element Analysis (FEA). The numerical calculation is carried out for two different geometric dimensions of the stepped-plate. Based on the obtained results, the smaller UT dimensions were chosen, and its prototypes were fabricated. The prototype's measured resonance frequency is 19.927 kHz compared to calculations getting an error of 0.073 kHz (0.37%). Also, to evaluate the effects of ultrasound on a drying process, the UT is integrated into a heat-pump drying machine for drying foods. The experiments were carried out on Codonopsis javanica using heat-pump drying method at air temperature 45 ± 0.5 °C, air humidity 18-20 %, air velocity 0.5 ± 0.1 m/s with and without ultrasonic intensity while keeping all other conditions and parameters constant. The results showed that the total drying time was reduced in the range of 25% to 42% depending on ultrasonic intensity, compared to heat-pump drying without ultrasonic intensity. The color of the dried products is also considered to testify the quality of the product when using UT in drying processes. The obtained results prove the effectiveness of the proposed approach in design of the UT for food dehydration.

Multimodal real-time frequency tracking of cantilever arrays in liquid environment for biodetection: Comprehensive setup and performance analysis.

We present a nanomechanical platform for real-time quantitative label-free detection of target biomolecules in a liquid environment with mass sensitivity down to few pg. Newly fabricated arrays of up to 18 cantilevers are integrated in a micromachined fluidic chamber, connected to software-controlled fluidic pumps for automated sample injections. We discuss two functionalization approaches to independently sensitize the interface of different cantilevers. A custom piezo-stack actuator and optical readout system enable the measurement of resonance frequencies up to 2MHz. We implement a new measurement strategy based on a phase-locked loop (PLL), built via in-house developed software. The PLL allows us to track, within the same experiment, the evolution of resonance frequency over time of up to four modes for all the cantilevers in the array. With respect to the previous measurement technique, based on standard frequency sweep, the PLL enhances the estimated detection limit of the device by a factor of 7 (down to 2pg in 5min integration time) and the time resolution by more than threefold (below 15s), being on par with commercial gold-standard techniques. The detection limit and noise of the new setup are investigated via Allan deviation and standard deviation analysis, considering different resonance modes and interface chemistries. As a proof-of-concept, we show the immobilization and label-free in situ detection of live bacterial cells (E. coli), demonstrating qualitative and quantitative agreement in the mechanical response of three different resonance modes.

Design and Analysis of Broadband LiNbO3 Optical Waveguide Electric Field Sensor with Tapered Antenna.

The three-dimensional (3D) simulation model of a lithium niobate (LiNbO3, LN) optical waveguide (OWG) electric field sensor has been established by using the full-wave electromagnetic simulation software. The influences of the LN substrate and the packaging material on the resonance frequency of the integrated OWG electric field sensor have been simulated and analyzed. The simulation results show that the thickness of the LN substrate has a great influence on the resonant frequency of the sensor (≈33.4%). A sensor with a substrate thickness of 1 mm has been designed, fabricated, and experimentally investigated. Experimental results indicate that the measured resonance frequency is 7.5 GHz, which nearly coincides with the simulation results. Moreover, the sensor can be used for the measurement of the nanosecond electromagnetic impulse (NEMP) in the time domain from 1.29 kV/m to 100.97 kV/m.

Spherical-Omnidirectional Piezoelectric Composite Transducer for High- Frequency Underwater Acoustics.

Spherical-omnidirectional acoustic source has become a powerful tool to provide a near-ideal omnidirectional beam pattern for acoustic tests and communications. Current spherical-omnidirectional acoustic sources do not combine an omnidirectional beam pattern with a high transmitting voltage response (TVR) in the frequency range of above 200 kHz. This work presents the design, fabrication, and measurements of a high-frequency spherical-omnidirectional transducer that can provide a near-ideal omnidirectional beam pattern and a high TVR. The active element of the transducer consists of six identical square coupons with spherical curvature 1-3 piezoelectric composites operating in thickness mode. Electroacoustic responses of the fabricated transducer in water were measured. The measured resonance frequency of the transducer was 280 kHz. The maximum TVR was 161.3 dB re 1 μ Pa/V@1 m. The horizontal and vertical beamwidths of the transducer were 360° and 346°, respectively. Measurements show that the spherical piezoelectric composite transducer has a favorable spherical-omnidirectional behavior and a high TVR at high frequency. These results demonstrate that the spherical piezoelectric composite transducer is potentially a strong candidate for a high-frequency underwater acoustic source that requires an omnidirectional response.

Vibration-based inverse graphical technique for thickness estimation of bulk acoustic wave (BAW) resonators: application for corrosion monitoring of sacrificial anodes

Resonant acoustic sensors have been used in a variety of applications that leverage the large sensitivity of mechanical resonance frequency to shift in geometric or mechanical properties of the sensor induced by the measurand. In applications such as structural health monitoring, accurate damage quantification requires development of precise models for resonator-measurand interactions or advanced system identification or optimization algorithms. In this paper, we utilize a graphical technique originally proposed for damage assessment in beams, to determine the extent of corrosion of sacrificial zinc anode discs instrumented with piezoelectric transducers. We develop analytical models for expressing natural resonance frequencies of the radial and transverse vibration modes of a disc in terms of material and geometric properties of its constituent elements. The underlying parameters (in this case, the thicknesses of the zinc and zinc oxide films) are extracted from measured resonance frequencies by finding roots of the characteristic determinant of these modes through graphical technique. Even though accelerated corrosion induced by impressed current results in non-uniform corrosion of the anode, the graphical technique with uniform-corrosion model shows excellent agreement with experimental results and is suitable for in-situ monitoring of sacrificial anodes used in cathodic protection systems. This technique requires no calibration or model of corrosion dynamics, and is computationally inexpensive unlike optimization techniques.

Determining the full elastic tensor using resonant ultrasound spectroscopy in extreme environments

Elastic moduli are fundamental thermodynamic susceptibilities that connect directly to thermodynamics, electronic structure and mechanic properties. Thus, determining the changes of elastic moduli as a function of time and temperature is a powerful tool to study a variety of phenomena. The Resonant Ultrasound Spectroscopy (RUS) technique is based on the measurement of mechanical resonance frequencies that can be made with extreme precision and used to compute the elastic moduli without corrections. In this talk, I will give show several examples of the use of RUS in different systems, ranging from magnetic phase transition, determining very small degrees of elastic anisotropy in metals as well as changes in time product of radioactive decay. I will discuss the latest advances made at Los Alamos on measuring and determination of elastic constants. This allow to track the resonance position with high precision, obtaining moduli with an absolute precision of 0.5% and relative changes smaller than part per 10 million.

Accurate Characterization of High-$Q$ Microwave Resonances for Metrology Applications

Microwave resonators are widely adopted as high sensitivity sensors in both applied and fundamental metrology, to measure a number of different physical quantities, such as temperature, humidity, pressure, length and material properties. High sensitivity, and thus potential high measurement precision and accuracy, can be achieved by resorting to high-quality-factor (Q) resonators. Nonetheless, in order to accurately measure a high-Q resonance and obtain low measurement uncertainty, as required by metrology applications, the entire measurement set-up must be carefully designed. This papers presents an overview of resonance frequency measurements for metrology applications, illustrating the various aspects and issues to be dealt with when pursuing highly accurate measurements, as well as of the most relevant achievements in this field.

Discriminative sensing of temperature and acoustic impedance by using forward Brillouin scattering in large effective area fiber

We experimentally clarified the characteristics of forward Brillouin scattering induced by radial acoustic modes (R 0,m ) in large effective area fiber. The measured resonance frequencies of R 0,m modes were shown to have different sensitivities to acoustic impedance. Then we performed discriminative measurement of temperature and acoustic impedance by selecting a pair of different R 0,m modes that would achieve the minimum measurement error, where we had successfully achieved small measurement uncertainties of 0.4 °C and 0.03 kg·s–1 · mm–2, respectively.