Vibrational Frequencies Research Articles

Thickness monitoring of threshing mixture on the oscillating plate of corn grain harvester

Cleaning is a critical operation in the corn grain harvesting process, and the operation is seriously affected by the uneven distribution of the threshing mixture on the oscillating plate. To monitor the thickness of the threshing mixture on the oscillating plate of the corn grain harvester, in this study, we adopted the lever principle to design a corn threshing mixture thickness monitoring device based on the piezoresistive effect and theoretically analyzed the lever impact mechanics. The factors affecting the force on the sensor of the monitoring device are the vibration frequency of the oscillating plate, the thickness of the threshing mixture, and grain moisture content, which were obtained through theoretical analysis. The operational performance of the corn threshing mixture thickness monitoring device was assessed through a set of single-factor experiments, revealing the influence laws of three factors on the impact voltage: vibration frequency, thickness of the threshing mixture, and grain moisture content. A back-propagation (BP)11Back-propagation (BP) neural network prediction model was established using an orthogonal experiment with impact voltage, vibration frequency, and grain moisture content as input layers and the thickness of the corn threshing mixture as the output layer. An STM32 microcontroller was used as the primary control unit to build a thickness monitoring data acquisition and processing system that could process and operate the impact voltage collected by the pressure sensor and the vibration frequency signal collected by a Hall sensor. The data were wirelessly transmitted to a PC to predict the thickness of the threshing mixture by using the trained BP neural network. The experimental results of monitoring the variation in corn threshing mixture thickness demonstrated that the device could effectively monitor changes in thickness. The monitoring accuracy of the monitoring device was found to be over 90%, and the system can be used for monitoring the threshing mixture thickness on the oscillating plate of the corn grain harvester.

Study on the Application of Vibration Energy Harvester Based on 3D Chip-scale Solenoids Coil in Rail Transit

Introduction: A 3D chip-scale solenoid coil was fabricated by micro-electro-mechanical system (MEMS) and wafer-level micro casting technology, and an electromagnetic vibration energy harvester was manufactured with an NdFeB permanent magnet. Methods: Three coils with different turns were designed, namely 45 turns, 90 turns, and 150 turns. The coils had a wire width of 40 microns, a pitch of 25 microns, and a thickness of 150 microns. The permanent magnet was cylindrical with a diameter of 1.8 mm. According to the length of the coil, three specifications of 3/6/10 mm were selected for the permanent magnet. Special PCB circuit testing tooling was processed to test the actual performance of three kinds of permanent magnet energy harvesters with different specifications. Results: The vibration frequency was set to 10 Hz~150 Hz, and the acceleration was designed to be 50 m/s2~300 m/s2. For the energy harvester with 90 turns, a maximum output power of 75 μW was obtained under vibration conditions of 100 m/s2 & 30 Hz. The experimental data showed that vibration frequency, acceleration, and sample size had a certain influence on the energy conversion and output power of vibration. Conclusion: Through the above study, the design and performance of vibration power generation devices can be optimized better to match the actual application requirements of rail transit.

Quantitative Structure-activity Relationship (QSAR) Modelling of Indomethacin Derivatives using Regression Analysis.

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) used for medication to reduce fever, spondylitis, or shoulder pain. It mainly works by the inhibition of prostaglandins, the endogenous signaling molecules. Fifteen indomethacin derivatives have been analyzed in relation to their physicochemical and molecular properties. Two-dimensional (2D) structures of fifteen indomethacin derivatives were drawn using the ACD Lab Chem Sketch version. Most of the topological parameters, such as wiener index (W), mean wiener index (Wa), Balaban indices (J), Balaban centric index (BAC), and molecular connectivity (χ), were calculated by using E Dragon software. The most common molecular file formats accepted in EDragon software were SMILES notations created online by Babel software and 2D structures of various derivatives, which were converted into 3D optimized structures using online CORINA, provided by Molecular Networks GMBH. 3D structures of compounds were also drawn on Gauss View software for calculations of various density functional theory (DFT) based quantum chemical descriptors, such as total energy (TE), softness (S), hardness (η), chemical potential (μ), highest occupied molecular orbital energy (HOMO), and lowest unoccupied molecular orbital energy (LUMO). All species were fully optimized in the gas phase with a 6-31+G* basis set. The harmonic vibrational frequency calculations were used to confirm that the optimized structures were minima, as characterized by positive vibrational frequencies. Combinations of various descriptors, such as D, ID, IOR, Log P, Mr, Mv, Mw, Pc, BAC, Pz, St, W, Wa, 0χ, 1χ, 2χ,3χ,4χ, 5χ, and Xeq have been found to be significant for modeling of activity. QSAR model no. 2: pIC50= -20.605 (±6.600) IOR - 0.747 (±0.454) I1 -5.083 (±3.478) Xeq + 51.647 optimized with empirical parameters with high statistical quality (R= 0.921, R2=0.848) was found to be the best model obtained. The QSAR model obtained suggests that substituents with a lesser value of the index of refraction and less electronegative groups were favourable for the activity, whereas indomethacin derivatives with a CH2CH2NHCONH(CH2)3ONO2 group at R1 position were unfavourable for the activity. The results were critically discussed based on regression data and cross-validation techniques. Pogliani factor Q and the results of the LOO (leave-one-out) method confirmed the reliability and predictability of the proposed models that could be highly beneficial for the future designing of new analogues with higher potency.

Boundary element method for hypersingular integral equations: Implementation and applications in potential theory

The main objective of this paper is to develop effective numerical methods to solve hypersingular integral equations arising in various physical and mechanical applications. Both surface and contour integrals are considered. The novelty of the proposed approach lies in the exact formulas obtained for an arbitrary planar polygon in hypersingular integral estimations. A one-dimensional hypersingular integral equation is derived for axially symmetrical configurations, and analytical formulas are established for calculating the hypersingular parts. It is proved that the hypersingular component of the surface integral is equal to its hypersingular component along the tangent plane. These exact formulas enable the development of an effective numerical method based on boundary element implementation. Benchmark tests are considered, and the convergence of the proposed methods is demonstrated. Problems in crack analysis are formulated and solved using both surface and contour hypersingular integral equations. A comparison of the results is made between boundary element methods and finite element methods for penny-shaped cracks. Boundary value problems in fluid-structure interaction are considered, and numerical simulations are performed. An estimation of modes and frequencies of panel and blade vibrations when interacting with liquids is carried out.

Forced vibration assessment of moderately thick carbon nanotube-reinforced composite plates

Carbon nanotubes, distributed in composite sheets with various arrangements, can lead to the development of materials with functionally graded properties. In the present study, the method of spectral components was used to investigate the free vibration frequencies and dynamic responses of single-layer sheets reinforced with carbon nanotubes. The spectral component method offers significant advantages for high-frequency dynamic problems, as it requires fewer fine elements to solve boundary conditions. Based on the first-order shear theory, the governing equations of sheet vibration are derived. The discrete Fourier transform is applied to convert the differential equations from the time domain to the frequency domain. Using dynamic shape functions obtained from the exact solutions, the stiffness matrix of the spectral element is constructed. Dynamic frequency responses are then derived, and time-domain responses are obtained using the inverse Fourier transform. The study extracted the exact natural frequencies of functionally graded sheets and verified them with results from the literature, showing high accuracy with a minimal number of elements. The spectral finite element method of fundamental natural frequencies for different ratios of modulus of elasticity and width-to-thickness ratios obtained were investigated and compared with the results of research. The forced vibration was addressed, demonstrating that the method efficiently captures dynamic responses under different carbon nanotube distributions, with spectral displacements verified through numerical comparison. These findings demonstrate the capability and efficiency of the spectral finite element method for analyzing carbon nanotube-reinforced composite plates.

Effect of para-substituents on NC bonding of aryl isocyanide molecules adsorbed on metal surfaces studied by sum frequency generation (SFG) spectroscopy.

The effect of para-substituents on the NC bond of aryl isocyanide molecules adsorbed on Au, Ag, Pt, and Pd surfaces was examined by vibrational sum frequency generation (VSFG) spectroscopy. The frequency of NC stretching vibration, υNC, depended on the electronic property of the substituents. When the substituents were more electron-withdrawing and more electron-donating, υNC shifted to lower and higher frequencies, respectively. However, υNC shifted to lower frequency again when the substituents were too electron-donating. The strong dependence of υNC on metal substrates was also observed, reflecting the difference in metal d-band energies, which leads to the difference in the contributions of σ-donation and π back-donation of the NC-metal coupling.

Enhanced Q-factor in microcantilevers using stiffened inertial amplifiers

Microcantilevers are widely employed in sensing applications because they are highly sensitive to changes in vibrational frequency. The Q-factor, a measure of the effectiveness of energy storage in resonant systems, is a crucial parameter that directly influences the sensitivity and performance of microcantilevers. Conventional approaches to improving the Q-factor by choosing certain materials or making changes to the shape have notable practical and economic constraints. This study introduces a new method that utilizes reinforced inertial amplifiers to significantly improve the Q-factor of microcantilevers. We introduce three setups: the standard amplifier, the compound amplifier, and the nested amplifier, each specifically engineered to enhance the system’s effective inertia. According to theoretical modeling, all arrangements enhance the Q-factor, with the nested design resulting in an impressive amplification of over 3000. These findings present a scalable technique to improve the sensitivity of microcantilevers, offering a potential approach for future experimental verification and utilization in precision sensing technologies.

Numerical simulation of impact response for pantograph slide plate

As a key component, the performance of pantograph slide plate is directly related to the normal operation of train and the stability of power supply. The pantograph slide plate is exposed to the complex environment and thus it would face mechanical impacts. In this paper, two types of slide plate models (wide and narrow) are constructed to explore the mechanical behavior of pantograph slide plate under impact using the finite element method. The results show that the slide plates rapidly deform at the beginning of the impact, and then the stress variation speed gradually slows down and tends towards a stable and low amplitude of self vibration. Under strong impact, the vibration frequency and amplitude of the slide plate significantly increase. The stress level of wide slide plate is lower than that of narrow slide plate. Narrow slide plate exhibits higher sensitivity and instability. This indicates that when the train is running at a high speed, factors such as track irregularities and airflow disturbances have a more significant impact on the narrow slide plate. This work provides valuable references for subsequent optimization design.

Exploring and Regulating Heteroatom-Electronegativity-Associated with Ring Aromaticity and Excited State Intramolecular Proton Transfer Mechanism for Benzothiazole-Based Fluorophore.

A novel fluorophore 2-(2'-hydroxy-5'-benzaldehyde phenyl) benzothiazole (HBBT) with excited state intramolecular proton transfer (ESIPT) characteristics, showing good selectivity for Cu+/Cu2+ ions had been synthesized experimentally (Molecules 2022, 27, 7678). However, its ESIPT mechanism and fluorescent performance related to atomic substituents have not been investigated systematically. In this work, two HBBT derivatives, 2-(2'-hydroxy-5'-benzaldehyde phenyl)benzoimidazole (HBBI) and 2-(2'-hydroxy-5'-benzaldehyde phenyl)benzopyrrole (HBBP), were obtained by respectively using -NH and -CH2 groups in place of the sulfur atom in the thiazole ring. The absorption/emission spectra and ring aromaticity as well as ESIPT processes of HBBT and its derivatives were studied using density functional theory (DFT) and time-dependent DFT (TD-DFT). The simulated absorption and fluorescence wavelengths of HBBT agreed well with the corresponding values obtained in the experiment. According to the analyses of geometry structures, electron densities, and infrared vibration frequencies, the intramolecular hydrogen bond becomes stronger upon light excitation. The frontier molecular orbitals were analyzed via establishing potential energy curves, and the ESIPT behavior was described deeply. Obviously, the NH-substitution makes ring 4 more aromatic, while the CH2-substitution changes ring 4 from aromatic to antiaromatic. The ESIPT process helps to alleviate the excited state antiaromaticity. The greater the antiaromaticity of the S1 state normal form, the higher the barrier of ESIPT.

Vibrational sum frequency generation (VSFG) spectroscopy of water adsorption on surfaces of yttria-stabilized cubic zirconia (YSZ).

Yttria-stabilized zirconia (YSZ) is found in a wide range of applications, from solid-oxide fuel cells to medical devices and implants. A molecular-level understanding of the hydration of YSZ surfaces is essential for optimizing its performance and durability in these applications. Nevertheless, only a limited amount of literature is available about the surface hydration of YSZ single crystals. In this study, we employ surface-sensitive non-linear vibrational sum frequency generation spectroscopy to investigate the hydration of YSZ(100), (110), and (111) single crystal substrates under ambient laboratory conditions. Three types of hydroxyl groups were identified at all three YSZ-D2O interfaces: (i) hydroxyls on the metal sites of Zr or Y resulting from the dissociative chemisorption of water, (ii) hydroxyls from proton adsorption to O sites formed from water dissociation, and (iii) hydroxyl groups as part of the physisorbed water at the interface.

Structural, DFT, Molecular Docking and Biological Activity of New Albendazole-Norfloxacin Mixed-Ligand Complexes: Promising Metal Complexes for Combating Microbial Resistance and Inflammation.

This study presents a comprehensive characterization of the Fe(III) (C1) and Co(II) (C2) complexes that were synthesized from the Albendazole (Alb) and Norfloxacin (Nor) ligands. The complexes exhibit remarkable thermal stability, low water solubility, and a non-electrolytic nature, characteristics that enhance their suitability for diverse applications. Conductivity measurements indicate molar conductivities of 9.85 and 8.59 Ω-1cm2mol-1, confirming their status as neutral molecules. Fourier Transform Infrared (FTIR) spectroscopy reveals significant ligand-metal interactions, marked by shifts in vibrational frequencies that confirm chelation, while Ultraviolet-Visible (UV-Vis) spectroscopy supports the identification of octahedral geometries for both complexes. Magnetic moment assessments align with their electronic configurations, and stoichiometric analysis consistently shows a 1:1:1 ratio, further validated by mass spectrometry. Thermal stability studies highlight anhydrous characteristics and distinct thermal decomposition behaviors, underscoring their structural integrity. Employing Density Functional Theory (DFT) calculations using the B3LYP functional, we evaluate the electronic properties of the ligands and their metal complexes, revealing reduced energy gaps (ΔE) of 2.29eV for C1 and 2.15eV for C2, significantly lower than those of the ligands (Alb: 4.61eV, Nor: 4.17eV), indicating enhanced reactivity and potential biological activity. Additionally, molecular electrostatic potential (MEP) maps provide insights into charge distributions, suggesting critical regions for interactions with biomolecules. Notably, the results demonstrate that metal coordination significantly enhances antibacterial/anti-fungal activity surpassing both the free ligands and the standard antibiotic Ofloxacin/Fluconazole. Furthermore, the complexes show significant improvement in anti-inflammatory activity by inhibiting protein denaturation more effectively than their ligand counterparts. Molecular docking studies reveal stronger binding affinities and interactions with antimicrobial target proteins 1HNJ and 5IKT, attributed to enhanced hydrophobic interactions and hydrogen bonding. These findings position C1 and C2 as promising candidates for developing effective antimicrobial therapies, highlighting the crucial role of metal ions in enhancing biological reactivity and addressing resistant strains of pathogens.

Research on the sensing properties and vibration reduction performance of self-sensing self-tuning magnetic fluid damper

Abstract The semi-active control damping system has gained popularity due to its quick response time and versatility. However, external sensors are susceptible to environmental interference, affecting system reliability and increasing complexity and maintenance costs, restricting their use. To address this, a self-sensing self-tuning magnetic fluid damper (SSMFD) is proposed. The vibration-measuring induction coil is wound on the damper to sense the magnetic fluid vibration information in real time, and the vibration signal is communicated to the self-tuning control circuit. The control circuit calculates and determines the dominant frequency of structural vibration, then outputs the relevant current signal to set the damper’s natural frequency to track the excitation frequency, resulting in self-tuning vibration reduction. First, the self-sensing unit’s output induced electromotive force model is created, followed by an expression of the damper’s natural frequency, indicating that the self-sensing unit can achieve self-tuning vibration reduction by tracking the excitation frequency. The multi-field coupling simulation model of the magnetic fluid damper is generated, and the induction coil coupling mode and damper excitation angle are defined to obtain the maximum induced voltage. Finally, an experimental platform was developed to assess the damper’s self-sensing and self-tuning vibration reduction performance. The experimental results show that the proposed SSMFD performs well, making it a feasible solution for achieving self-sensing and self-tuning vibration reduction.

High-Level Calculation for Assessing the Atmospheric Reactivity of Pentachlorophenol with Hydroxyl Radical: Mechanism and Kinetics.

This work aims to investigate the reactivity of the pentachlorophenol (PCP) compound, C6Cl5OH, with a hydroxyl (OH) radical in the gas phase. Geometry optimizations and vibrational frequency calculations were performed using DFT-M06-2X/6-311++G(d,p). Single-point energy calculations were carried out using the single-reference coupled cluster method, specifically CCSD(T), and the multiconfigurational CASPT2 level of theory to characterize the atmospheric degradation processes of PCP with OH radicals and to identify which chemical species resulting from their decomposition could remain in the gas phase. The performance of various families of basis sets was tested. The widely used augmented-correlation-consistent basis set family aug-cc-pVXZ-DK (X = D, T, and Q) was compared to the atomic natural orbital basis sets ANO-RCC-VXZP (X = D, T, and Q). The energy profile at 298 K showed that the Cl- and OH-abstractions are not energetically favorable. H-abstraction and OH-addition/Ck (k = 1-6) are characterized by the lowest Gibbs energies of activation and are strongly exothermic. The canonical transition state theory (TST) with a simple Wigner tunneling correction is used to predict the rate constants over the 220-400 K temperature range for each reaction channel. The overall rate constant at 298 K based on our calculations is about 3.25 × 10-13, 3.10 × 10-15, and 2.21 × 10-15 cm3 molecule-1 s-1 at M06-2X, CASPT2/ANO-RCC-VQZP, and CASPT2/aug-cc-pVQZ-DK levels of theory, respectively. The PCP atmospheric lifetime at 298 K is predicted to be in the range from 1 to 12-16 years at 0 km in the presence of variable OH concentration (9.00 × 105 to 1.50 × 107 molecules cm-3) based on CASPT2 data.

Dual-Vibration-Assisted Charge Transport Through Hexabenzocoronene in Single-Molecule Junctions.

Gaining deep understanding and effective regulation of the charge transport mechanism within molecular junctions is essential for the development of electronic devices. In this work, a series of hexabenzocoronene-based single-molecule junctions are successfully constructed, and their temperature-dependent charge transport properties are studied. It is found that rotational vibrations of both benzene and hexabenzocoronene rings are sequentially excited as the temperature increases, and the electron-vibration coupling enhances charge tunneling. In addition, the transition temperature between distinct vibration-assisted tunneling modes and the activation energies showstrong correlations with the molecular vibration frequency and molecular length. This study unveils the distinct dual-vibration-assisted molecular tunneling mechanism, significantly enhancing the ability to precisely control molecular charge transport and develop functional molecular devices.

Experimental study on compaction characteristics of coarse-grained soils with typical particle shapes affected by vibration frequencies

Coarse-grained soils, common fillers in subgrades, bear vibration loads in the construction stage, the compaction effects of which are affected by internal and external factors such as particle shapes and vibration frequencies. To enhance the understanding of compaction performance, this study investigated the vibration-induced deformation and energy dissipation of coarse-grained soils with two typical-shaped particles (pebbles and rubbles) through vibration compaction tests with different frequencies. Results show that both resilience modulus and damping ratio increase with increasing frequency, and the resilience modulus of rubbles is more stable compared with pebbles. Energy dissipation decreases with increasing vibration cycles at low frequencies, yet it increases with increasing vibration cycles at high frequencies. The dry density increment of rubbles is greater than that of pebbles, which is closely related to energy dissipation. Furthermore, the relationships between energy dissipation and dry density increment affected by particle shapes were discussed by discrete element simulations.

Response of a 4-nitrothiophenol monolayer to rapid heating studied by vibrational sum frequency spectroscopy.

A monolayer of 4-nitrothiophenol adsorbed on an Au substrate was heated by illuminating the substrate with a 19ps laser pulse of 532nm wavelength. Within 91ps, the temperature of the sample increased from room temperature by 113K. Vibrational sum frequency spectroscopy was used to characterize the adsorption geometry of the molecules in the ordered domains in the monolayer film. Upon heating, the initially ordered monolayer largely lost its structure. While the molecules are initially tilted by about 50° with respect to the surface normal, the analysis indicates that the mean tilt angle increased to 80° with a spread for individual molecules of up to a tilt angle of 40° upon heating. The evolution of this loss of order lagged about 100ps behind the temperature rise of the substrate.

Application of the Integral Energy Criterion and Neural Network Model for Helicopter Turboshaft Engines’ Vibration Characteristics Analysis

This article presents a vibration signal analysis method to diagnose helicopter turboshaft engine defects such as bearing imbalance and wear. The scientific novelty of the article lies in the development of a comprehensive approach to diagnosing helicopter turboshaft engine defects based on the vibration signals amplitude and frequency characteristics integral analysis combined with a neural network for probabilistic defect detection. Unlike existing methods, the proposed approach uses the energy criterion for the vibration characteristics. It averages the assessment of unique signal processing algorithms, which ensures reliable defect classification under flight vibration conditions. The method is based on representing vibration signals as a sum of harmonic oscillations supplemented by noise components, which helps to identify deviations from typical values. The developed method includes a state function in which the amplitudes and frequency characteristics from nominal parameters estimate deviations. When the critical threshold is exceeded, the function signals possible malfunctions. A multilayer neural network is used to classify defect types, providing high classification accuracy (from 0.985 to 0.994). Computer experiments on the developed seminaturalistic modeling stand confirm that the method can detect increased vibration levels, which is the potential failure indicator. Comparative analysis shows the proposed method’s accuracy and noise resistance superiority, emphasizing the importance of introducing modern technologies to improve aircraft operation reliability and safety.

Refined Metamodel Disturbance Observer-Based Control for Coarse Pointing Assembly Under Constraints

The target tracking performance of the coarse pointing assembly (CPA) is a critical factor in determining the data transmission efficiency of the inter-satellite laser communication. However, under the influence of multiple disturbances, such as gimbal coupling torque, friction, and satellite-transmitted vibration, the angle tracking performance of the CPA can be decreased, which then affects the safety of the system in terms of angular velocity. To address the performance and safety requirements of the CPA, this paper proposes a refined metamodel disturbance observer-based state constraints controller. First, a refined metamodel disturbance observer is proposed to achieve accurate disturbance estimation by combining the data-driven state-space Kriging metamodeling method with a refined disturbance observer. Both disturbance numerical data and partially known information (e.g. vibration frequency and structure) are fully utilized to reduce estimation conservatism. Second, based on the observer, a state constraint controller is designed to ensure the angle tracking performance and angular velocity constraints. Finally, the effectiveness and robustness of the proposed control method are validated through numerical simulations, indicating an enhanced angle tracking performance compared to the traditional disturbance observer-based control method.

Design and modeling of three-mode nonlinear hybrid piezoelectric-electromagnetic vibration energy harvester for harvesting multi-band vibration energy on the freight wagon axle box

Abstract With the rapid development of rail transit system, it is becoming more demanding for structural health monitoring (SHM) of the train. It is crucial to supply power for sensing devices on the freight wagon to ensure the safe operation of rail transit systems. Three-mode nonlinear hybrid piezoelectric-electromagnetic vibration energy harvester (TNHVEH) with a three-layer pickup system has been designed and applied to efficiently harvest vibration energy on the axle box of freight wagons for providing the power of the sensors for online SHM. Dynamic coupling model of the vehicle-harvester system is built to devote the relationship between the operation bandwidth and the nonlinear degree of TNHVEH for broadening the operation frequency band. Simulation and experimental results demonstrate that the resonant frequencies of the three pickup systems of TNHVEH are concentrated around 27, 70, and 120 Hz, matching the representative frequencies of axle box vibrations. A maximum output voltage of 2.97 V and output power of 29.4 μW under an optimal load of 300 kΩ at 0.5 g acceleration is achieved. It successfully lights up 53 LEDs with ‘ECJTU’ patterns, providing a solution to the power supply problem of microelectronic devices on freight wagons.

Influence of Raoul Husson’s neurochronaxic theory for the development of research on the physiological mechanisms of voice production in the Soviet Union (1950–1970s)

The influence of the neurochronaxic theory of phonation of the French physiologist Raoul Husson (1901–1967) on the development of research on voice formation in the Soviet Union, mainly in the 1950–1970s, is discussed. Husson contrasted the neurochronaxic theory with the traditional myoelastic theory of voice formation. The myoelastic theory considers the vocal folds as a self-oscillatory system. Vibrations are caused by the energy of the air flow. According to Husson’s concept, vibrations of the vocal cords do not depend on subglottic pressure. The frequency of vibration of the vocal cords corresponds to the frequency of impulses arriving along the recurrent nerve. To explain the high frequency of vibration of the vocal cords, Husson used Wever’s “Volley Principle”. According to this principle, the activity of each subsequent nerve fiber occurs during the refractory phase of the previous fiber. The responses of all nerve fibers are summed up into a common high-frequency oscillation. In 1950–1970s, Soviet physiologists took an active part in testing the new concept proposed by Husson. They came to the conclusion that both mechanisms, myoelastic and neurochronaxic, are involved in the functioning of the vocal apparatus. But the recurrent nerve does not directly control the vibrations of the vocal cords, but indirectly. Žhinkin called this control system the “code principle,” when a command is sent to the vocal cords to change their physical characteristics, changing the properties of the self-oscillating system.