Vibrational Frequencies Research Articles

Theoretical and experimental study of rigid rapier weft insertion vibration

In this study, vibration equations and models were established utilizing D’Alembert’s principle to address the resonance challenge of a rigid rapier loom operating in high-speed reciprocating motion, and the equations were subsequently solved using Galyokin’s methodology. A laboratory apparatus was constructed to evaluate the findings of the first-order vibration frequency under various rapier extension lengths to validate the precision of the theoretical model, which necessitated recalibration. The accuracy of the theoretical model is confirmed by comparing its predicted results with those of the experiments. In this report, the rigid rapier is further examined in order to correct the trapezoidal acceleration within the perspective of the vibration of the rigid rapier influenced by varied rapier head masses. The results demonstrate that as the mass of the rapier head increases, the maximum apex deviation of the rigid rapier during the weft-induced process also escalates. To enhance the stability of the rigid rapier gravitating process and to provide theoretical guidance and design implications in engineering, the theoretical model of this research can also examine the influence of gravity, rapier material, rapier dimension, and other variables on the oscillation of the rigid rapier gravitation process.

Influence of materials and processes on the robustness of apparent porosity control methods for fair-faced concrete

Fair-faced concrete is a new type of concrete that directly uses the surface of concrete as the facing, with good surface integrity, no chiseling and repairing after forming, and no need for decoration. In recent years, it has developed rapidly after being introduced into China, but there are some problems, the stability of pore control is difficult and the formation mechanism is insufficient. It also exists chromatic aberration. Aiming at the formation mechanism of apparent pores in fair-faced concrete, by changing raw materials and mix ratio of fair-faced concrete, adjusting raw materials, construction process and formwork parameters, this paper put forward the control interval of high robustness parameters of fair-faced concrete with few apparent pores and excellent aesthetic grade. It makes it possible to prepare fair-faced concrete repeatedly and stably with a good economy. It also has good guiding significance for practical projects. The material parameters included initial gas content, maximum particle size of coarse aggregate, plastic viscosity coefficient, initial dynamic yield stress and bleeding rate. Construction process parameters included vibration frequency, vibration time and vibration amplitude. Formwork parameters included release agents with different contact angles. The results show that the initial gas content of the fair-faced concrete slurry was 2%–3%, the particle size of the coarse aggregate was 5 mm–25 mm, the plastic viscosity coefficient of the fair-faced concrete slurry was 5 Pa·s-10 Pa s, the yield stress was 100 Pa–200 Pa, the water secretion rate was 8%–10 %, and the vibration frequency was 10,000 times/min-12,000 times/min. When the vibration time was 20 s–25 s, the vibration amplitude was 1.0 mm–1.2 mm, and the contact angle was 102°–112°, the apparent porosity of the fair-faced concrete could be controlled well.

Picking up Good Vibrations through Quartic Force Fields and Vibrational Perturbation Theory.

Quartic force fields (QFFs) define sparse potential energy surfaces (compared to semiglobal surfaces) that are the cheapest and easiest means of computing anharmonic vibrational frequencies, especially when utilized with second-order vibrational perturbation theory (VPT2). However, flat and shallow potential surfaces are exceedingly difficult for QFFs to treat through a combination of numerical noise in the often numerically computed derivatives and in competing energy factors in the composite energies often utilized to provide high-level spectroscopic predictions. While some of these issues can be alleviated with analytic derivatives, hybrid QFFs, and intelligent choices in coordinate systems, the best practice is for predicting good molecular vibrations via QFFs is to understand what they cannot do, and this manuscript documents such cases where QFFs may fail.

Synchronized shock wave and compliant wall interactions: Experimental characterization and aeroelastic modeling

The static and dynamic interaction of a normal shock wave (upstream Mach number 1.35) with a compliant wall is characterized experimentally by schlieren visualizations and an optical displacement sensor. Depending on the location of the shock wave along the compliant wall, three different regimes of interaction are found: large-amplitude synchronized regime, small-amplitude synchronized regime and unsynchronized regime. The regime of large-amplitude synchronized oscillations is found for shock locations close to the mid-point of the compliant wall along the streamwise direction; at this location, the coupled system locks to the second vibration frequency of the structure. Three regimes of small-amplitude synchronized oscillations are found depending on the shock position. When the shock is located upstream the center of the compliant wall, the shock may oscillate either periodically at the frequency of the first vibration mode or quasi-periodically with highest amplitudes at the three frequencies of the vibration modes. When the shock is located downstream the center of the compliant wall, the shock oscillates periodically at the frequency of the third vibration mode. Finally, close to the trailing edge of the compliant wall, the shock oscillation is not synchronized with the compliant wall which oscillates with a very small amplitude. An empirical model is proposed to investigate the energy exchange between the flow and the compliant wall during the limit cycle oscillations. A negative aerodynamic damping – and, hence, the possibility of a limit cycle – is observed when a sufficiently extended separation is considered in the model for the pressure distribution at the wall.

The molecular structure and spectra of diphenylmethane under the external electric field

Diphenylmethane (DPM) is an important raw material for organic synthesis. Due to its wide range of application, it has become a research hotspot. To study the effect of external electric field (EEF) on DPM, density functional theory (DFT) is employed to optimize the ground state geometry of DPM under electrostatic fields of 0–0.0125 a.u. (0–0.6428 × 1010 V/m), and the molecular total energy is obtained. On this basis, the vibrational frequencies of DPM under EEF are calculated, and its infrared (IR) spectra are obtained. Finally, the time-dependent density functional theory (TDDFT) is employed to investigate the change in the UV–Vis spectra of DPM under EEF. The results indicate that EEF has strong impact on the molecular geometry configuration. With the enhancement of EEF, the vibration Stark effect of IR spectra is obvious, the UV–Vis absorption peaks are significantly redshift, and the molecule molar absorption coefficient decreases gradually. This work provides theoretical support for the wider application, as well as reference significance for other aromatic compounds.

Effects of vibration on natural convection in a square inclined porous enclosure filled with Cu-water nanofluid

PurposeThe purpose of this paper is to investigate the effects of gravitational modulation on natural convection in a square inclined porous cavity filled by a fluid containing copper nanoparticles.Design/methodology/approachThe present study uses a system of equations that couple hydrodynamics to heat transfer, representing the governing equations of fluid flow in a square domain. The Boussinesq–Darcy flow with Cu-water nanofluid is considered. The dimensionless partial differential equations are solved numerically using finite difference method based on alternating direction implicit scheme. The cavity is differentially heated by constant heat flux, while the top and bottom walls are insulated. The authors examined the effects of gravity amplitude (λ), vibration frequency (σ), tilt angle (α) and Rayleigh number (Ra) on flow and temperature.FindingsThe numerical simulations, in the form of streamlines, isotherms, Nusselt number and maximum stream function for different values of amplitude, frequency, tilt angle and Rayleigh number, have revealed an oscillatory behavior in the development of flow and temperature under gravity modulation. An increase of amplitude from 0.5 to 1 intensifies the flow stream (from |ψmax| = 21.415 to |ψmax| = 25.262) and improves heat transfer (from Nu¯ = 17.592 to Nu¯ = 20.421). Low-frequency vibration below 50 has a significant impact on the flow and thermal distributions. However, once this threshold is exceeded, the flow weakens, leading to a gradual decrease in heat transfer rate. The inclination angle is an effective parameter for controlling the flow and temperature characteristics. Thus, transitioning the tilt angle from 30° to 60° can increase the flow velocity (from 22.283 to 23.288) while reducing the Nusselt number (from 16.603 to 13.874). Therefore, by manipulating the combination of vibration and inclination, it is founded that for a fixed frequency value of σ = 100 and for increased amplitude (from 0.5 to 1), the flow intensity at inclination of 60° is boosted, and an increase of the heat transfer rate at inclination of 30° is also observed. Convective thermal instabilities may arise depending on the different key factors.Originality/valueTo the best of the authors’ knowledge, this study is original in its examination of the combined effects of modulated gravity and cavity inclination on free convection in nanofluid porous media. It highlights the crucial roles of these two important factors in influencing flow and heat transfer properties.

A Low-Frequency Vibration Sensor Based on Ball Triboelectric Nanogenerator for Marine Pipeline Condition Monitoring.

Marine pipeline vibration condition monitoring is a critical and challenging issue, on account of the complex marine environment, while powering the required monitoring sensors remains problematic. This study introduces a vibration sensor based on a ball triboelectric nanogenerator (B-TENG) for marine pipelines condition monitoring. The B-TENG consists of an acrylic cube, polyester rope, aluminum electrodes, and PTFE ball, which converts vibration signals into electrical signals without the need for an external energy supply. The experimental results show that B-TENG can accurately monitor the frequency, amplitude, and direction of vibration in the range of 1-5 Hz with a small error of 0.67%, 4.4%, and 5%, and an accuracy of 0.1 Hz, 0.97 V/mm, and 1.5°, respectively. The hermetically sealed B-TENG can monitor vibration in underwater environments. Therefore, the B-TENG can be used as a cost-effective, self-powered, highly accurate vibration sensor for marine pipeline monitoring.

Structure, Tautomeric, and intramolecular hydrogen bond of Difluorobenzoylacetone; IR, UV, NMR, and quantum calculation studies

The molecular structure, tautomerism, spectroscopy properties, and intramolecular hydrogen bonding of 4,4-difluoro-1-phenyl-1,3-butanedione, also known as difluorobenzoylacetone (DFBA), have all been analyzed using density functional theory (DFT) calculations and spectroscopic techniques (IR, UV, and NMR). The results were compared with previously reported values for trifluorobenzoylacetone (TFBA) and benzoylacetone (BA). The energy difference between the two stable cis-enol forms,calculated at the B3LYP/6–311++G** level, is 0.96 kcal/mol.Therefore, the coexistence of both forms in comparable ratios is possible, as revealed by comparing the calculated and experimental vibrational band frequencies and their intensities. Furthermore,various computational methods were employed to examine the intramolecular hydrogen bond (IHB) strength and molecular stability,including geometry, atoms in molecules (AIM), and natural bond orbitals (NBO) theories. The hydrogen bond strength of DFBA falls between that of BA and TFBA, beinggreater than TFBA but lower than BA. Transition state study show that tautomerism between both forms occurs via the proton transfer.

Fluorescence Excitation and Dispersed Fluorescence Spectra of the First Electronic Excited (S1) State of peri-Hexabenzocoronene (C42H18) Isolated in Solid para-Hydrogen.

Large polycyclic aromatic hydrocarbons (PAH) and their cationic, hydrogenated, and protonated derivatives have long been considered as promising candidates for the carriers of the diffuse interstellar bands. peri-Hexabenzocoronene (peri-HBC, C42H18) is a large, compact PAH, and, to the best of our knowledge, the largest centrosymmetric all-benzenoid PAH for which electronic spectroscopy data has been published. In this work, we present the dispersed fluorescence and fluorescence excitation spectra of the first electronic excited (S1) state of peri-HBC isolated in solid para-H2 and provide the first detailed vibronic analysis of observed features. The observed spectra agree with the emission and absorption spectra simulated according to optimized geometries and scaled harmonic vibrational frequencies calculated at the density functional theory (DFT) level using a Franck-Condon Herzberg-Teller approach; the spectral bands are associated solely with vibrational normal modes of approximate e2g symmetry and their combinations with vibrational modes of approximately a1g symmetry. We clearly observed the position of the S1-S0 electronic transition origin of peri-HBC at 22,088 cm-1 (452.7 nm), which was unreported previously. The matrix shift of ∼110 cm-1 to the red relative to the gas-phase value was estimated by comparison of two reported gas-phase bands with our work. Because of the significant deviation from the reported wavelengths of DIB, the weakness of the S1-S0 electronic transitions, and the lack of reported DIB at <400 nm where the intense S4 ← S0 band of peri-HBC is located, peri-HBC is unlikely to contribute to DIB.

Structural design and multi-objective optimization of an MR isolator based on flow valve-cone rubber structure

Due to the distinctive working environment of high precision machining and manufacturing field, it poses challenges in meeting the isolation requirements, including limited installation space, multi-dimensional vibration, and a wide range of vibration frequencies. To tackle these obstacles, this paper introduces a magnetorheological (MR) isolator that offers adjustable vertical damping characteristics while guaranteeing three-axis vibration isolation through an inclined cone structure. First, the structure of the isolator was designed by combining a flow valve damper with a conical rubber structure. Second, in pursuit of lightweight design and enhanced magnetic field strength, collaborative simulations using ANSYS and Maxwell are conducted to subject the critical components of the isolator to multi-objective optimization. The optimization results demonstrate that the mass of the isolator has been reduced by approximately 27.7%, while the magnetic field intensity has increased by around 20%. Finally, the performance of the MR isolator was verified through static testing and dynamic testing, respectively. The experimental results demonstrate that the isolator can generate a maximum damping force of approximately 778[Formula: see text]N when exposed to a current of 1.5[Formula: see text]A. Compared to the initial value of 445.06[Formula: see text]N at 0[Formula: see text]A, there has been an approximate increase of 1.74 times.

THE ENERGY BALANCE METHOD COUPLED WITH THE GALERKIN METHOD FOR LOCAL FRACTIONAL NONLINEAR OSCILLATION

The method of solving the vibration frequency of local fractional nonlinear oscillators under general initial conditions is studied by coupling the energy balance method with the Galerkin method. One test case of fractional vibration is given to prove the feasibility of this method.

Sowing Performance of the Seeder Drill for the 2BYG-220 Type Combined Rapeseed Planter under Vibration Conditions

The direct sowing of rapeseed requires shallow tillage for stubble removal, which can cause significant vibrations that impact the seed metering device, thereby affecting the quality of seeding. This study focuses on a double-row hole-wheel-type seed metering device on the 2BYG-220 type combined rapeseed planter. Initially, vibrations experienced by the seed drill during field operations were measured and analyzed, revealing that the vibration frequencies during field operations predominantly ranged between 0 and 25 Hz. Consequently, an eccentric wheel–return-spring-type vibration seed metering test rig was designed, manufactured, and set up. By swapping out the eccentric wheel on the test rig, the amplitude was mainly concentrated within 3 mm. The test results indicate that amplitude had a minimal impact on the performance of the double-row hole-wheel-type rapeseed seed metering device, whereas vibration frequency had a more significant effect. When the vibration frequency was between 0 and 10 Hz, the seed metering device maintained a stable output between 7.6 and 8.2 g/min, with minimal impact from vibrations: the coefficient of variation for seeding uniformity ranged between 35.81% and 44.58%, indicating stability and good uniformity. However, when the vibration frequency ranged from 10 to 24 Hz, the output of the seed metering device decreased rapidly and exhibited a linear relationship with frequency changes, with a determination coefficient (R2) of 0.92376. The coefficient of variation for seeding uniformity increased rapidly and also showed a linear relationship with frequency changes, with a determination coefficient (R2) of 0.87973. Vibrations with frequencies greater than 10 Hz had a considerable impact on the performance of the seed metering device.

Synthetic route for O,S‐coordinated organotin (IV) aldehydes: Spectroscopic, computational, XRD, and antibacterial studies

Numerous synthetic routes have been established for the synthesis of organotin (IV) derivatives of carboxylates, thiocarbamates, thiols, alcohols, amines, Schiff bases, etc. However, no synthetic path has been still developed for the synthesis of organotin (IV) aldehydes. We have synthesized four O,S‐coordinated organotin (IV) aldehydes (1–4) of the general formulas LSn(S)(Cl)R2 (where R2 = Me2, n‐Bu2, Ph2 for 1–3, respectively) and LSn(S)Ph3 (4) by reaction of 4‐(dimethylamino)benzaldehyde (L) with KOH, CS2, and R2SnCl2/Ph3SnCl in methanol. The synthesized products were characterized by microanalysis (CHN), FT‐IR analysis, UV–visible spectroscopy, NMR spectroscopy (1H and 13C), thermogravimetric analysis (TGA), computational studies, and single‐crystal XRD. Elemental analysis data were agreed well with the molecular composition of the products. FT‐IR spectroscopy has shown a significant lowering of C=O vibrational frequency after ligand–metal coordination. The electronic spectroscopy of complexes 1–4 demonstrated the π–π* (342–343 nm) and n–π* (279–296 nm) transitions, with the band gap values of 3.15–3.38 eV. 1H NMR spectra displayed distinct signals for the ligand skeleton and organotin (IV) moieties. 13C NMR spectroscopy exhibited an upfield shift of carbonyl oxygen after ligand–metal coordination. The thermogravimetric analysis revealed the thermal stabilities of complexes up to a temperature of 190 to 320°C. Single‐crystal XRD analysis of product 4 has shown a distorted trigonal bipyramidal geometry around Sn (IV), in which the three phenyl groups were positioned equatorially while the carbonyl oxygen (from the aldehyde) and the sulfur atom occupied the apical positions. Employing the 6‐31G(d,p) basis set and the CAM‐B3LYP functional, time‐dependent density functional theory (TD‐DFT) computations were performed for the calculation of absorbance maxima, oscillator strength (f), and matching molecular designations. MEP maps and HOMO–LUMO energy gaps were predicated on the CAM‐B3LYP/6‐31+g(d,p) level of theory and were used to resolve GRD, including chemical potential (μ), global hardness (η), global softness (S), electronegativity (χ), electrophilicity (ω), ionization potential (IP), and electron affinity (EA). The phenyltin (IV) derivatives (3 and 4) have shown a fantastic biofilm inhibition of Escherichia coli, which was even higher as compared with that of the reference drug ciprofloxacin. The bioactivity of 2 against Bacillus subtilis was equivalent to that of the ciprofloxacin. The products 2 and 3 have shown very little (less than 10%) toxic hemolytic effects demonstrating their possible safe use for the human beings.

Effect of Excitation Vibration at Different Frequencies on Pick Cutting

The pick vibration model was established and analyzed, and discussed the influence of vibration at different frequencies on the cutting load. Then a discrete element model of the interface coal seam is established in EDEM to analyze the change of cut load at different vibration frequencies. The conclusion shows that it is more suitable to apply high frequency vibration when the coal seam content is high, and it is more suitable to apply low frequency vibration when the rock layer content is more.

Processing and analysis of friction vibration signal of diamond-like carbon film microtextured dry gas seal rings

PurposeThis paper aims to analyze the characteristics of friction vibration signals and identify the vibration excitation source at the start and stop stage of microtextured end face of dry gas seals.Design/methodology/approachThe friction pair consists of a diamond-like carbon (DLC) film microtextured seal ring and a spiral groove seal ring. Friction vibration signal feature extraction method based on harmonic wavelet packet and spectrum analysis was proposed. Signals were collected using acceleration sensor, acquisition card and LabVIEW software. Vibration acceleration signal was decomposed into 32 frequency bands using MATLAB wavelet packet transformation. The 32nd band coefficient was extracted for reconstruction, time-domain and spectral waveforms were obtained and spectra before/after denoising were compared.FindingsThe end face of the DLC film microtextured seal ring generates a good dynamic pressure effect, and the friction and vibration reduction effects are obvious. The harmonic wavelet packet can decompose the vibration signal conveniently and precisely. In the case of this experiment, the frequency of vibration of the seal ring is 7500 HZ.Originality/valueThe results show that the method is effective for the processing of friction vibration signal and the identification of vibration excitation source. The findings will provide ideas for the frictional vibration signal processing and basis for further research in the field of tribology of dry gas seal ring.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0084/

Non-destructive vibration-based monitoring analysis of PV modules with encapsulant degradation by frequency change

In engineering applications, the frequency analysis represents a first and practical step to collect relevant parameters for structural and mechanical diagnostics. Any possible material / component degradation and deterioration can be prematurely detected by frequency modifications that exceed a certain alert value. In this paper, the attention is given to the dynamic mechanical analysis of commercial photovoltaic (PV) modules, in which the solar cells are typically encapsulated in thin viscoelastic interlayers made of Ethylene-Vinyl Acetate (EVA), which are primarily responsible for the load-bearing capacity of the sandwich PV system. As a major effect of ageing, ambient conditions, non-uniform / cyclic thermal gradients, humidity and even extreme mechanical / thermal loads, the rigidity of these films can largely modify and decrease, thus possibly affecting the mechanical capacity of the PV module, and even exposing the solar cells to fault. Knowledge of the effective bonding level is an important step for diagnostic purposes. In this regard, the present study is based on a preliminary non-destructive experimental analysis, and on an extensive parametric Finite Element (FE) numerical investigation of full-scale commercial PV modules of typical use in buildings. The attention is given – for PV module arrangements of technical interest – to the effect of EVA stiffness in terms of vibration modes and frequency sensitivity. As shown, especially compared to newly installed PV modules, any kind of stiffness decrease is associated to major frequency modifications for the composite system, and in the worst configuration, such a frequency scatter can decrease down to −40% the original condition. Such a marked stiffness decrease would be implicitly associated to a weak mechanical performance of the sandwich section, with major stress peaks and deflections in the PV system, even under ordinary loads. The presented results, in this sense, suggest that major consequences can be prevented and minimized by monitoring the vibration frequency of PV modules.

Intrinsic features of flow-induced stability of a square cylinder

Vortex-induced vibrations and galloping of an elastically mounted square cylinder are investigated for cylinder mass ratio m* = 2–50, damping ratio ζ = 0–1.0, mass-damping ratio m*ζ = 0–50 and flow reduced velocity Ur = 1–80. We home in on the effects of m*, ζ, m*ζ, $({m^\ast } + m_{a\textrm{0}}^\ast )\zeta$ and $({m^\ast } + m_{ae}^\ast )\zeta$ on the critical reduced velocity Urc marking the onset of galloping, where $m_{a\textrm{0}}^\ast $ is the quiescent-fluid added mass ratio and $m_{ae}^\ast $ is the effective added mass ratio. Vibration responses, forces, vibration frequencies and added mass ratios are studied and discussed. The different branches of vortex-induced vibrations have different dependencies of $m_{ae}^\ast $ on Ur. The $m_{ae}^\ast $ in the initial branch is positive and drops rapidly with Ur, but that in the lower branch is negative and declines gently. In the galloping regime, $m_{ae}^\ast $ jumps from negative to positive at the onset of galloping, declining slightly with increasing Ur. Our results and prediction equations show that when ζ = 0, Urc is independent of m* for m* ≥ 5, albeit slightly higher for m* = 3. The latter is ascribed to mode competition. When ζ &gt; 0, Urc linearly increases with increasing ζ. Detailed analysis substantiates that m*ζ or $({m^\ast } + m_{a\textrm{0}}^\ast )\zeta$ does not serve as the unique criterion to predict the galloping occurrence. Here, we propose a new combined mass-damping parameter $({m^\ast } + m_{ae}^\ast )\zeta$ in the relationship between galloping onsets and structural properties, which successfully scales all data of Urc at different m* and ζ values.

Extraction and evaluation of cable forces of a cable-stayed bridge based on amplitude and phase estimation method

In order to identify the time-varying frequency and amplitude of structural vibration based on the bridge structural health monitoring data and obtain the cable force of cable-stayed bridges in real time, a spectrum analysis method based on amplitude and phase estimation (APES) was proposed in this study. The amplitude spectrum of the acceleration data is first calculated by the APES method, the real-time spectrogram of the cable is obtained by the sliding window method. Then the modal frequency and amplitude are automatically extracted from the real-time spectrum by using a frequency extrusion post-processing technique, which can be regarded as the average value of the instantaneous frequency and amplitude respectively. Next, the fundamental frequency of the cable is extracted by using an automatic identification method, and the performance of the proposed method is verified. Finally, real-time scoring of cable forces and structural condition assessment is achieved with consideration of the moderation index model as well as the material strength. The results show that the APES method can use shorter calculation samples than the traditional Fast Fourier Transform (FFT) to obtain higher resolution and more accurate amplitude, which provides a theoretical basis for the real-time identification of fundamental frequency based on short-term monitoring data. The frequency extrusion post-processing-algorithm can reduce the spectrum recognition delay and improve timeliness of the cable force evaluation. The time-varying cable force with an interval of 10 s can be used to reflect the health status of the cable in time. The research results can provide technical support for the real-time extraction of cable force of long-span cable-stayed bridges, and can also provide an effective basis for component condition evaluation and bridge maintenance decision-making.

Simulation and experimental studies on surface quality of vibration-assisted ECM

ABSTRACT Electrochemical machining (ECM) offers a superior technology for manufacturing hard-cutting metals such as modified Inconel 718 (IN718). However, in many cases, poor surface quality arises because of the specific dissolution characteristics of the material, hindering further application of the process. Vibration-assisted ECM (VA-ECM) has been proposed in the hope of solving the problem by oscillating the cathode. A multiphysics model was developed for pulsed ECM (PECM) and VA-ECM. Systematic experiments were performed to clarify the mechanism of cathode oscillation on surface quality and verify the computational results. With 20 Hz vibration frequency and 25% duty cycle, the surface roughness reaches 0.39 µm, show that higher oscillation frequency and lower duty cycle are effective in improving surface quality. Finally, dissolution models of modified IN718 under PECM and VA-ECM are proposed. By oscillating the cathode, electrolyte fluctuation is enhanced, electrolytic products are removed effectively, the surface quality is improved significantly.

Investigation on Hirshfeld surface analysis, molecular geometry, DFT, MEP, and molecular docking analysis on benzotriazole oxalate against SARS-CoV-2 virus

Investigation on DFT, Molecular docking, Hirshfeld surface analysis, ADME characteristics Molecular Geometry, FT-IR, MEP analysis, and UV–Vis studies of Benzotriazole oxalate (BTO) is discussed here. BTO belongs to the monoclinic system with space group P21/c. BTO is a tiny chemical that interacts well with the SARS-CoV-2, based on small molecule docking studies with the target protein. The estimated vibrational frequencies (Fourier Transforms –Infrared spectrum) of the BTO molecule are compared and it exhibits excellent agreement with the experiment. The strengthening of protein-ligand electrostatic interactions is made possible by MEP. Using a 2D fingerprint plot and Hirshfeld Surfaces, the chemical surface and hydrogen bonding interactions in the BTO crystal structure were located and examined. Density Functional Theory (DFT)-B3LYP calculations using the 6–31++G (d, p) basis set predict the optimal geometry, including the bond length and bond angle of BTO. The characteristics of absorption, distribution, metabolism, and excretion were examined using the preADMET web server.