Duty Factor Research Articles

Study on Electrically Modulated Quasi-Continuous Wave Fe: ZnSe Solid-State Laser with Hundred-Hertz.

Iron-doped binary chalcogenide crystals are very promising for tunable solid-state lasers operating over the 3~5 μm spectral range. Fe: ZnSe is one of the most important gain crystals with the obvious advantages of material characteristics and conversion efficiency. By adjusting the output mode of the pump source, an Fe: ZnSe laser can operate in two modes at liquid nitrogen temperatures: continuous wave (CW) and pulse output. In terms of CW output, the Fe: ZnSe laser obtained a maximum 2.63 W continuous power output which was confined to the power of the pump source. An optical-to-optical efficiency of 47.05% was acquired. Direct electrical modulation was applied to the pump source. The highest average power of the quasi-CW laser, whose central wavelength is 4.02 μm, has a value of 253 mW with an optical-to-optical efficiency of 42.88% and a full width at half maximum (FWHM) of 23 nm when the pulse frequency is 100 Hz of 10% duty factor. The output waveform is consistent with the modulation waveform applied to the pump source. We report to the first of our knowledge an electrically modulated quasi-CW Fe: ZnSe laser in the pulse regime, equipped with features of compactness in structure, ignoring additional modulators, convenience in control, high efficiency, and sustainable operation, of great interest for solving numerous scientific and applied problems.

Ultrasonic Vibration-assisted Electrochemical Discharge Machining of Quartz Wafer Micro-Hole Arrays

The micro-hole machining of quartz wafers depends on photolithography techniques akin to those used in semiconductor fabrication. These methods present challenges due to high equipment setup costs, large space requirements, and environmental pollution risks. This research applies ultrasonic vibration assistance in electrochemical discharge machining to create an array of micro-holes on quartz wafers. In the experiments, a self-prepared tungsten carbide micro-electrode array served as the tool electrode. This electrode was a 2 × 2 square array, with needles measuring 30 × 30 μm. A series of experiments was conducted to investigate the effects of various machining parameters, including working voltage, feed rate, duration time, duty factor, and ultrasonic power level, on the characteristics of the micro-hole array. The characteristics included average hole diameter and through-hole surface morphology. The experimental objective was to achieve a through-hole diameter of 80 μm with an accuracy of ±8 μm. During the electrochemical discharge machining, suitable ultrasonic vibrations can thin the insulating gas film coating on the electrode surface, resulting in a more uniform gas film. As the insulating gas film’s thickness decreased, so did the critical voltage needed for the electrochemical discharge machining, reducing the hole’s diameter expansion. The ultrasonic vibration assistance can enable the satisfaction of the dimensional accuracy requirement. The experimental results indicate that ultrasonic vibration assistance can effectively improve the processing capacity and reduce sample fragmentation. A working voltage of 44 V, feed rate of 1 μm/6 s, duration time of 30 μs, duty factor of 30%, and ultrasonic power level of 1 resulted in better inlet and outlet surface morphology without outlet fragmentation. Moreover, the average diameters of the inlet and outlet were roughly 80 μm while meeting the through-hole diameter of 80 μm with accuracy of ±8 μm.

Nanoparticle Incorporation to Enhance Titanium Alloy Electric Discharge Machining Capabilities

The primary objective of this study was to examine the effects of the Powder-blended Micro Electric Discharge Machining (PMEDM) technique on micromachining applications, specifically when sea water is employed as the dielectric medium. Tiny apertures with a width of 200µm were punctured over Ti-6Al-4V plates. In the initial round of experimentation, the machining performance was evaluated by subjecting sea water to various process variables without the inclusion of any other ingredients. The effects of input variables, including electrode material, hole voltage, current, Pulse-on-time, and Duty factor, on the Material Removal Rate (MRR), Tool Wear Rate (TWR), Overcut (OC), Circularity Error (CE), and Taper Ratio (TR) were analysed by conducting tests in accordance with Taguchi's L18 plan design. The method employed to ascertain the optimal parametric configuration for multi-objective enhancement involved utilising the strategy of soliciting inclination based on similarity to an ideal arrangement. The present study aimed to investigate the effects of foreign materials on the dielectric-based miniature electrical discharge machining (EDM) process in sea water. This was achieved by utilising powders with varying weight concentrations and molecule sizes, including non-conductive (Al2O3), semi-conductive (SiC), and conductive (Al) powders. The experimental setup ensured that the variable boundaries were maintained at their ideal settings. The results indicate that the choice of tool has a notable influence on the functioning of micro EDM when sea water is employed as the dielectric, without the inclusion of extraneous particles. The performance metric of multi-objective execution in PMEDM is influenced by the conductivity of supplementary compounds. An 83.18 percent increase in Material Removal Rate (MRR) was observed when SiC added compounds were utilised in Powder Mixed Electrical Discharge Machining (PMEDM). Conversely, there was a drop in Tool Wear Rate (TWR) by 36.42 percent, Open Circuit voltage (OC) by 21.48 percent, Current Efficiency (CE) by 45.15 percent, and Tool Roughness (TR) by 22.87 percent.

A longitudinal rat model for assessing postoperative recovery and bone healing following tibial osteotomy and plate fixation

BackgroundRodent models are commonly employed to validate preclinical disease models through the evaluation of postoperative behavior and allodynia. Our study investigates the dynamic interplay between pain and functional recovery in the context of traumatic osteotomy and surgical repair. Specifically, we established a rat model of tibial osteotomy, followed by internal fixation using a 5-hole Y-plate with 4 screws, to explore the hypothesis that histological bone healing is closely associated with functional recovery.ObjectiveOur primary objective was to assess the correlation between bone healing and functional outcomes in a rat model of tibial osteotomy and plate fixation.MethodsSeventeen male Sprague–Dawley rats underwent a metaphyseal transverse osteotomy of the proximal tibia, simulating a fracture-like injury. The resultant bone defect was meticulously repaired by realigning and stabilizing the bone surfaces with the Y-plate. To comprehensively assess recovery and healing, we performed quantitative and qualitative evaluations at 2, 4, 6, and 8 weeks post-surgery. Evaluation methods included micro-CT imaging, X-ray analysis, and histological examination to monitor bone defect healing. Concurrently, we employed video recording and gait analysis to evaluate functional recovery, encompassing parameters such as temporal symmetry, hindlimb duty factor imbalance, phase dispersion, and toe spread.ResultsOur findings revealed complete healing of the bone defect at 8 weeks, as confirmed by micro-CT and histological assessments. Specifically, micro-CT data showed a decline in fracture volume over time, indicating progressive healing. Histological examination demonstrated the formation of new trabecular bone and the resolution of inflammation. Importantly, specific gait analysis parameters exhibited longitudinal changes consistent with bone healing. Hindlimb duty factor imbalance, hindlimb temporal symmetry, and phase dispersion correlated strongly with the healing process, emphasizing the direct link between bone healing and functional outcomes.ConclusionsThe establishment of this tibia osteotomy model underscores the association between bone healing and functional outcomes, emphasizing the feasibility of monitoring postoperative recovery using endpoint measurements. Our overarching objective is to employ this model for assessing the local efficacy of drug delivery devices in ameliorating post-surgical pain and enhancing functional recovery.

Analyzing beam-gas interactions in an cyclotron beam

For the Isotope Decay At Rest (IsoDAR) experiment in neutrino physics (searching for sterile neutrinos), we have developed a novel compact isochronous cyclotron with direct injection through an axially embedded RFQ. For IsoDAR to be decisive within five years of running, 10 mA of protons, cw at 80% duty factor are needed on a neutrino production target. To alleviate space charge in the cyclotron driver, we accelerate 5 mA of , to be broken up into 10 mA of protons after extraction from the cyclotron. An open question that we are answering with this paper is whether the beam losses from gas-stripping (the removal of electrons from through the interaction of the beam ions with the residual gas in the accelerator) are going to be a significant challenge. Using a newly added feature to the well-established Object-Oriented Parallel Accelerator Library code, we calculate gas-stripping losses in the IsoDAR cyclotron using realistic beam distributions, magnetic fields, gas composition, and pressure. We show that to maintain losses due to dissociation below 1% over the entire acceleration region, a vacuum of at least 6 × 10−7 mbar is required.

Reference Values and Determinants of Spatiotemporal and Kinetic Variables in Recreational Runners.

Identifying atypical lower limb biomechanics may help prevent the occurrence or recurrence of running-related injuries. No reference values for spatiotemporal or kinetic variables in healthy recreational runners are available in the scientific literature to support clinical management. To (1) present speed- and sex-stratified reference values for spatiotemporal and kinetic variables in healthy adult recreational runners; (2) identify the determinants of these biomechanical variables; and (3) develop reference regression equations that can be used as a guide in a clinical context. Descriptive laboratory study. This study involved 860 healthy recreational runners (age, 19-65 years [38.5% women]) tested on an instrumented treadmill at their preferred running speed in randomly allocated, standardized running shoes with either hard or soft cushioning. Twelve common spatiotemporal and kinetic variables-including contact time, flight time, duty factor, vertical oscillation, step cadence, step length, vertical impact peak (VIP), time to VIP, vertical average loading rate, vertical stiffness, peak vertical ground-reaction force (GRF), and peak braking force-were derived from GRF recordings. Reference values for each biomechanical variable were calculated using descriptive statistics and stratified by sex and running speed category (≤7, 8, 9, 10, 11, 12, 13, 14, and ≥15 km/h). Correlations and multiple regression analyses were performed to identify potential determinants independently associated with each biomechanical variable and generate reference equations. The mean running speed was 10.5 ± 1.3 km/h and 9 ± 1.1 km/h in men and women, respectively. While all potential predictors were significantly correlated with many of the 12 biomechanical variables, only running speed showed high correlations (r > 0.7). The adjusted R2 of the multiple regression equations ranged from 0.19 to 0.88. This study provides reference values and equations that may guide clinicians and researchers in interpreting spatiotemporal and kinetic variables in recreational runners. The reference values can be used as targets for clinicians working with recreational runners in cases where there is a clinical suspicion of a causal relationship between atypical biomechanics and running-related injury.

Metabolic cost and mechanical work of walking in a virtual reality emulator.

The purpose of this study was to investigate the metabolic cost (C), mechanical work, and kinematics of walking on a multidirectional treadmill designed for locomotion in virtual reality. Ten participants (5 females, body mass 67.2 ± 8.1kg, height 1.71 ± 0.07m, age 23.6 ± 1.9years, mean ± SD) walked on a Virtuix Omni multidirectional treadmill at four imposed stride frequencies: 0.70, 0.85, 1.00, and 1.15Hz. A portable metabolic system measured oxygen uptake, enabling calculation of C and the metabolic equivalent of task (MET). Gait kinematics and external, internal, and total mechanical work (WTOT) were calculated by an optoelectronic system. Efficiency was calculated either as WTOT/C or by summing WTOT to the work against sliding frictions. Results were compared with normal walking, running, and skipping. C was higher for walking on the multidirectional treadmill than for normal walking, running, and skipping, and decreased with speed (best-fit equation: C = 20.2-27.5·speed + 15.8·speed2); the average MET was 4.6 ± 1.4. Mechanical work was higher at lower speeds, but similar to that of normal walking at higher speeds, with lower pendular energy recovery and efficiency; differences in efficiency were explained by the additional work against sliding frictions. At paired speeds, participants showed a more forward-leaned trunk and higher ankle dorsiflexion, stride frequency, and duty factor than normal walking. Walking on a multidirectional treadmill requires a higher metabolic cost and different mechanical work and kinematics than normal walking. This raises questions on its use for gait rehabilitation but highlights its potential for high-intensity exercise and physical activity promotion.

Performance Level Affects Full Body Kinematics and Spatiotemporal Parameters in Trail Running-A Field Study.

Trail running is an emerging discipline with few studies performed in ecological conditions. The aim of this work was to investigate if and how biomechanics differ between more proficient (MP) and less proficient (LP) trail runners. Twenty participants (10 F) were recruited for a 9.1 km trail running time trial wearing inertial sensors. The MP athletes group was composed of the fastest five men and the fastest five women. Group differences in spatiotemporal parameters and leg stiffness were tested with the Mann-Whitney U-test. Group differences in joint angles were tested with statistic parametric mapping. The finish time was 51.1 ± 6.3 min for the MP athletes and 60.0 ± 5.5 min for the LP athletes (p < 0.05). Uphill sections: The MP athletes expressed a tendency to higher speed that was not significant (p > 0.05), achieved by combining higher step frequency and higher step length. They showed a tendency to shorter contact time, lower duty factor and longer flight time that was not significant (p > 0.05) as well as significantly lower knee flexion during the stance phase (p < 0.05). Downhill sections: The MP athletes achieved significantly higher speed (p < 0.05) through higher step length only. They showed significantly higher knee and hip flexion during the swing phase as well as higher trunk rotation and shoulder flexion during the stance phase (p < 0.05). No differences were found with respect to leg stiffness in the uphill or downhill sections (p > 0.05). In the uphill sections, the results suggest lower energy absorption and more favorable net mechanical work at the knee joint for the MP athletes. In the downhill sections, the results suggest that the more efficient motion of the swing leg in the MP athletes could increase momentum in the forward direction and full body center of mass' velocity at toe off, thus optimizing the propulsion phase.

Larger Achilles and plantar fascia induce lower duty factor during barefoot running

ObjectivesTendons play a crucial role allowing the storage and release of mechanical energy during the running cycle. Running kinematics, including duty factor, constitute a basic element of the runner's biomechanics, and can determine their performance. This study aimed to analyze the link between Achilles tendon and plantar fascia morphology and running parameters, considering the influence of wearing shoes versus running barefoot. DesignCross-sectional study. Methods44 participants (30 men and 14 women) engaged in two running sessions, one with shoes and one without, both lasting 3 min at a consistent speed of 12 km/h. We captured running kinematic data using a photoelectric cell system throughout the sessions. Before the trials, we measured the thickness and cross-sectional area of both the Achilles tendon and plantar fascia using ultrasound. ResultsThe Pearson test revealed a significant correlation (p < 0,05) between Achilles tendon and plantar fascia morphology and contact time (r > −0.325), flight time (r > −0.325) and duty factor (ratio of ground contact to stride time) (r > −0.328) during barefoot running. During the shod condition, no significant correlation was found between connective tissue morphology and kinematic variables. ConclusionsIn barefoot running, greater size of the Achilles tendon and plantar fascia results in a reduced duty factor, attributed to longer flight times and shorter contact times.

Effects of particle size and thickness of quartz sand on the webbed foot kinematics of mallard (Anas platyrhynchos).

The webbed foot structure of mallards (Anas platyrhynchos) exhibits effective anti-subsidence properties when walking on soft ground. To investigate the effects of quartz sand particle size and thickness on joint angles and the movement patterns of webbed feet, we created a testing substrate with quartz sand and utilized high-speed cameras and kinematic analysis tools for data acquisition. Mallards mainly adjusted the tarsometatarso-phalangeal joint (TMTPJ) during touch-down and lift-off stages in response to increasing particle size or enhanced ground roughness. Conversely, adjustments to the intertarsal joint (ITJ) predominantly took place during mid-stance. Conversely, mallards predominantly adjusted the ITJ during touch-down and lift-off when coping with increased quartz sand thickness, with TMTPJ adjustments mainly occurring at touch-down. As quartz sand particle size increased, the TMTPJ angle increased, the ITJ angle decreased, toe closure advanced, and the duty factor decreased throughout the entire stride cycle. In contrast, increasing quartz sand thickness led to more delayed TMTPJ adjustments, slower webbed foot closure, and an increased duty factor throughout the stride cycle. Mallards modify their leg posture to notably decrease the touch-down foot angle upon encountering sandy terrain. This action subsequently forms a depression beneath their feet, contributing to sand consolidation and limiting flow. During the stance phase, the mallard's weight is distributed across the webbed foot, generating minimal pressure and preventing significant subsidence while walking on sandy ground.

Effect of Pulsed Current Duty Factor on Deformation Behavior of Aluminum Bronze

Effect of Pulsed Current Duty Factor on Deformation Behavior of Aluminum Bronze

The efficacy of antibiotic-eluting material in a two-stage model of periprosthetic joint infection.

Periprosthetic joint infections occur in about 2% of patients who undergo primary total joint arthroplasty, a procedure performed over 1 million times in the United States. The gold standard of treatment is a two-stage revision. This study aimed to establish a two-stage procedure in a preclinical small animal model (rat) to test and compare the efficacy of an antibiotic-eluting material in managing infection. Joint replacement was simulated by transchondylarly implanting a polyethylene (PE) plug into the distal femur and a titanium screw in the proximal tibia. Methicillin-sensitive Staphylococcus aureus (MSSA) 108 CFU/mL was injected into the tibial canal and the joint space before wound closure. The control groups were killed on postoperative day (POD) 18 (n = 12) and on POD 42 (n = 4) to assess both early and later-stage outcomes in the control group. The test group underwent revision surgery on POD 18 for treatment using gentamicin-eluting polyethylene (GPE, n = 4) and was observed until POD 42 to evaluate the efficacy of treatment. Our results showed that the bone loss for the treatment group receiving GPE was significantly less than that of the control (p < 0.05), which was supported by the histology images and an AI-tool assisted infection rate evaluation. Gait metrics duty factor imbalance and hindlimb temporal symmetry were significantly different between the treatment and control groups on Day 42. This animal model was feasible for evaluating treatments for peri-prosthetic joint infections (PJI) with a revision surgery and specifically that revision surgery and local antibiotic treatment largely hindered the peri-prosthetic bone loss. Statement of clinical significance: This revision model of peri-prosthetic infection has the potential of comparatively evaluating prophylaxis and treatment strategies and devices. Antibiotic-eluting UHMWPE is devised as at tool in treating PJI while providing weight bearing and joint space preservation.

A laterally excited bulk acoustic resonator with scattering vias in electrodes

Laterally excited bulk acoustic resonators (XBARs) using interdigital electrodes are currently limited in potential 5G applications due to the accompanied spurious modes and small capacitance. This Letter presents an XBAR with scattering vias in electrodes, named SV-BAR. The non-parallel boundaries thoroughly disrupt the coherent formation of standing waves in the lateral direction, thereby suppressing the higher-order spurious modes. The duty factor of SV-BAR is optimized as 0.5 using COMSOL Multiphysics finite element analysis for the 50 Ω impedance matching. The SV-BAR is fabricated using a 390 nm Z-cut LiNbO3 on an insulator substrate and exhibits an impressive ratio of Zp/Zs near 64.5 dB, a Kt2 of 21.80% at 4.762 GHz, as well as a large value f · Bode_Qmax · Kt2 (3.43 × 1011). The measured temperature coefficient of frequency is −69.8 ppm/°C, which can be compensated using SiO2 thin films. The SV-BAR provides an effective solution for high-performance radio frequency filters for 5G communication.

Study and design of the coupled cavity with ladder RFQ and IH DTL structure for transportable neutron source

A transportable accelerator-driven neutron source is under development in Xi'an Jiaotong University (X-TANS), aiming at realizing various outdoor applications, such as on-site degradation diagnosis of concrete infrastructures and analysis of raw materials. To downsize the accelerator cavity for X-TANS, we coupled the Ladder RFQ and an Interdigital H-type Drift tube linac (IH-DTL) into a single cavity to combine the strength of the RFQ's efficient bunching efficiency and DTL's high accelerating gradient and to distantly reduce the weight and size of the linac. To achieve electromagnetic resonance between two structures and a high coupling factor, a novel coupled structure was adopted by adjusting the last supporting plate at the exit of RFQ. The mode separation between 0-mode and π-mode was expanded to 7.96 MHz. Consequently, the 15 mA proton beam can be accelerated to 2.5 MeV with a length of 1.73 m and the effective transmission of above 90%. The dissipated cavity power was 96.87 kW with an operation frequency of 200 MHz and a duty factor of 3%. The design concept of the coupled structure and the results of the beam dynamics design, electromagnetic simulation and multi-physics will be comprehensively presented in this paper.

Optimization of process conditions of Powder Mixed Electric Discharge Machining of Nickel based Superalloy using Grey Wolf Optimizer algorithm

The Powder-Mixed Electric Discharge Machining (PMEDM) process has been drawing the attention of researchers since it could successfully overcome some of the limitations of the conventional Electric Discharge Machining (EDM) process. There was extensive research carried out on the PMEDM process to explore various possibilities for enhancing the process output. In the present work, an experimental study has been undertaken to investigate the influence of three conductive powders: zinc, cobalt, and molybdenum, while machining Nimonic 75, a nickel-based superalloy, by the EDM process. The work material considered in the study has been widely used in the aerospace industries and in applications involving higher temperatures. The experiments were carried out based on the Response Surface Methodology using the Box–Behnken design. Using the experimental data, regression equations were formed to predict the outcome of the process, which are Material Removal Rate (MRR), Electrode Wear Ratio (EWR), and Surface Roughness (SR). This work attempted to optimize the EDM machining parameters using the Grey Wolf Optimizer (GWO) algorithm combined with the Utility concept. The optimum conditions obtained by the GWO algorithm were: Powder – Molybdenum; Concentration of powder – 5.4 g/L; Discharge current – 4 A; Duty factor – 0.8.

Parametric optimization of electric discharge machining of Ni 55.65Ti based shape memory alloy using NSGA II with TOPSIS

Nickel–Titanium based shape memory alloys (SMAs) are a unique category of smart materials that possess remarkable properties like super-elasticity, shape memory effect, high wear and corrosion resistance, thereby rendering them appropriate for uses such as composite structures, aerospace, and biomedical uses etc. These distinctive features make these alloys ‘difficult in machining’ using the traditional approach of machining process. In the present investigation, machinability aspects of Ni55.65Ti-SMAs using non-traditional electric discharge machining process has been studied. The effect of input process parameters i.e., pulse time ON, duty factor, peak current on the surface roughness and material removal rate has been investigated. The output responses viz. Minimum surface roughness along with maximum material removal rate having values of 6.828 μm and 4.552 mm3/sec respectively were achieved. Furthermore, empirical modelling and ANOVA study have been executed based on the full factorial design analysis. The non-dominated sorting genetic algorithm IIalgorithm IIalg2 commonly known as NSGA II, used crowding distance approach for multi-objective process optimization. The results obtained with NSGA-II were again ranked using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) approach to give a more thorough understanding of the solution space and opt for the best possible solution.

To examine the effect of input parameters of rotary EDM on surface roughness of cryogenically treated Monel 400

Rotary electric discharge machining (REDM) has an advantage over traditional EDM in that the tool speed can be varied to achieve better surface characteristics of machined components. Cryogenic treatment also improves the machining efficiency of non-traditional machining processes such as EDM. REDM is used in this study to establish a relationship between response parameters and control parameters while machining cryogenic treated alloy Monel-400 with a cryogenically treatedcopper electrode. The RSM approach was used to design experiments to investigate the effect of parameters such as tool speed, peak current, pulse on time, and duty cycle on surface roughness. An experimentally validated regression modal has been proposed. As per SEM examination, the typical surface produced for the setting of low pulse energy (at pulse on time:100 µs; Current:12 A; duty factor: 0.40; and tool rotation = 800 rpm) is found to be finer and showing shallow carters.

A phased array ultrasound system with a robotic arm for neuromodulation.

Ultrasonic neuromodulation (UNMOD) provides a non-invasive brain stimulation. However, the high-resolution region-specificity of UNMOD with a single element transducer combined with a mechanical positioning system could have limits due to the intrinsic positioning error from mechanical systems. A phased array system could lead to highly selective neuromodulation with electronic control. A specialized phased-array system with a robotic arm is implemented for a rhesus monkey model. Various primary motor cortex areas related to tail, hand, and mouth were stimulated with a 200μm step size. The ultrasonic parameters were ISPTA of 840mW/cm2, pulse repetition frequency of 100Hz, and a 5% duty factor at 600kHz. The induced movement were recorded and analyzed. Separate digits, mouth, and tongue motions were successfully induced by electronically controlling the focus. The identical body part movement could be induced when the focus was moved back to the identical primary motor cortex with electronic control. Accordingly, the reproducibility of UNMOD could be partially validated with rhesus monkey model. A phased-array system appears to have a potential for the non-invasive and region-selective neuromodulation method.

Analysis of the DC/DC Zeta topology converter ripples by applying its limiting continuous mathematical model

Objectives. A DC/DC Zeta topology converter represents a unipolar electronic device for converting an input positive voltage into a stabilized output voltage of the same polarity, which can be set at voltages both below and above the input voltage. The aim of this work is to analyze Zeta converter circuitry, which requires the following tasks to be solved: using Kirchhoff’s Circuit Laws, obtain systems of equations describing converter operation in the phase of energy accumulation and in the phase of energy transfer; using a method proposed by A.I. Korshunov, combine the resulting systems of equations into a marginal continuous mathematical model; using expressions describing constant components of currents and voltages in Zeta converter, analyze their ripples and obtain equations for their calculation; compare the current and voltage values obtained from the continuous limiting mathematical model with the Zeta simulation results.Methods. The tasks are solved using Kirchhoff’s rules and the method for obtaining the limiting continuous mathematical model proposed by A.I. Korshunov. The results are analyzed using a circuit modelling in NI Multisim.Results. It is shown that the phase coordinates of the mathematical model tend to real values of converter currents and voltages at a switching frequency of the power switch of more than 200 kHz. A strong correspondence was established between the calculated ripple values and their values obtained in the simulation (when changing the duty factor).Conclusions. Mathematical models comprise the basis of unified calculation methods for any radio electronic circuit. The developed limiting continuous mathematical model allows a range of changes in current flowing through the choke windings and voltages on capacitor plates to be evaluated, including their maximum and minimum values for various converter parameters, such as power switch switching frequency, duty factor, element ratings, etc. Obtaining this information in turn enables the rational selection of the electronic component base of the converter.

Experimental investigation of micro-machining on borosilicate glass using mist flow aided WECDM

Wire electro-chemical discharge machining (WECDM) process is a variant of electro-chemical discharge machining process and is a novel method to machine electrically non-conductive materials. In the present research investigation, an in-house developed WECDM setup with mist flow was used to generate micro channels on borosilicate glass. The electrolyte was provided in the form of mist, formed with the combination of electrolyte and compressed air. The mist flow system was used to control the machining process that improved the stability of the spark, and flushing in the machining zone resulted in a smooth surface of machined channels. Electrolyte concentration, duty factor, wire feed rate, and mist flow rate were chosen as input process parameters, and their effect on output quality characteristics such as material removal rate and width of cut was evaluated. the performance of were during. The addition of the mist flow technique in the process resulted in an improvement in surface finish, heat affected zone (HAZ) and discharge characteristics. ANOVA analyses were carried out to obtain the significant process parameters that affected the output characteristics. Scanning electron micrograph images were captured in order to analyze the surface morphology of the machined channel and revealed thermal cracks, HAZ, irregular surface and recast layer in the samples machined with low mist flow rate as compared to samples machined using high Mist flow rates.