Duty Cycle Research Articles

Defluoridation by positive single-pulse current electrocoagulation from photovoltaic wastewater: Energy consumption assessment and mechanism analysis

The presence of fluoride ions (F−) in photovoltaic (PV) wastewater significantly affects the integrity of the ecological environment. In contrast to direct current electrocoagulation (DC-EC), positive single-pulse electrocoagulation (PSPC-EC) shows a significant reduction in both the formation of passivation films on electrodes and the consumption of electrical energy. Under the experimental conditions of an Al–Al–Al–Al electrode combination, an electrode spacing of 1.0 cm, a NaCl concentration of 0.05 mol L−1, an initial pH of 5.6, an initial F− concentration of 5 mg L−1, a current density of 5 A m−2, a pulse frequency of 500 Hz, and a 40 % duty cycle, the achieved equilibrium F− removal efficiencies were 84.0 % for DC-EC and 88.0 % for PSPC-EC, respectively, accompanied by power consumption of 0.0198 kWh·mg−1 and 0.0073 kWh·mg−1. The flocs produced in the PSPC-EC process were characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy and it is revealed that the F− removal mechanisms in the PSPC-EC process include co-precipitation, hydrogen bond complexation, and ion exchange. When the actual PV wastewater was finally subjected to treatment under the optimal PSPC-EC conditions, the F− concentration in the wastewater was reduced from 4.6 mg L−1 to 1.4 mg L−1. This paper provides both a theoretical framework and a technological basis for the application of PSPC-EC in the advanced treatment of PV wastewater.

Improved performance of linear induction motors based on optimal duty cycle finite-set model predictive thrust control

Linear induction machines (LIMs) find widespread adoption in various applications, owing to their inherent advantages such as low noise, compact turning radius, and excellent climbing capability. LIMs are extensively utilized in linear metro applications. However, in practical operations, the output thrust shrinks with the increase in speed, which is attributed to end effects. This phenomenon leads to a reduction in efficiency. In addition, fluctuations in the normal force impact system stability, posing disturbances to the suspension system. To address these challenges, this paper suggests a finite-set model predictive thrust control (FS-MPTC) for a drive system employing a linear induction motor (LIM). The FS-MPTC optimizes the duty cycle for the active voltage vector and allocates the remaining period to one of the zero voltage vectors. The selected zero voltage vector reduces the switching transition between it and the active voltage vectors. The duty cycle is calculated for the six voltage vectors by incorporating the deadbeat concept and the derivative value for the electromagnetic thrust. In the prediction stage of the FS-MPTC, the computed duty cycle and the corresponding voltage vector are used simultaneously and repeated for the six voltage vectors. The cost function comprises two terms: the error between the reference thrust and predicted thrust value as the first term and the error between the rated primary flux linkage and its predicted value as the second term. The reference thrust is generated from the outer speed control loop. To validate the effectiveness of the proposed control approach, Japanese 12000 linear induction machine parameters are employed for verification. Comparative analysis of the performance between the suggested control method with the optimal duty cycle and the same process with a fixed duty cycle demonstrates superior performance when utilizing the optimal duty cycle. Finally, the proposed FS-MPTC with the optimal duty cycle offers a promising solution to enhance the operational efficiency of the LIM-based drive systems.

Intermittent low-dose far-UVC irradiation inhibits growth of common mold below threshold limit value.

Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and allergies in the immunocompetent, they can cause life-threatening diseases in the immunocompromised. Currently, there is an unmet need for new strategies to reduce or prevent mold infestations. Far-UVC technology can inactivate microorganisms while remaining safe for humans. This study investigates the inhibitory efficacy of far-UVC light at 222 nm on the growth of common mold-producing fungi, specifically Penicillium candidum, when delivered in low-dose on-off duty cycles, a configuration consistent with its use in real-world settings. The inhibitory effect of the low-dose duty cycles was assessed on growth induced by i) an adjacent spore-producing P. candidum donor and ii) P. candidum spores seeded directly onto agar plates. In both setups, the far-UVC light significantly inhibited both vertical and horizontal growth of P. candidum, even when the UV doses were below the Threshold Value Limit of 23 mJ/cm2. These results suggest that far-UVC light holds the potential to improve indoor air quality by reducing or preventing mold growth, also when people are present.

Constraining the Low-mass End of the Black Hole Mass Function and the Active Fraction of the Intermediate-mass Black Holes

We investigate the black hole mass function (BHMF) and the Eddington ratio distribution function (ERDF), focusing on the intermediate-mass black holes (IMBHs) with masses down to M • ∼ 104 M ⊙. Based on the active galactic nuclei (AGNs) with a detected broad Hα emission line, we construct a sample of 14,242 AGNs at redshift z < 0.35, including 243 IMBHs with M • < 106 M ⊙. By jointly modeling the BHMF and ERDF via the maximum posterior estimation, we find that the BHMF peaks at ∼106 M ⊙ and exhibits a relatively constant value of 10−4 Mpc−3 dex−1 at the low-mass end. By comparing the derived BHMF of type 1 AGNs with the galaxy mass function based on the updated black hole mass–host galaxy stellar mass relation, we derive the active fraction. We also determine the active fraction for all AGNs using the upper and lower limit of the type 1 fraction. The active fraction decreases from 15%–40% for massive galaxies (M ⋆ > 1010 M ⊙) to lower than ∼2% for dwarf galaxies with M ⋆ ∼ 108 M ⊙. These results suggest that the black hole occupation fraction is expected to be ∼50% for low-mass galaxies (M ⋆ ∼ 108.5–109 M ⊙) if the duty cycle is similar between IMBHs and supermassive black holes.

Choked Precessing Jets in Tidal Disruption Events and High-energy Neutrinos

It has been suggested that relativistic jets might have been commonly formed in tidal disruption events (TDEs), but those with relatively weak power could be choked by the surrounding envelope. The discovery of high-energy neutrinos possibly associated with some normal TDEs may support this picture in the hypothesis that the neutrinos are produced by choked jets. Recently, it was noted that disrupted stars generally have misaligned orbits with respect to the supermassive black hole spin axis, and highly misaligned precessing jets are more likely to be choked. Here we revisit the jet breakout condition for misaligned precessing jets by considering that the jet could be collimated by the cocoon pressure while propagating in the disk wind envelope. The jet head opening angle decreases as the jet propagates in the envelope, but the minimum power of a successful jet remains unchanged in terms of the physical jet power. We further calculate the neutrino flux from choked precessing jets, assuming that the cocoon energy does not exceed the kinetic energy of the disk wind. We find that neutrino flux from highly misaligned choked jets is sufficient to explain the neutrinos from AT2019aalc, while it is marginal to explain the neutrinos from AT2019dsg and AT2019fdr. The latter could be produced by weakly misaligned choked jets, since the duty cycle that the jet sweeps across increases as the misaligned angle decreases. We also show that the population of choked TDE jets could contribute to ∼10% of the observed diffuse neutrino flux measured by IceCube.

Effects of current control modes on the morphological and biological properties of graded FeCrNi metal-matrix coatings containing Al2O3 nanoparticles for cardiovascular applications

Implant coatings represent the most effective strategy to address multiple issues, ultimately increasing implant longevity and improving implant compatibility. In this study, we investigated the electrodeposition of a novel graded FeCrNi/Al₂O₃ coating on a 316L substrate for cardiovascular implants using direct current (DC) and pulsed current (PC). The effects of a current density range of 3-11Adm⁻² and decreasing the duty cycle from 90% to 50% and subsequently to 10% on the concentration of Al₂O₃ nanoparticles in the FeCrNi matrix, as well as on the microstructure and morphological properties, were studied using scanning electron microscopy (SEM). Additionally, structural characterization of the FeCrNi/Al₂O₃ films was performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). To assess the cytocompatibility of the samples, human coronary artery endothelial cells (HCAEC) were used. The results indicate that the PC provides a uniform microstructure and a smoother surface compared to the direct current DC. The study also reveals that the PC results in fewer defects and microcracks in the coating due to reduced formation of chromium hydrides in the layer and a significant reduction in stress during the deposition process. When using PC, an increase in particle incorporation in the coating was achieved, but no effect of changing the duty cycle was found. The highest deposition rate of Al₂O₃ was achieved at a current density of 11Adm⁻² with an electrolyte containing 10gL⁻¹ Al₂O₃. The FeCrNi/Al₂O₃ coatings exhibit low cytotoxicity when deposited using a high alumina content and DC, showing cell viability of over 90%. However, only a few samples demonstrated cell viability higher than 80% on day three. The proposed composite coating may represent an initial step towards improving implant coatings for cardiovascular stent materials.

Stereotactic depth electrode placement for chronic subthreshold cortical stimulation: surgical technique video.

Neurostimulation is an increasingly common treatment option for medically intractable epilepsy. SANTE (Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy) and Responsive Neurostimulation (RNS) System are landmark neurostimulation trials that utilized either duty cycle or a responsive stimulation paradigm. A seizure-free outcome is rarely observed with responsive and duty cycle neurostimulation devices. Chronic subthreshold cortical stimulation (CSCS) is a promising treatment for adult drug-resistant epilepsy involving eloquent cortex and has demonstrated safety and efficacy. Herein, the authors describe the surgical technique as well as details of stimulation programming involved in CSCS placement to facilitate the adoption of this promising treatment. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2422.

An instrumentation amplifier with series switch pseudo resistor DC-servo loop realizing 0.16-Hz high-pass corner

This paper presents an instrumentation amplifier for electrocardiogram (ECG) signal recording. A DC servo loop (DSL) based on a series-switch pseudo resistor (S2PR ) is utilized to suppress the effect of the unavoidable electrode DC offset effectively. The two-step pulse generation circuit realizes two sets of pulse signals with shallow duty cycles, and the pulse signals drive the path switches and virtual switches in the S2PR, respectively. Virtual switches reduce the channel charge injection effect, and finally, a great equivalent resistance with high linearity is realized. The continuous DSL realized based on S2PR can suppress the electrode DC offset of ±180 mV. At the same time, the active area of the DSL is significantly reduced. The proposed instrumentation amplifier is realized in a standard 0.18-μm CMOS process. Simulation results show the DSL designed with a 1.8-V supply introduces a 0.16-Hz high-pass corner. The power consumption of the S2PR-DSL is 92.7 μW. The gain of the instrumentation amplifier is 39.8 dB, and the input-referred noise at the TT corner is 1.78 μVrms over a bandwidth of 0.5 Hz to 150 Hz. The input impedance of the instrumentation amplifier is 772.2 MΩ, when the input signal frequency is 50 Hz, and the total harmonic distortion (THD) of a 10-mVpp input sinusoidal signal at 9.033 Hz is −61.6 dB.

Mass property estimation on [formula omitted] via unscented Kalman filter using RCS thrusters

Estimation of spacecraft mass properties in the presence of noise is a nontrivial problem that, when properly addressed, can substantially reduce the crew time devoted to cargo management, control effort expended to manage fuel mass, or both. The estimation of such properties is treated here using a dual unscented Kalman filter (UKF) where the dynamics of the rigid-body spacecraft are formulated on the special Euclidean group SE(3) and its tangent bundle TSE(3) to avoid singularity and nonuniqueness issues found in attitude parameterization sets. The dual UKF on TSE(3) is developed, and a specific methodology is proposed for the estimation of the constant mass properties. An excitation approach is employed in the mass property estimation scheme. Arbitrary sensor suite placements are considered and implemented in the measurement model to capture real-world spacecraft behavior. Furthermore, a reaction control system with duty cycle constraints and noisy thrust values is implemented to account for uncertainty in the excitation inputs. With these features, the methods contained herein are found to be effective at estimating mass properties.

PP01.22 Single Institution Experience of MRI-Guided Radiotherapy for Thoracic Tumors and Clinical Characteristics Impacting Treatment Duty Cycle

PP01.22 Single Institution Experience of MRI-Guided Radiotherapy for Thoracic Tumors and Clinical Characteristics Impacting Treatment Duty Cycle

SOLAR POWERED HIGH GAIN DC-DC CONVERTER WITH FPGA CONTROLLER FOR PORTABLE DEVICES

A solar-powered converter design is necessary for portable devices with increased gain and reduced ripple in overall operation. This research presents a photovoltaic-powered Field Programmable Gate Array (FPGA) based on increased gain multiple output converter design and analysis. The dynamic panel input makes it difficult to operate the load. To control and make the input static to satisfy the demand, perturb and observe with a load balancing algorithm technique are used. The converter gained output is high, and batteries are used to balance the loads when solar irradiance is low. Simulation results were carried out with the presented converter circuit that can be operated with a 12V supply as input from a renewable power source. The output gain ratio of 14 to a minimum of 40% duty cycle operating at a switching frequency of 20 kHz has been achieved. The proposed methodology is transferred to hardware by connecting with the reconfigurable FPGA Spartan-6 development board to manage the dynamic load control system's complex logic and high processing ability. The overall performance is compared with various pre-existing systems, tabulations are made with the analysis, and experimental results are also illustrated at the end.

Quantum maximum power point tracking (QMPPT) for optimal solar energy extraction

Solar energy is key to achieving a more environmentally responsible future. One way to exploit it is to use semiconductor technology through solar panels to generate clean, sustainable, and controllable energy. However, the use of such solutions must be optimised by methods such as maximum power point tracking (MPPT) to extract the maximum available solar energy. Although MPPT algorithms have been widely used and improved, the use of newer approaches, such as quantum computing, appears to hold the promise of achieving new performance levels, particularly for real-time MPPT implementation. The goal of this work is to develop and test a quantum algorithm for the photovoltaic (PV) energy MPPT problem using quantum particle swarm optimisation. The performance of the classic and quantum MPPT algorithms was evaluated under three main operating conditions: normal, high-temperature, and partial shading conditions. This represents a variety of environmental scenarios that can affect the efficiency of solar power generation. According to the study's results, the classical algorithm recorded 0.15% more power than the quantum algorithm in normal operating conditions, and the quantum algorithm generated 3.33% more power in higher temperature tests and 0.89% more power in the partial shading test. Moreover, the quantum algorithm recorded lower duty cycles for the three tests. While the classical algorithm may have a slight edge in power output under normal operation conditions, the quantum algorithm indicates superior performance in challenging conditions and consistently reveals more promising overall efficiency.

Microstructural modification and enhanced mechanical properties in Zr50-Ti50 alloy via low temperature electron wind force annealing

This study investigates the microstructural transformations and associated property enhancements in a Zr50-Ti50 alloy annealed at only 120 °C with low duty cycle current pulses. Microanalysis with electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) show the formation of alpha lath structure, typically observed in much higher thermal annealing temperatures. EBSD and XRD analyses revealed the formation and/or growth of the lath structure, with notable changes in pole distributions and the appearance of a distinct peak at 52.5° in the XRD spectrum. The lath structure is quantified using FiJi weka segmentation machine learning technique. Nanoindentation data showed an increase in the average hardness from ~7 to ~8 GPa and a corresponding increment in the reduced modulus from 127 to 148 GPa. The observed increase in low-angle grain boundaries (LAGBs) from 4% to 12% further complements the findings, suggesting a complex interplay of microstructural features contributing to the overall improvement in the mechanical properties. The proposed low temperature annealing technique demonstrates the predominant role of the electron wind force for tailoring the microstructure and mechanical performance of ZrTi alloys, providing insights that could have implications for the broader field of materials engineering.

MCU-based Safer Coagulation Mode by Nonfixed Duty Cycle for an Electrosurgery Inverter.

The arcing-involved pulsating coagulation mode with both active and blank periods is essential for modern electrosurgery. This paper begins with a comprehensive introduction to such a pulsating mode, followed by its implementation challenges. Then, an industrial-scale low-speed microcontroller unit (MCU), TMS320F28379D, is utilized to exemplify the proposed output sampling and data-transferring strategy on a gallium nitride (GaN)-based high-frequency inverter that enables coagulation mode with interweaved active periods and blank periods. The inverter prototype fills the active period with 390 kHz sinusoids of amplitude ranging from hundreds to thousands of Volts, while maintaining null outputs during blank periods. The strategy of sampling the above-mentioned sinusoidal outputs, coupled with their data transfer facilitated by direct memory access (DMA), is also articulated for subsequential power computation. Besides that, a novel nonfixed duty cycle approach, featuring an alterable number of sinusoids as the active period, is proposed and integrated into the GaN-based inverter to enhance mode safety. Finally, the power tracking performance of the mode is evaluated initially on resistive load, secondarily on resistive plus capacitive load (R-C), and thirdly on fresh biotissue with the appearance of electrical arcing. The existing necessity of the null blank periods is examined at the end of the paper.

An instrumentation amplifier with series switch pseudo resistor DC-servo loop realizing 0.16-Hz high-pass corner

This paper presents an instrumentation amplifier for electrocardiogram (ECG) signal recording. A DC servo loop (DSL) based on a series-switch pseudo resistor (S2PR ) is utilized to suppress the effect of the unavoidable electrode DC offset effectively. The two-step pulse generation circuit realizes two sets of pulse signals with shallow duty cycles, and the pulse signals drive the path switches and virtual switches in the S2PR, respectively. Virtual switches reduce the channel charge injection effect, and finally, a great equivalent resistance with high linearity is realized. The continuous DSL realized based on S2PR can suppress the electrode DC offset of ±180 mV. At the same time, the active area of the DSL is significantly reduced. The proposed instrumentation amplifier is realized in a standard 0.18-μm CMOS process. Simulation results show the DSL designed with a 1.8-V supply introduces a 0.16-Hz high-pass corner. The power consumption of the S2PR-DSL is 92.7 μW. The gain of the instrumentation amplifier is 39.8 dB, and the input-referred noise at the TT corner is 1.78 μVrms over a bandwidth of 0.5 Hz to 150 Hz. The input impedance of the instrumentation amplifier is 772.2 MΩ, when the input signal frequency is 50 Hz, and the total harmonic distortion (THD) of a 10-mVpp input sinusoidal signal at 9.033 Hz is −61.6 dB.

Transcranial focused ultrasound activates feedforward and feedback cortico-thalamo-cortical pathways by selectively activating excitatory neurons.

Transcranial focused ultrasound stimulation (tFUS) has been proven capable of altering focal neuronal activities and neural circuits non-invasively in both animals and humans. The abilities of tFUS for cell-type selection within the targeted area like somatosensory cortex have been shown to be parameter related. However, how neuronal subpopulations across neural pathways are affected, for example how tFUS affected neuronal connections between brain areas remains unclear. In this study, multi-site intracranial recordings were used to quantify the neuronal responses to tFUS stimulation at somatosensory cortex (S1), motor cortex (M1) and posterior medial thalamic nucleus (POm) of cortico-thalamo-cortical (CTC) pathway. We found that when targeting at S1 or POm, only regular spiking units (RSUs, putative excitatory neurons) responded to specific tFUS parameters (duty cycle: 6%-60% and pulse repetition frequency: 1500 and 3000 Hz ) during sonication. RSUs from the directly connected area (POm or S1) showed a synchronized response, which changed the directional correlation between RSUs from POm and S1. The tFUS induced excitation of RSUs activated the feedforward and feedback loops between cortex and thalamus, eliciting delayed neuronal responses of RSUs and delayed activities of fast spiking units (FSUs) by affecting local network. Our findings indicated that tFUS can modulate the CTC pathway through both feedforward and feedback loops, which could influence larger cortical areas including motor cortex.

Synergistic Thermal and Electron Wind Force-Assisted Annealing for Extremely High-Density Defect Mitigation.

This study investigates the effectiveness of combined thermal and athermal stimuli in mitigating the extremely high-density nature of dislocation networks in the form of low-angle grain boundaries in FeCrAl alloy. Electron wind force, generated from very low duty cycle and high current density pulses, was used as the athermal stimulus. The electron wind force stimulus alone was unable to remove the residual stress (80% low-angle grain boundaries) due to cold rolling to 25% thickness reduction. When the duty cycle was increased to allow average temperature of 100 °C, the specimen could be effectively annealed in 1 min at a current density of 3300 A/mm2. In comparison, conventional thermal annealing requires at least 750 °C and 1.5 h. For specimens with 50% thickness reduction (85% low-angle grain boundaries), the electron wind force was again unable to anneal the defects even at 3300 A/mm2 current density and average temperature of 100 °C. Intriguingly, allowing average concurrent temperature of 200 °C eliminated almost all the low-angle grain boundaries at a current density of 700 A/mm2, even lower than that required for the 25% thickness reduced specimens. Comprehensive electron and X-ray diffraction evidence show that alloys with extremely high defect density can be effectively annealed in less than a minute at approximately 200 °C, offering a substantial improvement over conventional high-temperature annealing.

Smart charging process development based on ant colony optimization machine learning for controlling lead-acid battery charging capacity

The Indonesian government has targeted 2.1 million two-wheeled electric vehicles and 2,200 four-wheeled electric vehicles (EV) by 2025. This is hampered by limited electricity supply and EV charging, which takes long time. Multi device interleaved DC-DC bidirectional converter has been applied and assessed as the most suitable method for battery EV and plug-in hybrid EV because it produces high power &gt;10 kW. For power below 10 kW, it is recommended to use a sinusoidal, Z-Source, and boost amplifier type converter. The smart charging (SC) system will be applied to electric vehicles, which only require a minimum charging power of around 169 W for four lead acid batteries. This paper focuses on an SC system that is capable of charging the battery quickly while still paying attention to the state of health (SoH) of the battery. The SC developed uses a DC-DC boost converter to increase the voltage produced by the switch mode power supply (SMPS). Estimated charging time is less than 30 minutes and still pay attention to the battery SoH. SC will also use pulse width modulation (PWM) as a duty power cycle regulator. This research applies a multi-layer perceptron (MLP) classifier to a neural network (NN). The results of the research show that smart charging can charge up to 600 W with an estimated charging time of around 11 minutes. The charging condition is above 60 % and the power duty cycle setting is 100 %. The power estimation results processed using the ant colony optimization (ACO) based neural network method show a root mean square deviation value of 0.010013430 for charging four lead acid batteries. These results are useful to help solve the problem of capacity requirements and battery charging speed for EVs, with good SoH

Smart charging process development based on ant colony optimization machine learning for controlling lead-acid battery charging capacity

The Indonesian government has targeted 2.1 million two-wheeled electric vehicles and 2,200 four-wheeled electric vehicles (EV) by 2025. This is hampered by limited electricity supply and EV charging, which takes long time. Multi device interleaved DC-DC bidirectional converter has been applied and assessed as the most suitable method for battery EV and plug-in hybrid EV because it produces high power &gt;10 kW. For power below 10 kW, it is recommended to use a sinusoidal, Z-Source, and boost amplifier type converter. The smart charging (SC) system will be applied to electric vehicles, which only require a minimum charging power of around 169 W for four lead acid batteries. This paper focuses on an SC system that is capable of charging the battery quickly while still paying attention to the state of health (SoH) of the battery. The SC developed uses a DC-DC boost converter to increase the voltage produced by the switch mode power supply (SMPS). Estimated charging time is less than 30 minutes and still pay attention to the battery SoH. SC will also use pulse width modulation (PWM) as a duty power cycle regulator. This research applies a multi-layer perceptron (MLP) classifier to a neural network (NN). The results of the research show that smart charging can charge up to 600 W with an estimated charging time of around 11 minutes. The charging condition is above 60 % and the power duty cycle setting is 100 %. The power estimation results processed using the ant colony optimization (ACO) based neural network method show a root mean square deviation value of 0.010013430 for charging four lead acid batteries. These results are useful to help solve the problem of capacity requirements and battery charging speed for EVs, with good SoH

Pulsed galvanostatic electrodeposition of tellurium nanostructures on stainless steel from copper anode slimes plating bath: Effect of pulse parameters

The electrochemical behavior of Te in alkaline media was determined by cyclic voltammetry and linear sweep voltammetry measurements. It indicated that TeO32− ion was first reduced to Te(s), then to Te22− ion. For the first time, the pulsed electrodeposition of tellurium on stainless steel has been studied in an alkaline bath and the effect of duty cycle, frequency, and current density on current efficiencies and morphology were indicated at room temperature. Pulse duty cycles ranging from 10 to 75%, frequencies ranging from 10 to 100 Hz, and current densities ranging from 7.5 to 30 mA/cm2 were employed. The morphology of the electrodeposition of tellurium samples was characterized by SEM. The results showed that due to increasing side reactions at higher current density, the current efficiency decreased with increasing current density. The results of Scanning Electron Microscopy (SEM) cleared that more compact structures with lower porosity were observed for the electrodeposits at lower current densities and less compact samples were obtained at higher current densities. It has been found that the current efficiency of tellurium plating decreases as the pulse duty cycle increases from 10% to 75%. Maximum current efficiency has been observed at 10% duty cycle. The study of the effect of duty cycle on morphology showed that the samples synthesized at a duty cycle of 10% and 25% have approximately similar appearance and particle size. With more increasing of duty cycles to 50 and 75% due to increasing hydrogen evolution rate and H2 bubbling at the electrode surface the morphology has been changed remarkably. The current efficiency of the deposit tellurium exhibited a strong dependence on the frequency. As frequency increases, the current efficiency almost decreases. In most cases, the maximum current efficiency is obtained at a 10 Hz frequency. The study of the effect of frequency on morphology showed that hydrogen evolution plays a significant role in the morphology formation of samples obtained at low pulse frequency (10 Hz), two processes of hydrogen evolution and anisotropic growth have key roles in morphology formation at medium pulse frequency (50 Hz) and anisotropic growth is the mechanism of morphology formation at high pulse frequency (100 Hz).