Pulse Generation System Research Articles

A comparison of ore pre-concentration efficiency between two high voltage pulse generator systems

High Voltage Pulse (HVP) enabled ore pre-concentration can potentially provide large energy savings and the ability to upgrade low-grade ores for the mining industry. Two types of pulse generator systems commonly used in HVP breakage are Marx generators and pulse transformers. This initial assessment compares the pre-concentration performance of a SelFrag Lab Unit (utilising a Marx generator) and a custom-built HVP machine (employing a pulse transformer) from Huazhong University of Science and Technology (HUST). Eight sets of experimental results using the two generator systems were collected. Two approaches were taken to analyse the data; a trendline approach using all eight sets of data, and a single-point comparison approach with matched specific energy inputs. The results show that there are significant differences in pre-concentration efficiencies with the HUST machine performing better. To elucidate the potential causes, the degree of size reduction (t10), breakage probability, and selective breakage were investigated for the two generator systems. It is likely that the efficiency of selective breakage is one of the major causes, with the HUST machine presenting better results at selectively breaking high-grade particles and consuming less energy. Additionally, the two generator systems have different energy per discharge levels; the effect of this difference should be investigated in future work.

ID: 344382 Passive Inductively-Powered Dual-channel Implantable Pulse Generator System for Rodent Sciatic Nerve Stimulation

ID: 344382 Passive Inductively-Powered Dual-channel Implantable Pulse Generator System for Rodent Sciatic Nerve Stimulation

Treatment of Spontaneous Tumors With Algorithmically Controlled Electroporation.

To study the safety and efficacy of algorithmically controlled electroporation (ACE) against spontaneous equine melanoma. A custom temperature sensing coaxial electrode was paired with a high voltage pulse generation system with integrated temperature feedback controls. Computational modeling and ex vivo studies were conducted to evaluate the system's ability to achieve and maintain target temperatures. Twenty-five equine melanoma tumors were treated with a 2000 V protocol consisting of a 2-5-2 waveform, 45 °C temperature set point, and integrated energized times of 0.005 s, 0.01 s, or 0.02 s (2500x, 5000x, and 10000x 2 μs pulses, respectively). Patients returned 20-50 days post treatment to determine the efficacy of the treatment. ACE temperature control algorithms successfully achieved and maintained target temperatures in a diverse population of spontaneous tumors with significant variation in tissue impedance. All treatments were completed successfully without and without adverse events. Complete response rates greater than 93% were achieved in all treatment groups. ACE is a safe and effective treatment for spontaneous equine melanoma. The temperature control algorithm enabled rapid delivery of electroporation treatments without prior knowledge of tissue electrical or thermal properties and could adjust to real time changes in tissue properties. Real time temperature control in electroporation procedures enables treatments near critical structures where thermal damage is contraindicated. Unlike standard approaches, ACE protocols do not require extensive pretreatment planning or knowledge of tissue properties to determine an optimal energy delivery rate and they can account for changes in tissue state (e.g., perfusion) in real time to simultaneously minimize treatment time and potential for thermal damage.

A Burst Mode and Variable Frequency Voltage Sharing Control Mechanism for an Adjustable High Voltage Pulsed Converter

This article presents a modular adjustable high-voltage pulse (MAHVP) generation system. The proposed MAHVP generation system uses a combination of full-bridge LLC resonant converters whose input terminals are connected in parallel and whose output terminals are in series to boost the output voltage; input parallel output series configuration efficiently increases the power holding capabilities of the overall system. The MAHVP generation system uses a novel burst mode and variable frequency voltage sharing (BMVFVS) control mechanism, the BMVFVS control mechanism senses the type of load if the MAHVP generation system needs to operate at a heavy load, it uses the variable frequency voltage sharing method to divide the power equally between the modules to enhance the overall performance. For light load conditions, the MAHVP generation system operates in burst mode, and the BMVFVS control mechanism combined with the frequency modulation technique is used to control the amplitude and pulsewidth of the output voltage smoothly and efficiently. A hardware prototype of 2.4 kW is developed, and experimental results are taken to verify the feasibility and validity of the proposed system, the maximum output voltage of the developed two-module prototype is tested up to 6 kV at the high efficiency of 97%.

Engineering Controllable Pulse Generation for Molecular Communication via Genetic Circuits

Synthetic biology provides the engineering community with a tool to build biological entities that are capable of carrying out desired signal processing functionalities. The design and study of genetic circuits that exhibit natural behavior can be helpful for an improved understanding of the principles and kinetics behind the gene expression behavior, as well as for engineering cellular systems for synthetic biology. In this paper, we propose a synthetic biology system capable of generating a pulse-shaped signal, which is a prevalent behavior in natural environment. In particular, our proposed pulse generation system divides the pulse generation functions into different cells which are connected by intercellular signaling molecules. More specifically, the system is consisted of three engineered cells with different digital logic functionalities, and the pulse generation exploits the alteration in logic state. To quantitatively describe the generated pulse, we not only analyze the individual behavior of each cell using Shea-Ackers formalism but also derive the intercellular signaling channel. Simulation results demonstrate that the pulse-shaped signal can be produced in a controllable manner by arranging cells in different spatial configurations.

Micro Electric Shocks Control Broadleaved and Grass Weeds

A search for energy efficient, non-herbicide weed control methods led to development of a novel electrical weeding technology. This study focuses on weed control efficiency and energy as elements of a system that would include machine vision and robotics to control escape weeds in field crops. Two pulse generation systems, one single and one multiple, were developed and evaluated at different delivered voltages and energies. Greenhouse trials using specially designed and built application and recording technology showed the application of precisely applied micro-shocks with precisely controlled direct current (DC) voltage, pulse number, pulse length and period (hereafter PMS) can kill small Lolium multiflorum Lam., Chenopodium album L., Amaranthus powellii S. Wats. and Solanum nigrum L. plants with minimal energy. Plants took as much as two weeks to die. Increasing applied energy increased effectiveness as determined by plant biomass reduction and death rate. Grasses appear difficult to control once tillering has commenced, and high voltages may destroy leaf blades but not growing points. Broadleaved plants took several days to show evidence of chlorosis which preceded senescence and death. Our results showed that 5 J is sufficient energy to bring about death or severe growth limitation in many seedlings up to 15 cm height. This is as little as 1% of the energy of, and more effective than, ultra-low energy treatments reported in other recent research. To control five herbicide resistant weeds m−2, the required energy would be about 0.25 MJ ha−1 plus transport and actuation energy for weed destruction, as compared to an optimum target of about 20–40 MJ ha−1 including transport suggested in the literature. PMS can effectively control broadleaved weed seedlings and small non-tillering grasses at a fraction of the energy required by commercially available systems. This indicates PMS has potential as a viable technology for hand-held electric weeders or as part of a site-specific robotic weeding system.

Forcing Power Supply of a Xenon Flash Lamp to Create a High Power Irradiation Facility

The article describes the technical characteristics of the software-controlled power supply system for generation of second-long light pulses by means of INP‑16/580 xenon flash lamps. The amplitude-time characteristics of luminous emission in a quasi-arc mode of lamp operation are formed by computer control of temporal current pulse shape in case of large energy deposition overloads. Methods of optimisation of light and engineering characteristics were defined accounting for non-linearity of the load of the thyristor unit and ambiguity of the dependence of luminous radiation on discharge current. The data on maximum acceptable operation parameters of pulse lamps with mains supply and natural air cooling and the results of physical modelling of radiation pulses with complex shape are presented.

Computationally efficient neural network classifiers for next generation closed loop neuromodulation therapy - a case study in epilepsy.

This work explores the potential utility of neural network classifiers for real-time classification of field-potential based biomarkers in next-generation responsive neuromodulation systems. Compared to classical filter-based classifiers, neural networks offer an ease of patient-specific parameter tuning, promising to reduce the burden of programming on clinicians. The paper explores a compact, feed-forward neural network architecture of only dozens of units for seizure-state classification in refractory epilepsy. The proposed classifier offers comparable accuracy to filterclassifiers on clinician-labeled data, while reducing detection latency. As a trade-off to classical methods, the paper focuses on keeping the complexity of the architecture minimal, to accommodate the on-board computational constraints of implantable pulse generator systems.Clinical relevance—A neural network-based classifier is presented for responsive neurostimulation, with comparable accuracy to classical methods at reduced latency.

Compact and Integrated High-Power Pulse Generation and Forming System

This paper presents comprehensive analytical, numerical and experimental research of the compact and integrated high-power pulse generation and forming system based on the flux compression generator and the electro-explosive forming fuse. The paper includes the analysis of the presented solution, starting from the individual components studies, i.e., the separate flux compression generator tests in field conditions and the forming fuse laboratory test, through the formulation of the extended quasi-empirical components models aimed at enabling their optimal parameters determination at the early design stage and ending with the description of the integrated system studies in field conditions. Based on detailed research, it was possible to achieve very high parameters of the generated pulses, i.e., overvoltages of up to 340 kV with the available source power reaching 25 GW. A very high convergence of the simulation and the results of experimental research has been obtained. The parameters of the presented system have been compared with other literature solutions and the selected topology of the high power pulse generation and forming system has been distinguished against other available ones, e.g., based on Marx generators and forming lines.

A Transfer Function Model Development for Reconstructing Radial Pulse Pressure Waveforms Using Non-Invasively Measured Pulses by a Robotic Tonometry System.

The primary goal of this study is to develop a mathematical model that can establish a transfer function relationship between the “external” pulse pressures measured by a tonometer and the “internal” pulse pressure in the artery. The purpose of the model is to accurately estimate and rebuild the internal pulse pressure waveforms using arterial tonometry measurements. To develop and validate a model without human subjects and operators for consistency, this study employs a radial pulse generation system, a robotic tonometry system, and a write model with an artificial skin and vessel. A transfer function model is developed using the results of the pulse testing and the mechanical characterization testing of the skin and vessel. To evaluate the model, the pulse waveforms are first reconstructed for various reference pulses using the model with tonometry data. They are then compared with pulse waveforms acquired by internal measurement (by the built-in pressure sensor in the vessel) the external measurement (the on-skin measurement by the robotic tonometry system). The results show that the model-produced pulse waveforms coinciding well with the internal pulse waveforms with small relative errors, indicating the effectiveness of the model in reproducing the actual pulse pressures inside the vessel.

Design of Adaptive DC Power Supply with Microcontroller Based Cuk Converter Circuit

Nowadays, the need for equipment sourced from DC power supplies is increasing. One of the DC–DC converter topology that can be DC source isCukConverter. Currently, we need an adaptive power supply that can generate current and voltage according to the power required by the load automatically. In this research, the Cuk-Converter circuit is driven through the Arduinonano as a pulse generator and circuit control system. The microcontroller has set a minimum current of 520mA to charge the battery. The test was carried out with a 12 Volt DC battery source, the output of the Cuk-Converter was a 3.7 Volt battery with a capacity of 50,000 mAh and 3Ah, and a 12 Volt 3 Ah accumulator. The output of the Cuk Converter is set in the range 2-19 Volt DC. The results show that the Cuk-Converter can charge the test battery with a minimum current of 520 mAh and a duty cycle in the range of 27-50%. This result performed the average error of the circuit and calculation was 13.9%.

Discharge analysis of EDM pulse generator

Electrical discharge machining (EDM) is a non-conventional manufacturing process used broadly in medical applications, aerospace industry and manufacturing in hard material fields. However, information about the process is still in an unfledged stage and it has been becoming a serious obstacle to its more improvements. In this paper, spark discharge condition is studied based on the simulated model of EDM spark pulse generator system equivalent form. Simulated model is verified by comparing with a series of experimental results. Frequency response is established through simplified model of EDM system. Influence of discharge time and stable discharge current on material removal rate (MRR) and stability of the system is analysed. This study is important to select the process parameters, and uses as a guidance to design the EDM spark pulse generator system.

Waveform Control of Multi-Pulse Flat-Top High Magnetic Field Based on Pulsed Generator System

Multi-pulse flat-top high magnetic field (MFHMF) can promote neutron diffraction, terahertz source and other research fields. Due to the limited heat dissipation capability of pulsed magnet, the magnet resistance gradually increases, which leads to inconsistencies of the waveforms and limits the quantity of flat-top magnetic field waveforms. For the sake of getting the MFHMF with high consistency, a pulsed generator-rectifier system is used as the power supply by analyzing the impedance characteristic of multi-pulse magnet in this paper. Based on the accurate external characteristics modeling of power supply, a control method of generalized model predictive control (GPC) is proposed. In this GPC method, a 3-level least square method (LSM) is designed to calculate the real-time magnet resistance, and the influence of disturbance by the magnetic resistance is eliminated by the controller. Finally, the results based on MATLAB/ Simulink simulation verified the feasibility and validity of the waveform control method of MFHMF.

A pulse generation system based on new method for testing performance of high-resolution nuclear spectroscopy systems

The paper presents a design and construction of uniform amplitude pulse generator for testing Differential Non-Linearity (DNL) of high-resolution nuclear spectroscopy systems. The paper describes two methods based on two new techniques called DAC Interpolation and Analog Multiplexer based design. A prototype of DAC interpolation technique has been designed and tested. **The method based on analog multiplexer and chain of resistors is simulated and the results of which is reported in the paper. The systems produce pulses with step size of 10 microvolt (µV), making them capable for calibrating spectroscopy systems with the resolution as high as 13-bit (8K). The systems are designed using commercially available components. The pulse generation system provides import substitute for commercially available imported models.

MoTe2 Saturable Absorber With High Modulation Depth for Erbium-Doped Fiber Laser

Transition metal dichalcogenides have recently been considered the candidates for saturable absorption materials due to their advantages in both electronic and optoelectronic. Compared with MoS2 and WS2, MoTe2 exhibits smaller bandgap. As a result, MoTe2 owns inherent advantages in the near-infrared applications. In this paper, the MoTe2 saturable absorber (SA) were prepared by the magnetron sputtering deposition method. Owing to the enhanced light-materials interaction between MoTe2 and evanescent field from the microfiber, the modulation depth of the MoTe2 SA was up to 26.97%. By assembling the MoTe2 SA into the erbium-doped fiber laser, the mode-locked fiber laser at 1.5 μm was demonstrated. The pulse duration of 111.9 fs was proved to be the shortest in the fiber lasers based on transition metal dichalcogenides. Moreover, the mode-locked fiber laser maintains the long-term stability. Our results suggest that the proposed MoTe2 SA is promising for the ultrashort pulse generation and stable system operation.

Factors Associated With High-Voltage Impedance and Subcutaneous Implantable Defibrillator Ventricular Fibrillation Conversion Success.

The ability to predict defibrillation efficacy at the time of subcutaneous implantable cardioverter-defibrillator implantation without the need to induce ventricular fibrillation might eliminate the need for defibrillation testing. The purpose of this study was to determine the association of high-voltage impedance and system implant position on ventricular fibrillation conversion success with a submaximal 65-J shock. In the subcutaneous implantable cardioverter-defibrillator IDE study (Investigational Device Exemption), a successful conversion test required 2 consecutive ventricular fibrillation conversions at 65 J in either shock vector. Chest radiographs were obtained after implantation. Patients with imaging and impedance data were included. Suboptimal device position was defined as an inferior electrode or pulse generator or electrode coil depth >3 mm anterior to the sternum. Absence of suboptimal positional parameters was defined as appropriate position. Conversion success rate was calculated among all 65-J tests. Of 314 patients who underwent subcutaneous implantable cardioverter-defibrillator implantation, 282 patients were included in this analysis. There were 637 inductions to test defibrillation at 65 J. Sixty-two conversion failures (9.7%) occurred in 42 (14.9%) patients. Lower body mass index and lower shock impedance were associated with higher conversion success rate, whereas white race was associated with lower conversion success rate. Suboptimal position was more common in obese patients. Inferior electrode and greater distance between the lead and sternum were associated with a higher impedance. When appropriate system position was achieved, conversion failure was not associated with high body mass index. Subcutaneous implantable cardioverter-defibrillator shock efficacy is associated with system position and high-voltage system impedance. A high impedance is associated with inferiorly placed pulse generator and electrode system, inadequate coil depth, and a lower rate of defibrillator success. URL: https://www.clinicaltrials.gov . Unique identifier: NCT01064076.

Development of an ultra-fast photomultiplier tube for gamma-ray Cherenkov detectors at the National Ignition Facility (PD-PMT).

A new ultra-fast photomultiplier tube and associated drivers have been developed for use in the next generation of gamma-ray high pressure gas Cherenkov detectors for inertial confinement fusion experiments at the National Ignition Facility. Pulse-dilation technology has been applied to a standard micro-channel-plate-based photomultiplier tube to improve the temporal response by about 10×. The tube has been packaged suitably for deployment on the National Ignition Facility, and remote electronics have been designed to deliver the required non-linear waveforms to the pulse dilation electrode. This is achieved with an avalanche pulse generator system capable of generating fast arbitrary waveforms over the useful parameter space. The pulse is delivered via fast impedance-matching transformers and isolators, allowing the cathode to be ramped on a sub-nanosecond time scale between two high voltages in a controlled non-linear manner. This results in near linear pulse dilation over several ns. The device has a built-in fiducial system that allows easy calibration and testing with fiber optic laser sources. Results are presented demonstrating the greatly improved response time and other parameters of the device.

Ns Pulsed Electric Field-Induced Action Potentials in the Circuital Model of an Axon.

Pulsed electric fields with duration in the sub- and ns time scale (nsPEFs) increase the permeability of cell membranes, enabling the transport of normally impermeant molecules into or out of the cell (electroporation). Such effect is associated to intracellular alterations and indicates nsPEFs as a new stimulus to modulate cell functions. In particular, studies dealing with the application of nsPEFs to excitable cells suggest their use for the stimulation/inhibition of cell excitation. In this paper, the circuital model per surface unit of the plasma membrane of an axon was developed to implement the Hodgkin and Huxley equations, describing the action potential activation process. For the first time, a power electronics circuital simulator was adopted. The model was first validated with conventional microsecond stimuli, and then it was employed to identify the conditions for cell excitation by nsPEFs. The results demonstrated the possibility of electrostimulation by nsPEFs at depolarization levels far below those required for inducing electroporation, and with ionic current dynamics similar to that induced by conventional stimuli, confirming recent experimental findings. Moreover, by using a power electronics tool, easier integration of the cell modeling with the design and optimization of pulse generation systems can be gained.

A high precision pulse generation and stabilization system for bolometric experiments

Bolometric experiments searching for rare events usually require an extremely low radioactive background to prevent spurious signals from mimicking those of interest, spoiling the sensitivity of the apparatus. In such contexts, radioactive sources cannot be used to produce a known signal to calibrate the measured energy spectrum during data taking. In this paper we present an instrument designed to generate ultra-stable and very precise calibrating pulses, which can be used to stabilize the response of bolometers during data taking. The instrument is characterized by the presence of multi-outputs, a completely programmable pulse width and amplitude and a dedicated daisy-chained optical trigger line. It can be fully controlled and monitored remotely via CAN bus protocol. An energy resolution of the order of 20 eV FWHM at 1 MeV (2 eV FWHM at 10 keV) and a thermal stability of the order of 0.1 ppm/̂C have been achieved. The device can also provide an adjustable power to compensate the low frequency thermal fluctuations that typically occur in cryogenic experiments.

이중충격파의 충격파형 동특성 분석에 근거한 충격시험장치의 순차적 설계

이중충격파의 충격파형 동특성 분석에 근거한 충격시험장치의 순차적 설계