Combined electric discharge “arc + discharge with liquid electrolyte cathode”

A combination of an electric arc and discharge with a liquid electrolyte cathode in a single discharge gap has been created. The plasma column of discharge with liquid electrolyte cathode formed a “hollow cylinder”. The electric arc was burned in a vapor-gas environment inside the “hollow cylinder”. The gas discharge current with liquid electrolyte cathode was set in the range of 5-10 A, and the arc current varied in the range of 1-10 A. Aqueous solutions of sodium chloride with a specific electrical conductivity of 10-15 mS/cm were used as a liquid electrolyte. Spectral studies have been carried out in the visible range of radiation. In the experiments, copper and duralumin metal cathodes were used.

Simultaneous Observation of Tungsten Spectra of W0 to W46+ Ions in Visible, VUV and EUV Wavelength Ranges in the Large Helical Device

Spectroscopic studies for emissions released from tungsten ions have been conducted in the Large Helical Device (LHD) for contribution to the tungsten transport study in tungsten divertor fusion devices and for expansion of the experimental database of tungsten line emissions. Tungsten ions are distributed in the LHD plasma by injecting a pellet consisting of a small piece of tungsten metal wire enclosed by a carbon tube. Line emissions from W0, W5+, W6+, W24+–W28+, W37+, W38+, and W41+–W46+ are observed simultaneously in the visible (3200–3550 Å), vacuum ultraviolet (250–1050 Å), and extreme ultraviolet (5–300 Å) wavelength ranges and the wavelengths are summarized. Temporal evolutions of line emissions from these charge states are compared for comprehensive understanding of tungsten impurity behavior in a single discharge. The charge distribution of tungsten ions strongly depends on the electron temperature. Measurements of emissions from W10+ to W20+ are still insufficient, which is addressed as a future task.

Using Machine Learning for the Classification of the Remaining Useful Cycles in Lithium-Ion Batteries

In order to keep up with the increasing focus on renewable energy, the demand for new battery technology and peripherals has likewise increased greatly. Given the relatively slow rate of change of new battery chemistry and technology, it is the peripherals to the batteries that are often relied upon to provide this necessary increase in performance. The 18650 battery with Lithium-Ion internal chemistry is one of the most widely used batteries and is depended upon in many industries to provide power portability and storage. Using an extensive freely available dataset compromising of the charge cycles of 121 18650 batteries, this paper evaluates multiple algorithms’ effectiveness at predicting the remaining useful cycles of a battery from a single discharge curve. Upon evaluation of the algorithms, ‘Weighted K Nearest Neighbours’ was shown to be the most accurate model and was further improved to ensure that the maximum accuracy was acquired. Finally, a user interface was created to allow for the demonstration of a potential use case for the model. This model and user interface show the potential for easy testing of batteries to determine the number of remaining useful cycles. This makes the possibility of re-purposing or extending the initial purpose of these batteries much greater, which is preferable from both an economic standpoint and an ecological one.

Design of Single Input Multiple Output Buck Converter with Light Load Efficiency

The major demand for portable electronics devices such as pagers, laptops, cellular phones etc. Single input multiple output (SIMO) converter will be proposed to give different supply voltages while keep up prolong battery life. A single-discharge (SDC) control scheme is introduce to simplify the Single inductor multiple output design, attain to low cross regulation, and to support board range of loads with decent efficiency of power. A Single discharge control single input multiple output buck converter with 4 outputs composed of comparators, phased-locked loop, finite state machine (FSM) controller, and an output stage. In addition to the basic switching functions, the FSM controller provides a state skipping feature to allow no-load regulation. Single input multiple output converter is available for less cost and used for maintaining long battery life and they are growing in vast range with rich feature portable electronic device. The design of converter is designed for limited range for prolonged battery life. The SIMO converters are used for the reduction of cost and switching losses, hence improve system efficiency. In our study, we proposed buck converter topology with single input of 24v and multiple output of 12v and 5v. The 12v voltage is used for electric vehicles. In electric vehicles it is used in horns and headlights. 5v voltage is used for small signal and stability analysis. The simulated conversion efficiency for peak power is 86% the power ranging for output is 50 to 300mW. The ICs exhibit has a low measured peak efficiency of 73% and cross regulation of 0.24 mV/mA because of parasitic bond wire resistance. The proposed system is simulated in MATLAB/Simulink software.

Numerical Study of Discharge Adjustment Effects on Reservoir Morphodynamics and Flushing Efficiency: An Outlook for the Unazuki Reservoir, Japan

The Unazuki Reservoir is located on the Kurobe River, which is influenced by a catchment with one of the highest sediment yields in Japan. Due to a sufficiently available discharge during flood events, annual sediment flushing with full water-level drawdown (i.e., free-flow sediment flushing) is conducted to preserve the effective storage capacity of the reservoir. Nevertheless, the upstream half of the reservoir (i.e., study segment) suffers from the excessive deposition of coarser sediments. Remobilization of these coarser materials and their transportation further downstream of the reservoir is a priority of reservoir owners for sustainable reservoir functions, such as flood-risk management and hydroelectric energy generation. In this paper, an already conducted sediment-flushing operation in the Unazuki Reservoir is simulated, and its effects on sediment scouring from the study segment of the reservoir together with changes in bed morphodynamics are presented. A fully 3D numerical model using the finite volume approach in combination with a wetting/drying algorithm was utilized to reproduce the hydrodynamics and bed changes using the available onsite data. Afterwards, the effects of discharge adjustment on the morphological bed changes and flushing efficiency were analysed in the study segment using an additional single-discharge pulse supplied from upstream reservoirs. Simulation results showed that an approximately 75% increase in the average discharge during the free-flow stage changed the dominant morphological process from deposition into an erosive mode in the study segment. If the increase in discharge reaches up to 100%, the flushed volume of sediments from the target segment can increase 2.9 times compared with the initiation of the erosive mode.

Study on ZrB2-Based Ceramics Reinforced with SiC Fibers or Whiskers Machined by Micro-Electrical Discharge Machining

The effects of different reinforcement shapes on stability and repeatability of micro electrical discharge machining were experimentally investigated for ultra-high-temperature ceramics based on zirconium diboride (ZrB2) doped by SiC. Two reinforcement shapes, namely SiC short fibers and SiC whiskers were selected in accordance with their potential effects on mechanical properties and oxidation performance. Specific sets of process parameters were defined minimizing the short circuits in order to identify the best combination for different pulse types. The obtained results were then correlated with the energy per single discharge and the discharges occurred for all the combinations of material and pulse type. The pulse characterization was performed by recording pulses data by means of an oscilloscope, while the surface characteristics were defined by a 3D reconstruction. The results indicated how reinforcement shapes affect the energy efficiency of the process and change the surface aspect.

Modeling of Dry-EDM Plasma Discharge

There is a growing interest in developing the dry EDM process as a sustainable alternative to the conventional liquid dielectric-based EDM process. It is shown that the dry EDM process possesses advantages over the conventional process in terms of thermal damage, recast layer, and tool wear. However, there is a need to increase the productivity of the dry EDM process for its successful adaptation in the industry. This paper presents a model of dry EDM plasma discharge with air as the dielectric medium. The model uses global modeling (‘0D’) approach in which equations of mass balance, energy balance, and plasma expansion are solved simultaneously to obtain a time-dependent description of the plasma in terms of its composition, temperature, diameter, and heat flux to electrodes. The model includes reaction kinetics involving 622 reactions and 55 species to determine the air plasma composition. A single discharge dry EDM operation is successfully simulated using the model, and the effect of discharge current on the plasma is studied. An increase in the discharge current increases the electron density, temperature, and diameter of the plasma linearly, while heat flux to the workpiece increases exponentially. Overall, the model provides an essential tool to study the dry EDM process mechanisms at a fundamental level and devise methods for process improvements.