Mutual effects between a gliding arc discharge and a premixed flame

Mutual effects between a gliding arc(GA)discharge at atmospheric pressure and a premixed CH_(4)/air flame were experimentally investigated.Effects of the flame on the GA were studied using simultaneous measurements of the current,the voltage,and the instantaneous images of the plasma columns.The GA in the flame has a thicker and more diffusive plasma column,and it is more frequently ignited at a smaller breakdown voltage than that in the air.The GA extension velocity and the gliding velocity in the flame are larger than those in the air.The electrode voltage drop of the GA discharge in the flame is about 160 V,whereas that in the air is about 220 V.Compared with the GA in the air,the different features of the GA in the flame can be explained by high-temperature,weakly ionized,and species-abundant environment that are generated by the premixed CH_(4)/air flame.Effects of the gliding arc discharge on the premixed flames were demonstrated using planar laser-induced fluorescence of hydroxyl radicals(OH)and formaldehyde(CH_(2)O).OH and CH_(2)O can be formed in the CH_(4)/air mixture in the presence of the GA due to kinetic effects,and the increase of OH and CH_(2)O shows the great potential of the GA for combustion enhancement.

Discharging patients home from the intensive care unit:A new trend

Discharging patients directly to home from the intensive care unit(ICU)is becoming a new trend.This review examines the feasibility,benefits,challenges,and considerations of directly discharging ICU patients.By analyzing available evidence and healthcare professionals'experiences,the review explores the potential impacts on patient outcomes and healthcare systems.The practice of direct discharge from the ICU presents both opportunities and complexities.While it can potentially reduce costs,enhance patient comfort,and mitigate complications linked to extended hospitalization,it necessitates meticulous patient selection and robust post-discharge support mechanisms.Implementing this strategy successfully mandates the availability of home-based care services and a careful assessment of the patient's readiness for the transition.Through critical evaluation of existing literature,this review underscores the significance of tailored patient selection criteria and comprehensive post-discharge support systems to ensure patient safety and optimal recovery.The insights provided contribute evidence-based recommendations for refining the direct discharge approach,fostering improved patient outcomes,heightened satisfaction,and streamlined healthcare processes.Ultimately,the review seeks to balance patientcentered care and effective resource utilization within ICU discharge strategies.

Effect and mechanism of on-chip electrostatic discharge protection circuit under fast rising time electromagnetic pulse

The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with the CMOS circuit,but also acts on the protection circuit.This paper establishes a model of on-chip CMOS electrostatic discharge protection circuit and selects square pulse as the FREMP signals.Based on multiple physical parameter models,it depicts the distribution of the lattice temperature,current density,and electric field intensity inside the device.At the same time,this paper explores the changes of the internal devices in the circuit under the injection of fast rising time electromagnetic pulse and describes the relationship between the damage amplitude threshold and the pulse width.The results show that the ESD protection circuit has potential damage risk,and the injection of FREMP leads to irreversible heat loss inside the circuit.In addition,pulse signals with different attributes will change the damage threshold of the circuit.These results provide an important reference for further evaluation of the influence of electromagnetic environment on the chip,which is helpful to carry out the reliability enhancement research of ESD protection circuit.

Effect of continuous nursing on rehabilitation of older patients with joint replacement after discharge

BACKGROUND Joint replacement is a common treatment for older patients with high incidences of hip joint diseases.However,postoperative recovery is slow and complications are common,which reduces surgical effectiveness.Therefore,patients require long-term,high-quality,and effective nursing interventions to promote rehabilitation.Continuity of care has been used successfully in other diseases;however,little research has been conducted on older patients who have undergone hip replacement.AIM To explore the clinical effect of continuous nursing on rehabilitation after discharge of older individuals who have undergone joint replacement.METHODS A retrospective analysis was performed on the clinical data of 113 elderly patients.Patients receiving routine nursing were included in the convention group(n=60),and those receiving continuous nursing,according to various methods,were included in the continuation group(n=53).Harris score,short form 36(SF-36)score,complication rate,and readmission rate were compared between the convention and continuation groups.RESULTS After discharge,Harris and SF-36 scores of the continuation group were higher than those of the convention group.The Harris and SF-36 scores of the two groups showed an increasing trend with time,and there was an interaction effect between group and time(Harris score:F_(intergroup effect)=376.500,F_(time effect)=20.090,Finteraction effect=4.824;SF-36 score:F_(intergroup effect)=236.200,Ftime effect=16.710,Finteraction effect=5.584;all P<0.05).Furthermore,the total complication and readmission rates in the continuation group were lower(P<0.05).CONCLUSION Continuous nursing could significantly improve hip function and quality of life in older patients after joint replacement and reduce the incidence of complications and readmission rates.

Optimization of reluctance accelerator efficiency by an improved discharging circuit

In this paper,an improved discharging circuit was proposed to quicken the decay of the current in the drive coil in a reluctance accelerator when the armature reaches the center of the coil.The aim of this is to prevent the suck-back effect caused by the residual current in drive coil.The method is adding a reverse charging branch with a small capacitor in the traditional pulsed discharging circuit.The results under the traditional circuit and the improved circuit were compared in a simulation.The experiment then verified the simulations and they had good agreement.Simulation and experiment both demonstrated the improved circuit can effectively prevent the suck-back effect and increase the efficiency.At the voltage of 800 V,an efficiency increase of 36.34% was obtained.

Effects of reservoirs on seasonal discharge of Irtysh River measured by Lepage test

The Irtysh River is an intemational river partially joining the territories of China, Kazakhstan, and Russia. Cascade reservoirs have been constructed in the upper reaches of the river and their effects on the seasonal discharge of the middle and lower reaches were analyzed considering the mean and dispersion of the seasonal discharge. The Lepage test, which is a nonparametric, two-sample test for detecting location and dispersion, was used to measure the significance of difference between the pre-dam and post-dam seasonal discharge. The results show that the reservoirs＇ effects on the seasonal discharge varied with the season. In the middle reaches of the river, the summer and autumn discharge decreased significantly and their inter-annual variabilities also decreased significantly. The summer and autumn precipitation over the Irtysh River Basin changed little before and after the operation of the reservoir, which indicates that the discharge changes mainly due to water storage of the reservoirs. The reservoirs store water in summer and autumn and store more water in a wet year, which leads to the reduction of the mean and dispersion of the summer and autumn discharge. The winter discharge increased significantly because the reservoirs released water for power generation. The spring discharge changed slightly. In the lower reaches, only the winter discharge increased significantly, and the other seasonal discharge changed slightly. The reservoirs＇ effects on the seasonal discharge are more significant in the middle reaches than in the lower reaches.

Effects of Hydroxyl Radicals on Introduced Organisms of Ship's Ballast Water Based Micro-Gap Discharge

With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship＇s ballast water. The surface morphology of Al2O3 dielectric layer was analysed using Atomic Force Microscopy （AFM）, where the size of Al2O3 particles was in the range of 2 μm to 5 μm. At the same time, the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship＇s ballast water were studied. The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase （CAT）, Peroxidase （POD） and Superoxide dismutase （SOD）. In addition, the quality of the ballast water was greatly improved.

Scale Effects and a Method for Similarity Evaluation in Micro Electrical Discharge Machining

Electrical discharge machining（EDM） is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of ＂scale effects＂ in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM.

Dynamic characteristics of charging effects on the dielectric constant due to E-beam irradiation:a numerical simulation

A series of synthetic variations of material intrinsic properties always come with charging phenomena due to electron beam irradiation.The effects of charging on the dielectric constant will influence the charging dynamic in return.In this paper,we propose a numerical simulation for investigating the dynamic characteristics of charging effects on the dielectric constant due to electron beam irradiation.The scattering process between electrons and atoms is calculated considering elastic and inelastic collisions via the Rutherford model and the fast secondary electron model,respectively.Internal charge drift due to E-field,density gradient caused diffusion,charges trap by material defect,free electron and hole neutralization,and variation in the internal dielectric constant are considered when simulating the transport process.The dynamics of electron and hole distributions and charging states are demonstrated during E-beam irradiation.As a function of material nonlinear susceptibility and primary energy,the dynamics of charging states and dielectric constants are then presented in the charging process.It is found that the variation in the internal dielectric constant is more with respect to the depth and irradiation time.Material with a larger nonlinear susceptibility corresponds a faster charging enhancement.In addition,the effective dielectric constant and the surface potential have a linear relationship in the charging balance.Nevertheless,with shrinking charging affect range,the situation with a higher energy primary electron comes with less dielectric constant variation.The proposed numerical simulation mode of the charging process and the results presented in this study offer a comprehensive insight into the complicated charging phenomena in electron irradiation related fields.

A Review on Chemical Effects in Aqueous Solution induced by Plasma with Glow Discharge

Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..

Mitigating Deep Dielectric Charging Effects at the Orbits of Jovian Planets

Deep dielectric charging/discharging,caused by high energy electrons,is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures.The Jovian planets,including Saturn,Uranus,Neptune and Jupiter’s moons,are believed to have robust electron radiation belts at relativistic energies.In particular,Jupiter is thought to have caused at least 42 internal electrostatic discharge events during the Voyager 1 flyby.With the development of deep space exploration,there is an increased focus on the deep dielectric charging effects in the orbits of Jovian planets.In this paper,GEANT4,a Monte Carlo toolkit,and radiation-induced conductivity(RIC)are used to calculate deep dielectric charging effects for Jovian planets.The results are compared with the criteria for preventing deep dielectric charging effects in Earth orbit.The findings show that effective criteria used in Earth orbit are not always appropriate for preventing deep dielectric charging effects in Jovian orbits.Generally,Io,Europa,Saturn(R_S=6),Uranus(L=4.73)and Ganymede missions should have a thicker shield or higher dielectric conductivity,while Neptune(L=7.4)and Callisto missions can have a thinner shield thickness or a lower dielectric conductivity.Moreover,dielectrics grounded with double metal layers and thinner dielectrics can also decrease the likelihood of discharges.

Abnormal Polarity Effects of Streamer Discharge in Propylene Carbonate under Microsecond Pulses

Propylene carbonate （PC） has a great potential to be used as an energy storage medium in the compact pulsed power sources due to its high dielectric constant and large resistivity. We investigate both the positive and negative breakdown characteristics of PC. The streamer patterns are obtained by ultra-high-speed cameras. The experimental results show that the positive breakdown voltage of PC is about 135% higher than the negative one, which is abnormal compared with the common liquid. The shape of the positive streamer is filamentary and branchy, while the negative streamer is tree-like and less branched. According to these experimental results, a charge layer structure model at the interface between the metal electrode and liquid is presented. It is suggested that the abnormal polarity effect basically arises from the electric field strength difference in the interface between both electrodes and PC. What is more, the recombination radiation and photoionization also play an important role in the whole discharge process.

Effects of Tailed Pulse-Bias on Ion Energy Distributions and Charging Effects on Insulating Substrates

Abstract A hybrid sheath model, including a fluid model and a Monte Carlo （MC） method, is proposed to study ion energy distributions （IEDs） driven by a radiofrequency （RF） with a tailed pulse-bias on an insulating substrate, where a charging effect is obviously caused by the ions accumulated. This surface charging effect will significantly affect the IEDs on the insulating substrate. In this paper, a voltage compensation method is employed to eliminate the charging effect by making the pulse-bias waveform have a certain gradient. Furthermore, we investigate the IEDs under the condition of different pulse-bias duty ratios, waveforms, amplitudes, and cycle proportions. It is found that the parameters of the pulsed source can effectively modulate the IEDs on the insulating substrate and the charging effect, and more desired IEDs are obtained by using the voltage compensation method with modulations of pulse parameters.

Interaction of solitary waves in magnetized warm dusty plasmas with dust charging effects

In consideration of adiabatic dust charge variation, the combined effect of the external magnetized field and the dust temperature on head-on collision of the three-dimensional dust acoustic solitary waves is investigated. By using the extended Poincaré-Lighthill-Kuo method, the phase shifts and the trajectories of two solitons after the collision are obtained. The effects of the magnitude and the obliqueness of the external magnetic field and the dust temperature on the solitary wave collisions are discussed in detail,

Effects of Macroparticle Sizes on Two-phase Mixture Discharge Under DC Voltage

随着放电等离子体在各个领域应用的不断扩大，两相体放电问题越来越重要，需要解决的基础问题之一即是两相体中放电发生、发展的特点和规律及影响因素。采用21种不同的介质材料研究直流电压下两相体放电的效应，由实验结果可知介质的介电常数对放电路径基本无影响，而介质颗粒的粒径大小对两相体放电路径的选择起决定作用，即粒径效应。此外，对颗粒介电常数、电场畸变、光电离作用和颗粒荷电等几个方面进行研究，可知两相体放电的粒径效应与颗粒粒径大小紧密相关。

Optimal Scheduling of PEV Charging/Discharging in Microgrids with Combined Objectives

While renewable power generation and vehicle electrification are promising solutions to reduce greenhouse gas emissions, it faces great challenges to effectively integrate them in a power grid. The weather-dependent power generation of renewable energy sources, such as Photovoltaic (PV) arrays, could introduce significant intermittency to a power grid. Meanwhile, uncontrolled PEV charging may cause load surge in a power grid. This paper studies the optimization of PEV charging/discharging scheduling to reduce customer cost and improve grid performance. Optimization algorithms are developed for three cases: 1) minimize cost, 2) minimize power deviation from a pre-defined power profile, and 3) combine objective functions in 1) and 2). A Microgrid with PV arrays, bi-directional PEV charging stations, and a commercial building is used in this study. The bi-directional power from/to PEVs provides the opportunity of using PEVs to reduce the intermittency of PV power generation and the peak load of the Microgrid. Simulation has been performed for all three cases and the simulation results show that the presented optimization algorithms can meet defined objectives.

Surface charge characteristics in a three-electrode surface dielectric barrier discharge

The surface charge characteristics in a three-electrode surface dielectric barrier discharge(SDBD)are experimentally investigated based on the Pockels effect of an electro-optical crystal. The actuator is based on the most commonly used SDBD structure for airflow control, with an exposed electrode supplied with sinusoidal AC high voltage, a grounded encapsulated electrode and an additional exposed electrode downstream supplied with DC voltage. The ionic wind velocity and thrust can be significantly improved by increasing DC voltage although the plasma discharge characteristics are virtually unaffected. It is found that the negative charges generated by the discharge of the three-electrode structure accumulate on the dielectric surface significantly further downstream in an AC period compared to the actuator with a two-electrode structure. The negative charges in the downstream region increase as the DC voltage increases.In addition, the DC voltage affects the time required for the positive charge filaments to decay.The positive DC voltage expands the ionic acceleration zone downstream to produce a greater EHD force. The amplitude of the DC voltage affects the electric field on the dielectric surface and is therefore a key factor in the formation of the EHD force. Further research on the surface charge characteristics of a three-electrode structure has been conducted using a pulse power to drive the discharge, and the same conclusions are drawn. This work demonstrates a link between surface charge characteristics and EHD performance of a three-electrode SDBD actuator.

Discharge evolution law of debris flow based on a sharp bend physical modeling test

For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel.

Formation mechanism of bright and dark concentric-ring pattern in dielectric barrier discharge

In this work,a bright and dark concentric-ring pattern is reported in a dielectric barrier discharge for the first time.The spatiotemporal dynamics of the bright and dark concentric-ring pattern are investigated with an intensified charge-coupled device and photomultiplier tubes.The results indicate that the bright and dark concentric-ring pattern is composed of three concentric-ring sublattices.These are bright concentric-ring structures,dark concentric-ring structures and wider concentric-ring structures,respectively.The bright concentric-ring structures and dark concentricring structures are alternately distributed.The bright concentric-ring structures are located at the centre of the wider concentric-ring structures.The wider concentric-ring structures first form from the outer edge and gradually develop to the centre.The essence of all three concentric-ring structures is the individual discharge filaments.The optical emission spectra of different sublattices are acquired and analysed.It is found that the plasma parameters of the three concentricring sublattices are different.Finally,the formation mechanism of the bright and dark concentricring pattern is discussed.