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This study investigates the thermal plasma pyrolysis process for inertizing the inorganic fraction of sewage sludge from municipal wastewater treatment plants. The aim is to assess its effectiveness in waste inertization. Lab-scale experiments were conducted to process the sludge thermally. Elemental composition analysis was done using x-ray fluorescence (XRF), thermogravimetry coupled with mass spectrometry (TGA-MS) and x-ray diffraction (XRD). The XRF analysis showed an initial composition of Si, Al, Fe, and Ca, corresponding to 86.8% of the inorganic matter of the sludge. TGA-MS analysis showed a significant mass loss between 200 and 650°C, corresponding to organic matter volatilization, methane conversion, and dehydrogenation of polymorphic silicon. XRD analysis revealed a dried sludge crystalline structure composed mainly by SiO2, CaCO3, and AlPO4, and after plasma treatment, the remaining composition of the slag was primarily SiO2 amorphous. Mass and energy balances, considering thermodynamic equilibrium and chemical reactions, are performed. The mass balance calculations identified the most probable composition of the sludge, and energy balance calculations determined a net energy requirement of 399 kWh for plasma inertization, with an additional 300 kWh to account for furnace losses. Solubility and leaching tests confirm the inert nature of the residue. Power requirements are estimated at 700 kW for processing 350 kg h−1 of decarbonized sludge. These findings are crucial for optimizing plasma inertization processes in wastewater treatment plants. This work presents a novel approach by combining a computational prediction for an industrial-scale plant with a direct experimental assessment of the plasma treatment process. [ABSTRACT FROM AUTHOR]

The thermal convection of compressible, partially ionized plasma has been investigated using nonlinear and linear analyses across three boundary configurations. Nonlinear analysis was carried out via the energy method, while linear analysis was assessed using the normal mode method. For free-free boundaries, exact solutions were obtained, whereas, for rigid-rigid and rigid-free boundaries, the higher-order Galerkin-weighted residual method was employed for numerical results. The critical Rayleigh numbers for both analyses coincide, indicating global stability and confirming the absence of subcritical regions. The impact of collisional frequency on energy decay was quantified, revealing a significant effect on the decay rate, although it does not affect the Rayleigh number. The principle of exchange of stabilities was confirmed in the linear analysis. Compressibility delays the onset of convection. The critical Rayleigh numbers were computed as 986.267, 2,561.64, and 1,650.97 for the free–free, rigid–rigid, and rigid–free cases, respectively, demonstrating that plasma confined between rigid–rigid surfaces exhibits the highest thermal stability. [ABSTRACT FROM AUTHOR]

Alumina is the most widely used oxide ceramic, and its applications are widespread in engineering and in biomedical fields. Its spheroidization was performed by a prototypal direct current (DC) thermal plasma, which was designed and installed at ENEA, investigating surface morphology, particle size distribution, crystallinity, spheroidization, and reactivity. Features such as morphology and porosity significantly influence the flowability of the powder on the printer bed and, consequently, the density of the printed parts. It has been reported that spherical powder shape is highly recommended in additive manufacturing (AM) due to its superior flowability compared to other shapes whose interaction between powder particles results in poor flowability. In this paper, the spheroidization process of alumina powders using two different DC plasma powers and two kinds of secondary gas is reported. The average value of the circularity of the powders, after plasma treatment, has always been greater than or equal to 0.8 with the degree of the spheroidization over 90% at high power. The best process parameters of the thermal plasma were properly selected to produce spherical powders suitable for AM applications, and powders with high circularity were successfully obtained. Forming, debinding, and sintering tests were performed to verify the processability and the densification of produced powders, with good results in terms of density (97%). [ABSTRACT FROM AUTHOR]

This paper presents a new method of path planning for an industrial robot manipulator that performs thermal plasma spraying of coatings. Path planning and automatic generation of the manipulator motion program are performed using preliminary 3D surface scanning data from a laser triangulation distance sensor installed on the same robot arm. The new path planning algorithm is based on constructing a function of the geodesic distance from the starting curve. A new method for constructing a geodesic distance function on a surface is proposed, based on the application of Discrete Exterior calculus methods, which is characterized by a high computational efficiency. The developed algorithms and their software implementation were experimentally tested with the robotic microplasma spraying of a protective coating on the surface of a jaw crusher plate, which was then successfully operated for crushing mineral-based raw materials. [ABSTRACT FROM AUTHOR]

Plasma–liquid reactions represent an emerging green chemical process for nitrogen fixation; however, these processes generally exhibit low selectivity for ammonium (NH4+). This limitation highlights the need to explore simple methods to increase NH4+; selectivity. In this study, a catalyst-free falling film dielectric barrier discharge plasma system was employed for the selective synthesis of NH4+. By manipulating the flow state of the discharge gas, NH4+ selectivity was found to increase by 138.4% in the sealed gas flow state compared to the flowing gas state. Furthermore, an increase in the discharge voltage positively influenced the NH4+ selectivity. This phenomenon can be attributed to higher energy input and longer reaction times, which facilitate the formation of nitrogen molecular ions, a critical intermediate in ammonia synthesis. The reaction products were analyzed by UV spectrophotometry and emission spectroscopy to investigate the underlying mechanisms of ammonia synthesis. This study reveals the highest reaction rate reported to date for ammonia synthesis via single-system plasma gas–liquid reactions and offers a novel way to improve both the yield and selectivity of ammonium synthesis via non-thermal plasma gas–liquid interactions. [ABSTRACT FROM AUTHOR]

The present work reports on the results of the synthesis and study of complex cesium lead bromide glass ceramics using classical heating and thermal plasma. The role of the substrate in the thermal plasma-assisted processes of growth has been disclosed. For reference, powder samples of these bromides were also synthesized. X-ray diffraction (XRD) revealed the presence of many material phases in all the samples except for the glass ceramics grown in a furnace using classical methods. The dominant phase was Cs4PbBr6 in most cases. However, CsPbBr3 was also present in some samples. Exotic phases such as solid Br2, metallic Cs (which dominates in one of the glass ceramic samples), and Cs4Pb9 were also observed. This indicates cesium segregation during the samples' growth and excess cesium in metallic form within the samples. The existence of CsPbBr3 quantum dots within or among the Cs4PbBr6 nanocrystals has been confirmed by photoluminescence (PL) measurements. Electron paramagnetic resonance (EPR) revealed the existence of Cs0–Cs0 dimers in a type of quantum dot undergoing a phase transition at 10 K. [ABSTRACT FROM AUTHOR]

The article discusses the contributions of John Hopfield and Geoffrey Hinton to artificial neural networks, leading to advancements in artificial intelligence technology. It also recognizes the late Mr. Guangzhao in Chinese science and Prof. Rohini Godbole in Indian collider physics, emphasizing gender equity in STEM. The Division of Plasma Physics (DPP) activities, including conferences and awards, are outlined, with the 2023 AAPPS-DPP conference awarding young researchers in plasma physics. The RMPP journal dedicated to plasma physics has been growing steadily since 2017, and the 2024 AAPPS-APCTP C. N. Yang Awards honored three young scholars for their physics contributions. The text also highlights achievements of physicists worldwide and initiatives by physics societies. [Extracted from the article]

This study investigates the paracetamol removal efficiency by multi-tip pulsed corona discharges, highlighting the conditions avoiding mutual effects between two consecutive streamer branching discharges generated by each tip. The results show that the production of reactive oxygen and nitrogen species (RONS) in the liquid phase and the efficiency of paracetamol removal are influenced by the distance between two contiguous tips due to the mutual effects for small inter-tip distances between 4 mm and 8 mm in the case of a fixed inter-electrode distance of 5 mm (i.e. distance between the tip summit and the water surface). Beyond an inter-tip distance of 12 mm (over twice the gap distance), the mutual effects of branching discharges were no longer observed since the field lines did not overlap, making the production and absorption of liquid-phase species more efficient. Furthermore, RONS production was almost linear when moving from one to four tip electrodes: [H2O2]1tip: 0.52 mg l–1 versus [H2O2]4tips: 1.99 mg l–1, a ratio of 3.82. Optimum values were reached for an inter-tip distance of 16 mm. In this case, the enhancement factor in this reactor configuration is the surface integration between the plasma and the liquid surface to be treated. Furthermore, the results show a quasi-exponential increase in the percentage of paracetamol degradation as a function of the number of electrodes, from 4% with a mono-tip configuration to over 78% for a treatment with a four tip one. [ABSTRACT FROM AUTHOR]

Nonlinear properties of dust-magnetosonic (DMS) waves are studied in a multispecies thermal dusty plasma, containing electrons, ions, and negatively charged dust particles. In this context, electrons and ions are assumed as inertialess, whereas dust particles are considered mobile or fluid. Solving together the coupled set of fluid-Maxwell equations and making use of the diagonalization matrix technique, the inviscid Burgers's equations are derived and analyzed both analytically and numerically. A solitary solution is used as an initial condition at τ = 0 , resulting in the formation of localized symmetric pulses, which can develop into small-scale nonstationary (asymmetric) shocklets with temporal progression (τ > 0). This leads to the nonlinear self-steepening of waves, propagating in the form of dust-fluid speed and magnetic field profiles in a dusty magnetoplasma. It is found that self-compression of the dust-fluid speed and magnetic field profiles occurs in the direction of propagation and is significantly influenced by the plasma parameters, including the plasma beta, the ion-to-electron temperature ratio, and ion-to-dust density ratio. Additionally, the effective phase and shock speeds are analytically analyzed. The present findings may prove useful for understanding the nonlinear characteristics of DMS waves in a plasma, where dust particulates play a significant role in the self-compression of waves due to the nonlinearity effect. [ABSTRACT FROM AUTHOR]

Inductively coupled plasma (ICP) is widely used in aerospace engineering and material processing for generating high-purity, high-temperature airflow, crucial for applications like thermal protection and plasma stealth. A scientific device developed at Xidian University utilizes ICP technology to simulate plasma sheath characteristics and enables high-resolution plasma diagnostics. This study applies machine learning (XGBoost algorithm) to predict temperature characteristics of quartz tubes in plasma generators, focusing on preventing overheating and improving system stability. Generated models are utilized to predict the temperature extremes and the heating rates of the quartz tube in various experimental conditions. By analyzing key features such as argon and air intake rates, intake durations, and coil voltage, this study demonstrates that machine learning delivers highly accurate predictions (R2 = 0.90 for temperature peaks and R2 = 0.82 for heating rates). This work also quantitatively emphasizes the significance of voltage and air intake parameters in determining the temperature characteristics of plasma generators and providing key insights for optimizing system performance and improving experimental standardization, ensuring their stable and long-lasting performance. [ABSTRACT FROM AUTHOR]

In this article, we investigate the edge localized mode (ELM)-free quiescent H (QH)-mode regime in the HL-3 tokamak via nonlinear MHD simulations. HL-3 (previously known as HL-2M) aims at high β plasmas and recently achieved its first H-mode operation. Large ELMs in H-mode discharges challenge the tolerance of plasma facing components in reactor-relevant tokamaks and small/no-ELM regimes become attractive options for existing and future fusion devices. A naturally ELM-free regime, QH-mode, is explored in this work with nonlinear extended MHD modeling for the HL-3 device. The simulation is conducted based on a realistic lower single null divertor configuration, and successfully produces a QH-mode plasma. Toroidal modes n = 0 , ... , 12 are simulated and the QH-mode plasma is dominated by a saturated n = 2 kink-peeling mode. After entering QH-mode, the plasma thermal energy becomes nearly stationary and the plasma pedestal is kept at a stable level. The saturated peeling instability produces an ergodized edge magnetic field region and some E × B convective cells, which enhance radial transport. The edge harmonic oscillation (EHO) as a characteristic feature of QH-mode plasmas is detected in the pedestal with a fundamental frequency (for the n = 1 mode) of 7.5 kHz. The EHO structures on the high-field side (HFS) and low-field side (LFS) are observed to be asymmetric. The EHO is dominated by the n = 2 mode with a frequency of 15 kHz on the HFS, while the n = 3 mode becomes dominant at the vicinity of ψ norm = 0.95 on the LFS. It is also found that density and temperature profiles show different responses to the EHO in the simulation. The dependence on the safety factor for accessing QH-mode is demonstrated with the QH-mode being lost when q95 is reduced from 2.5 to 2.3. The EHO is absent in this scenario and a bursting ELM-like activity is observed instead. [ABSTRACT FROM AUTHOR]

In the gravitational potential well of a galaxy, the behavior of outflows has been studied in different geometries i.e. constant flux tube, divergent and extreme divergent environments. First of all, we describe the hydrodynamic model by which we approach the outflows system. This model treats all the waves as fluids and applies fluid mechanics to them(cosmic rays, thermal plasma & Alfvén wave). Whereas outflows mean the gas regime above and below the center of the galactic disk, and we have taken it as a system where interaction between cosmic rays and plasma occurs. After discussing the hydrodynamic three-fluid model, we define three geometrical structures which can be acquired by outflows and relate these structures with thermal plasma, cosmic and Alfvén waves pressures, thus seeking for its behavior. The solution of the system is categorically divided into three branches, supersonic, subsonic and unphysical solutions.The most interesting of all is the transonic solution, a solution that evolves from subsonic to supersonic. First of all, we discuss only thermal plasma outflows and explain their evolution in three cases of outflows environments, followed by the addition of cosmic waves and Alfvén waves. After discussing three fluid outflows in different structures, we compared the results of thermal outflows with three fluid outflows and see how the addition of waves in the system affects the dynamics of the system. At last, the findings of this paper are discussed. [ABSTRACT FROM AUTHOR]

The present work deals with the Argon (Ar) Thermal plasma‐induced surface modification of Cu and its correlation with the electrical and field emission (FE) properties. Polycrystalline Cu targets were treated with Ar thermal plasma under atmospheric pressure at different treatment times ranging from 5 min to 30 min. XRD patterns revealed the absence of new phase in treated samples. However, significant variation in peak intensities and shifting is observed, which is explained on the basis of thermal plasma ions induced defect generation and annihilation processes. The electrical conductivity of processed Cu targets measured by four‐probe method ranges from 1.9 MS/m to 70 MS/m and is well correlated with the crystallite size variation. Surface modification induced work function alternations investigated by employing Scanning Kelvin Probe (SKP) technique are in the range of 4.69 eV 4.97 eV. The irradiated morphology explored by optical and scanning electron microscopy analyses revealed the formation of localized melt pools, grains, hillocks, spheroids, and sputtered patches, which are explainable on the basis of Coulomb's explosion, thermal spike model, plasma‐induced sputtering, and re‐deposition. FE properties of thermal plasma‐treated Cu are measured in diode configuration by measuring I‐V characteristics of target under ultra‐high vacuum condition. The improved FE parameters such as turn‐on field (Eo), field enhancement factor (β), and maximum current density (Jmax) come out to be in the range of 3–7.5 V/μm, 1715–3223, and 284–872 nA/cm2, respectively and their correlation with plasma‐induced surface structural, morphological and work function modifications is discussed. [ABSTRACT FROM AUTHOR]

Meaningful deployment of plasma water-based nitrogen fixation in agricultural application is hindered primarily due to its poor synthesis rate in compact systems. The study reports a directly deployable thermal plasma based portable catalytic compact system, offering typical synthesis rate as high as 1035 mg/min for nitrate and 635 mg/min for nitrite directly from naturally abundant atmospheric air and water. Developed technology is clean, sustainable, easily decentralizable, and completely free from fossil fuels and harmful intermediates like ammonia. The system avoids safety hazards and costs related to the requirements of continuous energy resources, pressurized environment for synthesis, regulated storage, refrigeration need, transportation of raw materials and distribution of fertilizer, as may be required by other competing technologies. Described system, consisting of air plasma torch, reaction chamber, water injection manifold and catalytic bed creates a unique nascent reactive plasma environment at ambient pressure that auto activates the catalyst in the field of thermal plasma for highly efficient fixation of nitrogen. Presented results indicate that use of combination catalysts with mechanically enhanced surface area allows drastic enhancement in the nitrogen fixation. Possible reaction chemistries, results of trials with different catalysts, time evolution of concentration, auto-conversion from nitrite to nitrate in aqueous media, time stability of concentration of the synthesized nitrate and observed remarkable effectiveness in the actual field trials are presented. Achieved synthesis rates are compared with those reported in literature in the area of thermal and non-thermal plasma. [ABSTRACT FROM AUTHOR]

Numerical investigations were conducted to analyze the coupling effects of pulsed H2 jets and nanosecond-pulsed actuation (NS-SDBD) in a supersonic crossflow. The FVM was employed to solve the multi-component 2D URANS equations with the SST k-omega turbulence model, while H2-air combustion was described using a seven species–seven reactions chain reaction model, and the plasma thermal effect was represented by a phenomenological model. The backward-facing step flows with an inlet Mach number of 2.5 and a pulsed jet frequency of 10 kHz under different actuation conditions were simulated. The combustion enhancement mechanism under an actuation frequency of 20 kHz was analyzed. Research indicates that compression waves induced by NS-SDBD enhance H2-air mixing and facilitate temperature transport as the flow progresses. This progress is significantly associated with the flow structures generated by pulsed jets. Under this condition, the fuel utilization rate in the flow field increased by 61.2%, the total pressure recovery coefficient increased by 5.34%, and the outlet total temperature slightly increased even with a 50% reduction in fuel flow rate. Comparative analysis of different actuation cases demonstrates that evenly distributed actuation within the jet cycle yields better effects. The innovation of this study lies in proposing and exploring a potential method to address inadequate combustion under high-speed inflow conditions, which couples NS-SDBD with pulsed hydrogen jets. [ABSTRACT FROM AUTHOR]

Spherical powders are required for many advanced manufacturing techniques due to their inherent requirement of flowability, either within feed tubes or during powder spreading. As advanced manufacturing of magnets continues to develop, new production methods for feedstocks are also sought. Plasma spheroidization is a high-yield method to produce spherical Nd–Fe–B powders from irregularly shaped particles, with advantages including high throughput and a well-controlled size distribution. Highly spherical Nd–Fe–B powders with large scale production (i.e., kg) have been demonstrated using an inductively coupled thermal plasma system; however, the magnetic properties of the output powder display significant degradation. The coercivity was decreased from the initial 8 kOe (636 kA/m) of the as-received to 0.7 kOe (55 kA/m) for spheroidized powders. Microstructural investigation reveals 6% Nd depletion caused by the extreme temperatures of the plasma, leading to the formation of low-coercivity α-Fe and a subsequent decrease in energy product. Post-spheroidization heat treatments with Nd can partially mitigate the coercivity degradation, increasing to 1.7 kOe (135 kA/m), potentially offering a pathway toward spherical powders for a range of applications. [ABSTRACT FROM AUTHOR]

The time-dependent rotational and vibrational temperatures were measured to study the shock-heated thermal nonequilibrium behaviors of CO with Ar, He, and H2 as collision partners. Three interference-free transition lines in the fundamental vibrational band of CO were applied to the fast, in situ, and state-specific measurements. Vibrational relaxation times of CO were summarized over a temperature range of 1110–2820 K behind reflected shocks. The measured rotational temperature instantaneously reached an equilibrium state behind shock waves. The measured vibrational temperature experienced a relaxation process before reaching the equilibrium state. The measured vibrational temperature time histories were compared with predictions based on the Landau–Teller model and the state-to-state approach. The state-to-state approach treats the vibrational energy levels of CO as pseudo-species and accurately describes the detailed thermal nonequilibrium processes behind shock waves. The datasets of state-specific inelastic rate coefficients of CO–Ar, CO–He, CO–CO, and CO–H2 collisions were calculated in this study using the mixed quantum-classical method and the semiclassical forced harmonic oscillator model. The predictions based on the state-to-state approach agreed well with the measured data and nonequilibrium (non-Boltzmann) vibrational distributions were found in the post-shock regions, while the Landau–Teller model predicted slower vibrational temperature time histories than the measured data. Modifications were applied to the Millikan–White vibrational relaxation data of the CO–Ar and CO–H2 systems to improve the performance of the Landau–Teller model. In addition, the thermal nonequilibrium processes behind incident shocks, the acceleration effects of H2O on the relaxation process of CO, and the characterization of vibrational temperature were highlighted. [ABSTRACT FROM AUTHOR]

The time-dependent rotational and vibrational temperatures were measured to study the shock-heated thermal nonequilibrium behaviors of CO with Ar, He, and H2 as collision partners. Three interference-free transition lines in the fundamental vibrational band of CO were applied to the fast, in situ, and state-specific measurements. Vibrational relaxation times of CO were summarized over a temperature range of 1110–2820 K behind reflected shocks. The measured rotational temperature instantaneously reached an equilibrium state behind shock waves. The measured vibrational temperature experienced a relaxation process before reaching the equilibrium state. The measured vibrational temperature time histories were compared with predictions based on the Landau–Teller model and the state-to-state approach. The state-to-state approach treats the vibrational energy levels of CO as pseudo-species and accurately describes the detailed thermal nonequilibrium processes behind shock waves. The datasets of state-specific inelastic rate coefficients of CO–Ar, CO–He, CO–CO, and CO–H2 collisions were calculated in this study using the mixed quantum-classical method and the semiclassical forced harmonic oscillator model. The predictions based on the state-to-state approach agreed well with the measured data and nonequilibrium (non-Boltzmann) vibrational distributions were found in the post-shock regions, while the Landau–Teller model predicted slower vibrational temperature time histories than the measured data. Modifications were applied to the Millikan–White vibrational relaxation data of the CO–Ar and CO–H2 systems to improve the performance of the Landau–Teller model. In addition, the thermal nonequilibrium processes behind incident shocks, the acceleration effects of H2O on the relaxation process of CO, and the characterization of vibrational temperature were highlighted. [ABSTRACT FROM AUTHOR]

This study explores the effects of chamber pressure on the electrical and thermodynamic characteristics of a low-pressure thermal plasma jet. The investigation focuses on current–voltage characteristics, arc voltage fluctuations, plasma jet temperature, electron density, and velocity within the range of 100–500 A arc current, at chamber pressures of 100 Pa, 1 kPa, and 3 kPa. Spectral analysis of the arc voltage reveals the presence of distinct frequencies, including restrike, Helmholtz, and acoustic modes, which exhibit varying behavior under different chamber pressure conditions. Restrike frequency shows an increase with decreasing chamber pressure, while Helmholtz frequency remains unaffected, and the power density of the acoustic frequency diminishes, eventually disappearing from the spectrum. The transition of the plasma jet from a continuum regime to a frozen state with decreasing chamber pressure is observed along with its shock structures. Optical emission spectroscopy is utilized to map the excitation temperature and electron density profile along the jet axis, demonstrating that the jet temperature and density peaks at the compression zone. Furthermore, Mach probe measurements of the plasma jet velocity at different axial locations, under various chamber pressure conditions, illustrate that the plasma jet maintains a supersonic state, regardless of chamber pressure. However, after the formation of a Mach disk, the jet velocity becomes subsonic. The highest velocity is achieved at 100 Pa chamber pressure, reaching Mach 2.9 at 50 mm from the anode exit. This research enhances our understanding of thermal plasma jets under low-pressure conditions, contributing to the advancement of knowledge in their applications across various domains. [ABSTRACT FROM AUTHOR]

The CO2 methanation reaction, or Sabatier reaction, is experiencing renewed interest in the context of large‐scale recycling of point CO2 emissions, leading to the power‐to‐gas technology. The reaction represents a flexible route to transform CO2 into methane by hydrogenation with (green) dihydrogen. This exothermic transformation takes place at a reasonable rate at temperatures above 200 °C and is directed to the targeted product at low temperatures. The CO2 methanation nevertheless remains kinetically limited due to the chemical stability of CO2 and the high bond dissociation energy for C═O in CO2. Therefore, the current urgent demand is for the development of catalysts and associated processes with superior activity for CO2 activation at low temperatures. This critical review aims to overview the state of the art of this low‐temperature technology using thermal, plasma and photo‐assisted catalysis. We summarize research advances around low‐temperature CO2 methanation, focusing on catalyst formulations (metal, supports and promoters), reaction mechanisms and suitable activation processes. We discuss each of these critical aspects of the technology and identify the main challenges and opportunities for low temperature (≤200 °C) CO2 methanation. [ABSTRACT FROM AUTHOR]

Spherical Gd 2 Zr 2 O 7 (GZO) powders with a uniform particle size distribution are successfully prepared using a novel industrial approach, which combines spray-drying process and thermal plasma sintering technology together. In this, GZO powders with pyrochlore structure as the main phase are first synthesized via a solid-state reactive route using a mixture of the milled Gd 2 O 3 powders and ZrO 2 powders as starting materials. The influence of sintering temperature on the microstructure of prepared powders is researched. Then, GZO granules are prepared after wet-grinding and spray-drying process, which exhibit a spherical shape with the average particle size of 46.5 μm. RF induction thermal plasma is finally used to sinter the granulated particles, and the influence of feeding rate on the properties of spherical powders is investigated. The apparent density of plasma sintered GZO spherical powders is increased from 1.53 g/cm3 to 2.29 g/cm3 when the feeding rate of granulated powders is 80 g/min, and further increased up to 3.90 g/cm3 when the feeding rate is 15 g/min. Such powders are in potential demand for plasma sprayed coatings and additive manufacturing techniques, and the successful synthesis of spherical GZO powders may guide the way toward the preparation of many other spherical rare earth zirconates powders. [ABSTRACT FROM AUTHOR]

The metastable phase molybdenum carbide-based (α-MoC 1-x) catalysts stand out as a class of the most promising representatives among the non-sulfide catalysts for the synthesis of higher alcohols (HAS) from syngas (CO/H 2) due to their noble metal-like characteristics, resistance to coking, sulfur tolerance and weak C–O bond dissociation. However, the synthesis of α-MoC 1-x commonly involves temperature-programmed ammonification and carburization (TPAC) or the consumption of noble metals. The α-MoC 1-x prepared by TPAC usually exhibited large particle size, low dispersion and poor catalytic performance. Herein, we developed a facile and continuous thermal plasma method for synthesizing nanosized α-MoC 1-x , which was highly dispersed on amorphous carbon (α-MoC 1-x /C-Pla). Compared with the α-MoC 1-x prepared by TPAC method (α-MoC 1-x -TPAC), the α-MoC 1-x /C-Pla catalyst exhibited higher CO conversion and excellent stability. The high dispersion and reactant adsorption/desorption capacity of α-MoC 1-x /C-Pla contributed to its high catalytic activity, while the anti-aggregation property of the nanosized α-MoC 1-x in α-MoC 1-x /C-Pla conferred the high stability for the α-MoC 1-x /C-Pla catalyst. [Display omitted] • A facile and continuous method for synthesizing α-MoC 1−x /C-Pla was developed. • Nanosized α-MoC 1−x particles were well dispersed on carbon in α-MoC 1−x /C-Pla. • α-MoC 1−x /C-Pla exhibited high activity and stability for syngas to higher alcohols. [ABSTRACT FROM AUTHOR]

A review of various mechanisms of suprathermal electron generation in tokamak plasma and an analysis of diagnostic systems for the study of the spatial evolution of electron beams are presented. It is planned to use detectors based on CdTe crystals to detect suprathermal x-ray emission (20–300 keV) at the T-15MD tokamak (R = 1.5 m, a = 0.67 m). Spatial resolution is provided by a system of tube collimators placed in detector chambers mounted in vertical, inclined, and equatorial diagnostic ports. To measure suprathermal x-ray emission spectrum, a set of CdTe spectrometric detectors and LaBr3(Ce) scintillation crystal detectors are used. The tomographic program is used to reconstruct spatial localization of the X-ray emission. The received spatial and temporal distribution of local suprathermal electron beams will be used to study a variety of physical phenomena, such as reconnection of magnetic field lines, nonlinear transport processes, distortion of the electron energy distribution function during powerful additional heating and current drive, and plasma perturbances that are important for the study of kinetic instabilities in plasma with fast ions. [ABSTRACT FROM AUTHOR]

This work presents the morphology of the melt products of alumina-magnesia spinel (MgAl2O4), obtained in a thermal plasma environment. The energy of the thermal plasma was realized through an electric arc plasma torch with a power of 12 kW, where the plasma is considered an effective medium for heating and melting refractory materials. The initial materials for producing MgAl2O4 spinel were: pure magnesium oxide MgO and aluminum oxide Al2O3; natural materials: the source of Al2O3—boehmite from bauxite deposits, Northern Urals, and the source of MgO—magnesite from the Khalilov and Savinsky deposits. It was established that, regardless of the nature of the materials, the crystallized melt products have a bulk density of 3.84 g/cm3, and the weight loss varies from 2 to 6 wt %. The morphology of the obtained spinel is represented by well-defined crystals arranged over an area of ~1.75 μm2, forming a textured surface with varying tilt angles. It is noteworthy that the morphology formation occurs in two interconnected stages: primary—surface crystallization of crystals with a diameter of 85 μm and a half-width into the matrix body h of 100 μm; secondary—localized crystallization of crystals with a diameter of 10 μm, randomly distributed throughout the matrix of the melt product. This is achieved through the development of convective flows from the surface into the melt droplet during intense heat exchange when the electric arc plasma torch is turned off. [ABSTRACT FROM AUTHOR]

In this work, we studied the effect of silver nanoparticles on the IR absorption mechanism in Ag/Ag2O composites. Ag/Ag2O composites were prepared by exposing silver films prepared by thermal evaporation to oxygen plasma afterglow. The infrared spectra of these samples were analysed. The results obtained showed that, the individual silver nanoparticles affect the vibrations of chemical bonds in Ag/Ag2O composites, and this is inferred from the gradual decrease in intensity when moving towards lower wavenumbers. In addition, it was found that the effect of individual silver nanoparticles is greatest in the frequency range of Ag–O bond vibrations and becomes weaker in the case of bonds with higher vibration energies. [ABSTRACT FROM AUTHOR]

This study examined the quality changes and shelf life of cold plasma (Cold plasma-optimized, S2: 30 kV/5 mm/6.7 min and Cold plasma-extreme, S3: 30 kV/2 mm/10 min) and thermally-treated (S4: 90°C/5 min) kiwifruit juice packed in glass and polyethylene terephthalate bottles stored at 5, 15, and 25°C. Cold plasma and thermally treated juice samples were analyzed for peroxidase activity, microbial enumeration, bioactive compounds degradation, and sensory quality for up to 120 days. The residual activity of peroxidase enzyme in S2 sample after cold plasma treatment was 23.85%, decreasing with increase in storage time and temperature. After cold plasma and thermal treatment, the aerobic mesophiles and yeasts and molds count were below detectable limits in kiwifruit juice. Aerobic mesophiles and yeasts & molds emerged in S2, S3, and S4 samples stored at 5°C after 70, 70, and 90 days, respectively. The total color change increased with increase in storage time and temperature, whereas ascorbic acid, total phenolic content, total antioxidant capacity, and overall acceptability decreased. The shelf life of S2 in glass bottles was 100, 80, and 60 days at 5, 15, and 25°C based on total color change ≥ 12, ascorbic acid loss ≥ 50%, microbial count ≥ 6 Log CFU/mL, or overall acceptability < 5. Quality indices, including total color change, overall sensory acceptability, and ascorbic acid, were modeled, and zero-order model performed better than first and second-order reaction models. Furthermore, Arrhenius, Eyring, and Ball models were employed to model temperature-dependent reaction rates, and the Ball model performed better. So, the zero-order reaction and Ball model were combined to predict kiwifruit juice's shelf life. [ABSTRACT FROM AUTHOR]

Predicting the gas-surface interactions of solid carbon is necessary for the design of many engineering systems that employ graphite. Experimental determination of the reaction rates improves the fidelity of those predictions. Here, we studied oxidation and nitridation of graphite by thermal and nonthermal plasma assisted processes. Experiments were conducted at a pressure of 2 kPa, higher than previous flow reactor experiments of this kind and closer to the conditions experienced in engineering applications. At these higher pressures, the limitations of mass transport and the interference between oxygen and nitrogen species become important. Reaction rates were determined from mass loss, reaction products were identified with mass spectrometry, and surface roughening was characterized by electron microscopy. [ABSTRACT FROM AUTHOR]

The influence of chemical composition and thermal treatment parameters on the crystallization processes of Ni-cordierite glasses obtained by thermal plasma has been investigated. It was determined that cordierite crystallization occurs at 1100°C. In NiO-containing glass-ceramics, a significant amount of a by-product phase of spinel (Mg,Ni)Al2O4 is present. During thermal plasma treatment, nickel oxide is reduced to metallic nickel, with its quantity in glass-ceramics being approximately about 2–3%. [ABSTRACT FROM AUTHOR]

This study applies the generalized photo-thermoelasticity theory to investigate thermo-hydro-mechanical interactions in a poroelastic half-space elastic semiconductor material with variable properties. The model represents a novel approach, treating the material as a uniform, fully saturated, poroelastic semiconductor half-space in alignment with the principles of dynamic poroelasticity within generalized photo-thermoelasticity. We initially applied time-harmonic loads, encompassing normal or thermal loads and plasma electron distributions to this medium. The study then explores the differences between coupled thermo-hydro-mechanical dynamic models and thermo-elastic dynamic models. We employed two-dimensional normal mode analysis to solve the resulting non-dimensional coupled equations. Subsequently, we examined the impact of non-dimensional displacement, excess pore water pressure, mechanical stress, carrier concentration (density), and temperature distribution on the poroelastic half-space medium. We then visually represented these effects. [ABSTRACT FROM AUTHOR]

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After its arrival at Jupiter in July 2016, Juno conducted a global survey of Jupiter's magnetosphere (especially the equatorial plasma disk region) with its highly eccentric polar orbit. Since then, the JADE instrument has accumulated a large amount of plasma measurements. Using a developed forward modeling method and the Alpine supercomputer cluster at CU Boulder, we fit all ion measurements between 10 and 50 RJ ${\mathrm{R}}_{\mathrm{J}}$ from PJ5 to PJ56, obtaining a dataset with 70,487 good fits that consists of the following set of plasma parameters: abundances of different heavy ions, density, temperature, and 3‐D bulk flow velocity of heavy ions. An overview of the dataset and an example use on flux tube interchange are presented to illustrate its effectiveness and usefulness. In the investigated interchange event that occurred at ∼ ${\sim} $14 RJ ${\mathrm{R}}_{\mathrm{J}}$, the plasma disk is variable and heated, with alternating hotter inflows and colder outflows, accompanied by small perturbations in the magnetic fields. This dataset has the potential for many applications. Key Points: A dataset from thermal plasma observations of Juno using a forward modeling methodThe dataset includes ion abundances, density, temperature, and 3‐D bulk flow velocityThe dataset consists of 70,487 data points obtained between 10 and 50 RJ from Juno orbits PJ5 to PJ56 [ABSTRACT FROM AUTHOR]

Multilayer plastic (MP) commonly used in food and beverage packaging is difficult to recycle due to its layered structure, resulting in its accumulation over time; the consequent environmental harm is further exacerbated by its short lifespan. This study investigates recycled low-value MP as a modifier for polymer-modified bitumen (PMB). However, the difference in polarity between MP and PMB mixtures is a challenge, resulting in their poor compatibility and reduced mechanical properties. To overcome this, low-value MP was treated with atmospheric cold plasma and thermal oxidation to enhance its compatibility with PMB. The results indicate that plasma and thermal treatments increase the hydrophilicity of low-value MP through the formation of low-molecular-weight oxidized molecules containing hydrophilic hydroxyl (-OH) and carbonyl (C = O) groups that act as an intermediary boundary layer between the low-value MP and asphaltene-rich bitumen. Further, the optimal oxidation conditions for MP are revealed as 60 s of plasma treatment followed by heating at 150 °C for 60 min. Mixtures of PMB and optimally oxidized MP have optimal compositions of 1 wt.%, with ductility and penetration values of 87.7 cm and 57.4 mm, respectively. [ABSTRACT FROM AUTHOR]

How magnetic reconnection is triggered or suppressed is an important outstanding problem. By considering pinching of a current sheet that has formed at non‐equilibrium, we show that the background plasma beta is a major controlling factor in the onset and nature of magnetic reconnection. A high plasma beta inhibits a current sheet from pinching down to kinetic scales required for collisionless reconnection, while a low beta facilitates it. A simple adiabatic model provides a good prediction for the reconnection‐enabled regions in thickness versus peak plasma beta space, which are confirmed by a series of particle‐in‐cell simulations with varying initial parameters. A strong dependency of the peak reconnection rate on the plasma beta is clearly predicted with reconnection being favored in low beta conditions. A finite guide field is an additional source of reconnection suppression, consistent with previous observations that reconnection requires a large enough magnetic shear angle for high‐beta situations. Plain Language Summary: Magnetic fields around the Sun and the Earth frequently release their stored energy into plasma energy in the form of a process called magnetic reconnection. However, this process does not occur in all situations, and so when and how it occurs is an outstanding question. In this paper, it is shown that a high plasma thermal pressure can counteract the magnetic pressure that would otherwise bring the fields to close proximity, preventing reconnection from happening. A component of the magnetic field that is not directly involved in reconnection, called the "guide field," also contributes to the suppression. Key Points: High plasma beta and/or guide field obstruct current sheet pinching to small scales required for collisionless reconnectionA simple adiabatic model predicts regions in parameters space where reconnection is enabled, verified by particle‐in‐cell simulationsThe tendency for reconnection onset aligns well with previous spacecraft observations [ABSTRACT FROM AUTHOR]

In the present study, the photocatalytic performance of ZnS/TiO2 nanocomposite was investigated through the photodegradation of Acid Blue 113 (AB113) dye under ultraviolet light exposure. TiO2 and ZnS-based nanocomposites suffer from relatively wide bandgap energy and low adsorption capacity which limit their photocatalytic applications. These problems can be suppressed by modifying the surface of nanocomposite particles by the non-thermal plasma. Herein, surface modification of the ZnS/TiO2 nanocomposite was performed using a dielectric-barrier discharge plasma under nitrogen (N2) and tetrafluoromethane (CF4) gases. The characteristics of the plasma-treated nanocomposites were evaluated by XRD, FTIR, Raman, FESEM, EDS, BET, BJH, and DRS analyses. According to the results, by applying plasma treatment, cation and anion vacancies are produced that reduces the band gap energy of the photocatalyst hence improves its performance. The results indicate that the photocatalytic efficiency of the N2-plasma-treated nanocatalyst has been almost two times higher than that of the untreated ZnS/TiO2. It was found that after 25 min of UV irradiation, the AB113 was almost completely degraded in the presence of N2-plasma-treated ZnS/TiO2 nanocomposite (about 95%), whereas, it was degraded by 64% and 46% in the presence of CF4-plasma-treated ZnS/TiO2 and untreated ZnS/TiO2, respectively. This study presents a new approach to designing cost-effective plasma-treated photocatalysts to degrade organic contaminants in wastewater. [ABSTRACT FROM AUTHOR]

The destruction of benzene in a dielectric barrier discharge (DBD) reactor was studied in this work. The effects of specific energy density, initial concentration and oxygen content on benzene degradation efficiency were investigated by experiment and matrix correlation analysis. The results showed that specific energy density was the most important factor on benzene removal with a Pearson's coefficient of 0.7, meanwhile both initial concentration and oxygen content presented the inverse influence. In addition, a model to study the plasma discharge process was developed by COMSOL simulation software and surface reactions were included in the model. The behavior of the plasma was described by the coupled equations of electron density, heavy matter density and electron mean energy, and the drift-diffusion equation was calculated. When the peak voltage is 30 kV, the terminal current obtained by the simulation is 0.03 A, and the corresponding output current measured by the experiment is 0.013 A. Simulated and experimental current change trends are the same, indicating that the method simulation is correct and reasonable. [ABSTRACT FROM AUTHOR]

The performance of plasma sprayed thermal barrier coatings (TBCs) is strongly dependent on the quality of the feedstock powders, which usually are fabricated by conventional spray drying and multi-step sintering methods. In this work, a novel supersonic plasma spheroidization technology was employed to fabricate the spherical nanocrystalline Sc 2 O 3 -Y 2 O 3 co-stabilized ZrO 2 (ScYSZ) powder. The deformation process from the irregular powder to the spherical one was stimulated by the COMSOL phase field simulation. The results suggested that the original irregular pyrolysis products of ScYSZ precursors were aggregated into spherical powders by plasma spheroidization technology. The COMSOL simulations verified that the powder changed from irregular particles to spherical ones. The spheroidized ScYSZ particles exclusively consisted of non-transformed t' -ZrO 2 phase and showed good fluidity, smooth surface and high apparent density, which were expected to have a broader application prospect in the field of TBCs and other ceramic coatings. [ABSTRACT FROM AUTHOR]

Linear gyrokinetic (GK) simulations using the Gyrokinetic Toroidal Code (GTC) [Lin et al., "Turbulent transport reduction by zonal flows: Massively parallel simulations," Science 281, 1835–1837 (1998)] have been performed to investigate Toroidicity-driven Alfvén Eigenmodes (TAEs) driven by the neutral beam injection (NBI) induced fast ions in the Mega-Amp Spherical Tokamak (MAST) to identify the non-perturbative and kinetic effects of thermal plasma. A specific TAE in MAST discharge 26887, with an on-axis NBI power of approximately 1.5 MW and plasma current around 800 kA, exhibited frequency chirping, and the tangential soft x-ray camera array resolved the radial mode structure peaked near | q | = 1.5. Various excitation methods were used in the GTC linear simulations, illustrating this code's capability to realistically represent the mechanisms and behaviors of fast ion-driven TAEs in spherical tokamaks. The radial structures from these GK simulations closely match measurements and calculations performed using the NOVA ideal MHD code, though with the frequencies approximately 10 kHz lower, likely due to various kinetic and non-perturbative effects. The simulations measured the damping rates due to continuum damping, radiative damping, and ion Landau damping, revealing that ion Landau damping has the most significant contribution to the total damping rate of the TAE. A comparison of growth rates of TAEs excited by fast ion Maxwellian and slowing-down distributions shows that the TAEs excited by a fast ion anisotropic pitch distribution (as part of the slowing-down distributions) are more unstable compared to those excited by a Maxwellian distribution with an equivalent fast ion beta. This shows that the use of fast ion anisotropy alters the number of fast ions to be in shear Alfvén resonance, and hence, it can greatly affect the stability of TAEs. These tests can be performed with the GTC but impossible with ideal MHD simulations, highlighting the necessity of kinetic simulations such as the GTC for a precise prediction of the TAE stability. [ABSTRACT FROM AUTHOR]

Context. Solar eruptive events, including solar flares and coronal mass ejections (CMEs), are typically characterised by energetically significant X-ray emissions from flare-accelerated electrons and hot thermal plasmas. However, the intense brightness of solar flares often overshadows high-coronal X-ray emissions from the associated eruptions due to the limited dynamic range of current instrumentation. Occulted events, where the main flare is blocked by the solar limb, provide an opportunity to observe and analyse the X-ray emissions specifically associated with CMEs. Aims. This study investigates the X-ray and extreme ultraviolet (EUV) emissions associated with a large filament eruption and CME that occurred on February 15, 2022. This event was highly occulted from the three vantage points of Solar Orbiter (∼45° behind the limb), Solar–TErrestrial RElations Observatory (STEREO-A), and Earth. Methods. We utilised X-ray observations from the Spectrometer/Telescope for Imaging X-rays (STIX) and EUV observations from the Full Sun Imager (FSI) of the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter, supplemented by multi-viewpoint observations from STEREO-A/Extreme-UltraViolet Imager (EUVI). This enabled a comprehensive analysis of the X-ray emissions in relation to the filament structure observed in the EUV. We used STIX's imaging and spectroscopy capabilities to characterise the X-ray source associated with the eruption. Results. Our analysis reveals that the X-ray emissions associated with the occulted eruption originate from an altitude exceeding 0.3 R⊙ above the main flare site. The X-ray time profile shows a sharp increase and exponential decay, and consists of both a hot thermal component at 17 ± 2 MK and non-thermal emissions (> 11.4 ± 0.2 keV) characterised by an electron spectral index of 3.9 ± 0.2. Imaging analysis shows an extended X-ray source that coincides with the EUV emission as observed from EUI, and was imaged until the source grew to a size exceeding the STIX imaging limit (180″). Conclusions. Filament eruptions and associated CMEs have hot and non-thermal components, and the associated X-ray emissions are energetically significant. Our findings demonstrate that STIX combined with EUI provides a unique and powerful tool for examining the energetic properties of the CME component of solar energetic eruptions. Multi-viewpoint and multi-instrument observations are crucial for revealing such energetically significant sources in solar eruptions that might otherwise remain obscured. [ABSTRACT FROM AUTHOR]

In recent years, the emission of greenhouse gases (GHGs) has increased significantly, contributing to global warming. Among these GHGs, CH4, CO2, and CO are particularly potent contributors. Remediation techniques primarily rely on materials capable of capturing, storing, and converting these gases. Catalytic processes, particularly heterogeneous catalysis, are essential to chemical and petrochemical industries as well as environmental remediation. Due to the growing demand for catalysts, efforts are being made to reduce energy consumption and make technologies more environmentally friendly. Green chemistry emphasizes minimizing the use of hazardous reactants and harmful solvents in chemical processes. Achieving these principles should be paired with processes that reduce time and costs in catalyst preparation while improving their efficiency. Non-thermal plasma (NTP) has been widely used for the preparation of supported metal catalysts. NTP has attracted significant attention for its ability to improve the physicochemical properties of catalysts, enhancing process efficiency through low-temperature operation and shorter processing times. NTP has been applied to various catalyst synthesis techniques, including reduction, oxidation, metal oxide doping, surface etching, coating, alloy formation, surface treatment, and surface cleaning. Plasma-prepared transition-metal catalysts offer advantages over conventionally prepared catalysts due to their unique material properties. These properties enhance catalytic activity by lowering the activation energy barrier, improving stability, and increasing conversion and selectivity compared to untreated samples. This review demonstrates how plasma activation modifies material properties and, based on extensive literature, illustrates its potential to combat climate change by converting CO2, CH4, CO, and other gases, showcasing the benefits of plasma-treated materials and catalysts. A succinct introduction to this review outlines the advantages of plasma-based synthesis and modification over traditional synthesis techniques. The introduction also highlights the various types of plasma and their physical characteristics across different factors. Additionally, this review addresses methods by which materials are synthesized and modified using plasma. The latter section of this review discusses the use of non-thermal plasma for greenhouse gas mitigation, covering applications such as the dry reforming of CH4, CO and CH4 oxidation, CO2 reduction, and other uses of plasma-modified catalysts. [ABSTRACT FROM AUTHOR]

A study of cosmic ray modified shock structures is presented for a system of four fluids consisting upon cosmic rays, thermal plasmas, forward and backward propagating self-excited Alfvén waves. A fluid model is employed to study the energy exchange mechanisms for the shock formation where cosmic rays, forward and backward propagating Alfvén waves are taken massless fluids in the comparison of thermal plasmas. This work may help to understand theoretical and observational perspective of the processes involved in supernova environment. [ABSTRACT FROM AUTHOR]

This study presents the comparative analysis of untreated, optimized non-thermal plasma (NTP)–treated (38 kV/631 s), extreme NTP–treated (45 kV/900 s), and thermally treated (95 ℃/12 min) pineapple juice (PJ) on enzyme activity, microbial count, protein structure, particle size, bioactive substances and, sensory, rheological, and biochemical attributes. The PJ treated with optimized NTP demonstrated merits over extreme NTP–treated and thermally treated in terms of the retention of bromelain, bioactive components, and biochemical attributes. Moreover, the fuzzy logic evaluation showed that optimized NTP–treated juice had superior sensory characteristics than extremely NTP– and thermally treated juice. The NTP approach, like thermal treatment (95 ℃/12 min), extends shelf life by assuring microbiological safety (<1 log10 cfu/mL) and enzyme inactivation (>90%). However, the thermal treatment resulted in loss of bioactive, sensory, and biochemical attributes. Particle size distribution indicates that NTP significantly (p < 0.05) reduced the sauter mean and volume mean diameter from 1617 to 894 nm and 1688 to 917 nm, respectively, which stabilized juice after treatment. NTP treatment substantially reduced the consistency from 1.22 to 0.31 mPa.sn and showed a pseudo-plastic behavior of juice. These results collectively imply that NTP has a tremendous ability to maintain bioactive compounds, and sensory and physicochemical attributes, as well as extend the shelf life of PJ. [ABSTRACT FROM AUTHOR]

Standard magnetic reconnection couples with both ions and electrons on different scales. Recently, a new type of magnetic reconnection, electron‐only reconnection without the coupling of ions, has been observed in various plasma environments. Standard reconnection typically has a reconnection outflow velocity of about one Alfvén speed. According to the scaling analysis, the electron outflow velocity is expected to be about one electron Alfvén speed in electron‐only reconnection. However, observations and simulations both find that the electron outflows are much slower than the electron Alfvén speed. In this letter, by performing two‐dimensional particle‐in‐cell simulations, we show that this is because ions play a role in electron‐only reconnection. The ions move slower than the electrons in the outflow direction, and such charge separation forms an in‐plane Hall electric field, which prevents the electrons from being accelerated to the electron Alfvén speed in electron‐only reconnection. Plain Language Summary: Magnetic reconnection is a fundamental plasma process during which magnetic field line topologies change and magnetic energy transfers to plasma kinetic and thermal energy. In standard collisionless magnetic reconnection, ions and electrons are both heated and accelerated to form high‐speed outflow. Theoretical analyses have been performed to successfully explain the fast outflow speed in standard magnetic reconnection. Recently, a new type of magnetic reconnection, electron‐only reconnection (in which there is no obvious ion heating and acceleration) has been reported to occur in various plasma environments. However, the same scaling analyses performed in electron‐only reconnection overestimate the outflow speed in the electron‐only reconnection by a factor of ∼10. Here, by performing two‐dimensional (2‐D) particle‐in‐cell (PIC) simulations, we show that the overestimation is due to the neglect of the role of ions. Because of the in‐plane Hall electric field caused by charge separation, electron outflow in electron‐only reconnection cannot be accelerated to the expected value. Key Points: Electrons are not accelerated to electron Alfvén speed in electron‐only magnetic reconnectionDeceleration of electron outflow caused by in‐plane Hall electric field should not be ignored [ABSTRACT FROM AUTHOR]

The development of reduced models provide efficient methods that can be used to perform short term experimental data analysis or narrow down the parametric range of more sophisticated numerical approaches. Reduced models are derived by simplifying the physics description with the goal of retaining only the essential ingredients required to reproduce the phenomena under study. This is the role of the gyro-fluid code FAR3d, dedicated to analyze the linear and nonlinear stability of Alfvén Eigenmodes (AE), Energetic Particle Modes (EPM) and magnetic-hydrodynamic modes as pressure gradient driven mode (PGDM) and current driven modes (CDM) in nuclear fusion devices. Such analysis is valuable for improving the plasma heating efficiency and confinement; this can enhance the overall device performance. The present review is dedicated to a description of the most important contributions of the FAR3d code in the field of energetic particles (EP) and AE/EPM stability. FAR3d is used to model and characterize the AE/EPM activity measured in fusion devices as LHD, JET, DIII-D, EAST, TJ-II and Heliotron J. In addition, the computational efficiency of FAR3d facilitates performing massive parametric studies leading to the identification of optimization trends with respect to the AE/EPM stability. This can aid in identifying operational regimes where AE/EPM activity is avoided or minimized. This technique is applied to the analysis of optimized configurations with respect to the thermal plasma parameters, magnetic field configuration, external actuators and the effect of multiple EP populations. In addition, the AE/EPM saturation phase is analyzed, taking into account both steady-state phases and bursting activity observed in LHD and DIII-D devices. The nonlinear calculations provide: the induced EP transport, the generation of zonal structures as well as the energy transfer towards the thermal plasma and between different toroidal/helical families. Finally, FAR3d is used to forecast the AE/EPM stability in operational scenarios of future devices as ITER, CFETR, JT60SA and CFQS as well as possible approaches to optimization with respect to variations in the most important plasma parameters. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of catalysts generated from metal–organic frameworks (MOFs) for the degradation of toluene in a linked non-thermal plasma/photocatalytic process. The porous tri-metal oxide catalyst (MCNOx) was derived from the metal organic framework (MOF-74) via an in situ pyrolysis strategy utilizing Mn-doped CoNi-MOF-74 as the precursor. The resulting MCNOx material exhibits a unique series of surface defects, which significantly enhances its catalytic activity. We found that MCNOx materials, due to their high specific surface area, regular porous structure, and excellent reducibility, can synergize well with NTP in the complete decomposition of toluene, which makes the NTP coupled catalytic system have better catalytic activity and CO2 selectivity. The toluene conversion temperature of T90 in the NTP synergistic thermocatalytic system was 250 °C for the 5MCNOx catalyst, which was also much higher than that of 1MCNOx (256 °C), 10MCNOx (258 °C), CNOx (270 °C), and 5MCNOx catalyst in the monocatalytic system (270 °C). In addition, the catalytic stability of MOF-derived MCNOx oxides and the influence of water vapor on catalytic activity were investigated, confirming their excellent catalytic performance. Finally, the importance of Mn doping in improving toluene oxidation activity on MOF-74 derived CNOx has been demonstrated, providing a viable strategy for developing a toluene oxidation catalyst. [ABSTRACT FROM AUTHOR]

This study explores the effect of plasma treatment on the wettability of titanium oxide (TiO2) films. TiO2 was prepared using the sol–gel method and deposited on glass substrates. One set of films was indium-doped, while both doped and undoped films were divided into groups receiving either thermal or plasma treatment. Plasma treatment significantly decreased the water contact angle for both neodymium-doped and undoped TiO2, indicating increased hydrophilicity. X-ray diffraction analysis revealed that both doped and undoped films maintained the same crystalline phase after plasma treatment, with a slight increase in peak intensity and amplitude. Ultraviolet–visible spectroscopy showed a decrease in the bandgap energy upon indium doping, suggesting the potential for enhanced photoactivity. In conclusion, this study demonstrates that plasma treatment effectively modifies the wettability of TiO2 films, and neodymium doping influences their optical properties. [ABSTRACT FROM AUTHOR]

This study explores the ignition and ablation of a propellant by plasma produced during the electrical explosion of aluminum wires. An experimental platform is established to investigate the mechanism underlying this process. Al wires of different diameters and single-base, double-base, and triple-base propellants are considered. The electrical explosion products of the Al wires and the ablated propellant are analyzed in detail. The results show that during the explosions, the peak voltage of a 0.1 mm-diameter Al wire is the highest and that of a 0.5 mm-diameter wire is the lowest. The discharge voltages are basically the same after the metal vapor is broken down and formed into a plasma discharge channel. The peak of the particle diameter distribution of the explosion products of a 0.1 mm-diameter wire is at about 25 nm, that of a 0.2 mm-diameter wire is around 35 nm, and that of a 0.5 mm-diameter wire is around 50 nm. The ablation effect of a single-base propellant consists mainly of thermal ablation by plasma and impact ablation by particles. The ablation of a double-base propellant is mainly thermal ablation, and the ablation of a triple-base propellant is mainly thermal ablation dominated by particle impacts. The thermal decomposition temperatures of different propellant components have a significant influence on the ablation process. These results have a wide range of applications, such as in the design of plasma generators and energetic materials in electrothermal chemical guns. [ABSTRACT FROM AUTHOR]

Low-cost micromanufacturing technique for forming copper foils into desired micro-parts plays an important role in facilitating the widespread application of copper foil. Here, the pulsed arc plasma generated by the pulsed voltage was used as a heat source to achieve thermal stress–induced bending of copper foil in an electrical discharge machining (EDM) machine. Metallic foil with a thickness of 0.1 mm and a cylindrical rod with scanning motion were used for the first time as tool electrodes in the EDM bending of workpieces. The effect of various processing parameters, such as polarity, machining time, discharge current, duty factor, and discharge frequency, on the bending angle was investigated by optical microscopy. The main factors affecting the bending angle and their working mechanisms were analyzed in depth. Experimental results showed that the bending angle of the copper foil increases with the increase of the discharge energy, which was mainly attributed to the increasing thermal gradient along the thickness direction of the copper foil. When the copper foil was used as the anode, the carbon deposition phenomenon in the copper foil effectively reduced the material removal caused by the pulsed arc plasma, which contributes to the surface integrity and performance of the copper foil. Furthermore, several typical bend-formed parts, including curved, sawtooth, and S-shapes, were formed using pulsed arc plasma. This work proves that pulsed arc plasma is a reliable and cost-effective heat source for achieving thermal stress–induced bending of copper foil. [ABSTRACT FROM AUTHOR]

Plasma-based methods present a highly efficient approach for reclaiming valuable metals and nanoparticles from discarded metal scraps and minerals. In this research, we employed the thermal plasma arc discharge (TPAD) method to synthesize mixed-phase spinal-type magnesium aluminate and magnesium oxide (MgAl 2 O 4 /MgO) nanocomposites ranging in size from 10 to 120 nm, using discarded MgAl alloy waste scraps as the primary material. By employing comprehensive characterization techniques such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDS), we successfully confirmed the formation of highly crystalline MgAl 2 O 4 /MgO nanocomposites, showcasing a nearly spherical morphology. The surface area of the prepared nanocomposites was investigated using Brunauer-Emmett-Teller (BET) analysis; the values are 51.3 m2g-1. The synthesized MgAl 2 O 4 /MgO nanocomposites displayed exceptional photocatalytic activity toward industrial wastewater and commercial dye. Moreover, investigated the storage properties of MgAl 2 O 4 /MgO nanocomposites as an electrode material, revealing a good specific capacitance of 379.2 F/g at a current density of 1 A/g, demonstrating pseudocapacitive behavior. These results offer valuable insights into sustainable waste utilization and the development of high-performance nanomaterials for practical applications in various fields. [ABSTRACT FROM AUTHOR]

This study explores the effect of plasma treatment on the wettability of titanium oxide (TiO2) films. TiO2 was prepared using the sol–gel method and deposited on glass substrates. One set of films was indium-doped, while both doped and undoped films were divided into groups receiving either thermal or plasma treatment. Plasma treatment significantly decreased the water contact angle for both neodymium-doped and undoped TiO2, indicating increased hydrophilicity. X-ray diffraction analysis revealed that both doped and undoped films maintained the same crystalline phase after plasma treatment, with a slight increase in peak intensity and amplitude. Ultraviolet–visible spectroscopy showed a decrease in the bandgap energy upon indium doping, suggesting the potential for enhanced photoactivity. In conclusion, this study demonstrates that plasma treatment effectively modifies the wettability of TiO2 films, and neodymium doping influences their optical properties. [ABSTRACT FROM AUTHOR]

In this study, we explore the potential of using laser-induced photo-fragmentation of O3 by UV radiation as a quantitative diagnostic tool in non-thermal O2-mixed plasmas. We analyze the optical processes of O3 using a comprehensive kinetic model with a 226 nm laser, which is typically used in the two-photon absorption laser-induced fluorescence (TALIF) measurement of O atoms. Our model demonstrates that the fluorescence intensity from atomic O fragments produced by the same laser is directly proportional to the population of precursor O3. This makes various diagnostic purposes achievable through the proposed O3 full photo-fragmentation (FPF) TALIF spectroscopy, including calibration of TALIF signals of O atoms and quantification of both O and O3 in O2-mixed plasmas. We present detailed theoretical principles, technical requirements, and successful examples of implementation for different diagnostic aims using the proposed O3 FPF-TALIF spectroscopy. However, we also specify the limitations of the developed diagnostic methods, particularly under low E/N conditions (<30 Td), where other interferential species such as the vibrationally excited ground-state O 2 ( X 3 Σ g − , v ≠ 0) are abundantly produced. [ABSTRACT FROM AUTHOR]