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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]

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]

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]

Thermal plasma melting was applied to mixtures of MgO, Al 2 O 3 and Tb 4 O 7 to synthesize the MgAl 2 O 4 :Tb3+ (0.1–10 % wt. Tb 4 O 7) luminescent ceramics series. Coarse-grained spinel materials (0.1–1 mm) with preferred crystal orientation were obtained. Structural, morphological (XRD and SEM) and spectroscopic (cathodoluminescence and Raman spectroscopy) analysis were used to investigate the influence of Tb 4 O 7 content on ceramics phase composition, cell parameter of MgAl 2 O 4 :Tb3+, the inversion degree, and luminescent properties. It was found that the thermal plasma synthesized spinel ceramics exhibit a non-controlled inversion degree. The formation of TbAlO 3 as a by-product was observed in materials containing more than 1 wt% of Tb 4 O 7. It was demonstrated that the thermal plasma melting method could be potentially applied for fast preparation of MgAl 2 O 4 :Tb3+ luminescent ceramics. [ABSTRACT FROM AUTHOR]

In Magnetic Resonance Imaging (MRI), manganese oxides are predominantly used as contrast agents (CAs) to enhance contrast of T 1 –weighted acquisitions. In this work, Mn 3 O 4 nanomaterials were synthesized by high temperature thermal plasma route and thoroughly characterized by structural, microscopic and biocompatibility investigations. The nanoparticles so obtained display both T 1 and T 2 MRI contrast properties. This was attributed to the fact that the nanomaterials synthesized by thermal plasma route possess higher saturation magnetization than those synthesized by various chemical methods. The presence of oxygen vacancies and relatively large size of the synthesized nanoparticles can also be regarded as other two reasons behind attainment of T 1 -T 2 dual contrast. Thermal plasma synthesized nanomaterials have never been earlier demonstrated as MRI CAs. Moreover, this is the first report presenting detailed characterization of the thermal plasma synthesized Mn 3 O 4. The microstructure of the synthesized Mn 3 O 4 nanoparticles was observed to be spherical in shape. The biocompatibility of the developed nanosystem was established by cell viability analysis. Finally, the efficiency of the agent for T 1 –T 2 contrast enhancement was confirmed through MRI experiments. This work lays the foundation of research on a new class of MRI CAs synthesized by thermal plasma. [ABSTRACT FROM AUTHOR]

The European Green Deal has set a target for Europe to achieve net-zero greenhouse gas emissions by 2050, necessitating a transition to more sustainable energy sources. Hydrogen gas (H 2) has emerged as a promising solution, with methane pyrolysis presenting a viable method for its production. This study explores the optimization of methane plasma pyrolysis for hydrogen and high-quality carbon production. Employing a statistical approach by a design of experiment software, critical process parameters are systematically analyzed to predict their impact within a defined range. Additionally, the paper conducts comprehensive characterization of the solid carbon produced during pyrolysis using imaging, spectroscopic and elemental analysis, and gas sorption analysis methods. The experimental investigation was conducted using a thermal plasma reactor with several settings of influential parameters including methane gas (CH 4) content in the plasma gas, electric current, and arc length. The DC-transferred plasma arc is formed using a variable gas mixture of argon gas (Ar) and CH 4, with a constant flow rate of 5 Nl/min. Thirteen tests were designed, evaluating responses such as power input, process stability, and H 2 yield. The H 2 yield indicates the hydrogen produced from CH 4 , with 100% representing total conversion. While the process exhibited inconstancy, attributed to reactor design constraints, a high H 2 yield of 67%–100% was achieved. The results indicate that a higher CH 4 content in the plasma gas and extended arc lengths disturb the plasma arc, hence reducing the H 2 yield. Increased power input, achieved through higher amperage levels, and a wider reaction zone eased by extending the arc length both led to an improved H 2 yield. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) revealed microstructural differences, with carbon samples from the filter exhibiting finer textures and carbon samples from the reactor larger sizes and dendritic particles. Raman spectroscopy confirmed crystalline graphitic-like structures with low defect concentrations, a finding supported by X-ray diffraction (XRD) analysis. Inductively coupled plasma mass spectroscopy (ICP-MS) analysis confirmed high-purity carbon with slight impurities from initial filter contamination. Brunauer-Emmett-Teller (BET) specific surface area calculations based on gas sorption analysis showed significant variations, with filter-collected samples exhibiting 40–170 m2/g and reactor-collected ones showing 7–30 m2/g. [Display omitted] • This study investigates a unique approach to optimizing the thermal plasma pyrolysis of methane. • A H 2 yield of 67%–100% was achieved utilizing a DC-transferred plasma arc furnace and an Ar and CH 4 mixture plasma gas. • A lower CH 4 content in the plasma gas and an optimized arc length improve the plasma arc and the H 2 yield. • The carbon shows crystalline graphitic-like structures with low defect concentrations. [ABSTRACT FROM AUTHOR]

Highly complex high entropy metal oxides (HEOs) have several unique characteristics, such as more active sites and material stability that improve the electrochemical charge storage capacity. In this study, HEOs (Mn, Ni, Mo, Co, Fe) 3 O 4 nanoparticles were synthesized using a thermal plasma route and its electrochemical energy storage performance was studied with two distinct electrolytes such as 1 M KOH and NaOH. The X-ray diffraction analysis revealed the phase pure spinel structured HEOs with crystalline size ranging from 13 to 29 nm. Scanning electron microscopy and electron dispersive X-ray spectroscopy results revealed the quasi-spherical morphology and uniform distribution of constitutional cations in the as-synthesized HEOs. The X-ray photoelectron spectroscopy results identified the oxidation states of cations in spinel HEOs. The charge/discharge studies of as-synthesized HEOs showed a specific capacitance of 215 F g-1 /26.9 mAh g-1 at a current density of 2 A g-1 in 1 M KOH electrolyte which is 156 % greater than 1 M NaOH electrolyte. Furthermore, a high capacitance retention of 91 % was achieved after completing 3000 cycles at 10 A g-1 current density which indicates that the HEOs have excellent charge/discharge reversibility. Electrochemical impedance spectroscopy revealed that the solution and charge transfer resistances of HEOs electrodes were 1.04 and 3.2 Ω, respectively. This novel synthesis strategy attempts to overcome the difficulties experienced by established methods for bulk manufacture of phase pure HEOs since thermal plasma method is a rapid and a single-step approach for the bulk production of nanomaterial. [ABSTRACT FROM AUTHOR]

Considering the urgent need for green energy carriers, hydrogen became a promising substitute for fossil fuel production via sustainable approach. Therefore, developing efficient photocatalysts using solar energy is the main issue. Here, we report experimental and computational studies on nature and influence of oxygen vacancies in different atomic layers of defective TiO 2-x nanotubes photocatalysts. Although there are several studies that opened a new avenue to understand how to fabricate suboxide TiO 2-x , there is no any comparative study reported on two main oxygen reduction techniques yet: cold plasma treatment and thermal hydrogenation. Oxygen vacancies and Ti3+ species produced by plasma reduction in a mixed Ar/H 2 (90/10) under pressure of 10−3 Torr efficiently increase charge carrier life time (at optimum 15 W power) resulting in higher H 2 production rate and significant incident photon to current efficiency (60%) in comparison with point defects produced by hydrogenation treatment. Various techniques utilized to fabricate oxygen deficient TiO 2-x can lead to the creation of defects in specific atomic layers within the crystal structure. Therefore, we develop an ab initio model of the oxygen vacancies' formation at different depths of TiO 2 slabs to study the effect of defects' position in the crystal lattice on electronic structure against energy levels of water splitting reaction. This research provides a new and deep insight for designing suboxide black TiO 2-x for efficient photocatalytic reactions especially for green energy production and environmental remediation. [Display omitted] • Oxygen vacancies in TiO 2-x nanotubes enhance H 2 production and IPCE efficiency. • Cold plasma generates surface defects, while thermal treatment creates bulk defects. • Surface oxygen vacancies and Ti3+ boost carrier lifetime and photocatalytic activity. • Ab initio model investigates the impact of defect position on electronic structure. • This research guides the design of TiO 2-x for efficient green energy production. [ABSTRACT FROM AUTHOR]

• PlasmaJet® is an efficient device for tumor ablation or dissection in cytoreductive surgery in patients with advanced stage ovarian cancer. • PlasmaJet® is effective for the treatment of significant mesenteric disease, with reduced morbidity for the patients with advanced stage ovarian cancer undergoing cytoreductive surgery. • Use of PlamaJet® in treatment of ovarian cancer could potentially reduce the need of bowel surgery. To compare the clinical appearance of "no residual disease" to the histological assessment of the same tissue when treated with PlasmaJet®. To determine if the treated tissue with a clinical appearance of "no residual disease" demonstrated histologically apparent damage to underlying structures. The main aims of the study were to compare the clinical appearance of 'no residual disease' to the histological assessment of the same tissue and to assess whether treatment with PlasmaJet® to produce a clinical appearance of 'no residual disease' causes no histologically apparent damage to the underlying structures. This prospective cohort study was conducted in Liverpool Women's NHS Foundation Trust between January 2019 and June 2020. Women with a diagnosis of advanced or presumed advanced stage ovarian cancer were approached and 20 women were recruited into the study. Tissue samples were collected from women with stage 3 or 4 ovarian cancer at either primary or interval debulking surgery. The clinical appearance of no residual disease was confirmed histologically in 84 % (n = 16) of cases. Fat was the only underlying tissue seen damaged in 21 % (n = 4) of cases. Bowel resection with stoma formation was needed in one case (5.26 %). PlasmaJet® ablated the malignant tissue in majority of the cases without causing any significant damage to the underlying tissue, it also reduced the need for stoma formation. This is a small study with encouraging results. PlasmaJet® could be a valuable tool in ovarian cancer surgery, it potentially could reduce the need for bowel surgery and allow treatment of significant mesenteric disease with reduced morbidity for the patient. [ABSTRACT FROM AUTHOR]

Monitoring creatinine levels is critical for evaluating renal function and muscular health in athletes. Creatinine is a waste product of creatine metabolism in skeletal muscle, and is filtered by the kidneys at a relatively constant rate. Elevated serum creatinine can indicate impaired kidney function, rhabdomyolysis, or skeletal muscle trauma. In athletes, creatinine levels increase after intense exertion due to muscle breakdown and myoglobin release. Abnormal creatinine signifies poor training adaptation, overtraining, or trauma. Therefore, close monitoring of creatinine in athletes provides insight into their physical condition. Current laboratory methods for measuring creatinine like Jaffe reaction and high-performance liquid chromatography are accurate but time-consuming, requiring blood sampling. Biosensors offer rapid, painless creatinine detection from small volumes, but current versions suffer from instability, use of mediators, and lack portability. Boron nitride nanotubes (BNNTs) are promising materials for electrochemical biosensing due to their structure, surface chemistry, and biocompatibility. Here, we report BNNT-based electrochemical biosensors for detecting creatinine in blood samples from athletes. BNNTs synthesized by induction thermal plasma technique were used to immobilize creatinine metabolizing enzymes. Creatinine levels were measured by chronoamperometry and compared to isotope dilution mass spectrometry. We demonstrate high sensitivity and selectivity of the BNNT biosensor with facile fabrication method and portable platform, promising for rapid creatinine monitoring in athletes. This can provide insight into muscular damage and renal function during training and competition. [ABSTRACT FROM AUTHOR]

Development of efficient photothermal catalysts made of earth-abundant elements is of prime importance for heterogeneous photocatalysis driven by solar light. Herein, we report for the first time the synthesis of NiTi@TiO 2 /Ni core-shell-satellite nanoparticles from pristine nitinol nanopowder (NiTi) by simple and easily scalable ultrasonically assisted hydrothermal treatment in pure water (T = 200 °C, P = 14 bar, f = 20 kHz, P ac = 17 W, τ = 3 h). Prepared material exhibits unique set of properties, such as strong capability of light-to-heat conversion, good magnetization, high stability, and remarkable thermally assisted photocatalytic hydrogen production (5.5 mmol h−1 g−1 at T = 90 °C). The core-shell-satellite morphology of NiTi@TiO 2 /Ni particles maximizes the contact area between the heat generating metallic core and photocatalytically active TiO 2 /Ni nanocrystalline shell providing the most efficient photothermal effect in the processes of H 2 production and CO 2 methanation without CO emission. In addition, significant magnetic susceptibility of the NiTi@TiO 2 /Ni nanoparticles allows their easy recovery from solution with an external magnetic field. Noncongruent surface oxidation of nanoalloys reported in this work paves the way to the preparation of new generation of catalysts with advanced photothermal properties. [Display omitted] • NiTi@TiO 2 /Ni photocatalyst was prepared from NiTi nanopowder by ultrasonically assisted hydrothermal treatment in water. • Obtained material exhibits strong capability of light-to-heat conversion, good magnetization, and high stability. • NiTi@TiO 2 /Ni nanoparticles exhibit remarkable activity for thermally assisted photocatalytic hydrogen production. • This material enables CO 2 methanation by in situ generated hydrogen in aqueous solutions. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) is recognized as a viable and environmentally friendly energy source, utilized across various domains, from large-scale chemical energy exports to small-scale power generation in remote areas. However, the storage and distribution costs of H 2 present significant challenges. Ammonia (NH 3) emerges as a carbon-free hydrogen carrier, backed by a robust international transport and storage infrastructure. On-site hydrogen production can be efficiently achieved through NH 3 decomposition, predominantly via thermal catalysis. One innovative approach involves plasma technology, which utilizes NH 3 , alcohols, or hydrocarbons to produce pure hydrogen in plasma reactors. Nonthermal plasma (NTP) in particular, for NH 3 decomposition and H 2 production, has garnered considerable interest owing to its higher energy efficiency than thermal plasma systems. Furthermore, integrating NTP with catalysis, termed plasma-assisted catalysis, creates a synergistic effect, enhancing NH 3 decomposition efficiency for H 2 production through improved plasma-catalyst interactions. Consequently, NTP-catalysis holds the potential to revolutionize NH 3 conversion and utilisation in the future. To date, there have been limited studies on NTP-assisted catalytic NH 3 decomposition. This review article compiles the latest NTP-assisted catalytic NH 3 decomposition methodologies for H 2 production. It delves into the basics of plasma-assisted NH 3 decomposition, including adsorption, desorption, and the synergistic processes during plasma catalysis. Additionally, it examines the impact of NTP on the chemical states and properties of various catalysts and provides a comprehensive analysis of the factors influencing NH 3 -plasma decomposition. • Nonthermal plasma-assisted catalysis NH3 decomposition for COx-free H2 production. • Full NH 3 decomposition achieved at ambient temperature and pressure by applied NTP. • Combining plasma with catalysis has improved the NH3 efficiency decomposition. • NTP catalysis can potentially revolutionize NH3 conversion and utilisation in the future. [ABSTRACT FROM AUTHOR]

(La,Sr)CoO 3 and (La,Sr) 2 CoO 4 dual phase powders were synthesized via thermal plasma to be used as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFC). This covered pure (La,Sr)CoO 3 as well as the composites where the fraction of (La,Sr) 2 CoO 4 was gradually increased reaching the mid-composition. Powders, all synthesized in the same condition, were extremely small in size, especially at mid-composition where they were close to 30 nm in size. Area specific resistance (ASR) determined from the symmetric cell imply improved cathodic performance at the mid-composition. Taking ASR = 0.15 Ω∗cm2 as benchmark, it was found that the (La,Sr)CoO 3 : (La,Sr) 2 CoO 4 = 0.53:0.47 cathode may be used at temperatures close 750 °C. Measurements taken from several runs however imply that the cathode performance was not stable and ASR values increases with cycling. This was attributed to the powder form of the cathode which would be expected to coarsen rapidly due to accelerated surface diffusion. • (La,Sr)CoO 3 -(La,Sr) 2 CoO 4 composite cathodes are synthesized via thermal plasma. • Particle size was smaller in cathodes with equimolar or near compositions. • Equimolar composite cathodes may be used at temperatures near 750 °C. • Less stable performance was assigned to non-layer nature of the cathode. [ABSTRACT FROM AUTHOR]

In this study, the plasma torch is utilized for the preparation of highly pure ZrO 2 from zircon (ZrSiO 4). The incorporation of H 2 into the discharge gas Ar improves the plasma physical parameters and serves as a reducing agent to promote the irreversibility of the pyrolysis reaction of ZrSiO 4. ZrSiO 4 powder is fed internally into a DC arc plasma torch through a powder feeder device. The DC torch generates thermal plasma that can fully heat all the ZrSiO 4 within a short period for pyrolysis, extraction, and separation, eventually producing high-purity ZrO 2. According to the results, the addition of H 2 to the working gas increases the material temperature in the flame by increasing the plasma temperature, thereby promoting the pyrolysis of ZrSiO 4. The temperature of the material is 2500–2600 °C, which is higher than the boiling point of the pyrolysis product SiO 2 while maintaining the high melting points of ZrSiO 4 and ZrO 2. Furthermore, H 2 plasma acts as a reducing agent in the pyrolysis reaction, where it combines with the O of the product to prevent the reversibility of the pyrolysis reaction of ZrSiO 4 and retains only ZrO 2. [ABSTRACT FROM AUTHOR]

Among various thermal plasma sources for CH 4 pyrolysis, singular direct current (DC) thermal plasma has limited capacity, erosion, and efficiency. However, the triple thermal plasma system has been applied for nanomaterial synthesis and exhibited results overcoming these limitations. This study used the triple thermal plasma system to investigate the most suitable conditions for CH 4 pyrolysis. CH 4 conversion rate and selectivity of H 2 and C 2 H 2 were analyzed by varying the CH 4 flow rate and quenching conditions at a fixed power supply of approximately 30 kW, and the specific energy requirement (SER) per 1 kg H 2 was compared with that of previous works. The maximum conversion rate was 97% at 50 L/min of CH 4 , which is approximately 7% higher than earlier studies under conditions with similar process enthalpy. In addition, the conversion of CH 4 to C 2 H 2 and further to heavier hydrocarbons proceeded one order of magnitude faster than the reaction time expected by the gas-phase reaction. This result is attributed to the easy penetration of CH 4 into the core region with the highest temperature and the strong interaction between the processing gas and graphite surface due to the arrangement of the torches in the triple plasma system. C 2 H 2 selectivity was relatively high, while it was less affected by the increase in the quenching gas than generally expected. This finding was attributed to the naturally fast quenching rate without quenching gas due to the structure expanding from the first to the second graphite. While quenching can enhance selectivity by stabilizing the radicals as intermediates such as H 2 or C 2 H 2 , it depressed the following reaction with dehydrogenation. Thus, the quenching conditions must be optimized. Finally, we demonstrated that the triple thermal plasma enhanced CH 4 pyrolysis regarding H 2 production efficiency. • The CH 4 pyrolysis process was applied to the triple thermal plasma system. • The maximum CH4 conversion rate of 97% was achieved at 500 kJ/mol of process enthalpy. • It was identified that the conversion of CH4 to heavier hydrocarbons is achieved fastly. • The SER of 39.44 kWh was accomplished, which was a superior result to other works. [ABSTRACT FROM AUTHOR]

• First report on air plasma mitigation of high temperature insulation wool (HTIW). • Single step, high temperature (>6000 K) green process. • Uses freely available air to generate plasma replacing costly gases like argon. • Mitigation of most of the commonly used HTIW addressed including residue analysis. • In-situ evolution of melt-pool temperature is directly captured using pyrometer. • Study supported with MHD simulation of plasma. High temperature insulation wool (HTIW) wastes, generated in large volume as a part of demolition and construction processes, are difficult to recycle and pose significant hazards to health and environment. Alkaline earth silicate wools (AESW) and alumino silicate wools (ASW) are the two major types. Typical constituents include silica and oxides of Ca, Al and Mg etc. in varying ratios, giving rise to their specific colours and inherited thermo-physical properties. Successful mitigation and reuse of such wools have not been explored enough. Possibly for the first time, the study makes an extensive investigation on air plasma mitigation of four most commonly used HTIW, namely, fresh rock wool, waste rock wool, waste stone wool and waste ceramic wool. This is a single step dry process. Use of freely available ambient air to generate plasma, extremely high enthalpy, presence of nascent atomic and ionic species and extremely high temperature make the process fast, efficient, economic and unique one to convert such wastes into valorised product. While the thermal field delivered by an air plasma torch has been derived from magneto-hydrodynamic simulation, the study makes a direct in-situ investigation of the evolution of thermal field in the melting zone using two colour pyrometer, and characterises the vitreous solidified end product using X-diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Analysis, Energy Dispersive X-ray Fluorescence Spectroscopy and Neutron Activation Analysis. Possible valorisation and use of the end product have been discussed in light of their observed elemental composition. [ABSTRACT FROM AUTHOR]

In this contribution, the performance and delamination mechanisms of air plasma sprayed (APS) yttria stabilized zirconia thermal barrier coatings (YSZ TBCs) under high intensity heat flux at 1600 °C was investigated. The plasma jet was adopted as the heat source with a combination of high temperature and high-speed jet-stream erosion. It was found that the YSZ topcoat would exfoliate when the vertical crack connected to the interior (interfacial/shear) cracks to form a free edge, which turned the mixed-mode buckle delamination into a mode I cracking. The thermo-mechanical analysis indicated that energy release rate associated with the transient cooling was the driving force for the interfacial cracks, while the vertical cracks were developed by the tensile stress during cooldown. The findings obtained in this study implied that the YSZ TBCs can be used for the thermal protection of combustor in ramjet engines. [ABSTRACT FROM AUTHOR]

Steam methane reforming reaction was carried out in a dielectric barrier plasma reactor. A systematic study is conducted to understand the influence of input power, flow rate, and water for the conversion, yield, and selectivity of the reaction over strategically designed catalysts. In particular, the production rate and selectivity of the products (H 2 , CO and C 2 hydrocarbons) are monitored. CeO 2 was used as packing material, mixed with oxides of manganese or copper and their combination. The optimum Cu/CeO 2 catalyst illustrated the production rate of 248.7 μmolg−1h−1 and 11.25 μmolg−1h−1 for H 2 , and CO, respectively at specific energy input of 19.8 JL-1. DFT calculations exhibit apparent change in electronic structure of the CeO 2 after inclusion of oxides of manganese and copper that enhance interaction with methane. Based on these findings, a plausible mechanism is elucidated which can help to design catalyst for other applications in non-thermal plasma atmosphere. [Display omitted] • Steam methane reforming reaction is investigated in a non-thermal plasma reactor. • H 2 , CO, C 2 hydrocarbons are obtained as products. • Oxides of Co and Mn are supported on ceria and tested as catalysts. • Among tested catalysts, Cu/Ce exhibited maximum production rate of H 2 and CO. • DFT suggests increase in electronic interaction with methane for Mn/Ce, and Cu/Ce. [ABSTRACT FROM AUTHOR]

The structural, optical, spectroscopic, and electrical transport properties of zinc oxide (ZnO) nanoparticles prepared using the solution precursor plasma spray (SPPS) technique were investigated for different feedstock solution concentrations such as 1-mol and 4-mol. Rietveld refined powder X-ray diffraction and Raman spectra reveal that the prepared ZnO crystallizes in a hexagonal wurtzite structure with no secondary phase. The crystallite sizes for 1-mol and 4-mol samples are 27.5 nm and 31.3 nm, respectively. Analysis of UV–vis spectra shows that ZnO's band gap has increased from 3.19 eV to 3.23 eV as the mole concentration has increased. The spherical nature and nano size of the ZnO are confirmed by the pictures obtained using field emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM). The presence of elements zinc and oxygen in the Zn2+ and O2− ionic states are revealed by X-ray photoelectron spectroscopy (XPS). Electrical study demonstrates that the initial mole concentration of ZnO powder affected both its electrical conductivity and dielectric constant. The activation energy value of electrical conductivity for 1-mol and 4-mol is 0.661 eV and 0.552 eV, respectively. The impedance analysis shows the electrode effect for the 1-mol sample whereas it is not observed for the 4-mol sample, which is further confirmed by modulus analysis. The presence of defect in the 1-mol sample results in a lower conductivity (3.68 × 10−12 S/cm at 1 Hz) than the 4-mol sample. The comprehensive analysis confirms that the structural, spectroscopic and electrical properties of the ZnO nanoparticle can be tunable to meet demand by changing the feedstock mole concentration in the SPPS process. [ABSTRACT FROM AUTHOR]

The high thermal stability of CO 2 makes its conversion low in conventional thermal catalysis. Comparatively, non-equilibrium plasma technique provides an efficient way for CO 2 hydrogenation under mild reaction conditions. Introducing effective catalysts to the dielectric barrier discharge (DBD) plasma reactor may further improve CO 2 hydrogenation performance. In this way, the interaction between plasma and catalysts is important to contribute CO 2 hydrogenation performance. Considering Ni-based catalyst is active for CO 2 hydrogenation, we used three different kinds of carrier materials including CeO 2 , γ-Al 2 O 3 and ZSM-5 as supports to prepare nickel-based catalysts by incipient impregnation in this paper. The supported Ni catalysts were tested for the plasma-induced CO 2 hydrogenation to CH 4 and C 2+ hydrocarbons in the DBD-plasma reactor. It was found that the 15Ni/CeO 2 catalyst achieved the best CO 2 conversion of 85.7% and nearly 100% CH 4 selectivity at 300 °C due to its high reducibility and CO 2 chemisorption capacity. In addition, a significant synergistic effect was found between DBD plasma and catalyst. The performance of plasma-catalysis was considerably better than that of thermal catalysis plus pure plasma reaction, and the synergistic effects were enhanced with increase of reaction temperature. Moreover, the mechanism of the synergistic effect was proposed by analyzing the optical emission spectroscopy (OES) of DBD plasma, which provides a theoretical basis for further optimizing and application of plasma-catalysis for CO 2 hydrogenation reaction. [Display omitted] • CO 2 hydrogenation to CH 4 and C 2+ hydrocarbons was enhanced by plasma-catalysis. • The 15Ni/CeO 2 showed better activity due to better reducibility and CO 2 chemisorption ability. • A synergistic effect between plasma and catalyst was enhanced with increase in reaction temperature. • The synergistic mechanism between plasma and catalysts was proposed. [ABSTRACT FROM AUTHOR]

Alumina (Al 2 O 3) remains one the most important engineering ceramic for industrial applications. In addition to the α phase, transition alumina phases have interesting characteristics. Controlling the obtained phase structure from alumina melt requires processes with extreme cooling rates and therefore limits the tailoring capabilities. This study investigates how the cooling rate of pure alumina affects its microstructural properties and phase structure in plasma-based processing. The paper reports phase changes in micron sized granulated alumina particles in high-temperature plasma spheroidization and compares the results to plasma sprayed alumina coatings. Both plasma processes involve melting of the material followed by subsequent rapid cooling. Direct comparison on the alumina phase transitions is obtained for the two methodically distinct processing routes, creating unique microstructures due to difference in their cooling rates. • Alumina properties can be adjusted by controlling the cooling rate in melt quenching. • The alumina phase structure can be reprogrammed to fit a specific application. • Plasma spheroidization allows a new way to study the intermediate phases in alumina. [ABSTRACT FROM AUTHOR]

• A block-Gauss-Seidel iterative algorithm and an adaptive matrix update algorithm are proposed to solve the magneto-thermal-mechanical coupling problems of tokamak structures during plasma disruptions. • The effectiveness, numerical stability and efficiency of the proposed methods are validated through coupling experiments. • The importance to consider the magneto-thermal-mechanical coupling effects and the flexibility of the proposed methods are revealed by the application to the dynamic analysis of HL-2M tokamak. Tokamak is a kind of device that uses strong magnetic fields to confine the hot nuclear fuel in plasma state and achieve the controlled thermonuclear fusion reaction. It is well-known that increasing the plasma elongation is beneficial for improving the performance of tokamak. However, high elongation is always along with a strong intrinsic vertical instability. The control system to neutralize the vertical instability of the plasma may fail. As a result, the plasma will move vertically and finally strike on the plasma-facing components accompanied by rapid thermal and current disruption. During this process, large eddy currents will be induced in the plasma surrounding conductive structures and high heat flux will be injected into the first wall of the vacuum vessel (VV). The eddy currents and the temperature gradient then produce strong Lorentz forces and thermal stress, which may cause excessive deformation or even failure of the device. Additionally, there are complicated magneto-thermal-mechanical coupling (MTMC) phenomena in the dynamics of the tokamak structures, which may have non-negligible influences on the distribution of the electromagnetic and mechanical loads and the dynamic response of the structure. To ensure the safety of the tokamak device, it is necessary to make quantitative evaluations of the coupling effects on the transient response of the VV and in-vessel structures during plasma disruptions. In this paper, efficient numerical methods were proposed for solving the structural dynamic problem with MTMC effects. The nonlinear interaction between the magneto-mechanical terms was linearized with a block-Gauss-Seidel iterative algorithm, and an adaptive matrix update algorithm was proposed to cope with the temperature effect on material properties. In addition, an MTMC experiment system with both electromagnetic load and thermal load was set up to demonstrate the validity and efficiency of the proposed numerical methods. Finally, the dynamic response of the vacuum vessel of HL-2M tokamak during a typical plasma disruption was simulated using our updated numerical code, and influences of the MTMC effects were quantitatively evaluated. [ABSTRACT FROM AUTHOR]

Traditional methods of disposing of oil-based drill cuttings do not provide the much-needed benign treatment. In this study, a skid-mounted thermal plasma processing device was developed with a designed maximum processing capacity of 0.8 kg/min. When the input power of the plasma torch is 10–50 kW, the temperature measured by the thermocouple is 385–1979 °C. After plasma treatment, the morphology of oil-based drill cuttings changes from jelly-like to vitreous state solid structure, and the content of organic matter decreases with the decrease in weight. Mass and volume reductions of 40.98–61.49% and 25.02–68.81%, respectively, were achieved in a treatment period of 0.5–3 min. The total organic compound reduction of 73.08–98.12% was equally achieved in the same treatment period. Due to the special structure of the glassy state residue, the leached concentration of toxic metals is far below the Chinese standard for landfill leachate discharge. This effectively solves the problem of secondary pollution of solid waste. Therefore, thermal plasma technology is an effective alternative method to treat oil-based drill cuttings. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of depositing graphene nanoplatelet (GNP)-reinforced yttria-stabilized zirconia (YSZ) composite coatings. The coatings were deposited from an ethanol-based mixed YSZ and GNP suspension using suspension plasma spraying (SPS). Raman spectroscopy confirmed the presence of GNPs in the YSZ matrix, and scanning electron microscopy (SEM) analysis revealed a desired columnar microstructure with GNPs distributed predominantly in the inter-columnar spacing of the YSZ matrix. The as-deposited YSZ-GNP coatings were subjected to different isothermal treatments—400, 500, and 600 °C for 8 h—to study the thermal stability of the GNPs in the composite coatings. Raman analysis showed the retention of GNPs in specimens exposed to temperatures up to 500 °C, although the defect concentration in the graphitic structure increased with increasing temperature. Only a marginal effect on the mechanical properties (i.e., hardness and fracture toughness) was observed for the isothermally treated coatings. [ABSTRACT FROM AUTHOR]

A novel thermal plasma process was developed, which enables economically viable commercial-scale hydrogen and carbon black production. Key aspects of this process are detailed in this work. Selectivity and yield of both solid, high-value carbon and gaseous hydrogen are given particular attention. For the first time, technical viability is demonstrated through lab scale reactor data which indicate methane feedstock conversions of >99%, hydrogen selectivity of >95%, solid recovery of >90%, and the ability to produce carbon particles of varying crystallinity having the potential to replace traditional furnace carbon black. The energy intensity of this process was established based on real-time operation data from the first commercial plant utilizing this process. In its current stage, this technology uses around 25 kWh per kg of H2 produced, much less than water electrolysis which requires approximately 60 kWh per kg of H2 produced. This energy intensity is expected to be reduced to 18–20 kWh per kg of hydrogen with improved heat recovery and energy optimization. [Display omitted] • A methane pyrolysis plasma process for high value carbon and hydrogen is presented. • Methane feedstock conversions of >99% were achieved. • Hydrogen selectivity of >95% was achieved. • Solid recovery of >90% was achieved. • Energy intensity of the first commercial plant is 25 kWh per kg of H2 produced. [ABSTRACT FROM AUTHOR]

In the present study, ZrO 2 based composites were synthesized in-situ and sintered by the novel RSPS-assisted carbothermal reduction of ZrSiO 4 (Z) in the presence of graphite (G) and Activated Carbon (AC). The RSPS process was performed using a vacuum furnace at different temperatures of 1400–1600°C for 5–15 min under an external pressure of 30 MPa. The thermodynamic analysis was conducted on the synthesis process by FactSage software. The microstructure development and mechanical properties of RSPS-ed ZrO 2 -based composites were investigated. The Phase evolution and phase content, as functions of temperature, were characterized using x-ray diffraction and FESEM/EDS analysis. The XRD studies showed that all primary ZrSiO 4 was decomposed into ZrO 2 , ZrC, SiC, and SiO 2 phases. The unreacted graphite or activated carbon was also identified in the samples. Finally, the hardness and flexural strength of the composites were examined by Vickers hardness and 3-point bending strength tests. The results indicate that the SPS-ed ZrSiO 4 + Activated Carbon composite (ZAS-3) has the best mechanical properties. A density of 2.87 ± 0.05 g/Cm3, an open porosity of 0.02%, a bending strength of 132.4 ± 11.2 MPa and a hardness of 9.86 ± 1.1 GPa were estimated for the SPS-ed ZrSiO 4 + Activated Carbon mixture of powders at 1600°C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Renewable powered plasma torches can heat a gas to temperatures >5000 K. • NO x formation from a plasma torch was investigated numerically and experimentally. • The NO x emissions using air as plasma torch is high, >10,000 mg NO 2 /MJ fuel. • A gas mixture of 25:75 vol-% H 2 :N 2 reduces the NO X emission <3000 mg NO 2 /MJ fuel. • Low NO x plasma torches can contribute to the decarbonization of the industry. Industrial thermal plasma torches can heat a gas up to 5000–20,000 K, i.e., well above the temperature needed to replace the heat generated from the combustion of traditional fossil fuels (e.g., coal, oil, and natural gas) in large-scale process industry furnaces producing construction materials (e.g., iron, steel, lime, and cement). However, there is a risk for significant NO x emissions when air or N 2 are used as plasma-forming gas since the temperature somewhere in the furnace always will be higher compared to the threshold NO x formation temperature of ∼1800 K. Torch NO x forms inside the high temperature region of the plasma torch (>5000 K) when air is used as gas. Process NO x forms instead when the hot gas (when air or nitrogen is used as plasma forming gas) from the plasma torch mixes with process air downstream the torch. By analysing the complex chemistry of both the torch- and process NO x formation with thermodynamic equilibrium and one-dimensional chemical kinetic calculations it was shown that adding H 2 to the plasma-forming N 2 gas significantly reduces the NO x emissions with more than 90 %. Verifying experiments with air, pure N 2 , and mixtures of H 2 and N 2 as plasma-forming gas were performed in a laboratory scale insulated laboratory furnace with different pre-heating temperatures of process air (293, 673, and 1073 K) which the plasma gas mixes with downstream the torch. Depending on the pre-heating temperature the NO x emissions were between 12,000–14,000 mg NO 2 /MJ fuel when air was used as plasma forming gas. Substantial NO x emission reduction occurs both when N 2 replaces air, where the NO x emissions was in the span of 8000–11,500 mg NO 2 /MJ fuel and furthermore when H 2 was mixed into the N 2 gas stream. For the highest degree of H 2 mixing (28.6 vol-%), the NO x emissions were between 450–1700 mg NO 2 /MJ fuel depending on the pre-heat temperature of the process air, i.e., a reduction of 88–96 % and 85–94 %, respectively when air or N 2 was used as plasma forming gas. The measured NO x emissions are then of the same order of magnitude as would be expected from the combustion of traditional fuels (coal, oil, biomass and pure H 2). Finally, by analysing the aerodynamics in an axisymmetric furnace with an experimentally validated computational fluid dynamics (CFD) model using reduced chemistry for the NO x formation (19 species and 70 reactions), further guidelines into the process of NO x reduction from thermal plasma torches are given. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polarity of GaN wurtzite was controlled by thermal ALD and ALA. • ALA buffer layer improved crystallinity of GaN thermal ALD. • 50 nm of high-quality GaN ALD with preferred orientation were deposited. • Self-limiting reaction of GaN was achieved within ALD growth rate regime. Ga-polar GaN thin films and N-polar GaN thin films were fabricated by using thermal ALD and plasma assisted ALA processes, respectively. The polarity of GaN wurtzite thin films was determined by cross-sectional STEM analysis of as-deposited films and top-view SEM images after KOH wet-etching. The crystallinity and grain size of thermal ALD GaN were drastically increased with the GaN ALA buffer layer. The ALA Ar plasma pulse in each ALD cycle decreased the oxygen and carbon impurity content and improved the crystallinity of GaN thin films by removing organic ligands. High purity GaN thin films were successfully deposited on oxide-free Si (1 1 1) substrate by using the ALA process with 100 ms of TDMAGa with push gas, 3 × 800 ms of N 2 H 4 , and 15 s of 25 W ALA plasma pulse with −25 V stage DC bias at 275 °C. The lowest FWHM value (0.59°), smooth surface morphology (RMS=1.0 nm), and 10–20 nm grain size of columnar GaN thin films were obtained by tuning process parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Submerged Ar/CO 2 thermal plasma utilized for degradation of Chloramphenicol. • 99 % degradation and 82 % mineralization achieved within 20 min of treatment. • Removal efficiency increased by 34 % with the addition of LaMnO 3 catalyst. • Energy yield increased from 102 mg/kWh to 144 mg/kWh in STP-LMO system. • Reduction in antimicrobial activity and phytotoxicity observed post treatment. The present study focused on the degradation of antibiotic Chloramphenicol (CAP), an emerging contaminant, using submerged thermal plasma (STP) technology. Almost 99 % degradation and 82 % mineralization were achieved within 20 min of treatment by Ar/CO 2 plasma, generated at 6.2 kW discharge power using a customized thermal plasma torch inside the aqueous solution. Kinetic analysis revealed first-order reaction for CAP degradation with a rate constant of 0.257 min−1. Long-lived species, such as H 2 O 2 , O 3 , NO 2 –, NO 3 –, and Cl- formed during plasma treatment were quantified. LaMnO 3 perovskite (LMO) nanopowder prepared through a novel thermal plasma route, was introduced as catalyst into the treatment system which enhanced the degradation and mineralization efficiency by 34 % and 17 %, respectively, showing a strong synergetic effect between STP and catalyst. The energy yield was elevated from 102 mg/kWh to 144 mg/kWh with the addition of catalyst into the STP treatment system. Liquid chromatography-mass spectroscopy was used to identify the various degradation intermediates produced during thermal plasma treatment and correspondingly possible degradation pathways were proposed. The antibacterial activity assessment results revealed a significant reduction in the antimicrobial activity of all treated solutions against Gram-positive Bacillus cereus and Gram-negative Pseudomonas aeruginosa bacteria. Additionally, seed germination and growth assessment revealed a reduction in phytotoxicity of the treated solutions. STP, combined with the LMO, proved highly effective in treating pharmaceutical contamination in aqueous medium. [ABSTRACT FROM AUTHOR]

CO 2 and CH 4 are converted to syngas by dry reforming of methane (DRM) reaction. This research investigated the effects of the Mg promoter on Al 2 O 3 -supported Ni catalysts and Mg calcination temperature on the DRM performance in a parallel plate dielectric barrier discharge reactor. The Mg promoter played a crucial role in the DRM performance, as increasing the Mg calcination temperature from 700 °C to 800 °C significantly improved the DRM performance and catalyst properties, including increased specific surface area, decreased total acidity, reduced crystallite and particle sizes, and more uniform dispersion of the Ni nanoparticles. Under these conditions, the H 2 and CO selectivity were 77.0 % and 70.7 %, the CH 4 and CO 2 conversion were 25.1 % and 20.6 %, and the energy efficiency was 8.4 %. In addition, the catalyst was associated with a lower coking rate (0.5 mg C/g cat h), a relatively low carbon deposit of 1.5 %, and a carbon loss of 2.8 %, possibly because the weak acidity hindered the Boudouard reaction and CH 4 decomposition. However, increasing the Mg calcination temperature to 900 °C increased the total acidity and Ni particle size, decreasing H 2 and CO selectivities and increasing carbon deposits on the catalyst surface. • CO 2 reforming of CH 4 (DRM) is a promising way to convert greenhouse gases into syngas. • The Ni/Mg–Al 2 O 3 enhances the DRM efficiency and diminishes the carbon formation in the DBD. • Higher Mg calcination temperature of 800 °C improves the catalyst property and DRM efficiency. • DRM performance is considerably enhanced in the DBD by the Ni/Mg–Al 2 O 3 with reduced acidity. • Coking rate, deposited carbon, and carbon loss are all reduced in the DBD by the Ni/Mg–Al 2 O 3. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low temperature degradation of n-undecane by plasma catalysis was achieved. • Co-doped CeO 2 catalyst with satisfied performance prepared via aerosol pyrolysis method. • At 90 °C and 45 J/L, n-undecane conversion and COx selectivity reached near 100 %. • High ratios of Ce3+ and Co3+ of the catalyst dominated n-undecane degradation. • Kinetic models were established underlying both thermal and plasma catalytic degradation. The catalytic degradation of long-chain alkanes presents a formidable challenge in environmental chemistry. n-Undecane (C11), a quintessential long-chain alkane, predominates as a component of volatile organic compounds (VOCs) emitted from the printing industry and diesel-powered vehicles. The uncontrolled release of these compounds into the atmosphere necessitates stringent measures. This study reports on the plasma-catalytic degradation of n-undecane over the CeO 2 based catalysts cooperated with cobalt (Co), manganese (Mn), aluminum (Al), nickel (Ni), iron (Fe), or magnesium (Mg) via aerosol pyrolysis method. Notably, the Co-doped CeO 2 catalyst with a Co:Ce atom ratio of 4:1, in conjunction with plasma, achieves an optimal degradation performance. Under the reaction conditions of 90 °C and an energy density of 40 J/L, C11 conversion and COx selectivity reached impressive levels of 100 % and 97 %, respectively. Characterization findings indicate that elevated ratios of Ce3+/(Ce3++Ce4+) and Co3+/(Co2++Co3+) are conducive to the catalytic degradation of C11. A kinetic model has been developed to elucidate the thermal and plasma catalytic degradation mechanisms. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of Dielectric Barrier Discharge Non-Thermal Plasma (DDBD-NTP) as a pretreatment method to enhance the degradation of rigid biodegradable plastics (RBP) during composting, specifically focusing on polylactic acid (PLA) products such as drinking cups (CS) and spoon handles (SH). Using a Single-Factor-At-A-Time (SFAT) design, the impact of NTP parameters, including input voltage and treatment duration, on the physicochemical properties was evaluated, and the subsequent degradation rate of RBP was assessed by measuring the degree of disintegration in a home-scale composter. The filamentary discharge mode of the DDBD plasma system selectively altered the surface characteristics of RBP without significantly affecting their bulk properties. High-voltage treatments significantly increased surface roughness and accelerated degradation rates, while low-voltage and short-duration treatments enhanced oxidation, as indicated by the increased O/C ratio (85.5% for SH and 66.1% for CS), showing a non-linear response to plasma intensity. Furthermore, NTP treatment reduced water contact angles (up to a 39.79% reduction for SH and 82.65% for CS), indicating enhanced hydrophilicity. All NTP-treated samples demonstrated significantly higher degradation rates compared to both untreated and thermally treated counterparts. Notably, 'high-voltage for short-duration' treatments, such as CS-3 and SH-3, exhibited the highest degradation rates among the samples. CS-3 achieved complete disintegration (100%) within 20 days, markedly exceeding the 2% observed in untreated CS samples. Similarly, SH-3 reached 36% disintegration after 35 days, considerably surpassing the 9% seen in untreated SH samples. The findings indicate that NTP treatment is a viable and sustainable method to enhance the biodegradation of plastic waste. [Display omitted] [ABSTRACT FROM AUTHOR]

• Commercial WO 3 –PS powder were upgraded to WO 2.9 –W 18 O 49 /carbon composite particles. • 2.45 GHz microwave plasma achieved thermal non-equilibrium reaction. • Broad absorption to NIR range and outstanding electrical properties were performed. • Excellent NIR-driven photocatalytic performance in RhB degradation was demonstrated. • WO 2.9 –W 18 O 49 homojunction and plasmonic properties enhanced photocatalytic activity. Photocatalytic water remediation is gaining much attention as a cost-efficient and environmentally friendly technology. We designed WO 2.9 –W 18 O 49 /carbon composite particles to overcome the drawbacks of semiconductor-based photocatalysts by extending light absorption capacity to the near-infrared region and achieving efficient charge separation. A 2.45 GHz microwave plasma successfully upgraded commercially available WO 3 and polystyrene powders to the composite particles through a fast reaction with the typical heating and cooling rates of 30 and 470 °C/s, respectively. The synthesized composite particles exhibited broad absorption in the UV–Vis-NIR range and outstanding electrical properties. Besides, excellent NIR-driven photocatalytic performance was demonstrated for the degradation of organic water pollutants (rhodamine B), with the WO 2.9 –W 18 O 49 homojunction contributing to sufficient spatial charge separation, resulting in considerably enhanced degradation rates by more than two orders of magnitude. [Display omitted] [ABSTRACT FROM AUTHOR]

The conversion of carbon dioxide (CO 2) through non-thermal plasma catalysis has received significant attention as a promising approach to address both environmental and energy challenges. This review paper offers a comprehensive overview of recent advancements in CO 2 conversion utilizing non-thermal plasma (NTP), focusing on its potential to achieve efficient and selective transformations of CO 2 into valuable products, such as fuels and chemicals, at moderate reaction conditions. The unique ability of NTP to activate CO 2 at ambient room temperature and atmospheric pressure offers a promising pathway to mitigate the greenhouse effect and reduce dependency on fossil fuels. We highlight the utilization of catalysts in combination with dielectric barrier discharge (DBD) plasma reactor, showcasing encouraging results in enhancing product selectivity and overall CO 2 conversion. Nevertheless, challenges associated with the conversion of CO 2 into specific oxygenates, like methanol, are also discussed. The maximum methanol selectivity reported from recent studies was ∼86 % from CO 2 hydrogenation reaction with DBD reactor. This review provides valuable insights for researchers working on sustainable CO 2 utilization strategies and aids in guiding future investigations in this burgeoning field. [Display omitted] • Comprehensive study focusing on gas discharge breakdown mechanism in Dielectric Barrier Discharge-NTP reactor. • Development in generation of chemicals & fuels focusing on CO 2 conversion via NTP & co-reactant with H 2 , CH 4 , and H 2 O. • Recent developments in plasma catalytic processes with special focus on selectivity(%) & conversion(%) using metal oxides. • Summarized bottlenecks in CO 2 transformation technology with opportunities and future perspectives. [ABSTRACT FROM AUTHOR]

• CO 2 and CO permeability, diffusivity and solubility in 91 polymers were reviewed. • CO 2 /CO selectivity decreases with temperature in all membranes. • The upper bound for the CO 2 /CO mixture has a low slope and trade-off. • CO 2 /CO separation is solubility-driven and there is almost no diffusion-selectivity. • CO 2 /CO selectivity lies between 7 and 20 for most polymers. The separation and removal of CO 2 from its mixtures with CO is gaining increasing interest due to the novel processes in which these two gases are mixed, such as the non-thermal plasma activated reaction of CO 2 splitting, a promising CO 2 utilisation route that could be performed using renewable energy. The aim of this review is to propose a novel database suitable for membrane scientists to evaluate the feasibility of membrane-based separation processes involving such gas mixture, not included in the original Robeson's works on the upper bound, nor in later developments. For this reason, we reviewed the data on the permeation, diffusion and sorption of these two gases in different classes of polymers, from polyolefins to polyimides and green polymers, spanning over a wide range of permeability values. Furthermore, we propose an upper bound for this separation, and provide a theoretical explanation for it. The separation mechanism is solubility-driven, and all polymeric membranes inspected in the literature show a CO 2 -selective behaviour, despite a very limited, or unfavourable, diffusion selectivity for CO 2 , which is consistent with empirical correlations. Consequently, the observed selectivity values are determined by the solubility-selectivity and are comprised mainly in the range 7–20, in agreement with known empirical correlations between the solubility and the critical temperature of the penetrants. Temperature has a detrimental effect on CO 2 / C O selectivity, as the activation energy for permeation of CO 2 is always lower than that of CO. In general, while the permeability can vary over several orders of magnitude depending on the polymer nature, selectivity mostly ranges between 7 and 20, which makes the trade-off mechanism between permeability and selectivity rather weak in the case of this mixture. Such an effect provides a wider variety of design choices, and makes this separation attractive for polymeric membranes, if carried out at low temperatures and with CO 2 -philic materials. A preliminary calculation of the separation obtainable with single-stage membrane unit for a binary mixture is carried out for some representative polymers. [ABSTRACT FROM AUTHOR]

Thermal stability is a crucial issue for engineering application of tungsten, especially as plasma facing material in future fusion reactor. Two kinds of ODS-W alloys of W-0.5Y 2 O 3 (WY) and W-0.5Y 2 O 3 -0.25Ti (WYT) were fabricated by ball milling and spark plasma sintering aiming at formation of oxide dispersoids with different crystallographic structures. Thermal stability of both ODS-W alloys was evaluated in terms of microhardness and microstructure evolution during isothermal aging at 1100 °C. Dispersoids of sesquioxide Y 2 O 3 were identified in sintered WY, while pyrochlore Y 2 Ti 2 O 7 with finer size and higher number density were developed in sintered WYT, resulting in higher bending strength of 1020 MPa and microhardness of 880 HV. Compared with sesquioxide Y 2 O 3 , complex dispersoids of pyrochlore Y 2 Ti 2 O 7 exhibited much better coarsening resistance during isothermal aging at 1100 °C up to 100 h, where the intracrystalline and GB dispersoids maintained around 10 nm and 30 nm, respectively. The excellent coarsening resistance of complex Y 2 Ti 2 O 7 with pyrochlore structure contributed to grain refinement and improved microstructure stability of WYT due to the effect of Zener drag. • Formation of complex Y 2 Ti 2 O 7 with pyrochlore structure was achieved in ODS-W alloy. • Complex dispersoids of Y 2 Ti 2 O 7 showed finer size and higher number density. • Intracrystalline dispersoids of Y 2 Ti 2 O 7 had coherent relationship with W matrix. • Pyrochlore Y 2 Ti 2 O 7 exhibited better coarsening resistance during aging at 1100 °C. • Thermal stability of ODS-W alloy was improved through formation of complex Y 2 Ti 2 O 7. [ABSTRACT FROM AUTHOR]

• 45 % CH 4 conversion via non-oxidative methane coupling in nanosecond pulsed discharges (NPD). • A Pd-Ag catalyst on a 3D-printed structured electrode promotes 76 % C 2 H 4 total selectivity and 34.4 % C 2 H 4 yield. • Produced H 2 can generate electricity via fuel cells to sustain the process and recover ∼16 % of the input energy. • The solid carbon in the vicinity of the discharge shows a mostly amorphous material with low surface area. Chemical valorization of methane (CH 4) via modular electrified reactors could represent a profitable avenue for biogas producers. Ethylene (C 2 H 4) is the most valuable product due to its large demand that results in high energy cost and carbon emissions. However, alternative electrified processes proposed so far cannot compete with the state-of-the-art fossil route in terms of energy efficiency. The catalytic plasma reactor presented in this work achieves 34.4 % C 2 H 4 yield from non-oxidative CH 4 coupling, by integrating a bimetallic Pd-Ag catalyst on the surface of a 3D-printed structured electrode in a nanosecond-pulsed-discharge plasma reactor. This performance sets a new benchmark for alternative C 2 H 4 production, potentially relying purely on renewable energy. Onsite energy generation via the excess hydrogen produced in the process could allow recovery of 16 % of the input energy. Moreover, the process produces solid carbon deposit that can be collected on the surfaces in proximity of the plasma discharge. This residue shows amorphous features and significant incorporation of metal particles coming from the electrodes surface. Hence, its low surface area hampers its application as carbon black analogue. [Display omitted] [ABSTRACT FROM AUTHOR]

Energy efficiency and conversion in a reverse-vortex microwave CO 2 plasma are enhanced by optimizing the thermal trajectories using a converging diverging nozzle in subsonic flows. The nozzle mixes cold, unconverted gas at the edge of the flow with hot, active gas in the middle of the flow. Temperature measurements are taken of the quartz tube as well as just above the nozzle inlet and directly after the nozzle and presented to elucidate differences in performance. Measurements show significant improvements in conversion and energy efficiency, especially at pressures close to atmospheric pressure (500 – 900 mbar). In addition an improvement in plasma stability when adding a converging diverging nozzle. Thermal measurements also point towards a shift in energy loss mechanisms when changing flow configurations. • High energy efficiencies (up to 48 %) in CO 2 microwave plasma are achieved in subsonic flows. • Addition of a mixing nozzle increases plasma confinement. • Changes in energy loss channels when switching flow configuration are identified. • Radiative losses through the resonator are reduced by >90 % by changing flow configuration. • Cooling rates as high as 5.0×106 K/s are achieved by use of a mixing nozzle. [ABSTRACT FROM AUTHOR]

The use of hydrogen as clean energy has attracted significant attention because conventional industrial hydrogen production processes show negative environmental impact, require intensive energy, and/or are dependent on natural gas. The main objective of this study is to develop an innovative and environment-friendly hydrogen production process utilizing biogas as an alternative to natural gas. Ionic liquid [Bmim][PF 6 ] shows high potential for the replacement of aqueous amine solutions for CO 2 absorption and are employed for biogas upgrading, while thermal plasma (TP), which is beneficial for converting electrical energy to chemical energy, is employed for the simultaneous production of clean "turquoise" hydrogen and solid carbon. In addition, an intercooler is used to improve CO 2 removal in the absorber. Heat and power integration are employed to enhance the performance of the upgrading process and thermal-plasma-assisted hydrogen production. All simulations were conducted using Aspen Plus V10.0 software. The simulated results show that the solid carbon production from biomethane increases compared to that in the proposed base case. The savings in both the heater used to preheat the TP reactor and the third flash drum are 100%, while the saving in power consumption in the compression section is 62.0%. Furthermore, sensitivity is investigated to determine the effect of biomethane composition on the performance of the proposed configuration. [Display omitted] • An attractive solution for both renewable hydrogen and solid carbon production. • The process employing [Bmim][PF6] with intercooler affords 99.7% pure biomethane. • The heating and power requirement can be saved 100% and 62%, respectively. • Increasing the methane composition in biogas increases hydrogen productivity. [ABSTRACT FROM AUTHOR]

High temperature thermal plasma gasification can treat non-homogeneous waste at increased conversion efficiency, compared to conventional gasification. A novel nitrogen plasma technology demonstration system is presented. The system can convert 20 kg/h of biomass to synthesis gas and is constructed inside a shipping container, which makes it mobile and suitable for application in remote rural areas of developing countries. An Aspen Plus model of the plasma gasification reactor was developed to enable energy and exergy analysis. The model gave good predictions of the real synthesis gas composition obtained during experimental runs. Simple gas and steam power cycles were also modelled to assess the feasibility of the system producing its own power. Based on typical composition of wood, it was found that the plasma torch power requirement is 20.7 kW. This amount of power can be generated using an open gas turbine cycle with compressor pressure ratio of 5 and turbine inlet temperature of 1007 °C. For a combined cycle case, using steam at 8 bar and 400 °C in a steam cycle, 14.6 kW of excess power becomes available. Alternatively, 68 kg/h of steam can be delivered, in addition to satisfying the torch requirement. • Plasma gasification can treat non-homogeneous waste at high conversion efficiency. • Plasma gasification requires significant power for the plasma torch. • A containerized nitrogen plasma system for small scale waste processing is presented. • The plasma torch power requirement can be satisfied by converting the syngas to power. • Exergy analysis identified non-avoidable and avoidable losses for future improvement. [ABSTRACT FROM AUTHOR]

A theoretical novel model in the context of the photo-thermoelasticity theory is examined. The novel mode is studied under the impact of the external magnetic field with strong intensity. The semiconductor medium is excited by a beam of light and the governing equations are taken during a one-dimensional (1D) deformation. The main parameters (thermo-elastic, electrical conductivity and optical constants) of the medium depending on the depth of the medium which is defined as functionally graded (FG). The hyperbolic two-temperature theory is taken into account to describe the acceleration of two distinct temperature. During the excitation transport processes and magnetic field, the main parameters can be chosen as a function of the axial distance and Hall current appears, respectively. The main equations are solved analytically using the Laplace transform technique. The complete solutions have been obtained in space–time domain when the convers of Laplace transform is used numerically under some mechanical, thermal and plasma conditions. The evaluation results are compared with the corresponding computational results obtained under the impacts of some parameters. [ABSTRACT FROM AUTHOR]

Hydrogenation is an essential step for heavy oil upgrading by raising the H/C ratio but commonly requires high H 2 pressure and high temperature. Non-thermal plasma provides a highly promising method for heavy oil hydrogenation at ambient conditions without a catalyst. Here we demonstrate a new approach to in - situ hydrogenation of ethylbenzene as heavy oil model compound using a pulsed dielectric barrier discharge plasma and examine the reaction mechanism upon impact by operating conditions. Results show that a higher H density is conducive to the aromatic ring hydrogenation, and the average H number added to the aromatic ring increases by ∼50% as the pulse repetition frequency increases. The high-energy electrons positively associated with the H radical density result in excessive cracking of ethylbenzene or the hydrogenated products, and the hydrogenation process is inhabited at high temperatures. Overall, a higher pulse repetition frequency, appropriate voltage amplitude, and lower temperature are determined to ensure the hydrogenation process. The present work may provide guiding principles for optimizing the reaction conditions for plasma-enabled aromatic ring hydrogenation and contribute to the future upgrading of heavy oils. Hydrogenation of aromatic compound in heavy oil is achieved through a H 2 pulsed discharge at ambient conditions without catalysts, revealing that higher pulse frequency, appropriate voltage amplitude, and lower temperature facilitate the hydrogenation. [Display omitted] • Pulsed H 2 plasma enables hydrogenation of ethylbenzene as heavy oil model compound. • High frequency kHz pulse power supply facilitates the aromatic ring hydrogenation. • High-energy electrons accelerate the decomposition of hydrogenated products. • Plasma-enabled hydrogenation is inhibited at higher temperatures. [ABSTRACT FROM AUTHOR]

We present a study of the unidentified X-ray source 1RXS J121902.7–630910 based on Suzaku X-ray Imaging Spectrometer observation. We aim at clarifying the nature of the emission from 1RXS J121902.7–630910. We found that the spectrum is well represented by a thermal plasma model with an electron temperature of kT e ∼ 3.7 keV, the upper limit of ionization time-scale of τ ∼ 5.6 × 10 10 cm−3 s, and the absorbing column density of N H ∼ 0.5 × 10 21 cm−2. We investigated the possible origin of 1RXS J121902.7–630910, and found optical counterpart candidates to this X-ray source. We conclude that it could be a point-like source compared to the analysis results of an extended source, and observations at other wavelengths are needed to confirm its nature. [ABSTRACT FROM AUTHOR]

Owing to its high capacity, silicon (Si) is a promising anode for meeting the escalating need for batteries with high energy density. Nonetheless, the substantial volumetric variation generated by lithiation/delithiation often results in the pulverization of Si, which substantially lowers its cycle stability. Graphene/graphene nanosheets (GNSs) with higher electrical conductivity and mechanical strength are anticipated to overcome these obstacles when employed as the coating matrix of silicon. Unfortunately, the majority of Si@graphene composites are not manufactured in situ , so that graphene is hardly to entirely encapsulate Si.The low-quality coating leads to the exposure of Si after cycles, resulting in a short cycle life. Herein, graphene nanosheets encapsulated silicon nanospheres (Si@GNSs) are synthesized in situ using a radio-frequency (RF) thermal plasma system, in which graphene and Si have strong interfacial chemical interactions. Further, free-standing Si@GNSs/reduced graphene oxide (Si@GNSs/rGO) paper was prepared using graphene oxide (GO) as a special 'binder'. When Si@GNSs/rGO paper is directly used as anode electrodes, it demonstrates a high reversible capacity (2270 mAh g−1 at 0.2 A g−1), outstanding rate performance (1569 mAh g−1 at 5.0 A g−1) and ultra-stable cycle performance (capacity retention of 98.55% for 2000 cycles at 3.0 A g−1). [Display omitted] • Si@GNSs composites were prepared in situ by the RF thermal plasma system. • The flexible Si@GNSs/rGO paper is prepared with GO as a special 'binder'. • Si@GNSs/rGO paper exhibits high capacity of 2250 mAh g−1 at 0.2 A g−1. • Si@GNSs/rGO paper show excellent rate performance of 1569 mAh g−1 at 5.0 A g−1. • After 2000 cycles, the capacity of Si@GNSs/rGO paper remains 98.55%. [ABSTRACT FROM AUTHOR]

Plasma methods are efficient processing for metal recovery from metal scrap, bearing minerals, electronic waste, etc. In this work, pure titanium nitride nanoparticles (TiN NPs) were synthesized from titanium scraps by the thermal plasma arc discharge (TPAD) method. TPAD synthesized TiN NPs have a highly crystalline nature with cubic and spherical morphologies with average particle sizes of 30–100 nm. Further, prepared TiN NPs involving surface modification (SM) or etching processes were investigated by using the non-thermal DC glow discharge plasma technique with air atmosphere at different processing times. SM@TiN NPs have a comparatively low crystalline, which was confirmed from the powder X-ray diffraction technique. SM@TiN NPs have very interesting core shell morphologies, which are due to the surface interactions of ionized air molecules. TiN and SM@TiN NPs have room-temperature ferromagnetic properties with high saturation magnetization (Ms) up to 2.6 and 3.0 emu/g and very high coercivity (Hc) of 235.5 Oe, respectively. TiN and SM@TiN NPs have superior energy storage performance with an outstanding specific capacitance of 192.8 and 435.1 F/g at a current density of 2 A/g with pseudocapacitive behavior. These results reveal that TiN and SM@TiN NPs have highly promising electrodes for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Previous studies indicated that big globular pores in air plasma sprayed (APS) thermal barrier coatings (TBCs) are more likely to remain after calcium-magnesium-alumino-silicates (CMAS) attack than are small ones. In this research, therefore, the CMAS attack behavior of an APS TBC with more big globular pores was investigated. It was demonstrated that the more-big-globular-pores APS TBC exhibited better resistance to exfoliation and intergranular corrosion, and chemical degradation than normal APS TBCs, while its pores can be easily filled by CMAS. Analysis on pore structures and CMAS infiltration characteristics indicated that the morphologies of the transition regions between the globular and the crack network pores may play an import role in determining the CMAS filling behavior for globular pores in APS TBCs. [ABSTRACT FROM AUTHOR]

Ceramic nanograined materials have desirable characteristics compared to their macroparticle counterparts but are rarely used in industrial applications due to issues with poor handleability and health hazards. Due to interparticle forces that become more dominant as the particle size decreases, it is difficult to use nanomaterials to fill dies, spread on surfaces, or flow through hoppers found in various manufacturing processes. Here we report a scalable gelcasting solution and unique emulsification process to create microspheres composed of nanoscale powders to enhance the flowability and handleability of nanomaterials. The gelcasting solution and emulsification process can be used with any nanoparticle composition that can be suspended in a liquid phase. This paper reports the effects of various parameters on zirconium diboride microsphere formation, such as surfactant content and mixing conditions. The microspheres maintain the nano-scale characteristics of the powder but improve its flowability by using cross-linked polyvinyl alcohol to combine irregularly shaped zirconium diboride nanoparticles with a particle diameter of 60 nm into larger spherical particles with a d 50 ∼25 μm. This hierarchical feedstock engineering design combine the positive characteristics of materials across both length scales and improve the flowability of the feedstock from a Hausner Ratio of 1.56 to 1.19. The materials produced using this technique can be used in thermal plasma spray, die filling for hot pressing or spark plasma sintering, and binder jet printing applications. [ABSTRACT FROM AUTHOR]

With hydrogen being promoted as a promising energy vector for a decarbonized world, low-carbon hydrogen production methods are of interest to replace the current Steam-Methane-Reforming production of "grey" hydrogen. While existing studies focus on the life-cycle-assessment of green hydrogen produced by water electrolysis, an alternative, which has attracted growing interest due to a much lower energy intensity (10–30 kWh/kgH2 < 50–60 kWh/kgH2), is turquoise hydrogen produced by the pyrolysis of methane. Specifically, this study conducts a life-cycle-assessment on hydrogen produced by the pyrolysis of methane via thermal-plasma. A sensitivity analysis is also conducted on the environmental-metric time-horizon and on the methane emissions rates. Results show that the carbon-intensity of hydrogen produced using this novel method is 88.3–90.8% lower than that of grey hydrogen. Furthermore, using renewable-natural-gas with a feedstock percentage as low as 8–18% leads to a negative hydrogen carbon-intensity (reaching −4.09 to −10.40 kgCO2e/kgH2 at 100% renewable natural gas), the lowest compared to grey, blue, and green hydrogen, making turquoise hydrogen a game-changer for the energy transition. [Display omitted] • Hydrogen produced by methane pyrolysis via thermal plasma has a very low carbon intensity of 0.91 kgCO2e/kg. • Sourcing of natural gas is the main factor impacting the carbon intensity. • Improving natural gas sourcing up to grade A (MiQ) reduces the carbon intensity of hydrogen to 0.45 kgCO2e/kg. • Replacing the natural gas feedstock with renewable natural gas gives a negative carbon intensity of hydrogen of -4.09 to -10.40 kgCO2e/kg. • Turquoise hydrogen performs better environmentally than grey and blue hydrogen, and using RNG, performs better than green hydrogen. [ABSTRACT FROM AUTHOR]