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In this study, nanostructures were introduced into bulk Si, and the P content in Si was increased. Arc melting, ball milling, and spark plasma sintering were used to prepare excess P-doped Si samples (Si1−xPx, x = 0.01, 0.03, 0.06, 0.09, and 0.12). In Si0.94P0.06, thermal conductivity decreased to 18 W m−1 K−1 at room temperature, which is about 10% of that of bulk Si. Transmission electron microscopy observation of Si0.94P0.06 revealed a linearly localized alignment, in addition to the nanostructures observed in the previous studies of P-doped Si samples. Linear alignments were composed of Si-P nanoprecipitates and defects linearly localized around dislocations. These sub-microstructures can reduce thermal conductivity; as a result, ZT at 973 K increased to 0.43, which is approximately three times higher than that of single-crystal Si. [ABSTRACT FROM AUTHOR]

A time-dependent hybrid plasma model composed of a zero-dimensional global model and a two-dimensional fluid model is proposed for simulation of plasma chemistry and transportation of plasma during Cr thin film deposition by deep oscillation magnetron sputtering (DOMS). The global model deals with plasma reactions in the ionization region near the target with discharge voltage and current waveforms as inputs. The temporal plasma characteristics calculated by the global model are utilized as a boundary condition for the two-dimensional fluid model to simulate high-density plasma transportation in the diffusion region through the entire macropulse period. The full momentum equation taking inertia force into consideration is applied for ion momentum conservation in the fluid model instead of using the drift-diffusion approximation, which ensures validity of the simulation for low-pressure plasmas. The deposition flux as well as the kinetic and potential energy fluxes transferred to the growing films are calculated by the hybrid model. Microstructure evolution of the DOMS deposited Cr thin films from zone I to zone T is attributed to the growing kinetic and potential energies as the charging voltage increases according to the structure zone diagram. The deposition rate loss in DOMS is explained by the back attraction effect, sputtering yield effect, and densification of the films. [ABSTRACT FROM AUTHOR]

This Perspective paper deals with an overview of particle-in-cell/Monte Carlo collision models applied to different plasma-propulsion configurations and scenarios, from electrostatic (E × B and pulsed arc) devices to electromagnetic (RF inductive, helicon, electron cyclotron resonance) thrusters, as well as plasma plumes and their interaction with the satellite. The most important items related to the modeling of plasma–wall interaction are also presented. Finally, the paper reports new progress in the particle-in-cell computational methodology, in particular, regarding accelerating computational techniques for multi-dimensional simulations and plasma chemistry Monte Carlo modules for molecular and alternative propellants. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasmas generated from a helium gas with admixtures of water vapor have numerous applications in biomedicine. It is important that the chemistry of such plasmas can be tightly controlled so that they may be tailored for their intended use. In this study, computational modeling is used to vary the pulse repetition frequency of a nanosecond-pulsed, pin-to-pin He + 0.25% H 2 O discharge in the range of 1–100 kHz to determine the influence of the pulse repetition frequency on the resulting densities of reactive oxygen species and the rates of dominant reaction pathways involving them. The plasma is simulated using the 0D plasma-chemical kinetics model GlobalKin. The pulse shape is kept constant. The afterglow duration is, therefore, dependent on the repetition frequency. Analysis of the bulk plasma chemistry after the plasma has reached equilibrium shows that the peak electron density is only weakly dependent on the pulse repetition frequency. Increasing the pulse repetition frequency is shown to increase the density of H, O, and OH radicals, while the relationship between the repetition frequency and the densities of species with longer lifetimes, namely, H 2 O 2 and O 3 , is found to be more complex. These are formed throughout the afterglow, and their density depends on the availability of reactant species, the afterglow duration, and the background gas temperature. This work concludes that the pulse repetition frequency is not a simple control parameter, especially for species that are predominantly produced in the afterglow. Detailed modeling is required for accurate control of species densities using the pulse repetition frequency. [ABSTRACT FROM AUTHOR]

Higher manganese (TE) silicide (HMS), an eco-friendly, low-cost, and earth-abundant p-type thermoelectric material, exposes a Nowotny chimney-ladder crystal structure, obeying the 14th-electron rule. Here, a hybrid composite of a carbon nanofiber (CNF) and HMS was synthesized by vacuum melting followed by spark plasma sintering, and its thermoelectric performance were demonstrated. The incorporation of CNF with HMS notably enhances the Seebeck coefficient and decline the thermal conductivity without significantly affecting the carrier concentration and electrical conductivity due to the interfacial energy filtering effect. A maximum Seebeck coefficient of 307 μV/K was recorded for the 0.5% CNF composite with HMS, leading to accomplish a high-power factor of 1755.63 μW/mK2 at 803 K. Also, interfaces, grain boundaries, and dislocations leading to the high magnitude of strain, confirmed from HR-TEM and strain analysis, leads to decrease in lattice thermal conductivity to 1.95 W/mK. As a result, HMS attains the peak zT value of 0.64, suggesting that carbon-based composites are a promising way to boost the thermoelectric performance of HMS-based compounds. [ABSTRACT FROM AUTHOR]

There is need for advancing minimally invasive diagnostic techniques for sex differentiation at early life-stage classes in sea turtles. The objectives of this study were to determine whether there are sex-specific effects on the metabolome of the loggerhead sea turtle (Caretta caretta) and to identify potential biomarkers for sex classification at early life-stage classes (50 post-hatchling and 50 juvenile). Comprehensive analyses including plasma chemistry (n = 100) and untargeted (n = 48) metabolomic analyses were performed. Unlike with plasma chemistry analytes, there were significant differences in the metabolomic profiles between sexes. Nine metabolites differed significantly between sexes, with several metabolites deserving greater attention as potential biomarkers: C22H32O6 and pantothenic acid was higher in females than in males, and carboxylic acid ester (C10H16O5), 1-methylhistidine and C7H14N2O7 was higher in males than females. These differences remained constant both across and within the same life-stage class. This work identified a discernible effect on the metabolic profile based on sex of loggerhead sea turtles and it suggests that these metabolites and/or their ratios could serve as potential biomarker candidates for sex classification in this species. This study demonstrates a distinct metabolomic profile between male and female loggerhead turtles at different physiological stages (posthatchling and juvenile animals) and proposes biomarkers for sex classification. [ABSTRACT FROM AUTHOR]

La10−xNdxSi6O27 (x = 0, 0.1, 0.2, 0.3) was synthesized via planetary grinding, and dense ceramic discs were prepared using SPS technology. The structure, microstructure, density, open porosity, total conductivity and electronic conductivity of the samples were measured and analyzed, respectively. La10−xNdxSi6O27 is characterized by a hexagonal apatite structure. The elements in the sample are distributed in a uniform manner and the content is consistent with the stoichiometry. The total conductivity of La10−xNdxSi6O27 exhibits an increase with the incorporation of Nd3+ content in the doped samples of x = 0.1, 0.2, and 0.3. The total conductivity of La9.7Nd0.3Si6O27 is the highest, reaching 5.39 × 10−3 S cm−1 at 850 °C. The electron mobility of the sample is less than 1%, which is suitable for use as a solid electrolyte. [ABSTRACT FROM AUTHOR]

BiCuSeO is a promising oxygen‐containing thermoelectric material due to its intrinsically low lattice thermal conductivity and excellent service stability. However, the low electrical conductivity limits its thermoelectric performance. Aliovalent element doping can significantly improve their carrier concentration, but it may also impact carrier mobility and thermal transport properties. Considering the influence of graphene on carrier‐phonon decoupling, Bi0.88Pb0.06Ca0.06CuSeO (BPCCSO)‐graphene composites are designed. For further practical application, a rapid preparation method is employed, taking less than 1 h, which combines self‐propagating high‐temperature synthesis with spark plasma sintering. The incorporation of graphene simultaneously optimizes the electrical properties and thermal conductivity, yielding a high ratio of weighted mobility to lattice thermal conductivity (144 at 300 K and 95 at 923 K). Ultimately, BPCCSO‐graphene composites achieve exceptional thermoelectric performance with a ZT value of 1.6 at 923 K, bringing a ≈40% improvement over BPCCSO without graphene. This work further promotes the practical application of BiCuSeO‐based materials and this facile and effective strategy can also be extended to other thermoelectric systems. [ABSTRACT FROM AUTHOR]

In this work, a plasma-assisted solvolysis method is proposed as an alternative method for the oxidative degradation of carbon fiber-reinforced composites (CFRCs). Nitrogen plasma ignition within bubbles in a concentrated nitric acid solution is employed, combining the synergistic effects of traditional nitric acid solvolysis and plasma chemistry. A comprehensive process flowchart, including steps such as composite pretreatment, matrix dissolution, fiber recovery and cleaning, solvent regeneration and reuse, and waste treatment, is also discussed, highlighting their importance in process effectiveness. Moreover, a study on the effect of the composite's mass on the plasma-enhanced solvolysis process is conducted, and the results are exploited for the calculation of critical parameters such as efficiency, recovery rates, capacity, fibers quality, energy consumption, consumption of raw materials, operational and installation costs, and environmental impact. A preliminary comparison to other recycling methods based on the literature findings is also attempted, and preliminary metrics to assess the sustainability of the recycling process are proposed. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma jets (APPJs) have attracted significant attention due to their ability to generate plasma without vacuum systems, facilitating their use in small areas of plasma processing applications across various fields, including medicine, surface treatment, and agriculture. In this study, we investigate the interaction between two helium plasma jets, focusing on the effects of varying flow rate, voltage, and directional angle. By examining both in-phase and out-of-phase configurations, this research aims to elucidate the fundamental mechanisms of plasma plume merging, which has critical implications for optimizing plasma-based material processing systems. We demonstrate that while increasing voltage and flow rate for the in-phase condition leads to an extended plasma plume length, the plumes do not merge, maintaining a minimal gap. Conversely, plasma plume merging is observed for the out-of-phase condition, facilitated by forming a channel between the jets. This study further explores the impact of these merging phenomena on plasma chemistry through optical emission spectroscopy, revealing substantial differences in the emission intensities of OH, the second positive system of N 2 , and the first negative system of N 2 + . These findings offer valuable insights into controlling plasma jet interactions for enhanced efficiency in plasma-assisted processes, particularly where plume merging can be leveraged to improve the treatment area and intensity. [ABSTRACT FROM AUTHOR]

This study analyzes the selective productions of nitrogen oxides and ozone in dielectric barrier discharge due to temperature controlled by the dual duty cycle. In this work, we varied the dual duty cycle of the output voltage in the power supply, which alternatively generates distinguished high and low‐temperature modes for selective productions of nitrogen oxides and ozone. The alternating nitric oxide and ozone by dual duty cycle were measured at a maximum of 100 ppm and 100 ppm in the gas phase, respectively. In the evaluation of DI water treated by dual duty cycle, nitrogen oxides, and ozone have been observed simultaneously in the liquid phase. These results offer new insights into the selective production of temperature‐dependent chemical characteristics for advanced plasma applications. [ABSTRACT FROM AUTHOR]

The development of a high-power and long-life thermionic ceramic cathode poses significant challenges, namely the need for high electron emission capacity at low temperature and excellent machinability. In this paper, the first-principles method was used to obtain the (La 0.5 Ba 0.5)B 6 with the lowest work function, and (La 0.5 Ba 0.5)B 6 –ZrB 2 composite with high relative density of 98.08 % was prepared by spark plasma sintering (SPS) at T = 1800 °C, under which the densification mechanism transformed from the particle rearrangement into the grain boundary diffusion, and the corresponding apparent activation energies were 282.75 kJ/mol and 466.54 kJ/mol, respectively. The maximum current density of 12.93 A/cm2 at T = 1500 °C of the composite was higher than that of 11.71A/cm2 at T = 1600 °C of LaB 6 , which can be attributed to the high Fermi level and weak electronic constraints of (La 0.5 Ba 0.5)B 6. The practical work function distribution (PWFD) of 0.36 eV indicated the composite had excellent emission uniformity. [ABSTRACT FROM AUTHOR]

The development of fibrous polymer scaffolds is highly valuable for applications in tissue engineering. Furthermore, there is an extensive body of literature for chemical methods to produce scaffolds that release nitric oxide. However, these methods often use harsh chemistries and leave behind bulk waste. Alkanolamine low‐temperature plasma (LTP) is unexplored and single‐step processing to form nitric oxide (NO) releasing constructs is highly desirable. The major question addressed is whether it is possible to achieve single‐step processing of spun polyester with alkanolamine plasma to achieve nitric oxide releasing capabilities. Herein we report the experiments, processes, and data that support the claim that it is indeed possible to produce such a bio‐functional material for potential biomedical applications, especially in cardiovascular implants. Among the tested alkanolamines, monoethylamine (MEA) plasma treated biomaterial outperformed in comparison with diethanolamine (DEA) and triethanolamine (TEA) in terms of NO release and cellular response. [ABSTRACT FROM AUTHOR]

Non-thermal plasma (NTP) catalysis is considered one of the most promising technologies to address a wide range of energy and environmental needs, such as carbon dioxide (CO2) conversion, NH3 synthesis, and volatile organic compounds (VOCs) removal. A systematic approach to optimizing NTP systems benefits from understanding VOCs' fundamental NTP destruction behavior and analyzing the correlations between molecular structures and conversion and selectivity. Herein, the mechanical performance of the toluene destruction in NTP is examined and compared with benzene bearing a similar molecular structure. Different experimental and theoretical techniques are applied, including synchrotron vacuum ultraviolet photoionization mass spectrometry(SVUV-PIMS), thermochemistry, and quantum chemistry. Comparatively, toluene is more readily destroyed under the same NTP conditions than benzene. More intriguingly, the distribution of the decomposition species is significantly different. The theoretical calculations reveal that the abundant methyl radicals generated in toluene decomposition mainly lead to the various species distribution. These radicals promote some reactions, such as the decomposition of obenzoquinone, one of the key intermediates, thus leading to new reaction pathways and products different from benzene. Finally, the critical mechanistic steps of toluene decomposition under the present non-thermal plasma conditions are established, which include the interactions between toluene and electrons or reactive radicals, the cleavage of the aromatic ring, and the various reaction pathways involving of methyl radicals. This study presents an effective approach to elucidate the distinct fundamental reaction mechanisms arising from subtle structural differences, offering new insights into the underlying plasma chemistry crucial for advancing various promising environmental and energy applications of non-thermal plasma systems. [ABSTRACT FROM AUTHOR]

A semi-empirical global model for a nitrogen discharge in a strong magnetic field is developed. The model is based upon experimental data from high-resolution Doppler and extreme-ultraviolet vacuum spectroscopy, which establish the plasma composition, discharge parameters, and, most importantly, electronic transitions. This allows the number of required molecular systems and atomic/ionic states to be reduced, thereby retaining only the essential plasma chemistry reactions. The set of 35 stiff non-linear ordinary differential equations is numerically integrated using an unconditionally stable adaptive method. Simulations show the existence of two solution branches with low and high electron temperature, respectively. A distinct hysteresis is exhibited by the discharge and illustrated for three typical N2 mass flow rates. The dependencies of the plasma parameters on the applied power are presented and discussed in detail, including in the vicinity of the bifurcation points. The efficiency of operation in the opposing limits of N2 discharge behavior as either a source of plasma or light emission is examined, with special emphasis on electric propulsion capabilities. [ABSTRACT FROM AUTHOR]

This study aims to explore the use of Dielectric Barrier Discharge (DBD) technology for the joint treatment of methane (CH4) and nitrogen oxide (NO) in the exhaust of Liquid Natural Gas (LNG) engines during cold starts and at mid to low loads when the exhaust temperature is below 500 °C. Through experiment and numerical simulation, the effect of discharge power on the removal efficiency of CH4 and NO in the exhaust of LNG engines was investigated under the condition of simulated flue gas temperature at 438 °C. A plasma chemical model suitable for analyzing the mixture of N2/O2/H2O/CH4/NO in the exhaust gases of LNG engines was constructed and validated. The study found that the conversion efficiency of CH4 and NO exhibits different trends with the increase of discharge power, and CH4 tends to be oxidized to CO under plasma conditions. Key reaction pathways for the DBD treatment of CH4, NO, CO, and NO2 were identified, and an important chemical reaction pathway with the potential for the joint treatment of CH4 and NO was found: CH3O2 + NO → CH3O + NO2. Additionally, the crucial pathways for the stable conversion of NO to NO2 were identified: O + NO + N2 → NO2 + N2 and NO + O3 → NO2 + O2, providing forward-looking theoretical guidance for subsequent research on plasma-facilitated selective catalytic reduction of NOx by CH4. [ABSTRACT FROM AUTHOR]

The fluid description is widely used for the multi-dimensional modeling of low temperature plasmas with complex chemistries due to their relative low computational cost. It relies, however, on a series of simplifying assumptions and some truncation of the moment equations for describing the non-equilibrium between the electrons, positive ions, negative ions, and the neutrals. In this paper, the classical assumption of isothermal negative ions is revisited for electronegative plasmas and, more particularly, for the fluid modeling of the transition between the plasma and its sheath. To do so, and in contrast to previous studies, the energy balance equation for the negative ions is also computed, and it allows us to derive the polytropic coefficient γ of the negative ions in addition to one of the positive ions. Strong variations in the sheath and presheath of the negative ions temperature and their polytropic coefficient are observed. The polytropic coefficient is shown to be a strongly varying function of space having for consequence that the negative ions are isothermal only in a very narrow extension of the presheath. For the case considered in this paper, both positive and negative ion flows are nearly adiabatic at the sheath-edge and become adiabatic inside the sheath. This paper shows that classical fluid modeling assumptions need to be verified for each system under consideration, most particularly while modeling the transition from plasma to a wall. [ABSTRACT FROM AUTHOR]

This work describes the plume chemistry of laser-ablated carbon–carbon (C–C) composite samples in vacuum, a range of air pressures, and in pure oxygen. Time-resolved spectra were measured from a plasma plume generated by laser-ablation at 248 nm. The focus of this work was on the detection of three chemical species, C2, CN, and CO in pressures from near vacuum (10−7 Torr) to air at atmospheric pressure (760 Torr). Emission from atomic carbon C I was predominant at 10−7 Torr, while molecular C2 Swan Band emission was observed at 10−7 Torr, at all air pressures, as well as in pure oxygen. Emission from the CN violet bands was observed only when ablating in air, but not in vacuum or pure O2, indicating that CN was the product of a chemical reaction between an ablated carbon species and N2 present in air, and not intrinsically present in the C–C composite targets. High-resolution emission spectra from C2 and CN were measured and fitted to vibrational and rotational temperatures. Time-resolved emission measurements of both these molecules were used to estimate their respective velocities as a function of pressure. No emission from excited state CO could be detected from 180–900 nm, even in pure O2. However, neutral and ground state CO and CO2 were both detected by measuring FTIR absorption spectra following the ablation of a composite target at 248 nm, in dry air at atmospheric pressure. The HITRAN database was used to calculate the concentrations of CO and CO2 produced per laser pulse. [ABSTRACT FROM AUTHOR]

In recent years, non-thermal plasma technology has emerged as one of the most promising candidates for decomposing CO 2. The fluid model, a powerful tool to investigate the plasma dynamics, is computationally costly in simulating complex CO 2 plasma with tens of particles and hundreds of reactions, especially driven by short pulsed voltages. In this paper, a deep neural network (DNN) is proposed to describe the discharge characteristics and plasma chemistry of CO 2 pulsed discharge at atmospheric pressure. The DNN is trained using the simulation data obtained from the fluid model and then continuously optimized by minimizing the loss function. The effectiveness and feasibility of the DNN are verified by comparing with the experimental measurement and the numerical simulation results. Compared to the time-consuming fluid simulations with tens of hours, the well-trained DNN typically requires only a few seconds to obtain the essential characteristics of CO 2 pulsed discharges with high accuracy, significantly improving the computational efficiency. The DNN prediction results show that increasing the pulse rise rate at a given voltage amplitude can effectively raise the discharge current and breakdown voltage, and the electric field in the sheath region also increases with the pulse rise rate. In addition, the density of the surface charge accumulated on the dielectric layer increases with the plateau duration, and then a strong induced electric field by the surface charges is established, which obviously improves the discharge current during the pulse fall phase. The predicted data also show that increasing the pulse rise rate and the plateau duration could effectively improve the density of product species, such as CO and O 2 , leading to an increase in CO 2 conversion. This study demonstrates that the DNN method is a reliable tool for obtaining the essential discharge characteristics of atmospheric CO 2 pulsed plasma and provides a promising avenue for future applications of DNN-based methods in non-thermal plasmas. [ABSTRACT FROM AUTHOR]

The thermal decomposition and ignition of high-performance high explosives occur via a mechanism where the solid phase sublimes and the parent molecules decompose rapidly in the gas phase to form unstable and charged intermediates. These intermediates continue to react and form the final products to release energy and do work. We have observed that the presence of electromagnetic energy significantly reduces the ignition temperature of a common high explosive, and data suggest that this occurs via electromagnetic interactions with the charged gas-phase intermediates. Here, we modified the thermal decomposition kinetic expressions for octogen (High Melt eXplosive, HMX) to couple the effects of an incident microwave (MW) field. This modified kinetic model is used to investigate our previous experimental work which showed that the surface temperature at ignition of HMX powder is reduced by the MW field. The Fridman–Macheret α-model is a common approach in plasma chemistry and was incorporated into the Henson/Smilowitz HMX kinetics; this effectively reduces the activation energy (Ea) by vibronically excited charged reactive intermediates. A modified kinetic model was implemented into the COMSOL Multiphysics Software. The thermal time to ignition was validated; as a result, plasma formation reduced the surface temperature by ∼23 °C compared to thermal ignition. With a validated kinetic model that can simulate both pure thermal ignition and mixed thermal/plasma ignition, we are able to simulate our previous experimental work showing that plasma ignition reduces the surface temperature at ignition compared to thermal initiation. [ABSTRACT FROM AUTHOR]

In present work, high entropy (MoTaTiVW)C X ceramics with different carbon stoichiometries (X = 3–6) were produced using spark plasma sintering. The microstructure, mechanical properties, and thermal properties of (MoTaTiVW)C X with different carbon stoichiometries were studied. At X = 3, the carbon deficiency resulted in a multiphase structure of the sample, (MoTaTiVW)C 3 with a Mo-rich carbide phase. At X = 3.5, the single-phase rock salt structure was formed despite carbon vacancies of up to 30 %. The relative density of (MoTaTiVW)C X gradually decreases as the carbon stoichiometry increases from X = 3 to X = 6. The concentration of carbon vacancies affects the sintering activation energy, which can enhance mass transfer and promote the densification process. The Vickers hardness of (MoTaTiVW)C X shows an overall decreasing trend as the carbon stoichiometry increases from X = 3.5 to X = 6, peaking at 20.4 ± 0.4 GPa at X = 3.5. The fracture toughness increases and then decreases, peaking at 4.4 ± 0.2 MPa m1/2 at X = 4. The thermal conductivity of (MoTaTiVW)C X gradually increases, then decreases and finally increases with the increase of carbon stoichiometry. At room temperature, the maximum value of thermal conductivity is 6.35 ± 0.29 W/m·K of (MoTaTiVW)C 5 and the minimum value is 5.32 ± 0.35 W/m·K of (MoTaTiVW)C 5.5. At 1000 °C, the thermal conductivity of (MoTaTiVW)C X ranges from 15.94 ± 0.37 W/m·K to 19.56 ± 0.45 W/m·K. As the concentration of carbon vacancies decreases, the decrease in point defect concentration will reduce the degree of lattice distortion, thereby reducing phonon scattering and affecting thermal conductivity. The study suggests that carbon stoichiometry can be used to adjust the microstructure, mechanical properties, and thermal properties of high entropy carbide ceramics. [ABSTRACT FROM AUTHOR]

In recent years, the in situ resource utilization of CO 2 in the Martian atmosphere by low-temperature plasma technology has garnered significant attention. However, numerical simulation is extremely time-consuming for modeling the complex CO 2 plasma, involving tens of species and hundreds of reactions, especially under Martian pressure. In this study, a deep neural network (DNN) with multiple hidden layers is introduced to investigate the CO 2 conversion in radio-frequency (RF) discharges at a given power density under Martian pressure in almost real time. After training on the dataset obtained from the fluid model or experimental measurements, the DNN shows the ability to accurately and efficiently predict the various discharge characteristics and plasma chemistry of RF CO 2 discharge even in seconds. Compared with conventional fluid models, the computational efficiency of the DNN is improved by nearly 10 6 times; thus, a real-time calculation of RF CO 2 discharge can almost be achieved. The DNN can provide an enormous amount of data to enhance the simulation results due to the very high computational efficiency. The numerical data also suggest that the CO 2 conversion increases with driving frequency at a fixed power density. This study shows the ability of the DNN-based approach to investigate CO 2 conversion in RF discharges for various applications, providing a promising tool for the modeling of complex non-thermal plasmas. [ABSTRACT FROM AUTHOR]

This document is a list of articles published in the journal "Thermal Spray Technology" between 1992 and 2010. The articles cover a range of topics related to thermal spraying, including the formation of coatings, particle behavior during spraying, and the properties of different types of coatings. Professor Pierre Léon Fauchais, a highly respected figure in the field, passed away in 2024 at the age of 86. He made significant contributions to the scientific community over six decades, serving as a mentor and guide to many scientists and engineers. His legacy in the field of thermal spraying is widely recognized and respected. [Extracted from the article]

When using uranium-238, thorium-232 and plutonium-239 isotopes, there is no need for expensive isotopic enrichment, and the use cycle of such nuclear fuel can be extended to 10-15 years. At the same time, the predicted reserves of thorium in the earth's crust are 3-5 times greater than uranium, and the use of ceramic nuclear fuel from oxide compositions based on thorium will make it possible to create ultra-small and small power plants for use in remote and hard-to-reach regions, in mines and quarries. However, ceramic nuclear fuel still has a significant drawback - low thermal conductivity. One of the promising areas for the further development of nuclear energy is the use of dispersion nuclear fuel, in which inclusions of fissile metals (uranium, thorium, plutonium) in the form of granulated oxide compositions (microspheres) are placed in a matrix with a high thermal conductivity coefficient. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing interest in skutterudite (SKD) compounds containing electronegative elements such as Br, Cl, S, Se, and Te, owing to their increased diversity and the versatility of filler atoms. This study focused on the thermoelectric performance of a series of (Ni, Te) co-doped SKDs filled with the electronegative element S, denoted as SxNi0.4Co3.6Sb11.2Te0.8 (x = 0, 0.1, 0.2, and 0.3). These compounds were prepared using a combination of a solid-state reaction and spark plasma sintering techniques. The results showed that (Ni, Te) co-doping introduced excess electrons in the SKD lattice, while the incorporation of the element S into the SKD voids optimized carrier concentration. This led to a considerable increase in the absolute Seebeck coefficient to 110.6 μV K−1 at ambient temperatures. The presence of S fillers induced phonon resonance scattering and point scattering, which reduced lattice thermal conductivity and ultimately improved the thermoelectric figure of merit zT, which reached 0.93 for S0.3Ni0.4Co3.6Sb11.2Te0.8 at 823 K. [ABSTRACT FROM AUTHOR]

Plasma-assisted reforming shows great promise for making ammonia compatible with current engine technology, with minimal modifications required. This study examines the impact of various discharge, flow, and composition parameters on ammonia conversion into hydrogen using a new well-stirred homogeneous plasma reactor. Gas chromatography was used to measure hydrogen and oxygen, while ICCD imaging evaluated plasma homogeneity. Initial mixture composition significantly influences the response to plasma conditions. Relative to the initial ammonia composition, the conversion of pure ammonia yields a lower hydrogen percentage when compared to air-diluted mixtures. Introducing air changes the relationship between pulsed energy deposition and hydrogen production, resulting in a more substantial increase in conversion. Efficiency calculations demonstrate that high ammonia content and high pulse frequencies improve yields, while longer residence times in the reactor result in higher temperatures, also increasing yields. These findings provide insights into the underlying mechanisms of ammonia cracking and reforming in a discharge, and will serve to promote further investigation into plasma reforming strategies. • Enhanced hydrogen production from plasma-assisted reforming of ammonia influenced by initial mixture composition. • Optimal hydrogen yields achieved with high ammonia content and high pulse repetition frequency of plasma discharges. • Effective reforming strategies demonstrated for longer residence times in reactor due to gas heating. [ABSTRACT FROM AUTHOR]

Streptococcus salivarius is a common, harmless, and prevalent member of the oral microbiota in humans. In the present study, the safety of S. salivarius UBSS-01 was evaluated using in silico methods and preclinical and clinical studies. In an acute toxicity study, rats were administered with 5 g/kg (500 × 109 CFU) S. salivarius UBSS-01. The changes in phenotypic behaviors and hematological, biochemical, electrolytes, and urine analyses were monitored. No toxicity was observed at 14 days post-treatment. The no observable effects limit (NOEL) of S. salivarius UBSS-01 was >5 g/kg in rats. In a 28-day repeat dose toxicity study, rats were administered S. salivarius UBSS-01 once daily at doses of 0.1, 0.5, and 1 g/kg (10, 50, and 100 billion CFU/kg, respectively) body weight. S. salivarius UBSS-01 did not influence any of the hematology parameters and clinical chemistry parameters in plasma and serum samples after 28-day repeated administration. No structural abnormality was observed in the histological examination of organs. Whole genome analysis revealed the absence of virulence factors or genes that may transmit antibiotic resistance. In the double-blind study with 60 human participants (aged 18–60 years), consumption of S. salivarius UBSS-01 for 30 days was found to be safe and results were comparable with placebo treatment These findings indicate that S. salivarius UBSS-01 may be safe for human consumption. [ABSTRACT FROM AUTHOR]

A microscale colorimetric assay was designed and implemented for the simultaneous determination of clinical chemistry tests measuring six parameters, including glucose (GLU), total protein (TP), human serum albumin (HSA), uric acid (UA), total cholesterol (TC), and triglycerides (TGs) in plasma samples. The test kit was fabricated using chromogenic reagents, comprising specific enzymes and binding dyes. Multiple colors that appeared on the reaction well when it was exposed to each analyte were captured by a smartphone and processed by the homemade Check6 application, which was designed as a colorimetric analyzer and simultaneously generated a report that assessed test results against gender-dependent reference ranges. Six blood checkup parameters for four plasma samples were conducted within 12 min on one capture picture. The assay achieved wide working concentration ranges of 10.45–600 mg dL−1 GLU, 1.39–10.0 g dL−1 TP, 1.85–8.0 g dL−1 HSA, 0.86–40.0 mg dL−1 UA, 11.28–600 mg dL−1 TC, and 11.93–400 mg dL−1 TGs. The smartphone-based assay was accurate with recoveries of 93–108% GLU, 93–107% TP, 92–107% HSA, 93–107% UA, 92–107% TC, and 99–113% TGs. The coefficient of variation for intra-assay and inter-assay precision ranged from 3.2–5.2% GLU, 4.6–5.3% TP, 4.3–5.3% HSA, 2.8–6.6% UA, 2.7–6.5% TC, and 1.1–3.9% TGs. This assay demonstrated remarkable accuracy in quantifying the concentration-dependent color intensity of the plasma, even in the presence of other suspected interferences commonly present in serum. The results of the proposed method correlated well with results determined by the microplate spectrophotometer (R2 > 0.95). Measurement of these six clinical chemistry parameters in plasma using a microscale colorimetric test kit coupled with the Check6 smartphone application showed potential for real-time point-of-care analysis, providing cost-effective and rapid assays for health checkup testing. [ABSTRACT FROM AUTHOR]

Plasma‐facing liquids (PFLs) facilitate the storage of reactive O and N species (RONS), including H2O2 and NO2−, which remain in the PFL after plasma treatment, and they can continuously influence the target immersed in the liquid. However, their behaviors and levels of generation and extinction depend strongly on the plasma characteristics and liquid condition. Therefore, understanding the effects of the liquid type on the plasma discharge characteristics and the RONS generated via plasma discharge is necessary. We compared the RONS generation and storage trends of deionized H2O and a high‐conductivity PFL, RPMI 1640, which is a well‐known cell culture medium commonly used to culture mammalian cells. RPMI 1640 acted as an electrode and enhanced the plasma discharge power by supplying abundant radicals and RONS. The production of gaseous hydroxyl radicals and NO markedly increased, which facilitated H2O2 and NO2− production in the PFL for the first 200 s, and then the increase in the RONS concentration stagnated. With respect to storage, as the components within RMPI 1640 exhibited high reaction constants for their reactions with H2O2, H2O2 elimination was completed in <30 min. Unlike H2O2, the concentration of NO2− in the PFL was unchanged. [ABSTRACT FROM AUTHOR]

Plasma‐induced CO2 hydrogenation process has received much attention, while the related plasma chemistry has not been profoundly explored. Herein, electron‐induced and thermochemical effects on CO2 hydrogenation in a dielectric barrier discharge reactor were investigated. The temperatures for the discharge pattern transition for CO2/H2, CO2/H2/N2, CO2/H2/Ar, and CO2/H2/He mixtures were 623, 623, 600, and 600 K, respectively. CO2 conversion was controlled by electron‐induced reactions and was sensitive to discharge pattern and electron density but not electron energy. In contrast, product formation was governed by the thermo‐induced chemistry. These results are useful for a better understanding of plasma‐induced CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

A new study from Canada has developed a process for efficiently extracting and recycling metals from used alkaline batteries. This method, called hydrometallurgy, uses aqueous solutions to extract the metals and is more cost-effective and energy-efficient than other methods. The researchers are now working on scaling up the technique for industrial use. The document also highlights various scientific studies in applied chemistry, including the conversion of carbon dioxide to carbon monoxide, the synthesis of synthetic diamonds, the growth of hydrocarbons from biogas, the reduction of CO2 to syngas and C2 hydrocarbons, the development of electronic spider silk sensors, the creation of reflective black paint for autonomous cars, the production of vanillin from ferulic acid, and the development of reversible supramolecular adhesives. Each study offers unique findings and potential applications in different fields. [Extracted from the article]

The balance of processes affecting electron density drives the dynamics of upper‐atmospheric electrical events, such as sprites. We examine the detachment of electrons from negatively charged atomic oxygen (O−) via collisions with neutral molecular nitrogen (N2) leading to the formation of nitrous oxide (N2O). Past research posited that this process, even without significant vibrational excitation of N2, strongly impacts the dynamics of sprites. We introduce updated rate coefficients derived from recent experimental measurements which suggest a negligible influence of this reaction on sprite dynamics. Given that previous rates were incompatible with the observed decay of the light emissions from sprite glows, our findings support that glows actually result from electron depletion in sprite columns. Plain Language Summary: Sprites are transient, filamentary luminous structures appearing between approximately 50 and 85 km above Earth's surface. While the primary sprite activity is ephemeral, lasting mere thousandths of a second, certain luminous features persist up to a hundred times longer. The key to understanding these enduring structures lies in the evolution of free electron populations that facilitate electrical conductivity. Here we show that a process that influences this population is slower than previously thought. This may explain why luminous structures can persist for so long. Key Points: Associative detachment of electrons in sprites proceeds almost exclusively from vibrationally excited N2We provide updated rate coefficients for electron associative detachmentIn models with the updated rates, sprite glows persist tens of milliseconds, in agreement with observations [ABSTRACT FROM AUTHOR]

This work represents a first attempt to include the complex variety of electron- molecule processes in a full kinetic particle-in-cell/test particle Monte Carlo model for the plasma and neutral gas phase in a Hall thruster. Particular emphasis has been placed on Earth's atmosphere species for the air- breathing concept. The coupling between the plasma and the gas phase is self-consistently captured by assuming the cold gas approximation and considering gas-wall and gas recycling from the walls due to ion neutralization. The results showed that, with air molecular propellants, all the most relevant thruster performance figures degraded relative to the nominal case using Xe propellant. The main reasons can be ascribed to a reduced ionization cross-section, a larger gas ionization mean free path due to lighter mass air species, and additional electron collisional power losses. While vibrational excitations power losses are negligible, dissociation and electronic excitations compete with the ionization channel. In addition, for molecular oxygen, the large dissociation leads to even faster atoms, further reducing their transit time inside the discharge channel. Future studies are needed to investigate the role of non-equilibrium vibrational kinetics and metastable states for stepwise ionization. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study of a new hybrid plasmatron scheme, which was used to realize a gas discharge at atmospheric pressure supported by continuous focused submillimeter radiation with a frequency of 263 GHz. The implemented design allowed organizing a self-consistent interaction between submillimeter radiation and the supercritical plasma in a localized area both in terms of gas flow and electrodynamic. It is experimentally shown that the gas discharge absorbs up to 80% of the introduced submillimeter radiation power. [ABSTRACT FROM AUTHOR]

Low‐temperature plasma‐assisted nitrogen fixation is a promising method for organic‐polluted soil/water remediation, that improves N‐fertilizer performance and mitigates ammonia emission. Our study explores a novel approach: plasma bubbles‐assisted ammonia treatment, and investigates the role played by various reactive substances in the oxidation of ammonia. The specific reaction pathways and the contribution of OH radicals in the ammonia oxidation process in O2 plasma treatment are determined. Air emerges as the optimal feed gas owing to a positive feedback loop in the reaction between NO2− and H2O2. Air plasma treatment enriches N in the ammonia solution and minimizes ammonia loss during treatment. This study offers new insights into an advanced plasma‐assisted ammonia treatment method. [ABSTRACT FROM AUTHOR]

A deep learning-based solution is proposed to resolve the highly non-linear ordinary differential equation (ODE) system of the plasma chemistry model. A feed-forward neural network (FNN) is built and trained based on the data generated by the existing global plasma kinetics code. Good agreement is achieved between the results obtained from the deep learning-based method and the traditional plasma kinetics solver for both argon and air discharge conditions. The results demonstrate that the temporal evolution of O-atom density predicted by both the FNN and the 0D model aligns closely with the measurements obtained from the fast ionization wave discharge. Furthermore, the differences in O-atom density between the predictions and measurements are the same order of magnitude. The computational costs of the ODE solver and the FNN model are compared and discussed in this work. The feasibility of using deep learning methods to resolve low temperature plasma chemistry systems is demonstrated through the tests shown in this study. [ABSTRACT FROM AUTHOR]

This document provides summaries of various scientific research papers. The first summary discusses the development of aerogel fibers that mimic the thermal insulation properties of polar bear hairs. The second summary highlights the creation of bacteria-grown vegan leather that dyes itself, offering a more sustainable alternative to traditional leather production. The third summary discusses the use of pyroelectrochemical cells for powering wireless devices in the Internet of Things. The fourth summary mentions the development of self-cleaning paints using photocatalytically active nanoparticles. The fifth summary describes a high-pressure electro-Fenton process for converting methane to formic acid. The sixth summary introduces a hybrid membrane-free cell for hydrogen production. The seventh summary discusses the use of nanoparticles derived from food waste to recover gold from electronic waste. The eighth summary mentions a nonthermal plasma-based strategy for carbon growth from biogas constituents. The ninth summary highlights the use of a bifunctional catalyst for efficient hydrogen production. The tenth summary discusses the selective conversion of methanol into high-purity hydrogen and carbon monoxide. [Extracted from the article]

In plasma-driven solution electrolysis (PDSE), gas-phase plasma-produced species interact with an electrolytic solution to produce, for example, nanoparticles. An atmospheric pressure plasma jet (APPJ) directed onto a liquid solution containing a metallic salt will promote reduction of metallic ions in solution, generating metallic clusters that nucleate to form nanoparticles. In this article, results from a computational investigation are discussed of a PDSE process in which a radio-frequency APPJ sustained in helium impinges on a silver nitrate solution, resulting in growth of silver nanoparticles. A reaction mechanism was developed and implemented in a global plasma chemistry model to predict nanoparticle growth. To develop the reaction mechanism, density functional theory was used to generate probable silver growth pathways up to Ag9. Neutral clusters larger than Ag9 were classified as nanoparticles. Kinetic reaction rate coefficients for thermodynamically favorable growth pathways were estimated based on an existing, empirically determined base reaction mechanism for smaller Ag particle interactions. These rates were used in conjunction with diffusion-controlled reaction rate coefficients that were calculated for other Ag species. The role of anions in reduction of Agn ions in forming nanoparticles is also discussed. Oxygen containing impurities or admixtures to the helium, air entrainment into the APPJ, and dissociation of saturated water vapor above the solution can produce additional reactive oxygen species in solution, resulting in the production of anions and O 2 - in particular. For a given molarity, delivering a sufficient fluence of reducing species will produce similar nanoparticle densities and sizes for all applied power levels. Comparisons are made to alternate models for nanoparticle formation, including charged nanoparticles and use of direct current plasmas. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue on plasma diagnostics development. It discusses the importance of plasma diagnostics in fusion energy research, space exploration, and industrial applications. The special issue features sixteen papers that cover various topics, including magnetic confinement fusion, beam plasmas, low-temperature plasmas, and astrophysical plasmas. The contributions provide updates and insights into the challenges and advancements in plasma diagnostics, serving as a catalyst for future endeavors in enhancing and optimizing next-generation plasma diagnostics. The document concludes with gratitude to the authors and reviewers for their contributions to the special issue. [Extracted from the article]

A plasma-chemical method is proposed for processing fuel oil, at a rate of 1000 kg/h. Mild plasma-chemical treatment results in considerable cracking of the high-boiling fuel-oil component. In plasma-chemical processing of fuel oil and subsequent distillation of the liquid components, the products are 6.7% gas, 48.0% residue, 11.2% solvent (from the onset of boiling to 250°C), and 34.1% heating oil (251–360°C). Distillation of the heating oil yields the following: 0.3% gas, 30.2% SMT low-viscosity marine fuel (251–330°C); and 3.6% number 5 fuel oil (331–360°C). The residue is characterized by penetration 150 dmm and softening temperature (by the ring and ball method) 73°C. It may be used in highway bitumen and as a raw material for delayed coking. The total power consumption in the plasma-chemical processing of 1000 kg of fuel oil is around 30–40 kW (including 6–8 kW in operation of the plasma-chemical reactor). [ABSTRACT FROM AUTHOR]

This article is a systematic review and meta-analysis that evaluates the effectiveness of atmospheric pressure cold plasma decontamination techniques for packaging materials. The review finds that cold plasma is a promising solution for reducing microbial contamination on packaging surfaces. The article highlights the importance of decontaminating food packaging to ensure the safety and quality of products in the food processing industry. It also discusses the various materials used in food packaging and the potential risks of contamination. The review suggests that future research should focus on optimizing cold plasma decontamination processes for industrial applications. Another document provides a summary of a research study on the effectiveness of plasma treatment in decontaminating packaging materials and food contact surfaces. The study analyzed various factors such as plasma systems, contamination characteristics, packaging materials, and the maximum inactivation achieved. The results showed that plasma treatments at atmospheric pressure are effective against foodborne pathogens, with varying efficacy against different types of microorganisms. The study suggests that future research should focus on optimizing treatment time and effectiveness, as well as transitioning from laboratory prototypes to industrial in-line systems. Additionally, there is a document that provides a list of references to scientific articles related to the decontamination of various surfaces using non-thermal plasma. These articles cover a range of topics, including the inactivation of bacteria and spores, the use of different types of plasma, and the effectiveness of plasma in different environments. The articles provide valuable information for researchers and practitioners interested in using non-thermal plasma for decontamination purposes. Lastly, [Extracted from the article]

Higher manganese silicides (denoted as MnSiγ ) are a prominent class of intermetallic compound for thermoelectric applications that crystallizes into a Nowotny Chimney Ladder (NCL) phase and constitutes a higher concentration of silicon with odd stoichiometry, typically represented by an irrational number. In this work, the genesis of Si odd stoichiometry and secondary phase relations in silicon-rich and silicon-deficient MnSix is presented to clarify the significance of labile (i.e., easily alterable) Si-subsystem in inheriting the modulated lattice structure with characteristic anharmonicity. The transport properties show an interrelation to the presence of a secondary phase, which is driven by the odd stoichiometry, where the thermoelectric figure of merit (zT) is found to be optimal for MnSi1.74. The structural characterization of rapidly solidified melt-spun ribbons and spark plasma sintered bulk specimens reveal a characteristic presence of MnSi and Si as secondary phases in Si-deficient (x ≈ 1.5) and Si-excess (x ≈ 2) compositions of nominal MnSix, respectively, that coexists with the major MnSiγ based NCL phase. This study provides the fundamental basis of phase evolution and the relevance of odd stoichiometry in silicon-rich manganese silicides which exhibit fascinating phonon dynamics in optimal MnSi1.74 stoichiometry. [ABSTRACT FROM AUTHOR]

The pharmacokinetics and tolerability of cannabinoids and their metabolites were determined in eight horses after enteral administration of a commercial CBD/CBDA-rich hemp oil product. Each horse was administered 2 mg/kg or 8 mg/kg CBD/CBDA or no treatment in a randomized cross-over design. Serial serum samples collected over 48 h were analyzed by high performance liquid chromatography with tandem mass spectrometry. Plasma chemistry analysis was performed at 0 h and 24 h. Vital parameters, pedometry, and blinded mentation and gait evaluations were recorded at intervals up to 24 h. Manure production and gastrointestinal transit time were tracked for 48 h after oil administration. The median maximal concentration of CBD and CBDA were 5.2 and 36.95 ng/mL in the 2 mg/kg group, respectively; and 40.35 and 353.56 ng/mL in the 8 mg/kg group. The median half-life of elimination was not calculated for the 2 mg/kg CBD treatment due to lack of time points above the lower quantifiable limit beyond the Cmax while it was 7.75 h in the 8 mg/kg group. CBDA absorption was biphasic. Pharmacokinetic parameters for tetrahydrocannabinol, tetrahydrocannabinolic acid, cannabigerolic acid, and 7-carboxy cannabidiol are also reported. No significant differences in any of the measured tolerability parameters were demonstrated between treatment groups. Single-dose enteral administration of CBD/CBDA-rich hemp extract up to 8 mg/kg does not appear to produce neurologic, behavioral, or gastrointestinal effects in horses. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue of the journal Materials titled "Advances in Plasma and Laser Engineering." The special issue focuses on the role of plasma and laser-based techniques in materials science, particularly in nanotechnology. The articles in the special issue cover a range of topics, including plasma etching and treatment of silicon and polyurethane, as well as laser processing of steel and silicon. The authors discuss the potential applications of plasma and laser techniques in various fields, such as electronics, energy, medicine, and construction. The document also suggests future challenges and opportunities for research in plasma and laser engineering, including the integration of plasma and laser technologies and the use of novel plasma and laser techniques. [Extracted from the article]

The filamentation dynamics of a nitrogen pulsed microwave discharge generated at the antinode of a standing electromagnetic wave at a pressure of 100 torr has been numerically simulated. The results of the dynamics of the main plasma parameters, such as the concentration of charged and excited species, gas temperature, and vibrational temperature of nitrogen, are presented. [ABSTRACT FROM AUTHOR]

Radio-frequency capacitively coupled plasmas (CCPs) are one of the key technologies enabling the latest etching processes in 3D NAND and FinFET manufacturing. These processes rely crucially on the precise control of the uniformity of ion/radical fluxes and ion angular and energy distribution function (IAEDF) in CCPs. The plasma behavior and scaling properties are dependent on the plasma chemistry in these processes, e.g., electro-positive Ar plasmas vs highly electro-negative O2 plasmas. With the large number of process and design parameters influencing the plasma properties, computational modeling has become an important tool in conjunction with experimental diagnostics in understanding the intricate physical mechanisms in CCPs. In this paper, a 2D particle-in-cell plasma model is used to study the kinetic behavior of low-pressure (<5 Pa) CCPs in two different representative chemistries: Ar and O2. The low-frequency RF source is at 1.356 MHz while 27.12 MHz is used for the high frequency. Simulations show a shift of the peak in the plasma density from the center of the chamber to the edge as the pressure increases from 0.3 to 2.6 Pa. The computed magnitude and spatial profile of electron density compare reasonably with experimental measurements over a range of pressure. Comparison between electro-positive and electro-negative plasmas are discussed. Modeling results for the dual frequency CCP highlight the effect of plasma uniformity on the IAEDF, especially near the outer edge of the electrodes. Collisions in the sheath increase the population of low-energy ions as the pressure is increased to 2.6 Pa. [ABSTRACT FROM AUTHOR]

We describe the design and main parameters of a fore-vacuum pressure, plasma-cathode electron source with an extended range of operating pressure. The source forms a ribbon electron beam with cross section 10 × 220 mm2 over a pressure range from 10–1 to 10 Pa. This wide pressure range is achieved by using two auxiliary hollow cathode discharge systems, between which there is a pressure difference. The beam current is up to 450 mA and the electron energy up to 8 keV. Inhomogeneity of the beam current density distribution is less than 15%. These beam parameters are advantageous for beam-plasma generation for the implementation of plasma chemical deposition of coatings. [ABSTRACT FROM AUTHOR]