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A fundamental equation of state in terms of the Helmholtz energy is presented for mixtures of nitrogen, oxygen, and argon at any composition. It is expressed in terms of the residual Helmholtz energy and can be used to calculate all thermodynamic equilibrium properties including vapor–liquid equilibria. The parameters of the equations for the pure-fluid and mixture contributions are fitted exclusively to molecular simulation data so that the model has a predictive character. The description of the mixture-specific reducing parameters is realized via generalized correlations of the critical parameters of the pure fluids so that an extension of the model to additional components can be implemented straightforwardly. Extensive comparisons to experimental data and the GERG-2008 reference equation of state show that the prediction of thermodynamic properties is satisfactory. [ABSTRACT FROM AUTHOR]

For many years, the recombination of excited ions of argon, Ar + ( P 1 / 2 2 ) , has been assumed negligible under ambient conditions as compared to the recombination of ground-state ions, Ar + ( P 3 / 2 2 ). This opinion was confronted with detailed experimental results that seem to clearly support it. Here, we propose a new interpretation in light of our recent calculations, which shows that the recombination efficiency is comparable for both fine-structure states. Noteworthily, in our model leading to a picture consistent with the experiment, residual dimer ions emerge from A r + ( P 1 / 2 2 ) due to non-adiabatic dynamics effects and interplay in measured data. [ABSTRACT FROM AUTHOR]

Laser diode absorption spectroscopy is used to experimentally measure Ar(1s5) metastable density and translational gas temperature within a 94 GHz microplasma. A square two-dimensional photonic crystal (PhC) at this resonance frequency serves to ignite and sustain the plasma from 20 to 200 Torr (2.7 × 103–2.7 × 104 Pa) by using millimeter wave power from 300 to 1000 mW. Metastable density within the plasma is estimated from the absorption line shape of the laser traversing the PhC. The metastable density reaches an order of 1019 m−3 at lower pressure and decreases as pressure increases. From the Lorentzian line shape of the absorption profile at 811.53 nm, the gas temperature is extracted and found to increase from 500 K at 20 Torr to 1300 K at 200 Torr. These data are analyzed and compared with a zero-dimensional plasma model and with previous experimental plasma results at 43 GHz. [ABSTRACT FROM AUTHOR]

This work studied the rovibrational absorption spectral line-shape parameters of the P(1)–P(10) and R(0)–R(9) lines for Hydrogen fluoride perturbed by argon in the 0–0, 1–0, and 2–0 vibrational bands at 20–1000 K. A dataset of beyond-Voigt line-shape parameters (pressure broadening and shifting parameters, their speed dependencies, and the complex Dicke parameters) has been theoretically determined for the first time from generalized spectroscopic cross-section calculated by the full quantum scattering calculations. Then these parameters were employed to predict the line shape and asymmetry based on the partially-correlated speed-dependent hard-collision and the partially-correlated quadratic-speed-dependent hard-collision profiles. The effect of each parameter on the line shape and line asymmetry was further studied, which revealed that the beyond-Voigt effects were indispensable to accurately describe the line shape contour. Our results are in good agreement with the available experimental observations and provide a comprehensive set of theoretical references for further experimental measurements. [ABSTRACT FROM AUTHOR]

Diode-pumped rare gas lasers (DPRGLs) have the potential for high-energy laser output with high beam quality. The metastable concentration >1014 cm−3 and pump intensity >10 kW/cm2 are required in developing high-power and efficient DPRGLs. However, the kinetics of 1s and 2p levels (Paschen notation) under these conditions is unclear yet, particularly regarding the adverse effects of interference energy levels (e.g., 1s4 and 2p1–2p8). This study addresses this gap by measuring the number densities of 1s and 2p levels in a diode-pumped plasma jet metastable argon laser. The experiment was conducted with a much higher number density of 1014 cm−3 and a higher pump intensity of 12 kW/cm2 than our previous works. The results indicate that the adverse effect of 1s4 accumulation could be partially compensated, and the relative population distribution of 2p energy levels remained unchanged. However, the high gas temperature (>1000 K) caused a significant negative impact of high 2p levels (2p1–2p8), and the air environment weakened the effect of He collision relaxation. [ABSTRACT FROM AUTHOR]

The importance of microwave device reliability and performance for microscale devices motivates a more fundamental understanding of breakdown mechanisms in this regime. Microwave breakdown theories predict breakdown when electron production balances electron loss. Electron production depends strongly on the ionization rate ν i ; however, previous studies either used the measured ν i in macroscale gaps or the empirical formula for DC voltage, inaccurately predicting ν i in microscale gaps. Alternatively, this work characterizes ν i in microwave microplasmas by using particle-in-cell simulations. We calculated ν i in argon gas at atmospheric pressure for 2–10 μm gaps under AC fields ranging from 1 to 1000 GHz. The behavior of ν i may be separated into two regimes by defining a critical frequency f c r that depends on the amplitude of the applied voltage, gap distance, and pressure. For frequency f < f c r , the electrodes collect the electrons during each cycle and the electron number oscillates with the electric field, causing ν i / f to roughly scale with the reduced effective field E e f f / p. For f > --> f c r , the phase-space plots indicate that the electrons are confined inside the gap, causing the electron number to grow exponentially and v i / p to become a function of E e f f / p. These results elucidate the ionization mechanism for AC fields at microscale gap distances and may be incorporated into field emission-driven microwave breakdown theories to improve their predictive capability. [ABSTRACT FROM AUTHOR]

Utilizing alternative propellants has been recognized as a strategy to reduce the total cost of propellants in electric propulsion-based missions. The aim of this study is to quantify the Hall effect thruster (HET) performance and operating characteristics using a Kr–Ar mixture to enable mission designers to evaluate the impact on mission and spacecraft design. We present the performance and plume plasma properties of the P5 5 kW-class HET operated with a Kr–Ar mixture with Ar volumetric flow rate fractions from 0 to 100%. The thruster is characterized at discharge power levels of 2.6 kW and 4.1 kW at constant discharge current and voltage over the range of Ar fractions. Despite higher ionization energy and lower mass of Ar, the thruster exhibited a similar level of thrust within 2% when comparing the pure Kr and 26%-Ar mixture cases. The derived ion energy distribution functions and analytical modeling suggest that the characteristic length for the ionization region is extended as the Ar fraction increases. The increased residence time of Kr at the extended ionization region and background energetic electrons from the ionized Ar neutrals are considered to cause this enhanced ionization of the injected Kr neutrals. This leads to a 6% higher Kr ion density at the 26%-Ar case even at the 16% less injected Kr neutral density than in the pure Kr case. The enhanced Kr ionization and generated Ar ions in the 26%-Ar case consequently led to a comparable thrust with that of the pure Kr case. The study indicates that mixing Ar with approximately 26% volumetrically with Kr can provide a similar or even higher thrust performance at the same discharge power. This will be particularly advantageous for various space missions that require high impulses by reducing the total cost of the propellant. [ABSTRACT FROM AUTHOR]

Weld surfacing is the process of applying a layer of metal to the surface of metal objects by simultaneously melting the substrate. As a result of this process, the metal content of the padding weld can be as high as several tens of percents. It is a method used to regenerate machine parts and improve the properties of the surface layer, increasing its resistance to abrasion, corrosion, erosion, and cavitation. It also supports the repair and creation of permanent protective coatings in the engineering, automotive, energy, and aerospace industries. This makes it possible to repair damaged parts instead of completely replacing them, saving time and production costs. Plasma surfacing technology is used for components that require high hardness and corrosion resistance under various environmental conditions. Plasma wire surfacing is not sufficiently presented and described in the current literature, which creates problems in determining the appropriate process parameters. The influence of variable plasma surfacing parameters on steel C45 significantly affects surfacing weld geometry, the dilution factor, and microhardness. Higher currents can increase the dilution factor, integrating more base metal into the weld pool, which may alter the chemical composition and mechanical properties of the weld. Variations in surfacing speed and heat input also affect the microhardness of the surfaced joint, with higher heat inputs potentially leading to softer welds due to slower cooling rates. Optimizing these parameters is essential to achieving desired surfacing weld characteristics and ensuring the structural integrity of C45 steel joints. This paper presents the influence of varying plasma surfacing parameters on the surfacing geometry, the dilution factor, and microhardness. The tests were carried out on a Panasonic TM-1400 GIII automated surfacing machine with CastoMag 45554S solid wire as the filler material. Flat bars of C45 steel were prepared, and then the variable parameters of the surfacing process were developed. Tests were carried out to determine the dilution factor, followed by microhardness measurements. The results showed a significant dependence of the effect of the parameters on the surfacing geometry and the dilution factor. [ABSTRACT FROM AUTHOR]

Melt pool dynamics in metal additive manufacturing (AM) is critical to process stability, microstructure formation, and final properties of the printed materials. Physics-based simulation, including computational fluid dynamics (CFD), is the dominant approach to predict melt pool dynamics. However, the physics-based simulation approaches suffer from the inherent issue of very high computational cost. This paper provides a physics-informed machine learning method by integrating the conventional neural networks with the governing physical laws to predict the melt pool dynamics, such as temperature, velocity, and pressure, without using any training data on velocity and pressure. This approach avoids solving the nonlinear Navier-Stokes equation numerically, which significantly reduces the computational cost (if including the cost of velocity data generation). The difficult-to-determine parameters' values of the governing equations can also be inferred through data-driven discovery. In addition, the physics-informed neural network (PINN) architecture has been optimized for efficient model training. The data-efficient PINN model is attributed to the extra penalty by incorporating governing PDEs, initial conditions, and boundary conditions in the PINN model. [ABSTRACT FROM AUTHOR]

Based on the Hagena scaling law, the cluster size in a gas jet is dependent on the equivalent diameter of a conical nozzle. In this work, the effect of the equivalent diameter deq of a conical nozzle on cluster size is separated into the individual effects of the throat diameter d and the half-opening angle α by comparing the Rayleigh scattering signals from gas jets. Nine types of conical nozzles with three different throat diameters (0.3, 0.5, and 0.7 mm) and three different half-opening angles (8.5°, 14.0°, and 24.2°) are used to produce argon gas jets at gas backing pressures from 10 up to 80 bar. The experimental results show that the effect of the throat diameter d is almost the same as that expected by the scaling law. However, the scaling law overestimates the effect of the half-opening angle α. The result is helpful for the precise characterization of cluster size and further understanding the interaction between intense laser and gas clusters. [ABSTRACT FROM AUTHOR]

An efficient and facile strategy has been developed for the synthesis of symmetrical pyridines in good to excellent yields from ketoxime acetates and DMFDMA in the presence of FeCl3 at 120 °C for 6 h under argon atmosphere. In this protocol, DMFDMA acts as an effective C1 synthon. The use of inexpensive catalysts, no need for additional ligands and additives, and excellent functional group tolerance are the perks of this protocol. [ABSTRACT FROM AUTHOR]

As a typical liquid-like thermoelectric material, Cu2 Se not only has good electrical transport performance, but also has low lattice thermal conductivity. Nanoengineering is an effective method to achieve high thermoelectric properties for thermoelectrics. However, nanoscale Cu2 Se particles are extremely easy to be oxidized in the process of synthesizing, thus affecting its thermoelectric performance. In order to study the effect of powder reduction on the thermoelectric performance of Cu2 Se, nano-sized Cu2 Se powders were synthesized by hydrothermal method. Hydrogen argon mixed gas ( hydrogen volume fraction of 5%) and pure argon were used to purge the powders, respectively. Cu2 Se bulk materials with density above 95% were prepared by spark plasma sintering. The results show that the oxygen content of Cu2 Se bulk is significantly reduced after powder reduction, and there is a 41% decrease in thermal conductivity at 800 K, with a 16% increase in ZT value. [ABSTRACT FROM AUTHOR]

The self-ignition of a propylene–oxygen–argon stoichiometric mixture with a volumetric argon content of 95% is studied. The experiments are performed on a shock tube, which is part of the Shock Tube Experimental Complex of the Institute of Mechanics of Moscow State University, in conditions behind the reflected shock wave. The time dependencies of signals from a piezoelectric pressure sensor, a thermoelectric detector, and an optical section configured to record the radiation of electronically excited radicals OH• (λ = 302 nm), CH• (λ = 427 nm, and molecular carbon (λ = 553 nm) are analyzed. The ignition delay times τign are measured in the temperature range T = 1200–2460 K and pressures p = 4.5–25 atm. The data obtained are compared with the results of other authors. [ABSTRACT FROM AUTHOR]

An 1/4 ladle water model is build, a differential flow bottom blowing method with different flow ratios is proposed, and an Eulerian multiphase flow model which coupling of the Eulerian model and the Volume of Fluid (VOF) interface tracking method was established to study the flow field, mixing time, slag eyes area and its fluctuation in ladle water model. The result shows that the mixing time increases first and then decreases with the increase of bottom blowing ratio. The mixing time is longest in single nozzle and reaches its shortest at ratio of 2:1. Compared to equal flow and single nozzle, using differential flow can reduce the slag eyes area. The calculated results of mixing time and slag eyes area agree well with the experimental results. Compared to the traditional equal flow bottom blowing method and single nozzle, using the differential flow with a flow ratio of 2:1 can reduce the stirring consumption caused by the collision between two streams, and the range of low-speed eddy current is reduced. The volume average values of turbulent kinetic energy and viscosity under equal flow and 2:1 differential flow are relatively close; after 2:1, they will significantly decrease with increasing bottom blowing ratio, reaching the minimum value during single nozzle. The model has a good capture effect on the sharp interface between water and oil. [ABSTRACT FROM AUTHOR]

Established a 1/4 water model experimental system to study the mixing phenomenon and slag eye during ladle refining process. On the basis of traditional equal flow bottom blowing method, differential flow bottom blowing methods with different flow ratios were proposed, the optimal bottom blowing ratio that minimizes mixing time and slag eyes area was founded, and the optimization effect of differential flow bottom blowing method on mixing time and slag eyes area at various angles and eccentricities was verified. The results indicate that the mixing time is the shortest in most cases when using the bottom blowing method with a differential flow ratio of 2:1 when the angle is within 135 deg, after 2:1, the mixing time increases with the increase of bottom blowing ratio, and the mixing time in single nozzle is the longest in almost all cases. The influence of nozzle angle on slag eyes area is greater than that of eccentricity. The differential flow bottom blowing method can significantly reduce the slag eyes area, and the bottom blowing ratio that minimizes the slag eyes area is 4:1. However, the fluctuation degree of slag eyes area will increase with the increase of bottom blowing ratio. [ABSTRACT FROM AUTHOR]

Examining the kinetics involved in the Argon Oxygen Decarburization (AOD) process, especially in the hotspot and emulsion zones within distinct reactors, can offer a deeper understanding of the refining mechanism in stainless-steelmaking. A predictive dynamic model has been formulated to estimate the effects of different refining processes, encompassing decarburization, desiliconization, demanganization, and chromium removal. The model includes a sub-model for heat loss calculation. The FactSage™ software, along with its macro programming capability, was utilized to incorporate thermochemical and kinetic information into the model. The model forecasts that the predominant chromium removal occurs within the hotspot zone, while carbon, silicon, and manganese removals occur in both the hotspot and emulsion zones. The predictions regarding the transient compositions of steel and slag, as well as the temperature of the steel bath, align with the plant data (Average of five heats), showcasing consistency. [ABSTRACT FROM AUTHOR]

A new method of efficiently transforming water vapor into hydrogen was investigated by dielectric barrier discharge (DBD) loaded with bamboo carbon bed structured by fibrous material in an argon medium. Hydrogen productivity was measured in three different reactors: a non-loaded DBD (N-DBD), a bamboo carbon (BC) bed DBD (BC-DBD), and a quartz wool (QW)-loaded BC DBD (QC-DBD). The effects of the quality ratio of BC to QW and relative humidity on hydrogen productivity were also investigated in QC-DBD at various flow rates. The reaction process and mechanism were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, N2 physisorption experiments, infrared spectroscopy, and optical emission spectroscopy. A new reaction pathway was developed by loading BC into the fibrous structured material to activate the reaction molecules and capture the O-containing groups in the DBD reactor. A hydrogen productivity of 17.3 g/kWh was achieved at an applied voltage of 5 kV, flow rate of 4 L/min, and 100% relative humidity (RH) in the QC-DBD with a quality ratio of BC to QW of 3.0. [ABSTRACT FROM AUTHOR]

To improve the phenomenon of serious power consumption of a ladle furnace, the impact of argon flow rate on power consumption in the refining process is investigated through theoretical calculations based on the principle of alternating current measurement using Rogowski coil and integrator circuit. The study divides the power supply phase into four distinct flow rate regions in a single furnace of DH36 steel, a low‐alloy, high‐strength ship plate steel commonly used in shipbuilding and offshore platforms. The analysis of active power, current, and voltage trends, along with average power consumption per second at each flow rate region, reveals a potential for efficient reduction in power consumption. Additionally, experiments with different argon flow rates (300, 400, and 500 NL min−1) during the power supply stages of multifurnace argon tests of AB/A steel show improvements in desulfurization rate, heating rate, processing time, and power consumption per ton of steel heated by 1 °C and power consumption per ton of steel per second. [ABSTRACT FROM AUTHOR]

High-temperature annealing (HTA) is one of the most promising techniques to produce high-quality, cost-efficient AlN templates for further epitaxial growth of AlGaN devices. Unfortunately, the yield of this process seems to be limited due to the restricting face-to-face configuration that is typically used, in which contaminations of the template surface can occur easily. A high yield is crucial for process transfer into industry. Indeed, templates that are annealed in open-face configuration suffer from surface degradation due to excessive AlN evaporation during the course of the annealing process. To highlight the physics that are restricting the open-face approach of the process, sublimation behavior of AlN at temperatures and atmospheres typically used in HTA processes has to be examined. In this study, we use the Knudsen effusion mass spectrometry technique to confirm the previously published results on equilibrium partial pressures of species above AlN. Based on the experimentally determined data and further AlN sublimation experiments, the apparent sublimation coefficient of AlN in N2 and Ar atmospheres at HTA process conditions can be derived. Despite N2 having a stabilizing effect on AlN during HTA, the still high decomposition rates of several hundred nanometers per hour can explain the excessive damage that is typically observed if AlN/sapphire templates are annealed in an open-face configuration. Finally, based on theoretical considerations, a strategy to reduce the sublimation of AlN during HTA in open-face configuration is suggested. [ABSTRACT FROM AUTHOR]

This paper is devoted to the experimental study of the characteristics of a continuous optical discharge (COD) sustained by high power continuous wave laser radiation at a wavelength λ = 1.08 μ m in high pressure argon. New data on the COD threshold laser power dependence of argon pressure in the range 20–50 bar is obtained. The COD threshold laser power is shown to be in good agreement with the data obtained by other authors and theoretical evaluations provided the contribution of plasma energy loss due to thermal radiation is taken into account properly. The maximum plasma temperature was estimated to be 20–21 kk or higher, favorable to obtain high UV spectral radiance. A study of the convective plume oscillations around COD in argon has been carried out. It is found that in the pressure range 25–35 bars the growth of the laser radiation power leads to a decrease in convection oscillation frequency from 33 to 29 Hz, while the radius of the convective plume grows accordingly. The oscillation frequency ν and characteristic radius of the convective plume r 0 were found to obey the similarity relation ν = 0.5 g / 2 r 0 previously established in experiments with COD in xenon. These results are promising for using COD in argon as a high brightness broadband UV radiation source. [ABSTRACT FROM AUTHOR]

Short pulses of millimeter wave (MMW) radiation at 43 GHz create microplasma within a photonic crystal for pressures from 40 to 600 Torr (1.3 × 103–8.0 × 104 Pa). Gas breakdown occurs within a photonic crystal, which acts as an electromagnetic resonator to create a strong initial electric field. The time response of the argon metastable density is experimentally determined during the pulse and in the afterglow using laser absorption. The metastable density overshoots the steady-state condition at the beginning of the pulse and during the afterglow. Modeling is presented to understand these observations. The overproduction of argon 1s5 at the beginning of each pulse is due to a concurrent overshoot in the MMW electric field within the photonic crystal. This field overheats the plasma electrons and enhances the production of excited states. The burst of argon metastables observed in the afterglow is due to the pooled energy of the plasma stored in electrons, ions, and excited states of argon. Understanding metastable production is an important intermediate step to ionization and is also critical in the study of diode-pumped rare gas lasers. [ABSTRACT FROM AUTHOR]

[Introduction] As a clean and efficient energy source, nuclear fusion promises to achieve global sustainable development in the future. For the first wall of Chinese helium-cooled solid breeder test blanket module, the temperature fields of helium, argon and nitrogen as coolants were calculated based on the design scheme of four coolant channels proposed by the Nuclear Thermal Security and Standardization Research Team. [Method] To calculate the heat transfer of different coolants in the first wall of the cladding module of fusion reactor, the B.S. Putukhov formula is used to calculate the heat transfer.[Result] Research indicates that the temperature field variations in the Be panel and RAFM steel are similar for helium, argon, and nitrogen as coolants. The maximum temperatures in the temperature fields are below the allowable temperature, meeting the safety requirements for temperatures. Nitrogen as a coolant offers the largest safety margin, followed by argon, with helium presenting a relatively smaller safety margin.[Conclusion] This study provides more optimization options for selecting the coolant for the first wall of the test blanket module of nuclear fusion reactor, thereby enhancing the safety margin of the first wall of the test blanket module of nuclear fusion reactor.

Background. According to the hypothesis of the study, the therapeutic efficacy of measures to treat hypoxic (ischemic) emergencies can be significantly increased by using an artificial gas mixture with normal or increased oxygen content and a high content of argon, being bioactive despite its chemical inertness.Objective. To experimentally evaluate the antihypoxic effects of argon on the example of acute massive blood loss in experimental animals.Methods. The study was carried out on 72 albino male gray rats with a baseline body weight of 220–250 g. The experiments were performed at the premises of the Konstantinov St. Petersburg Nuclear Physics Institute of the Kurchatov Institute and the Smorodintsev Research Institute of Influenza (Russia). Prior to the experiment, the animals were quarantined for 2 weeks in the vivariums of the performing organizations. Acute massive blood loss in rats was formed by taking blood (12 ± 1% of body weight on average) using syringe method by transcutaneous cardiac puncture. Rats were randomized into 3 groups (24 individuals each) depending on the gaseous medium where the animal was placed after artificial blood loss. Composition of the applied gaseous medium in the comparison groups: medium No. 1 — oxygen 21% vol.; argon — 30% vol.; nitrogen — the rest; medium No. 2 — oxygen 21% vol.; argon — the rest; medium No. 3 (control) — air. The postoperative follow-up (post-conditioning) for 8 hours involved assessing and recording the following indicators: survival/lethality rates; recovery rates (anesthesia recovery, somatic mobilization); clinical symptoms of possible intoxication with the gas mixture during inhalation exposure. The surviving animals were then monitored for 4 days to evaluate their health and behavioral performance. Upon completing the observation period, the animals were euthanized.Results. After artificially-induced blood loss, all the non-survivors died within 1.5–8 hours after the operation. In group 1 (post-conditioning in medium No. 1), the lethality of laboratory animals amounted to 4 individuals out of 24 (16%); in group 2 (post-conditioning in medium No. 2) — 2 individuals out of 24 (8%). In the control group, the lethality rate was significantly higher — 10 animals out of 24 (42%). The surviving animals demonstrated no lethality or morbidity within 4 days after the exposure. Analysis of outcomes between experimental groups and controls revealed that the significance of differences in the lethality index between group 1 and control (by Fisher’s two-sided criterion) comprised p = 0.06; between group 2 and control — p = 0.017. When the statistical “power” of the experimental group was increased (by combining samples 1 and 2), the significance of differences in outcomes in this group compared to the control accounted for p < 0.001.Conclusion. The conducted studies confirmed the hypothesis about the pronounced antihypoxic effect of argon, which significantly increased the survival rate of experimental animals after massive artificially-induced blood loss.

We theoretically investigate the photoelectron angular distribution induced in argon atoms using an XUV+IR two-color scheme, comprising a Ti:sapphire laser pulse and its 13th harmonic. The photoelectron angular distributions (PADs) are computed by directly solving the three-dimensional time-dependent Schrödinger equation (TDSE) within the single active electron approximation. Particular attention is devoted to analyzing the contributing continuum partial waves of the emitted photoelectrons to the formation of the photoelectron angular distribution. We found that the shapes of the obtained angular distributions for both harmonic and sideband peaks are consistent with the predictions of the generalized Fano rule for the absorption and emission of photons. Moreover, the structure of the energy spectrum of the ejected photoelectrons is presented and discussed where we can remark that the sideband SB + 1 peak is slightly higher than the sideband peak SB − 1 . [ABSTRACT FROM AUTHOR]

Owing to the energy-efficient attributes of electrochromic technology, there has been a growing emphasis on the fabrication of electrochromic devices with high-contrast and stable performance. As an electron donor, the deliberate incorporation of oxygen vacancies into an electrochromic material is poised to significantly elevate the film's electrochromic characteristics. In this study, we successfully synthesized one-dimensional W 18 O 49 nanowires thin films with enhanced oxygen vacancies using a straightforward combination of solvothermal reactions and annealing in Ar. In comparison to films annealed in air, those treated in argon (Ar) exhibited a higher concentration of oxygen vacancies, resulting in improved light absorption characteristics. The optimal annealing conditions were determined to be 400 °C for 40 min. Under these conditions, the thin film demonstrates enhanced electrochromic performance, exhibiting a notable 71.6% modulation in transmittance, a 27.2% increase compared to the air condition. It displays a rapid response time (T b = 3.3 s, T c = 3 s), high coloration efficiency (CE = 55.9 cm2 C−1), and excellent cycling stability (with a ΔT retention rate of 93.9% after 750 cycles). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of laser trabeculoplasty (LTP) on subsequent surgery with combined phacoemulsification/Kahook Dual Blade goniotomy (phaco-KDB) in patients with open-angle glaucoma or intraocular hypertension. Patients and Methods: Patients undergoing phaco-KDB between 2019 and 2021 were divided into previously LTP treated and previously non-LTP treated, and LTP-treatment included argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). The primary goal was to investigate if previous LTP influenced later surgical outcome of phaco-KDB. The secondary goal was to investigate if the outcome of LTP could be predictive of the outcome of subsequent phaco-KDB. We also compared IOP- and medication reductions between LTP and non-LTP treated patients. Results: A total of 111 LTP treated patients were compared to 139 non-LTP treated patients. In LTP treated patients, surgical success of phaco-KDB was 82.9%, compared to 88.5% in non-LTP treated patients (P=0.20). Reductions in IOP and medications were similar between groups. Furthermore, within the LTP group, patients with successful LTP-treatment had a subsequent surgical success of phaco-KDB in 80.7%, compared to 83.0% in patients with unsuccessful LTP-treatment (P=0.765). Conclusion: Previous LTP treatment does not predict the outcome of phaco-KDB. Furthermore, no correlation was found between the LTP effect and a later surgical success of phaco-KDB. [ABSTRACT FROM AUTHOR]

Herein, the effects of the bottom shape of the submerged entry nozzle (SEN) on the molten steel flow and size distribution of argon bubbles are analyzed in a steel continuous casting slab strand using multiple‐size‐group approach. The type of nozzle bottom includes the well bottom, flat bottom, and mountain bottom. Most of argon bubbles are larger than 4.5 mm inside the SEN and the mold at the three types of nozzles. The frequency distribution of bubbles inside the SEN increases from 28.29% to 32.65% and 35.74% for 5.0–5.5 mm bubbles and decreases from 53.71–50.49% and 47.38% for 5.5–6.0 mm bubbles with the nozzle bottom varied from the flat to mountain and well shape, respectively. The number density of argon bubbles with 4.0–5.5 mm diameter in the mold decreases and increases for 5.5–6.0 mm bubbles with the nozzle bottom varying from the well to flat and mountain shape, respectively. In addition, the results of the industrial trials show that inclusions adhesion and aggregation at the bottom of the nozzle are eliminated using the flat bottom SEN casting. Meanwhile, the mechanism of SEN clogging under the different types of nozzle bottoms is analyzed. [ABSTRACT FROM AUTHOR]

We report angle-resolved energy spectra of electron emitted in the interaction of slow singly charged heavy ions with Mg surface. The work is focused mainly on the excitation of plasmons of Mg under Argon impact. Potential excitation of plasmons occurs when incoming ions are neutralized at the expense of the potential energy carried by incoming ions. The process competes with the known mechanisms of neutralization via Auger transitions. Differently from Al samples, our results show that the neutralization of Ar+ ions at Mg is dominated by the excitation of surface plasmons by the potential energy released in the electron capture process that neutralizes incoming ions. Bulk plasmon excitation is observed at higher impact energy and is ascribed to fast electrons excited by the transfer of the kinetic energy of incoming particles. The data show that bulk plasmon excitation occur inside the bulk, while the theoretically predicted excitation by potential energy transfer of incoming projectiles is not observed. [ABSTRACT FROM AUTHOR]

This study investigates the development and application of advanced predictive modeling techniques to address the critical environmental challenge of fugitive emission mitigation in industrial valve seal stacks, specifically in the context of the oil and gas sector. Emphasizing the reduction of greenhouse gas emissions, the research systematically evaluates the effectiveness of multiple seal-stack configurations in minimizing emissions. The experimental framework utilizes argon gas as a surrogate for methane to simulate real-world scenarios. The research employs a comprehensive suite of predictive models, including advanced statistical and machine learning algorithms such as linear regression, ridge regression, Lasso (least absolute shrinkage and selection operator), MARS (multivariate adaptive regression splines), and elastic net. These models are rigorously tested to ascertain their predictive accuracy in estimating the emission levels of two different seal-stack arrangements. Each seal stack contains five individual seals of PTFE and AFLAS in different sequences. The MARS model, identified for its superior performance, is then applied to predict the efficacy of various seal-stack configurations against the stringent ISO 15848–1 standards for allowable emission limits. The results of this comparative analysis offer critical insights into the optimal combination of seal stacks, contributing significantly to the advancement of environmental sustainability practices in industrial applications. This research not only provides a methodological framework for predictive analysis in this domain but also underscores the importance of integrating environmental considerations into industrial design and operation. [ABSTRACT FROM AUTHOR]

Mo 2 AlB 2 is a new and metastable phase in the MAB phase family. The lamellar Mo 2 AlB 2 compound is considered to be an optimal candidate for preparing 2D MoB nanosheets. However, studies have less focused on its thermostability as compared with other MAB phases. In this work, the thermal stability of Mo 2 AlB 2 was studied under Ar atmosphere to understand its limited applications. The results showed that Mo 2 AlB 2 slowly decomposed at above 800 °C, but completely decomposed into MoB and Al at 1100 °C for only 0.5 h. Based on the experimental results and density functional theory calculations, the decomposition mechanism of Mo 2 AlB 2 phase was analyzed. [ABSTRACT FROM AUTHOR]

Aluminum-oxygen equilibria for varying concentration of aluminum (0.0008–23.35 wt pct) content have been established at 1873 K. The experiments were carried out in an inert (high-purity argon) atmosphere by melting pure electrolytic iron with master alloy of Fe-Al in an alumina crucible and equilibrating the Fe-Al-O melt at 1873 K for two hours. A two-stage heating method in an inert gas fusion absorptiometry and scanning electron microscopy-automated inclusion analysis (SEM-AIA) have been employed to estimate the insoluble oxygen content in the samples. Aluminum-oxygen equilibria have been established separately for the total and dissolved oxygen contents. Thermodynamic analysis has been carried out using higher order interaction parameters, namely, Wagner interaction parameter formalism (WIPF) truncated at 2nd order, Darken's quadratic formalism, and the Cubic formalism. Among these formalisms, the experimental analysis has been found to be in good agreement with thermodynamic analysis based on Cubic formalism. [ABSTRACT FROM AUTHOR]

The effects of divertor pumping on divertor detachment and core performance are investigated using SOLPS-ITER simulations for the H-mode discharges with argon (Ar) seeding on EAST. The simulation results show that a relatively low pumping speed (S) is advantageous for achieving divertor detachment due to an increased Ar density and enhanced radiative dissipation. On the other hand, a relatively low S results in a high Ar density in the core region, which is detrimental to the core performance. Increasing S improves the particle removal capacity, which is not conducive to obtaining detachment but is conducive to reducing the Ar accumulation in the core region. In order to evaluate the compatibility of detachment and high core plasma performance, the impact of S on the divertor Ar retention (measured by impurity compression CAr and enrichment EAr) and the corresponding physical mechanisms were analyzed. In cases with relatively low and medium upstream density ( n e , sep OMP ), a higher S is beneficial to increase CAr and EAr, i.e. better core-divertor compatibility, mainly due to the diminished neutral diffusion towards the upstream and the enhanced net force on the Ar towards the target. At relatively high n e , sep OMP , both CAr and EA show no clear change with increasing S. This is because the negative contribution of the reduced relative distance between the Ar ionization front and the velocity stagnation point of the Ar ions to the Ar retention becomes significant with increasing S, which can even offset the positive contribution of the neutral diffusion and the net force. [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (LPBF) is a prospective and promising technique of additive manufacturing of which there is a growing interest for the development and production of Fe-based bulk metallic glasses and amorphous–nanocrystalline composites. Many factors affect the quality and properties of the resulting material, and these factors are being actively investigated by many researchers, however, the factor of the inert gas atmosphere used in the process remains virtually unexplored for Fe-based metallic glasses and composites at this time. Here, we present the results of producing amorphous–nanocrystalline composites from amorphous Fe-based powder via LPBF using argon and helium atmospheres. The analysis of the microstructures and phase compositions demonstrated that using helium as an inert gas in the LPBF resulted in a nearly three-fold increase in the amorphization degree of the material. Additionally, it had a beneficial impact on phase composition and structure in a heat-affected zone. The received results may help to develop approaches to control and improve the structural-phase state of amorphous–nanocrystalline compositional materials obtained via LPBF. [ABSTRACT FROM AUTHOR]

We present the gas-phase synthesis of 2-methyl-prop-1-ene-1,1-diol, an unreported higher energy tautomer of isobutyric acid. The enol was captured in an argon matrix at 3.5 K, characterized spectroscopically and by DFT computations. The enol rearranges likely photochemically to isobutyric acid and dimethylketene. We also identified propene, likely photochemically formed from dimethylketene. [ABSTRACT FROM AUTHOR]

Ein einkerniges, T‐förmiges Palladium(I)‐d9‐ Metalloradikal (3), stabilisiert durch einen sterisch anspruchsvollen PNP‐Liganden mit Carbazolgerüst, wurde durch die Reduktion des Chloridokomplexes oder thermische Pd−C‐Bindungshomolyse des entsprechenden Neopentylkomplexes erhalten. Unter CO‐Druck bildete sich der Pd(I)‐Carbonylkomplex, der durch Röntgenbeugung strukturell charakterisiert wurde. Die Delokalisierung des ungepaarten Elektrons zum Carbonylkohlenstoff hin wurde durch EPR‐Spektroskopie nachgewiesen und durch DFT‐ und ab initio Methoden theoretisch modelliert. Das teilweise reduzierte und radikalisierte CO reagierte langsam mit Di(tert‐butyl)disulfid unter homolytischer S−S‐Spaltung und C−S‐Bindungsbildung zu dem entsprechenden Metallothioester. [ABSTRACT FROM AUTHOR]

The photoredox-catalyzed decarboxylative cross-coupling reaction of aryl acetic acids and aryl nitriles has been achieved under an argon atmosphere in high yields. This method provides a fast way to obtain prevalent aryl acetic acids from an abundant natural source. A tentative radical mechanism has been proposed. [ABSTRACT FROM AUTHOR]

A method for activating water by plasma of an electrodeless torch discharge in a microwave electromagnetic field in argon in an environment of water vapor, at atmospheric pressure, to obtain a pure solution of hydrogen peroxide H2O2 without impurities in distilled water is proposed. It is shown that the main mechanism for the formation of atomic hydrogen H• and hydroxyl HO• radicals in the water decomposition is photolysis under the influence of excimer vacuum ultraviolet radiation of argon plasma. Hydrated electrons can be an additional source of radicals in liquid water when the plasma torch comes into contact with the water surface. Today plasma technologies are widely used to produce activated water containing hydrogen peroxide, to solve environmental problems, to increase productivity in agriculture, and for medical use. [ABSTRACT FROM AUTHOR]

For atmospheric argon RF dielectric barrier discharges, a self-consistent one-dimensional fluid model based on the drift-diffusive approximations of the particles is established to investigate the role of the neutral gas temperature on the discharge process and the plasma characteristics. A finite difference method is used to solve numerically the model, and the numerical results are obtained for the cases that the neutral gas temperature varies from 300 to 600 K. It shows that an increase in the neutral gas temperature causes a decrease in the ionization rate peak and a decrease in the plasma density, but the electric field and the electron temperature do not change very much. Moreover, the discharge mode transition from α mode to α-γ mode occurs because the growing ion flux induces more secondary electron flux, even if the ions entering the sheaths decrease. In addition, the ground state ionization and the ground state excitation are the main collisions in the argon discharges. When metastable atoms are focused on, the three-body quenching is also an important collision progress. [ABSTRACT FROM AUTHOR]

The complex multiphase flow behavior during the continuous casting of steel was investigated through a physically modeled full-scale liquid metal system. This system was operated using a stopper control system (2.5 ton Bi–Sn system). The obtained data, including nozzle pressures, were processed using a concise analytical model. Compared to water modeling, the use of a low-melting-point alloy (58% Bi and 42% Sn eutectic) allows for a full-scale system with material properties closer to those of steel (e.g., interfacial tension). An industrial-scale stainless-steel stopper and a submerged entry nozzle (SEN) were mounted on the system to prevent air permeation due to the negative pressure in the nozzle. Argon gas was injected into an industrial stopper–rod system through an argon line embedded in the stopper. The analytical model characterizes the pressure loss, flow separation, and cavitation of the stopper control system by considering the effects of argon in the nozzle. This study proposes the mapping of the pressure loss, throughput, flow separation, and cavitation based on the gas fraction and stopper position. [ABSTRACT FROM AUTHOR]

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A new equation of state for argon was developed with the view of extending the range of validity of the equation of state previously proposed by Tegeler et al. and obtaining a better physical description of the experimental thermodynamic data for the whole fluid region (single-phase, metastable, and saturation states). As proposed by Tegeler et al., this equation is also based on a functional form of the residual part of the reduced Helmholtz free energy. However, in this work, the fundamental equation for Helmholtz free energy was derived from the measured quantities CV(ρ, T) and P(ρ, T). The empirical description of the isochoric heat capacity CV(ρ, T) was based on an original empirical description explicitly containing the metastable states. The thermodynamic properties (internal energy, entropy, and free energy) were then obtained by combining the integration of CV(ρ, T). The arbitrary functions introduced by the integration process were deduced from a comparison between calculated and experimental pressure P(ρ, T) data. The new formulation is valid for the whole fluid region from the melting line to 2300 K and for pressures up to 50 GPa. It also predicts the existence of a maximum of the isochoric heat capacity CV along isochors, as experimentally observed in several other fluids. For many applications, an approximate form of the equation of state for the liquid phase may be sufficient. A Tait–Tammann equation is therefore proposed between the triple-point temperature and 148 K. [ABSTRACT FROM AUTHOR]

The Trachenko–Brazhkin equation of the minimal possible viscosity is analysed, emphasising its validity by the account of multibody interactions between flowing species through some effective masses replacing their true (bare) masses. Pressure affects the effective masses, decreasing them and shifting the minimal viscosity and the temperature at which it is attained to higher values. The analysis shows that effective masses in the Trachenko–Brazhkin equation are typically lighter compared bare masses; e.g., for tin (Sn) the effective mass is m = 0.21mSn, whereas for supercritical argon (Ar), it changes from m = 0.165mAr to m = 0.129mAr at the pressures of 20 and 100 MPa, respectively. [ABSTRACT FROM AUTHOR]

The purpose of the research is to analyze the possibility of obtaining an amorphous nanostructured state from the original amorphous state by ion irradiation. The processes of phase formation in the Fe75Mo5Si6B14 amorphous alloy under the influence of argon ion irradiation were investigated using the methods of highly sensitive dilatometry, microhardness measurements, and electron microscopy. The surface treatment of the amorphous alloy with argon ions was carried out at a voltage on the anode of 1 kV and a current through the sample of 1 mA. The surface morphology of the amorphous alloy treated with argon ions was studied under a LensSEI scanning electron microscope. The structure of amorphous alloys is characterized by the presence of frozen-in crystallization centers. It was found that the phenomenon of nanocrystallization is not observed during exposure to ion irradiation for up to 30 minutes. This is explained by the fact that, as a result of ion irradiation, the local temperature on the surface of the sample rises and reaches such values, at which, according to the thermodynamic theory of thermal stability, the frozen centers of crystallization can dissolve in the amorphous matrix. When the ion irradiation time of the source alloy is increased to 45 minutes, a decrease in thermal stability of 25 °C and an increase in microhardness of 8.2% are observed, therefore, the alloy is strengthened. This indirectly indicates the formation of an amorphous-nanocrystalline state in the alloy. Structural changes are also confirmed by the results of studies of the amorphous alloy surface morphology by scanning electron microscopy. After irradiation, both the number of crystal nuclei and their average size increase significantly (from 20 nm in the source alloy to 65 nm in the irradiated one). The changes in the number and size of crystal nuclei are explained by the fact that at an irradiation time of 45 minutes, the temperature in the regions of the ion tracks reaches threshold values and thermodynamic conditions are created for the growth of frozen crystallization centers. [ABSTRACT FROM AUTHOR]

In this work, PVA/NaI consisting of polyvinyl alcohol (PVA) and sodium iodine (NaI) is irradiated using argon at fluence (45×10 1 6 , 90×10 1 6 , and 135×10 1 6 ion/cm2). The structure is investigated by XRD technique. The influence of argon ion is studied theoretically by SRIM/TRIM simulations. The target vacancies are recorded 46/ion, target displacements are 47/ion, and the replacements atoms are 1/ion. Also, the dielectric properties were determined in the frequency of 100 Hz to 5 MHz. With an average fluence 90×10 1 6 ions/cm2, electrical conductivity and dielectric constants have increased to twice their initial value. Additionally, after being exposed to an ion beam, the dielectric loss is reduced to around half of its original value. For both the control and irradiation samples, the attenuation and half layers were estimated. The dielectric characteristics of the irradiated samples were found to improve. Numerous uses, including energy storage and batteries, are rendered possible by these results. [ABSTRACT FROM AUTHOR]

Microinclusions in steel will significantly affect mechanical performance of final products and therefore require serious concern during metallurgical process. Herein, the collision, coalescence as well as floatation of bubble–inclusion coexisting system is fully studied through a new mathematical model. It comes to the following conclusions: as bubbles rise, they induce a flow of liquid steel from their upper surface to their lower surface, and inclusion droplets rise and collide in the wake of the bubble. The velocity of the bubbles is affected by their deformation, with deformation rates being linked to the Weber number. The coalescence time of these inclusions is primarily influenced by viscosity and surface tension. Coalescence accelerates with higher surface tension or reduced viscosity, and this phenomenon can be described by a formula, which is developed by simulation results. According to this formula, coalescence time of 3CaO·Al2O3 is 20% longer than that of 12CaO7·Al2O3. Consequently, 12CaO7·Al2O3 is more prone to coalescence. The movement of inclusions can be controlled by adjusting gas volume and flow rate. Moreover, promoting coalescence can be achieved by altering the viscosity of inclusions and the surface tension coefficient, making it easier to remove these unwanted inclusions. [ABSTRACT FROM AUTHOR]

A GPU-based implementation of the Hybrid Monte Carlo (HMC) algorithm is presented to explore its utility in the chemistry of solidification at the example of liquid to solid argon. We validate our implementation by comparing structural characteristics of argon fluid-like phases from HMC and MD simulations. Examining solidification, both MD and HMC show similar trends. Despite observable differences, MD simulations and HMC agree within the errors during the phase transition. Introducing voids decreases the solidification temperature, aiding in the formation of a well-structured solids. Further, our findings highlight the importance of larger system sizes in simulating solidification processes. Simulations with a temperature dependent potential show ambiguous results for the solidification which may be attributed to the small system sizes. Future work aims to expand HMC capabilities for complex chemical phenomena in phase transitions. [ABSTRACT FROM AUTHOR]