Search

The target surface to be treated in reality is often not smooth and horizontal and may also be in different tilting angles. The treatment of the tilted dielectric surface by the atmospheric pressure plasma jet (APPJ) undoubtedly increases the complexity of surface modification. Therefore, a two-dimensional fluid model is established to reveal the internal mechanism of the interaction between the He APPJ and the tilted dielectric surface by means of numerical simulation. The distribution of the gas flow in a small angular range (0°, 3°, 5°, 8°, 10°, and 15°) is studied. In addition, the effects of the tilt angle on the jet morphology, discharge dynamic properties, and species distribution of the He APPJ are emphatically discussed. It is found that the jet morphology and parameters are no longer symmetrical under the tilted surface. With the increase in the tilt angle, the enhanced electric field in the upper surface region leads to the increase in the ionization rate and electron density here, and also accelerates the propagation speed of the jet to the dielectric surface in the atmospheric environment. Driven by the electric field force, the jet is closer to the dielectric surface, resulting in a decrease in the thickness of the cathode sheath and an increase in the surface charge density in the area to the right of the central axis. The influence of the gas flow structure leads to the shortening of the jet development distance and a decrease in the jet velocity on the upper surface. N and O also form higher fluxes on the upper surface due to the increase in the electron density. [ABSTRACT FROM AUTHOR]

A reduced pressure glow discharge is produced by passing a high-power pulsed DC source of 0–500 W with a frequency of 50 Hz across two parallel disk electrodes. A hydrogen peroxide aqueous solution is used as a flowing gas for discharge generation. Optical emission spectroscopy is employed to diagnose the discharge generated at a reduced pressure of 0.2 mbar with an electrode gap of 4 cm. The spectra are recorded at a power density of 9.4 mW/cm3 and typically lie in the visible wavelength range of 380–880 nm. The spectra are analyzed using the line intensity ratio method to estimate electron temperature and density. The results indicated that the electron temperature and density are, respectively, 0.87 eV and 6.4 × 1014 cm−3. [ABSTRACT FROM AUTHOR]

The microwave electrothermal thruster (MET) utilizes wave-exited microdischarges to heat gas flows, enhancing the specific impulse of the thruster. Our computational study investigates a 17.5 GHz helium-propellant MET, employing a two-dimensional, axisymmetric fluid model of plasma coupled with electromagnetic wave and gas flows. The discharges operate in the glow regime, remaining weakly ionized, and in thermal non-equilibrium. The plasma densities reach approximately 10 20 m − 3 , and the gas temperature is around 2000 K. Even a slight off-resonant frequency operation results in a significantly lower plasma density and gas temperature. Gas heating, primarily driven by electromagnetic Joule heating, plays a critical role in influencing the overall discharge behavior. The measured peak thrust and specific impulse are 8.24 mN and 292 s, respectively, at a mass flow rate of 3.2 mg/s with 30 W of power. Compared to a cold gas thruster, there is a significant increase in the specific impulse by a factor of approximately 1.7. The enhanced performance trades off with propulsive efficiency, which decreases by a factor of 1.5 from the peak 65% at 10 W. This is due to higher energy losses to cavity walls from heat conduction with increased power. These findings underscore the critical balance between the input power and mass flow rate to improve the MET performance, highlighting the importance of power management to maximize thrust and efficiency. Furthermore, the predicted thrust and specific impulse agree well with experimental values for nominally similar MET thruster studies in the literature. [ABSTRACT FROM AUTHOR]

Photothermal spectroscopy, and more specifically photothermal interferometry (PTI), is a highly sensitive technique for measuring gas and aerosol concentrations. Numerous implementations of different PTI configurations have demonstrated the versatility of the technique. This theoretical study presents a comprehensive analysis and an optimization of the PTI optical path length (OPL) amplitude using characteristic times. We investigate how the OPL amplitude depends on the dimensions and orientations of the interferometer laser beam and the continuous-wave excitation laser beam. This analysis quantifies the impact of advection on the OPL amplitude based on the relative orientation of the two laser beams and the gas flow direction. It is analytically shown that the possibilities for photothermal OPL amplitude optimization are limited when thermal diffusion is dominant. Theoretically, advection has the potential to double or cancel the OPL amplitude, depending on the specific configurations. In summary, we provide an in-depth understanding of the design and parameter considerations required when tailoring and optimizing a PTI sensor for different fields of applications. [ABSTRACT FROM AUTHOR]

Equilibrium thermodynamics describes the energy exchange of a body with its environment. Here, we describe the global energy exchange of an ideal gas in the Coutte flow in a thermodynamic-like manner. We derive a fundamental relation between internal energy as a function of parameters of state. We analyze a non-equilibrium transition in the system and postulate the extremum principle, which determines stable steady states in the system. The steady-state thermodynamic framework resembles equilibrium thermodynamics. [ABSTRACT FROM AUTHOR]

Regulatory authorities in biopharmaceutical industry emphasize process design by process understanding but applicable tools that are easy to implement are still missing. Soft sensors are a promising tool for the implementation of the Quality by Design (QbD) approach and Process Analytical Technology (PAT). In particular, the correlation between viable cell counting and oxygen consumption was investigated, but problems remained: Either the process had to be modified for excluding CO 2 in pH control, or complex k L a models had to be set up for specific processes. In this work, a non-invasive soft sensor for simplified on-line cell counting based on dynamic oxygen uptake rate was developed with no need of special equipment. The dynamic oxygen uptake rates were determined by automated and periodic interruptions of gas supply in DASGIP® bioreactor systems, realized by a programmed Visual Basic script in the DASware® control software. With off-line cell counting, the two parameters were correlated based on linear regression and led to a robust model with a correlation coefficient of 0.92. Avoidance of oxygen starvation was achieved by gas flow reactivation at a certain minimum dissolved oxygen concentration. The soft sensor model was established in the exponential growth phase of a Chinese Hamster Ovary fed-batch process. Control studies showed no impact on cell growth by the discontinuous gas supply. This soft sensor is the first to be presented that does not require any specialized additional equipment as the methodology relies solely on the direct measurement of oxygen consumed by the cells in the bioreactor. • Non-invasive soft sensor method for simplified on-line cell counting. • Implemented in exponential growth phase of CHO cells. • Dynamic oxygen uptake rate as only predictor resulted in a correlation coefficient of 0.92. • No negative influences on cell growth as oxygen starvation was prevented. • 5-k cross validation showed RMSE of 0.7 × 106 cells/mL. [ABSTRACT FROM AUTHOR]

Recently, the use of wearable smart devices has significantly increased; however, sweat can corrode the outer-layer films, thereby decreasing their transmittance, conductivity, and overall functionality. In this study, fluorine-doped tin oxide (FTO) films for wearable smart devices were prepared via magnetron sputtering. The effects and mechanism of O2 gas flow in plasma on the properties of the fabricated films were investigated. Minor changes were observed in the film morphologies, with the preferred orientations shifting from polar (101) to nonpolar (110) and standard positions. As the O2 flow rate increased from 0 to 2 sccm, the transmittance of the film within the visible spectrum increased from 83% to 89%, with sheet resistance values in the order of 102–106 Ω sq−1. Following immersion in an acidic sweat solution, the film without O2 peeled off, whereas several corrosion pits were observed in the films with 1 or 2 sccm O2. Conversely, following immersion in an alkaline sweat solution, several pits were observed in the films without O2, while the other films exhibited excellent corrosion resistance. The transmittance of the films immersed in different solutions did not significantly differ. Notably, the sheet resistances of the films treated with 1 sccm O2 met the industrial requirement of 3000 Ω. Moreover, the coexistence of polar and nonpolar planes provided transparency and conductive stability to the FTO films treated with 1 sccm O2. Our study aimed to not only enhance the transmittance and sweat-corrosion resistance but maintain the conductivity of the outer screen layer of a wearable smart electronic device. [ABSTRACT FROM AUTHOR]

Pt nanoparticles (NPs) loaded on TiO 2 photocatalyst as cocatalyst is well-known for significantly enhancing photocatalytic H 2 production from an aqueous methanol solution since Pt NPs in contact with the TiO 2 surface can improve the charge separation by accepting photoexcited electrons. In this study, another catalytic role of Pt NPs was clearly evidenced by a simple method, using a flow reactor and gas mixture of methanol and water in argon carrier, in which TiO 2 photocatalyst and separately supported Pt NPs are located without physical contact. It was demonstrated that hydrogen radical species, generated on the TiO 2 photocatalyst, are capable of migrating through a quartz wool layer of several millimeters in length and reach the Pt NPs on alumina support, where coupling of the hydrogen radical to form H 2 molecules is catalytically promoted by the Pt NPs. [Display omitted] • Mixture of TiO 2 and Pt/Al 2 O 3 promotes photocatalytic H 2 production and selectivity. • Experiments with a flow reactor evidenced catalytic role of Pt cocatalyst. • Pt NPs catalyze coupling of hydrogen radicals to form H 2. • Hydrogen radical can migrate for millimeter scale in gaseous reaction mixture. • Shorter distance between TiO 2 and Pt NPs gives higher H 2 production rate. [ABSTRACT FROM AUTHOR]

Rare earth ytterbium monosilicate (Yb 2 SiO 5) is one of the most ideal candidates for environmental barrier coatings. In this paper, Yb 2 SiO 5 coating was successfully fabricated by atmospheric plasma spraying technology. The effect of main gas flow rate and spraying powder composition on the microstructure and phase composition of Yb 2 SiO 5 coating were systematically investigated to solve the volatilization of SiO 2 during plasma-spraying process. The results showed that Yb 2 SiO 5 coating was relatively dense with the less internal defects under the main gas flow rate of 35 L/min, and the main gas flow rate from 30 L/min to 40 L/min had no significant effect on the melting effect of spraying powder and the porosity of coating. Yb 2 SiO 5 coating was composed of Yb 2 O 3 , Yb 2 SiO 5 two crystal phases and amorphous phase. The phase composition of coating was not affected by the change of main gas flow rate. After heat-treatment at 1400 °C for 20 h, Yb 2 SiO 5 crystal phase precipitated from the coating, and the content of Yb 2 SiO 5 phase reached 74.29 mol%, and the remaining phase was Yb 2 O 3 phase. The Yb 2 SiO 5 -25.71 mol% SiO 2 coating was still dense, the content of Yb 2 SiO 5 crystal phase was up to 97.76 mol% after heat-treatment, and the content of Yb 2 Si 2 O 7 phase was only 2.24 mol%, indicating that excessive addition of a certain amount of SiO 2 could compensate for the volatilization of SiO 2 , so as to prepare Yb 2 SiO 5 coating with approximate stoichiometric ratio. [ABSTRACT FROM AUTHOR]

To improve the oxidation and ablation resistance of SiC f /SiC composites, the as-synthesized ultrafine HfB 2 powder was used as the modification phase to fabricate SiC f /SiC-HfB 2 composites, and their oxidation and ablation behaviors were investigated. Compared with the unmodified SiC f /SiC composites, the oxidation resistance at 800–1500 °C and the ultra-high temperature ablation resistance of SiC f /SiC-HfB 2 composites were significantly improved. After oxidation, a compact compound glass scale consisting of HfO 2 , HfSiO 4 and Si-Hf-O glass was formed, providing the effective oxidation protection. A dual-phase oxide scale composed of HfO 2 skeleton and Si-Hf-O glass was formed after ablation, exhibiting the high viscosity, the significant oxygen-blocking effect and resistance to gas flow scouring. The improved oxidation and ablation resistance of SiC f /SiC-HfB 2 composites could be attributed to the effective protective role of oxygen-blocking scales formed during the oxidation and ablation processes. [ABSTRACT FROM AUTHOR]

Recent (sub)millimetre polarization observations of protoplanetary discs reveal toroidally aligned, effectively prolate dust grains large enough (at least |$\sim 100$| |$\mu$| m) to efficiently scatter millimetre light. The alignment mechanism for these grains remains unclear. We explore the possibility that gas drag aligns grains through gas–dust relative motion when the grain's centre of mass is offset from its geometric centre, analogous to a badminton birdie's alignment in flight. A simple grain model of two non-identical spheres illustrates how a grain undergoes damped oscillations from flow-induced restoring torques which align its geometric centre in the flow direction relative to its centre of mass. Assuming specular reflection and subsonic flow, we derive an analytical equation of motion for spheroids where the centre of mass can be shifted away from the spheroid's geometric centre. We show that a prolate or an oblate grain can be aligned with the long axis parallel to the gas flow when the centre of mass is shifted along that axis. Both scenarios can explain the required effectively prolate grains inferred from observations. Application to a simple disc model shows that the alignment time-scales are shorter than or comparable to the orbital time. The grain alignment direction in a disc depends on the disc (sub-)structure and grain Stokes number (St) with azimuthal alignment for large St grains in sub-Keplerian smooth gas discs and for small St grains near the gas pressure extrema, such as rings and gaps. [ABSTRACT FROM AUTHOR]

Star formation is a multiscale problem, and only global simulations that account for the connection from the molecular cloud-scale gas flow to the accreting protostar can reflect the observed complexity of protostellar systems. Star-forming regions are characterized by supersonic turbulence, and as a result, it is not possible to simultaneously design models that account for the larger environment and in detail reproduce observed stellar systems. Instead, the stellar inventories can be matched statistically, and the best matches found that approximate specific observations. Observationally, a combination of single-dish telescopes and interferometers are now able to resolve the nearest protostellar objects on all scales from the protostellar core to the inner |$10\, \mathrm{au}$|⁠. We present a new non-parametric methodology which uses high-resolution simulations and post-processing methods to match simulations and observations using deep learning. Our goal is to perform a down-selection from large data sets of synthetic images to a ranked list of best-matching candidates with respect to the observation. This is particularly useful for binary and multiple stellar systems that form in turbulent environments. The objective is to accelerate the rate at which we can do such comparisons, remove biases from hand-picking matches, and contribute to identifying the underlying physical processes that drive the creation and evolution of observed protostellar systems. [ABSTRACT FROM AUTHOR]

The solid form of the uranyl peroxide cage (UPC) cluster LiU28 (Li28[(UO2)28(O2)42]) was irradiated by 5 MeV He2+ ions to achieve doses up to 42 MGy. An intermediate compound formed that reacts with atmospheric CO2 to form uranyl carbonates. The role of water in the UPC to uranyl carbonate transformation was studied by flowing either dry or hydrated Ar over samples during He2+ irradiation, and by storing samples in dry and humid environments before and after irradiation. Raman, infrared, and X-ray photoelectron spectroscopies and electrospray ionization mass spectrometry were used to characterize solid Li–U28 salts before and after He2+ irradiation. The highest yield of uranyl carbonates occurred when hydrated Ar gas was flowed across the sample during He2+ irradiation. Electron paramagnetic resonance spectroscopy provided evidence of hydroxyl and superoxide radicals in both unirradiated and γ-irradiated Li–U28. [ABSTRACT FROM AUTHOR]

Power‐to‐methane (PtM) offers an efficient opportunity for surplus renewable energy storage, but heat management is a major challenge for conducting the highly exothermic methanation reaction. To address this challenge, this study presents the first successful demonstration of core‐shell catalyst pellets in a pilot‐scale reactor for CO2 methanation. Experiments in a wall‐cooled fixed‐bed reactor are conducted with diluted and undiluted reactant feed under systematic variation of cooling temperature and inlet gas flow rate. The results show that core‐shell catalyst pellets significantly reduce the hot‐spot temperature while maintaining comparable reactant conversions to uncoated catalyst pellets at the same conditions. Additionally, core‐shell catalyst pellets allow for undiluted reactant feed at comparably low hot‐spot temperatures (approx. 600 °C). [ABSTRACT FROM AUTHOR]

ABSTRACT The use of millimeter quartz tubes to generate non‐thermal plasma in contact with liquid is widely applied in medicine, such as the effective disinfection of catheter tubes and tooth cavities. Here, the effects of tube diameter and gas flow rate on discharge dynamics and reactive species characteristics of nanosecond pulse needle‐water discharge are studied using an ICCD camera and optical emission spectra. The discharge diffusion is increased significantly by an appropriate combination of tube diameter and gas flow rate. Besides, the discharge intensity, emission spectra intensities of reactive species, gas temperature, and electron density increase with the increase of quartz tube diameter and gas flow rate, which contributes to enhance the production of OH and H2O2 species in aqueous samples. [ABSTRACT FROM AUTHOR]

In order to quantify the failure performance of PEMFCs' C/C composite bipolar plates (BPs) under considering the uncertainty in multiscale sizes and loads, the failure probability function (FPF) of BPs at cold start is estimated. A three-stage multiscale simulation method is proposed for mechanical behavior analysis of multi-component heterogeneous composites. And the efficient estimation of FPF for C/C composite BPs is achieved via the proposed multiscale simulation method and decoupling sparse integration method, in which the unified density weight is constructed to decouple the double-loop framework of analyzing FPF, thereby reducing the computational complexity. Results indicate that the dangerous positions of BPs are around the gas flow channels and bolt holes. And the dangerous components are the carbon matrix and the interface between the matrix and fiber. The radius of elliptical fibers affects the distribution of failure factors on microscopic components, thereby affecting the variation of failure probability with fiber sizes significantly. The distribution parameter of composite layer thickness in BPs has a significant effect on structural safety, and the FPF result can be used to effectively guide the design of structure. Therefore, the proposed method is of great significance for guiding the rapid parameter design of composite BPs. • Multiscale and multi-component failure analysis method is first proposed for BPs. • FPF of BPs is decoupled by constructing the unified density weight function. • Dangerous failure position and component are determined in C/C composite BPs. • Influences of macro and micro parameters on FPF of BPs are clarified and analyzed. [ABSTRACT FROM AUTHOR]

A highly sensitive optical fiber gas pressure sensor with temperature monitoring is proposed and demonstrated. It is based on a slightly tapered fiber with an inner micro-cavity forming an in-fiber Mach–Zehnder interferometer (MZI), and a micro-channel is drilled into the lateral wall of the in-fiber micro-cavity using a femtosecond laser to allow gas to flow in. Due to the dependence of the refractive index (RI) of air inside the micro-cavity on its gas pressure and the high RI sensitivity of the MZI, the device is extremely sensitive to gas pressure. To prevent fiber breakage, the MZI is housed in a silicate capillary tube with an air inlet. Multiple modes are excited by slightly tapering the inner micro-cavity, and the resonance dips in the sensor's transmission spectrum feature different linear gas pressure and temperature responses, so a sensitivity matrix algorithm can be used to achieve simultaneous demodulation of two parameters, thus resolving the temperature crosstalk. As expected, the experimental results demonstrated the reliability of the matrix algorithm, with pressure sensitivity reaching up to ~−12.967 nm/MPa and temperature sensitivity of ~89 pm/°C. The features of robust mechanical strength and high air pressure sensitivity with temperature monitoring imply that the proposed sensor has good practical and application prospects. [ABSTRACT FROM AUTHOR]

Thermal analysis is widely employed for the characterization of nanomaterials. It encompasses a variety of techniques that allow the evaluation of the physicochemical properties of a material by monitoring its response under controlled temperature. In the case of carbon nanomaterials, such as carbon nanotubes and graphene derivatives, thermogravimetric analysis (TGA) is particularly useful to determine the quality and stability of the sample, the presence of impurities and the degree of functionalization or doping after post-synthesis treatments. Furthermore, TGA is widely used to evaluate the thermal stability against oxidation by air, which can be, for instance, enhanced by the purification of the material and by nitrogen doping, finding application in areas where a retarded combustion of the material is required. Herein, we have evaluated key parameters that play a role in the data obtained from TGA, namely, gas flow rate, sample weight and temperature rate, used during the analysis. We found out that the heating rate played the major role in the process of combustion in the presence of air, inducing an increase in the temperature at which the oxidation of CNTs starts to occur, up to ca. 100 °C (from 1 °C min−1 to 50 °C min−1). The same trend was observed for all the evaluated systems, namely N-doped CNTs, graphene produced by mechanical exfoliation and N-doped reduced graphene samples. Other aspects, like the presence of impurities or structural defects in the evaluated samples, were analyzed by TGA, highlighting the versatility and usefulness of the technique to provide information of structural aspects and properties of carbon materials. Finally, a set of TGA parameters are recommended for the analysis of carbon nanomaterials to obtain reliable data. [ABSTRACT FROM AUTHOR]

Atomically thin molybdenum disulfide (MoS2) is a two-dimensional semiconductor with versatile applications. The recent adoption of liquid molybdenum precursors in chemical vapor deposition has contributed significantly to the reproducible wafer-scale synthesis of MoS2 monolayer and few-layer films. In this work, we study the effects of the carrier gas flow rate on the properties of two-dimensional molybdenum disulfide grown by liquid-precursor-intermediate chemical vapor deposition on SiO2/Si substrates. We characterized the samples using Optical Microscopy, Scanning Electron Microscopy, Raman spectroscopy, and Photoluminescence spectroscopy. We analyzed samples grown with different nitrogen carrier flows, ranging from 150 to 300 sccm, and discussed the effect of carrier gas flows on their properties. We found a correlation between MoS2 flake lateral size, shape, and number of layers, and we present a qualitative growth model based on changes in sulfur provision caused by different carrier flows. We show how the use of liquid precursors can allow for the synthesis of homogeneous, single-layer flakes up to 100 µm in lateral size by optimizing the gas flow rate. These results are essential for gaining a deeper understanding of the growth process of MoS2. [ABSTRACT FROM AUTHOR]

Gas evolution and flow patterns inside an alkaline electrolyzer cell strongly affect efficiency, although such effects have not been explored in detail to date. The present study aims to critically analyze the dependence of cell performance on the multiphase flow phenomena, defining some key metrics for its assessment using CFD. Six performance indicators, involving gas accumulation, bubble coverage, and flow uniformity, are applied to a 3D CFD model of an alkaline cathodic cell, and possible optimizations of the cell geometry are evaluated. The results demonstrate the complexity of defining the optimal indicator, which strictly depends on the case study and on the analysis at hand. For the cell analyzed herein, the parameters linked to the electrode volume fraction were indicated as the most influential on the cell efficiency, allowing us to define the best geometry case during the optimization. Furthermore, a sensitivity analysis was conducted, which showed that higher mass flow rates are generally preferable as they are linked to higher bubble removal. Higher current densities, allowing enhanced gas production, are instead associated with slightly lower efficiencies and stronger nonuniformity of the electrolyte flow inside the cell. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The OBJECTIVE: of this study was to analyze the use of rebound tonometry, as a noninvasive diagnostic tool, in arachnids. METHODS: 5 juvenile (yearling) female and 1 juvenile male curlyhair tarantulas (Tliltocatl albopilosus, previously Brachypelma albopilosum) were used to track estimated ventral opisthosoma pressures over a 9-month period of time. Younger, growing animals were selected as they are more likely than adults to go through multiple molts throughout the 9 months of the study length. An iCare TONOVET TV01 rebound tonometer was used to measure the estimated ventral opisthosoma pressures of the spiders. Measurements were obtained from the ventral opisthosoma, 1 of the thinnest areas of exocuticle throughout the body. Readings were obtained once per week from the ventral opisthosoma for the first 2 months, then once every 2 weeks for 1 month, then back to once per week for the remainder of the study. Additional measurements were obtained following each ecdysis, after a 2% body weight sampling of hemolymph, and at the end of the study to evaluate readings in response to induction of general anesthesia with 5% isoflurane gas and oxygen flow at 2 L/min for 10 minutes. RESULTS: The average of all estimated ventral opisthosoma pressure when spiders were not in molt was 26.19 mm Hg (SD, 3.54), with a statistically significant decrease postmolt to an average of 15.31 mm Hg (SD, 3.81), followed by a gradual increase back to premolt pressures over a 3-week period with an average of 22 days (SD, 1.93). Estimated ventral opisthosoma pressures decreased post hemolymph removal. There is not sufficient evidence that estimated ventral opisthosoma pressures changed over time following the anesthesia. CLINICAL RELEVANCE: This study demonstrates that tonometry can be used to generally assess the estimated ventral opisthosoma pressure, which could correlate with where a spider is in an ecdysis cycle. [ABSTRACT FROM AUTHOR]

Of the total carbon footprint of Australia, 7% is attributed to healthcare. In the UK, inhalational agents make up 5% of the healthcare carbon footprint. This systematic review aims to determine which methods of education about the environmental impact of inhalational anaesthetic agents can be utilised to promote behaviour change, reducing the anaesthetic-related carbon footprint. This systematic review sourced records from CINAHL, EMBASE, ERIC, JBI and MEDLINE from 1970 to March 2022. The search identified 589 records, 13 of which met eligibility criteria after the screening process, in which 10 of these records were conference abstracts. Education curricula focused on inhalational agent choice (69%), lowering the fresh gas flow during maintenance anaesthesia (69%), encouraging alternatives such as total intravenous anaesthesia (23%) and/or switching off the gas on transfer (8%). The most common teaching techniques utilised in education curricula were didactic lectures (85%), visual prompts (54%), emails (46%), and conversation forums (31%). All but one study reported a positive relationship between teaching sessions and behavioural change resulting in lower inhalational anaesthetic use by participants and their organisations, reducing healthcare-associated emissions. This systematic review has demonstrated that single education sessions as well as multi-focused, multimodal education curricula on the topic of greener anaesthesia can be beneficial in promoting behavioural change. [ABSTRACT FROM AUTHOR]

Effective length of swirl flow is important for its application in the industry, however, the length of the swirl flow in a horizontal pipe is largely unexplored. In this article, effects of swirl on a horizontal bubbly flow and its development in a 25 mm horizontal pipe with a length of 4 m were studied by an experimental and theoretical method. In the experiments, the superficial gas velocities ranged from 0.068 to 0.566 m/s and the liquid velocities ranged from 0.283 to 1.132 m/s. The results show that: instead of dispersed bubbles in the non-swirl bubbly flow, a gas column flow is transformed downstream of the swirler; then, it breaks up into separated gas slugs, and finally, transforms to a non-swirl bubble flow. The pressure drop in the swirl flow gradually decreases and approximates to that in the non-swirl flow along the streamwise direction. The transition mechanism for the gas column flow was proposed here, and the transition criteria of the gas column flow were developed based on Kelvin–Helmholtz instability, then, the effective length of swirl on the gas column flow can be predicted. [ABSTRACT FROM AUTHOR]

Vertical gas and dust flows in protoplanetary discs waft material above the mid-plane region in the presence of a protoplanet. This motion may alter the delivery of dust to the planet and its circumplanetary disc, as well as through a planetary-induced gap region and hence the inner disc chemistry. Here, we investigate the impact of a massive embedded planet on this material transport through the gap region. We use 3D global hydrodynamic simulations run using FARGO3D with gas and dust species to investigate the dust filtration and the origin of material that can make it through the gap. We find small dust particles can pass through the gap as expected from results in 2D and that this can be considered in two parts – filtering due to the planetary-induced pressure maximum and filtering due to accretion on to the planet. When gas accretion on to the planet is included, we find that the larger dust grains that cross the gap (i.e. those with |$\mathrm{St} \sim 10^{-4}$|⁠) originate from regions near the mid-plane. We also find that dust and gas that enter the planet-carved gap region pass through the Hill sphere of the planet, where the temperature is likely to be strongly enhanced compared with the mid-plane regions from which this material originated. Considering the application of our simulations to a Jupiter-mass planet at |$\sim 100\ \mathrm{au}$|⁠ , this suggests that CO ice is very likely to desorb from grains in the close proximity of the planet, without requiring any fine-tuning of the planet's location with respect to the CO snowline. [ABSTRACT FROM AUTHOR]

The study aims to comprehend the behavior of nitrogen in the argon oxygen decarburization (AOD) process during the production of nitrogen‐alloyed stainless steels, where the precise adjustment of nitrogen content plays a crucial role in enhancing productivity. Furthermore, the objective is to investigate the rate of change in nitrogen content when blowing a mixture of nitrogen and argon, instead of using pure nitrogen or argon alone. Hence, both nitrogenation and denitrogenation cases are examined, and kinetic models are developed. While solution thermodynamics can predict the final nitrogen content, the kinetics are influenced by the gas flow rate, steel temperature and composition, and levels of the surface active elements in the steel. By integrating a previously developed thermodynamic equilibrium equation with the kinetic models, nitrogen contents in the range of 0.150–0.400% can be reliably predicted. Consequently, the equations can be applied to predict nitrogen content during both the nitrogenation and denitrogenation stages in the reduction and desulfurization phases of the AOD process. [ABSTRACT FROM AUTHOR]

A 3D discrete phase model (DPM)‐ and volume of fluid–coupled model is developed to investigate the multiphase flow in a 260 ton argon‐stirred ladle. The flow field and interfacial behavior in the argon‐stirred ladle are accurately predicted. Then, the Lagrangian DPM is used to trace the motion of inclusions in the liquid steel. Residence time maps, which provided the residence time required for inclusions travelling from the bulk liquid steel to the steel–slag interface, are proposed and plotted as functions of inclusion diameter and percentage of inclusions. For inclusions smaller than 10 μm, the average residence time is size‐independent but decreases from 175 to 93 s with an increment in the gas flow rate from 50 to 400 NL min−1. With increasing the inclusion size, the average residence time is dependent on both gas flow rate and inclusion diameter. When the inclusion diameter increases to 1000 μm, the average residence time is almost independent of the gas flow rate. The current model overestimates the inclusion removal rate. However, this overestimation indicates that only appropriately considering the behavior of inclusions at the steel–slag interface can accurately predict the removal of inclusions in argon‐stirred ladles. [ABSTRACT FROM AUTHOR]

Gas bubbling can be an effective means to float out alumina inclusions from liquid steel in a ladle. However, large spherical cap bubbles are formed when using porous plugs, as the liquid steel is nonwetting to the porous refractory. These bubbles rise rapidly through the liquid steel, forming a fast‐moving bubble plume, restricting contact times. Sized microbubbles, by contrast, have now been generated in liquid metals by shearing methods, involving linear crossflows to an entering flow of gas, or alternatively by rotational shearing. Combined with these convective shearing forces, local kinetic energy of turbulence can also play an important part in determining final microbubble size distributions. As microbubbles have much smaller rise velocities and present a far greater inclusion capture surface area than those of a single large bubble of the same gross volume, this will allow us to remove sub‐50 μm inclusions from liquid steel. It is expected that this goal will require a redesign of current ladle shrouds. [ABSTRACT FROM AUTHOR]

Original coal reservoir contains massive free and adsorbed methane, that directly affects the mechanical properties and permeability of coal with its unique dual effects, which may, thus, promote the gestation and occurrence of mine gas disasters. Mining disturbance and borehole drainage can facilitate the plastic rupture of surrounding rock mass, which would result in the gas migration law becoming more complex that, in turn, would be difficult to explain based on classical elastic deformation theory. Therefore, understanding elastoplastic deformation behavior and gas migration law relating to coal under engineering disturbance is crucial for preventing gas disasters. First, when mechanical and adsorption induced effects of gas on coal are considered, a concept of effective total pore pressure has been proposed. From which, calculation of plastic deformation in accordance with non-associated flow rule, a constitutive model that considered elastoplastic deformation (EPC Model) was established to simulate deformation and failure characteristics. Following that, a permeability jump coefficient was introduced to describe the sudden increase in permeability following damage and failure in coal, and an elastoplastic damage-permeability model (EPDP Model) was further deduced on basis of cubic law. Finally, through triaxial compression-seepage experimental data to verify the established EPC Model and EPDP Model. The results revealed that gas would weaken coal's mechanical properties (peak strength and elastic modulus) by changing its microstructure, whose deterioration would become more obvious with an increase of gas pressure. The changes to the permeability curve were of an "S" type, which showed a good corresponding relationship with the change trends relating to whole stress–strain curve. Both the EPC Model and the EPDP Model exhibited satisfactory matching effects with experimental data. Furthermore, EPDP Model was popularized and applied, with its universality being verified by the experimental data relating to a reduction in pore pressure seepage. This research will provide a new thinking for ensuring safe and efficient production in coal mines. Highlights: When the double effect of gas on coal were examined, Terzaghi's effective stress principle was modified appropriately, and a concept of effective total pore pressure has been proposed. The plastic strain on coal during triaxial compression was calculated, and an elastoplastic constitutive model that investigated gas action was further deduced. A permeability jump coefficient was introduced to describe permeability change following damage and failure to coal, thereby, making it possible to establish a damage-permeability model during elastoplastic deformation. The damage-permeability model was simplified appropriately, in order for it to be suitable to be employed as a classical elastic permeability model appropriate during CBM extraction stage, with its application scope of the permeability model being extended. [ABSTRACT FROM AUTHOR]

This article outlines techniques for optimizing input parameters for the welding process, such as welding current, speed, and gas flow rate in relation to weld bead geometry and Dilution, using Response Surface Methodology (RSM). In the wire arc additive manufacturing (WAAM) process, single-weld bead stability and quality play a prominent role in the final manufactured part's quality and shape. A single-bead geometry model was initially established using RSM, and experiments were carried out using a central composite design of experiments for depositing Inconel 718 in WAAM. The design factors and responses were analyzed using multiple regression equations, and the validity of the resulting regression equations was evaluated using ANOVA. The researchers fabricated a multi-layer structure with optimal parameters, including a welding current of 210 A, 6.91 mm/s speed, and a gas flow rate of 25 l/min. Optical microscopy characterized the microstructures, revealing small dendritic grains in the top layer, equiaxed in the middle and side regions, and columnar in the lower region. The current study benefits industrial applications for developing the Inconel 718 superalloy WAAM structure. [ABSTRACT FROM AUTHOR]

Wetting–drying cycles have a significant impact on the gas diffusion coefficient (Dp) and gas permeability (ka) of unsaturated soils. The soil volume change during wetting–drying cycles limits the application of the traditional rigid-wall device for measuring ka and Dp , due to the gas preferential flow along the interface between soil and the rigid-wall container. Although flexible-wall devices for measuring ka are available, no such device exists for measuring Dp. Thus, the effects of wetting–drying cycles on Dp remain unclear, particularly for fine-grained soil. The present study developed a flexible-wall device to investigate the effects of a wetting–drying cycle on the Dp and ka of unsaturated soils. Both the flexible- and rigid-wall devices were adopted to measure ka and Dp of three soil types, including fine sand, silt and kaolin. The rigid-wall device could overestimate ka by up to approximately one order of magnitude, whereas it overestimated Dp by approximately 2–3 times. Regardless of ka and Dp , the difference in measurements between the rigid- and flexible-wall devices became more significant at a lower water content and along the drying path because of the gas preferential flow caused by soil shrinkage in the rigid-wall device. Accordingly, the kaolin exhibited the largest difference in ka and Dp as measured by the flexible- and rigid-wall devices because it had the largest clay minerals and the finest particle size, resulting in the largest volume shrinkage. The ka and Dp measured by the flexible-wall device along the drying path were generally larger than those along the wetting path, probably because of entrapped gas in the soil caused by water spray during wetting. [ABSTRACT FROM AUTHOR]

In fluid dynamics, the Atwood number is a dimensionless parameter that quantifies the density difference between two fluids. It is calculated as A t = (ρ 1 − ρ 2) / (ρ 1 + ρ 2) , where ρ 1 and ρ 2 represent the densities of the respective fluids. This research employs high-fidelity numerical simulations to examine the Atwood number impacts on Richtmyer–Meshkov (RM) flows triggered by a shocked forward-pentagonal bubble. Five distinct gases — SF 6 , Kr, Ar, Ne, and He — are considered within the forward-pentagonal bubble, encompassed by N 2 gas. In these simulations, a third-order discontinuous Galerkin approach is applied to solve a two-dimensional set of compressible Navier–Stokes-Fourier (NSF) equations for two-component gas flows. To discretize space, hierarchical modal basis functions based on orthogonal-scaled Legendre polynomials are employed. This approach simplifies the NSF equations into a set of ordinary differential equations over time, which are solved using an explicit third-order SSP Runge–Kutta algorithm. The numerical results highlight the notable impact of the Atwood number on the evolution of RM flows in the shocked forward-pentagonal bubble, a phenomenon not previously reported in the literature. The Atwood number exerts a significant influence on the flow patterns, leading to intricate wave formations, shock focusing, jet generation, and interface distortion. Moreover, a comprehensive analysis of the these impact elucidates the mechanisms driving vorticity formation during the interaction process. Additionally, the study conducts a thorough quantitative examination of the Atwood number impacts on the flow fields based on integral quantities and interface features. [ABSTRACT FROM AUTHOR]

An airlift pump is a vertical tube that utilizes the buoyant effects of a gas to lift a liquid. Unlike a standard mechanical pump, the liquid flow rate through the airlift pump is not directly controlled; rather, it depends on the supplied gas flow rate, the tube length and diameter, and the relative height of the liquid supply free surface (submergence ratio). The present study uses the commercial CFD code ANSYS CFX to model the isothermal, 3D, transient flow in an airlift pump using water and air. The model applies pressure boundary conditions at both ends of the tube and specifies the mass flow rate of air through multiple openings in the side of the tube. The bottom of the tube is an inlet of water only and the outlet is a two-phase flow opening. A time-dependent, homogeneous, VOF two-phase RANS CFD modelling approach is used with the air treated as an ideal gas. This work found that a complete 3D domain was necessary for consistent prediction of the airlift performance and physically realistic two-phase flow structures. Statistical analysis of the two-phase flow structures was applied to characterize airlift pump instability and better understand the physics of the airlift pump. [ABSTRACT FROM AUTHOR]

The development of flow assurance technology in submarine pipelines affects the safety, efficiency, and economy of deepwater natural gas development. In this study, in order to accurately predict the hydrate formation risk in deepwater submarine pipelines, a novel mathematical prediction model of hydrate formation risk has been established. The model has been applied and sensitivity analysis of typical factors has been carried out. The model prediction results show that: (1) Due to the low temperature of the seabed, hydrate formation region (HFR) often exists in submarine pipelines. (2) When other conditions are constant, hydrate formation region increases with the decrease in seawater temperature. (3) When other conditions are constant, the temperature drop, and the length of hydrate formation region decrease with the increase of gas transmission rate. (4) When other conditions are constant, the temperature drop, and the length of hydrate formation region decreases with the increase of gas transport temperature. (5) Reasonable setting of gas transmission temperature and gas transmission rate can help to reduce the hydrate risk and consumption of inhibitors during submarine natural gas transmission. Highlights: The hydrate risk prediction model for submarine pipeline is established. The model has been applied in submarine pipeline natural gas transmission. The T-P distribution characteristics in submarine pipeline are analyzed. The hydrate formation region in submarine pipeline is determined. [ABSTRACT FROM AUTHOR]

Conical diffusers are widely used in technical devices (gasifiers, turbines, combustion chambers) and technological processes (ejectors, mixers, renewable energy). The perfection of flow gas dynamics in a conical diffuser affects the intensity of heat and mass transfer processes, the quality of mixing/separation of working media and the flow characteristics of technical devices. These parameters largely determine the efficiency and productivity of the final product. This article presents an analysis of experimental data on the gas-dynamic characteristics of stationary air flows in a vertical, conical, flat diffuser under different initial boundary conditions. An experimental setup was created, measuring instruments were selected, and an automated data collection system was developed. Basic data on the gas dynamics of air flows were obtained using the thermal anemometry method. Experimental data on instantaneous values of air flow velocity in a diffuser for initial velocities from 0.4 m/s to 2.22 m/s are presented. These data were the basis for calculating and obtaining velocity fields and turbulence intensity fields of the air flow in a vertical diffuser. It is shown that the value of the initial flow velocity at the diffuser inlet has a significant effect on the gas-dynamic characteristics. In addition, a spectral analysis of the change in air flow velocity both by height and along the diffuser axis was performed. The obtained data may be useful for refining engineering calculations, verifying mathematical models, searching for technical solutions and deepening knowledge about the features of gas dynamics of air flows in vertical diffusers. [ABSTRACT FROM AUTHOR]

A gas pressure distribution calculation method for viscous laminar and intermediate flows is developed. By introducing the pseudo-conductance for viscous laminar flow, linearized equations describing pressure distribution are obtained. In intermediate flow, the pressure distribution is iteratively obtained. The validity of the method is confirmed by demonstrating a pressure in a long-tube flow path with various flow rates. The result smoothly connects theoretical curves of molecular flow and viscous laminar flow between two regions. Then, the calculation method is applied to an actual device and is compared to the measurement. The comparison between the calculation and measurement shows the qualitative agreement and reveals the requirement for a more detailed implementation of the actual conditions. [ABSTRACT FROM AUTHOR]

Various technologies and equipment are used to reduce greenhouse gas emissions. For example, the method of adsorption is used to capture carbon dioxide (CO2) from the smoke emissions of cement industries. In the adsorption process using zeolites, devices such as adsorbers are typically employed. Zeolites, a versatile group of aluminosilicate materials, are known for their high surface area and selective adsorption properties, making them effective for CO2 capture. The effectiveness of the adsorber depends on many factors, including its geometric dimensions and shape. Adsorbers with a central inlet flow have uneven gas distribution at the entrance to the adsorbent layer, which reduces their operational efficiency. To eliminate this disadvantage, various devices installed at the output of the adsorber inlet are usually used. Analysis of such devices shows that they do not provide maximum adsorption efficiency. To study the efficiency of zeolite operation for capturing carbon dioxide contained in the smoke gases of cement industries, the design of a laboratory adsorber was proposed, featuring a cyclone and distribution device in its lower part. The cyclone prevents the adsorbent from being contaminated by drip fluid, which reduces the efficiency of the adsorption process in the gas, and the distribution device reduces the uniformity of gas distribution at the entrance to the adsorbent layer. This paper proposes a computational fluid dynamics (CFD) model and design of the distribution device, which was analyzed and modified to significantly increase the uniform distribution of gas at the entrance to the adsorbent layer. Compared with other designs of distribution devices, the proposed design is simpler and performs better under varying gas flow rates. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new design of plasma-assisted injector to ignite or stabilize combustion is presented. This design is intended to produce discharges that penetrate the combustion chamber instead of staying at the wall. This plasma-assisted injector, simple and robust, allows compact designs for a weakly intrusive implementation in engines, and is compatible with either air or fuel, depending on the process or application. A prototype was manufactured, implemented and tested with quasi-DC discharges on the LAPCAT2 Dual Mode Ramjet combustor at LAERTE facility in ONERA. Combustion tests showed earlier ignition and increased pressure when the plasma was turned on with a measured plasma power of 1.4 kW. • Presentation of the design and principle of a new plasma assisted injector. • Demonstration of its ability to generate discharges penetrating the flow. • Characterization of the discharge dynamics and its interaction with the gas flow. • Comparison of the discharge behavior in hydrogen vs air. • Ability of the plasma assistance to enhance supersonic combustion. [ABSTRACT FROM AUTHOR]

The promising routes of metallic additive manufacturing favor the fabrication of refined functional components. Nonetheless, dealing with the Laser Powder Bed Fusion (L-PBF) parameters and costs for making the most of this technology is still an issue. The challenge gets bigger when considering less explored parameters, such as the process atmosphere and build location. So, this study aimed to address the main differences in microstructure, crystallography, mechanical properties, and surface finishing of maraging steel components manufactured under two different atmospheres (N2 and a mixture of 75%Ar-25%He atmospheres) and three build locations arranged along the gas flow direction. Based on experimental characterizations, the porosity fraction, microstructural constituents and metallurgical flaws, phase composition and martensite matrix crystallographic parameters, macrotexture, mechanical properties, roughness, and surface residual stress were investigated and compared for the different manufacturing conditions. The porosity fraction had the most expressive changes with the gas type and the build location, reaching a 53% overall reduction under N2 and a 112 to 302% rise for the front located sample compared to the others. The underlying mechanisms involved in the observed results, mainly related to process by-products behavior, were discussed. Broadly, the N2 atmosphere stands out over the analyzed properties. These findings underscore the role of atmospheric selection in the LPBF process, considering the overall quality and performance of the fabricated material and the possibility of cost reduction. [ABSTRACT FROM AUTHOR]

In this novel study, BaCe 0.9 Y 0.1 O 3– δ , BaCe 0. 9 Eu 0.1 O 3– δ , BaCe 0.9 Nd 0.1 O 3– δ , and BaCe 0.9 Dy 0.1 O 3– δ powders were synthesized by the self-combustion method and processed into thick porous films (60–70 % porosity) to investigate the water vapor sensing properties in the 400–700 °C temperature range. All samples showed a stable response value to water vapor in the whole temperature range, expressed as impedance ratio in dry and wet argon (Z dryAr / Z wetAr), and were able to detect 0.03 vol% of water vapor at 550 °C within the impedance range of 103 Ω at 100 Hz. The response values increased with the partial pressure of water and decreased with the temperature, whereas the maximal value of 3.41 reached the BaCe 0.9 Eu 0.1 O 3– δ sample at 550 °C and p (H 2 O) = 4.28 kPa. The average response time was several seconds and only slightly changed with the material type and experimental conditions. The recovery time depended on temperature and the Z dryAr / Z wetAr ratio, whereas the increase in the gas flow rate from 100 cm3/min to 200 cm3/min significantly reduced the recovery time for the BaCe 0.9 Eu 0.1 O 3– δ sample from 230 s to 55 s at 550 °C and p (H 2 O) = 2.14 kPa. All the samples exhibited stability and a high degree of reversibility after multiple exchanges of wet and dry atmospheres at different temperatures. Yet, their tendency to deteriorate in the presence of CO 2 might challenge a potential application in aggressive environments. [ABSTRACT FROM AUTHOR]

Carbon black has been successfully converted into silicon carbide by reacting it with SiO vapor at 1500 °C under Ar gas environment. The influence of reaction temperature, duration and Ar gas flow rate on the final product was examined. The structural and microstructural property of synthesized SiC was characterized using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Micrographs of synthesized SiC showed that the final product was an agglomeration of SiC nano-powder of 50–500 nm size and nano-whiskers/fibres having a diameter of 50–500 nm and lengths in 0.1–10 μm depending on Ar gas flow rate. The higher conversion of C into SiC was observed at 1500 °C with Ar gas flow rate ∼250 ml/min. [ABSTRACT FROM AUTHOR]

Steelmaking has shown an increasing concern toward nonmetallic inclusions, leading to new technologies in the secondary metallurgy of steel. Although the typical inclusion removal procedure is by injecting inert gas into the ladle, this vessel does not fulfill all the requirements to accept a porous structure tailored to produce “clean steels.” Consequently, the spotlight has moved to the tundish, the last vessel before solidification, in which gas injection can continuously operate. Therefore, this work focuses on understanding the influence of typical gas flow rates (10–60 NL/min) on the kinetics of inclusion flotation, considering two bubble diameters (0.6 and 1.1 mm). For this purpose, experimental measurements were conducted in a water model, where glass hollow spheres played the role of inclusions, and their concentration was fitted by an exponential decay. In general, injecting bubbles into the system contributed positively to a faster and greater flotation of particles. The smaller bubbles led to a higher maximum efficiency, whereas the larger ones allowed a shorter time scale (i.e., a faster removal), defining a trade‐off to tune the bubble size. Regarding the gas flow rate, the results indicate an optimum range to decrease the time scale, and suggestions for bubble curtains in tundishes are drawn. [ABSTRACT FROM AUTHOR]

The increasing demand for high-quality welds in various industries such as automotive, aerospace, and shipbuilding has led to the need for more efficient welding processes. Cold Metal Transfer (CMT) welding offers several advantages over traditional welding methods. This study investigates the CMT welding process applied to High-Strength Low-Alloy (HSLA) steel plates, focusing on optimizing weld parameters for enhanced joint quality and mechanical performance. The CMT process was selected for its ability to provide low heat input, thereby minimizing thermal distortion, and preserving the mechanical properties of the HSLA material. Key welding parameters, including welding speed (10–30mm/s), wire feed rate (2–4m/min), heat input (1.8–2.4kJ/mm), arc voltage (12–16V), and gas flow rate (3–5L/min), were systematically varied to assess their impact on weld integrity and strength. Uncertainty analysis is conducted and came out to be 3.25% which lies in an acceptable range. The AHP–TOPSIS analysis was conducted to identify the most important welding process parameters and equipment for achieving high-quality welds in CMT welding of steel. The results showed that welding speed, wire feed rate, and gas flow rate were the most important process parameters for achieving high-quality welds. In the AHP analysis, Tensile Strength achieved the highest priority (39%) while Impact Toughness (22%) followed it. After prioritizing the variables, an inter-relationship between the most favorable inputs with outputs is established using Artificial Intelligence (AI). Prediction analysis is performed to establish the most optimal welding setting among thousands of input sets. The sample with set 1 was found to be the best choice for producing high-quality welds in CMT welding of steel. The optimal parameter values were found to be a welding speed of 25mm/s, wire feed rate of 3m/min, arc voltage of 12V, gas flow rate of 5L/min, and heat input of 1.5kJ/mm yielding a tensile strength of 460MPa, hardness of 42HRC, impact toughness of 29 J, radiation of 110W/m2, convection of 90W/m2, and conduction of 150W/m2. This study provides valuable insights into the effective use of CMT for welding HSLA steel, offering practical guidelines for achieving high-quality welds in structural applications. [ABSTRACT FROM AUTHOR]

The electrochemical regeneration of reduced nicotinamide adenine dinucleotide (NADH) using [Rh(Cp*)(bpy)Cl]+ holds significant promise for the industrial synthesis of chiral chemicals. However, challenges persist due to the high consumption of NADH and the limited efficiency of its cyclic regeneration, which currently hinder widespread application. To address these obstacles, based on in‐situ growth of 3D ordered metal‐organic framework (NU‐1000) on the surface of graphite felt, [Rh(Cp*)(bpy)Cl]+ were immobilized on the Zr6 nodes of NU‐1000 by solvent‐assisted ligand incorporation (SALI), and applied in a flow bioreactor. Moreover, we employ a gas diffusion electrode (GDE) to oxidize H2, providing a clean proton source for the electrochemical regeneration of NADH. Consequently, highly efficient enzymatic electrocatalytic synthesis of L‐lactate was achieved when coupled with L‐lactate dehydrogenases (LDH) as a model reaction, and the total turnover number (TTN) reached 19600 and 1750 for [Rh(Cp*)(bpy)Cl]+ and NAD+ after 48 h, corresponding to a high turnover frequency (TOF) of 2350 h−1 and 210 h−1 for [Rh(Cp*)(bpy)Cl]+ and NAD+, respectively. This work provides new insights for the construction of efficient enzymatic electrosynthesis systems in industrial production. [ABSTRACT FROM AUTHOR]

Angstrom‐scale fluidic channels offer immense potential for applications in areas such as desalination, molecular sieving, biomolecular sequencing, and dialysis. Inspired by biological ion channels, nano‐ and angstrom (Å)‐scale channels are fabricated that mimic these molecular or atomic‐scale dimensions. At the Å‐scale, these channels exhibit unique phenomena, including selective ion transport, osmotic energy generation, fast water and gas flows, and neuromorphic ion memory. However, practical utilization of Å‐scale channels is often hindered by contamination, which can clog these nanochannels. In this context, a promising technique is introduced here for unclogging 2D channels, particularly those with sub‐nanometre dimensions (≈6.8 Å). The voltage‐cycling method emerges as an efficient and reliable solution for this challenge. The electric field effectively dislodges contaminants from the clogged Å‐scale channels, facilitating ion and molecular transport. This study provides practical guidelines for reviving clogged nano‐ and Å‐scale channels, thereby enhancing their applicability in various ion and molecular transport applications. [ABSTRACT FROM AUTHOR]

The oxidation of ammonium sulfite must be inhibited to improve the economy and cycle performance of the ammonia flue gas desulfurization process. A stirred bubbling reactor was used to investigate the macrokinetics of oxidation inhibition of ammonium sulfite by sodium thiosulfate in wet ammonia desulfurization. The effects of initial SO32−${\rm SO}^{2-}_{3}$ concentration, Na2S2O3 concentration, pH value, gas flow rate, and temperature on the oxidation rate were discussed. The results show that the apparent activation energy of the reaction is 37.3 kJ/mol. The macrokinetics equation of sodium thiosulfate inhibiting sulfite oxidation in the ammonia desulfurization process was established. Combined with the kinetic model, it is inferred that the rate of sodium thiosulfate inhibiting ammonium sulfite oxidation is controlled by the intrinsic chemical reaction. The results can provide a reference for the regeneration of ammonium sulfite in the wet ammonia desulfurization process. [ABSTRACT FROM AUTHOR]

This study focuses on the S-to-H2SO4 industry by investigating the chemical looping combustion (CLC) process utilizing Fe-based and Cu-based oxygen carriers (OCs), which are widely applied in CLC technology. The primary objective is to conduct combined CLC reactions of these two metal carriers in a three-zone temperature tube furnace, aiming to achieve a higher SO2 yield than what is attainable by reacting a single metal carrier with S. The investigation reveals promising industrial applications, offering potential benefits in terms of reducing equipment costs, enhancing energy efficiency, and lowering the emissions of the H2SO4 production industry. Through a series of experiments, the study examines the effects of reaction temperature and material molar ratios on SO2 generation. The solid reaction products were characterized using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS). The experimental results indicate that the combined Cu-based and Fe-based OCs exhibit a higher SO2 yield during the reduction stage compared to using either Fe-based or Cu-based OCs independently. Under optimal conditions, with a carrier gas flow rate of 300 mL/min, an Fe2O3/S molar ratio of 6:1 in the second temperature zone, and a reaction temperature of 900 °C, the total SO2 yield in the third temperature zone reached approximately 85%. This was achieved at a reaction temperature of 850 °C, with an Fe2O3/S molar ratio of 6:1 in the first half of the zone and a CuO/S molar ratio of 12:1 in the second half of the zone. SEM-EDS analysis further revealed that the combined OCs showed no significant signs of agglomeration or sintering after 10 cycles of the reaction. However, Cu-based carrier particles increased in size by 50%, while Fe-based carrier particles remained relatively stable. Additionally, the low mass-to-atom ratio of S on the surface of OCs after the cyclic reaction suggests that the reduced-state OCs can be fully oxidized and regenerated following the release of SO2 during oxidation. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD) is a crucial technique in the preparation of high-quality thin films and coatings, and is widely used in various industries including semiconductor, optics, and nuclear fuel, due to its operation simplicity and high growth rate. The complexity of the CVD process arises from numerous parameters, such as precursor chemistry, temperature, pressure, gas flow dynamics, and substrate characteristics. These multiscale parameters make the optimization of the CVD process a challenging task. Numerical simulations are widely used to model and analyze the CVD complex systems, and can be divided into nanoscale, mesoscale, and macroscale methods. Numerical simulation is aimed at optimizing the CVD process, but the inter-scale parameters still need to be extracted in modeling processes. However, multiscale coupling modeling becomes a powerful method to solve these challenges by providing a comprehensive framework that integrates phenomena occurring at different scales. This review presents an overview of the CVD process, the common critical parameters, and an in-depth analysis of CVD models in different scales. Then various multiscale models are discussed. This review highlights the models in different scales, integrates these models into multiscale frameworks, discusses typical multiscale coupling CVD models applied in practice, and summarizes the parameters that can transfer information between different scales. Finally, the schemes of multiscale coupling are given as a prospective view. By offering a comprehensive view of the current state of multiscale CVD models, this review aims to bridge the gap between theory and practice, and provide insights that could lead to a more efficient and precise control of the CVD process. [ABSTRACT FROM AUTHOR]

The article deals with the H2 consumption for different processing conditions and the composition of the processed pellets during the direct reduction process. The experiments are carried out at 600–1300 °C, with gas pressures of 1–5 bar, gas flow rates of 1–5 L min−1, and basicity indices of 0 to 2.15. Pellets with different compositions of TiO2, Al2O3, CaO, and SiO2 are analyzed. The gas flow rate is crucial, with 0–10 L min−1 leading to an H2 consumption of 0–5.1 kg H2/kg pellet. The gas pressure (0–10 bar) increases the H2 consumption from 0 to 5.1 kg H2/kg pellet. Higher temperatures (600–1300 °C) reduce H2 consumption from 5.1 to 0 kg H2/kg pellet, most efficiently at 950–1050 °C, where it decreases from 0.22 to 0.10 kg H2/kg pellet. An increase in TiO2 content from 0% to 0.92% lowers H2 consumption from 0.22 to 0.10 kg H2/kg pellet, while a higher Fe content (61–67.5%) also reduces it. An increase in SiO2 content from 0% to 3% increases H2 consumption from 0 to 5.1 kg H2/kg pellet. Porosity structure influences H2 consumption, with the average pore size decreasing from 2.83 to 0.436 mm with increasing TiO2 content, suggesting that micropores increase H2 consumption and macropores decrease it. [ABSTRACT FROM AUTHOR]

The multiphase circumgalactic medium (CGM) hosts critical processes that affect galaxy evolution such as accretion and outflows. We searched for evidence of these phenomena by using the EW co-rotation fraction (⁠|$f_{\rm EWcorot}$|⁠) to study the kinematic connection between the multiphase CGM and host galaxy rotation. We examined CGM absorption from Hubble Space Telescope / Cosmic Origins Spectrograph (including, but not limited to, Si  ii , C  ii , Si  iii , C  iii , and O  vi) within |$21\le D\le ~276$| kpc of 27 galaxies. We find the median |$f_{\rm EWcorot}$| for all ions is consistent within errors and the |$f_{\rm EWcorot}$| increases with increasing N |$({{{\rm H} \rm{\small I}}})$|⁠. The |$f_{\rm EWcorot}$| of lower ionization gas decreases with increasing |$D/R_{\rm vir}$|⁠ , while O  vi and H  i are consistent with being flat. The |$f_{\rm EWcorot}$| varies minimally as a function of azimuthal angle and is similar for all ions at a fixed azimuthal angle. The larger number of O  vi detections enabled us to investigate where the majority of co-rotating gas is found. Highly co-rotating O  vi primarily resides along the galaxies' major axis. Looking at the |$f_{\rm EWcorot}$| as a function of ionization potential (⁠|${{\rm d}{({f_{\rm EWcorot}})}}/{{\rm d}{(\rm eV)}}$|⁠), we find a stronger co-rotation signature for lower ionization gas. There are suggestions of a connection between the CGM metallicity and major axis co-rotation where low-ionization gas with higher |$f_{\rm EWcorot}$| exhibits lower metallicity and may trace large-scale filamentary inflows. Higher ionization gas with higher |$f_{\rm EWcorot}$| exhibits higher metallicity and may instead trace co-planar recycled gas accretion. Our results stress the importance of comparing absorption originating from a range of ionization phases to differentiate between various gas flow scenarios. [ABSTRACT FROM AUTHOR]