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This study investigates the effects of varying the electrode rotational speed in rotary tungsten inert gas (rotary TIG), a novel wire arc additive manufacturing technology. Rotary TIG aims to mitigate the directional nature of the TIG WAAM process, producing weld beads with uniform cross-sections conducive to additive manufacturing. Scripts were developed to analyze the characteristics of deposited single bead profiles. The results demonstrate that increasing the electrode rotational speed leads to increased height at the expense of the width in the weld bead profiles. Additionally, rotary TIG weld bead profiles exhibit a parabolic shape and a geometry forecast model was developed. The effect of electrode rotation speed has been magnified; a metallurgical analysis reveals that the internal structure loses its uniformity as the rotational speed decreases. Furthermore, a thermofluidic dynamic simulation was developed to replicate the rotary TIG welding process. This simulation confirms that electrode rotation speed impacts geometry, aligning with experimental findings. [ABSTRACT FROM AUTHOR]

COSINUS will be among the first underground experiments to operate Transition Edge Sensors in a dry dilution refrigerator, measuring temperature changes on the order of μ K. A pulse tube cryocooler is used to cool down to 3K, trading simplified handling, by not using liquid noble gases, for an increased vibration noise level in the acoustic frequency range. As the signals measured with a TES are in the same frequency region, it is necessary to decouple the detectors from all possible noise sources. In COSINUS, a two-level passive decoupling system was developed and tested using piezo-based accelerometers. At the first level, the refrigerator is mechanically isolated from all external noise sources. For the second level an internal spring-based system was developed and tested on a mockup system. On the first level a reduction of the vibrational background up to a factor 4 below 10 Hz could be measured. On the second level a resonance frequency of 1.2 Hz with damping of higher frequencies was achieved. [ABSTRACT FROM AUTHOR]

In this study, 1.2-mm thick hot-dip galvanized (120 GSM) DP600 steel plates were used as the base material to compare various modes of metal inert gas (MIG) brazing in terms of process stability, bead morphology, microstructure, and mechanical properties. The pulsed-MIG process produces joints with flatter and wider bead morphology, indicating better wettability compared to cold metal transfer (CMT) and standard-MIG processes. This difference is due to the higher heat input of the pulsed-MIG process at the same wire feed rate (WFR). Analysis of voltage-current signals, probability distribution curves, and cyclograms reveals that the CMT-MIG process is the most stable and defect-free, while the standard-MIG process becomes less stable with increasing WFR. Joints brazed using the pulsed-MIG process have significantly higher shear-tensile strength compared to the other two modes, primarily due to higher wettability. Three modes of failure—horizontal interface (mode 1), vertical interface and bead (mode 2), and base metal (mode 3)—were observed. Excessive wettability reduces the cross-sectional area, negatively impacting static and dynamic performance, especially in pulsed brazing joints under high load amplitudes. Conversely, the bumpy beads in CMT and standard-MIG processes enhance the cross-sectional area, providing better resistance against failure along the vertical interface and bead. This study offers a comprehensive database and guidance for selecting appropriate brazing methods depending on joint application, considering the limitations of each brazing process. [ABSTRACT FROM AUTHOR]

Plasma-catalysis has attracted significant interest in recent years as an alternative for the direct upgrading of methane into higher-value products. Plasma-catalysis systems can enable the electrification of chemical processes; however, they are highly complex with many previous studies even reporting negative impacts on methane conversion. The present work focuses on the non-oxidative plasma-catalysis of pure methane in a Dielectric Barrier Discharge (DBD) reactor at atmospheric pressure and with no external heating. A range of transition and noble metals (Ni, Fe, Rh, Pt, Pd) supported on γ-Al2O3 are studied, complemented by plasma-only and support-only experiments. All reactor packings are investigated either with pure methane or co-feeding of helium or argon to assess the role of noble gases in enhancing methane activation via energy transfer mechanisms. Electrical diagnostics and charge characteristics from Lissajous plots, and electron temperature and collision rates calculations via BOLSIG+ are used to support the findings with the aim of elucidating the impact of both active metal and noble gas on the reaction pathways and activity. The optimal combination of Pd catalyst and Ar co-feeding achieves a substantial improvement over non-catalytic pure methane results, with C2+ yield rising from 30% to almost 45% at a concurrent reduction of energy cost from 2.4 to 1.7 and from 9 to 4.7 . Pd, along with Pt, further displayed the lowest coke deposition rates among all packings with overall stable product composition during testing. [ABSTRACT FROM AUTHOR]

The development in attosecond physics allows for unprecedented control of atoms and molecules in the time domain. Here, ultrashort pulses are used to prepare atomic ions in specific magnetic states, which may be important for controlling charge migration in molecules. Our work fills the knowledge gap of relativistic hole alignment prepared by femtosecond and attosecond pulses. The research focuses on optimizing the central frequency and duration of pulses to exploit specific spectral features, such as Fano profiles, Cooper minima, and giant resonances. Simulations are performed using the Relativistic Time-Dependent Configuration-Interaction Singles method. Ultrafast hole alignment with large ratios (on the order of one hundred) is observed in the outer-shell hole of argon. An even larger alignment (on the order of one thousand) is observed in the inner-shell hole of xenon. In this work, the authors investigate the distribution of holes with different magnetic quantum numbers in noble gas atoms, ionized by femtosecond and attosecond pulses. They achieve high control over hole alignment by adjusting pulse parameters and exploiting specific spectral features. [ABSTRACT FROM AUTHOR]

In general, mantle-derived volatiles are mainly released into the atmosphere through volcanoes in mid-ocean ridges and subduction zones. However, relatively little attention has been paid to the emission of volatiles from continents on the Earth's surface. It has recently been shown that significant amounts of gases such as carbon dioxide of mantle origin are emitted from continental rifts. Continental degassing has been reported in various ways around the world, however compared to mid-ocean ridges where the depleted upper mantle contributes significantly or arc volcanoes affected by subduction slabs, geochemical generalization is still in progress. In particular, in continental environments, other volatile sources may be added due to the distribution of the subcontinental lithospheric mantle. In the previously reported mantle xenolith samples, components such as noble gases are distinct from the mid-ocean ridge gases, and volcano/fault-related gases on some continents also showed different characteristics. Here, this work proposes representative values of volatiles of the lithosphere by synthesizing the geochemical data of gases emitted from the continent that have been reported until recently. In addition, this study provides a new perspective by considering the recently reported gas results from South Korea. [ABSTRACT FROM AUTHOR]

The soft ionization mechanism of helium-based plasma seems to be understood while it still remains challenging in argon-based plasma, although many studies have used argon plasmas as a soft ionization source with good ionization efficiencies. In this study, helium, argon, krypton, and xenon were fed into the same discharge geometry, a flexible micro-tube plasma (FµTP), to determine the ionization mechanisms. The FµTPs operated with the named noble gases obtained comparable ionization efficiencies by MS measurements. The optical emission results showed that N2+ were the dominant ions within the helium-FµTP and noble gas ions were dominant for the other plasmas. These ions support the development of excitation and eventually stop at the end of the capillary. Therefore, Penning ionization and charge transfer between plasma and ambient air/analytes in the open atmosphere have been proven not to be the primary soft ionization mechanism. Furthermore, it was found that photoionization played a minor role in soft ionization. Using helium as a diagnosis gas in front of the discharge capillary nozzle of the FµTP, where the sample is usually positioned, shows that helium can be ignited by all of these FµTPs. This demonstrates that the excitation of a diagnosis gas as well as the ionization of analytes is independent of the type of the discharge gas. An alternative mechanism that a transient potential created by the ions is responsible for the soft ionization is subsequently proposed. [ABSTRACT FROM AUTHOR]

Due to its high-quality weld seam and excellent arc stability, narrow gap Tungsten Inert Gas (TIG) welding has become a critical technology for welding thick metal plates. However, this technology has the problem of insufficient sidewalls penetration, which has a significant impact on the performance of the components. This study provides a comprehensive overview of three optimization methods, including mechanical improvement, field control, and composite welding. It critically analyzes the principles and research status of each method. The advantages and disadvantages of these methods have been summarized. In Outlook, application scenarios for auxiliary processes have been presented. Further, there is a prospect for the development of an ultra-long arc narrow gap TIG welding process. [ABSTRACT FROM AUTHOR]

In laser powder bed fusion (L-PBF) manufacturing, inert gas flow aids in removing spatters and fumes generated during laser-material interaction, ensuring quality of fusion and consequently, the quality of the manufactured parts. This study examines gas flow homogeneity's impact on part quality across the build plate. To do this, gas velocity mappings near the manufacturing plate (XY plane) and at four heights (Z-axis) were performed on a Renishaw AM400 machine using a Pitot tube and a hot-wire anemometer. Four gas inlet configurations are compared to maximize the permissible velocity at the build plate level (1 to 2 m/s) with the constrain of preventing the powder bed from being blown away. AlSi10Mg aluminum sample density measurements served as performance indicators, to quantify the effect of gas flow variations, taking into account their positions within the manufacturing bed. High-speed camera observations and numerical simulations supplemented the analysis. Results indicate gas flow inlet arrangement significantly influences flow homogeneity, reducing non-uniformity by almost 40%. Porosity is also reduced by around 20% and porosity variations on the build plate are reduced by more than 25%. Sample density increases primarily at the plate center and farthest from the gas inlet. Areas closest to the inlet show no significant density change compared to the standard configuration. [ABSTRACT FROM AUTHOR]

Despite recent progress, ischemic heart disease poses a persistent global challenge, driving significant morbidity and mortality. The pursuit of therapeutic solutions has led to the emergence of strategies such as ischemic preconditioning, postconditioning, and remote conditioning to shield the heart from myocardial ischemia/reperfusion injury (MIRI). These ischemic conditioning approaches, applied before, after, or at a distance from the affected organ, inspire future therapeutic strategies, including pharmacological conditioning. Gasotransmitters, comprising nitric oxide, hydrogen sulfide, sulfur dioxide, and carbon monoxide, play pivotal roles in physiological and pathological processes, exhibiting shared features such as smooth muscle relaxation, antiapoptotic effects, and anti-inflammatory properties. Despite potential risks at high concentrations, physiological levels of gasotransmitters induce vasorelaxation and promote cardioprotective effects. Noble gases, notably argon, helium, and xenon, exhibit organ-protective properties by reducing cell death, minimizing infarct size, and enhancing functional recovery in post-ischemic organs. The protective role of noble gases appears to hinge on their modulation of molecular pathways governing cell survival, leading to both pro- and antiapoptotic effects. Among noble gases, helium and xenon emerge as particularly promising in the field of cardioprotection. This overview synthesizes our current understanding of the roles played by gasotransmitters and noble gases in the context of MIRI and cardioprotection. In addition, we underscore potential future developments involving the utilization of noble gases and gasotransmitter donor molecules in advancing cardioprotective strategies. [ABSTRACT FROM AUTHOR]

The breakdown and discharge ignition in discharge tubes with a diameter of about 1 cm and a length of 80 cm in inert gases (neon, argon, krypton, and xenon) at a pressure of about 1 Torr are studied experimentally. The tube is illuminated by radiation from continuous or pulsed light sources in the visible spectrum range. A ramp voltage with a small slope steepness (of about 50 V/s) is applied to the anode of the tube. Previously, the authors established that under these conditions external illumination can increase the breakdown voltage in several times. This effect was explained by the appearance of a charge on the tube wall as a result of photodesorption of electrons from its inner surface. In this work, it is found that charging the wall begins only when the anode potential approaches the breakdown potential measured without illumination. In addition, it is found that during the increase in the voltage on the anode and charging the wall, the anode potential differs from the breakdown potential by a constant and small value (less than 200 V). [ABSTRACT FROM AUTHOR]

The effect of the dust grain flows on a spatial dusty structure in a stratum of a glow discharge in two inert gases (neon and argon) in a weak magnetic field was studied. The discharge parameters were determined that are necessary for the creation of three-dimensional dusty structures made from dust grains of the same size in both gases in a magnetic field. The dependences were obtained of the angular velocities of the dusty structures in the two gases on the magnetic field and on the gas pressure. The rotation speeds of the dust grains in the magnetic field were used to compare the ion fluxes acting on the dust formations. [ABSTRACT FROM AUTHOR]

There are 2 main problems with the current periodic table: artificial breaks from a given noble gas to the next alkali metal (along with the common protrusion of the "f" block) and hydrogen placed in the alkali group, although this gas also exhibits halogen properties. This paper proposes arranging chemical elements in a square spiral with hydrogen at the centre. This element is also above lithium but passes above fluorine to connect with helium, representing its dual alkali and halogen nature effectively. Then the spiral moves outwards in a counter-clockwise direction, avoiding artificial breaks and following the natural direction of reading for the "s" and "p" blocks elements placed at the bottom of the spiral. Furthermore, this proposed square spiral improves upon previous Janet´s and Benfey´s representations with a more regular shape to draw, an effective depiction of the dual nature of hydrogen, and easily identifiable orbital blocks without the need for protrusions. [ABSTRACT FROM AUTHOR]

In this chapter, we will consider the mechanism of inhibition efficiency, stability of inhibitors, which determines the reliability and duration of ignition prevention, and the mechanism of synergy between the combined action of an inhibitor and inert gases. Special consideration will be given to the effect of inhibitors on flame propagation and detonation. [ABSTRACT FROM AUTHOR]

Noble gases are accreted to the giant planets as part of the gas component of the planet-forming disk. While heavier noble gases can separate from the evolution of the hydrogen-rich gas, helium is thought to remain at the protosolar H/He ratio Y proto ∼ 0.27 –0.28. However, spacecraft observations revealed a depletion in helium in the atmospheres of Jupiter, Saturn, and Uranus. For the gas giants, this is commonly seen as indication of H/He phase separation at greater depths. Here, we apply predictions of the H/He phase diagram and three H/He-EOS to compute the atmospheric helium mass abundance Y atm as a result of H/He phase separation. We obtain a strong depletion Y atm < 0.1 for the ice giants if they are adiabatic. Introducing a thermal boundary layer at the Z-poor/Z-rich compositional transition with a temperature increase of up to a few 1000 K, we obtain a weak depletion in Uranus as observed. Our results suggest dissimilar internal structures between Uranus and Neptune. An accurate in-situ determination of their atmospheric He/H ratio would help to constrain their internal structures. This is even more true for Saturn, where we find that any considered H/He phase diagram and H/He-EOS would be consistent with any observed value. However, some H/He-EOS and phase diagram combinations applied to both Jupiter and Saturn require an outer stably-stratified layer at least in one of them. [ABSTRACT FROM AUTHOR]

The appearance of the population difference in the ground state of the -system due to the spontaneous decay of the upper level into lower ones is considered. The resulting asymmetry of the coherent population trapping resonance is shown to lead to a frequency shift of the quadrature signal, which nonlinearly depends on the optical field intensity. In this case, this contribution is not suppressed due to the use of high modulation frequencies compared to the relaxation rate of ground state polarization (analogue of the Pound–Drever–Hall technique). A significant smallness of this shift when using a binary mixture of noble buffer gases is discussed. [ABSTRACT FROM AUTHOR]

We developed in this paper the used methodology to describe the Lennard-Jones potential of two atoms in rare gas. In this treatment we supposed that one atom could be described by a harmonic oscillator. The interaction potential is developed at short and long ranges. The results showed that the obtained physico-chemical parameters such as the oscillator frequency, the atom mass, and the atom charge well reproduce the Lennard-Jones potential. Then the potential well depth and the effective equilibrium diameter are expressed in function of the oscillator frequency, the atom mass and charge. [ABSTRACT FROM AUTHOR]

For mechanical properties of titanium, oxygen content is important. In re-certifying O mass fraction in the Ti certified reference material ERM-EB090b, instrumental photon activation analysis (IPAA) was used as an alternative to the inert gas fusion technique. IPAA utilizes 15O measurable only via the nonspecific annihilation gamma line 511 keV. Interferences from other radionuclides can be suppressed by optimizing photon energy and irradiation-decay-counting times, and for most interfering radionuclides corrected via their specific gamma lines. The present re-evaluated IPAA results for O content 3.56 ± 0.59 g/kg matches closely the assigned certified value 3.57 ± 0.19 g/kg. [ABSTRACT FROM AUTHOR]

Henry's law constant, which describes the proportionality of dissolved gas to partial pressure of free gas in liquid–gas equilibrium systems, can also be applied to mass transport applications. In this work, we investigated an approach for determining the solubility of noble gases in a molten salt liquid utilizing the equilibrium concept of Henry's gas constant. Henry's gas constant is described as a mathematical function dependent on the van der Waals radius of the noble gas and the temperature of the molten salt. The alteration in Gibbs free energy encompasses contributions from both surface and volume energies. Enthalpy and entropy are deduced from these surface and volume energies in the Gibbs free energy formulation. A comparative analysis was conducted between the conventional method and our proposed model. Moreover, useful chemical properties can be determined from examination of surface and volume energies. Our findings provide an accurate and general theory of Gibbs free energy that can be validated experimentally based on the model proposed herein. This work unifies the prediction of Henry gas constant and subsequently the entropy and enthalpy calculation for noble gases in a molten salt solution to a single functional form using van der Waals radius of the gas and temperature of the system. This functional form is then used to perform a multiple regression method to find two parameters corresponding to the surface energy and volume energy. These two parameters are consistent between all combinations of noble gas and molten salt. [ABSTRACT FROM AUTHOR]

A large pool of data on the detonation hazard of hydrogen in mixtures with oxygen and air additionally diluted by inert gases and in the presence of steam in the mixture are reported. The most important parameter is the critical energy of detonation initiation, which serves as a measure of the explosion hazard of combustible systems: the smaller the critical energy, the more hazardous the mixture. The number of correct measurements of the critical energy of detonation initiation in scientific publications is rather limited (which is even more true for waves with different symmetries). [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 goal of this study is to provide scientific knowledge on mechanical and microstructural properties of Grade-9 titanium (Gr-9-Ti), which was fabricated using tungsten inert gas welding-assisted wire-fed layer manufacturing (TIG-assisted WFLM). Anisotropy in the tensile properties of manufactured WFLM wall was studied through a combination of cutting and examination of tensile specimens at different orientations (0°, 45°, 90°). The mechanical properties of wall fabricated by TIG-assisted WFLM are superior to those of wrought alloys. The complex thermal history (CTH) that occurs during the process results in variation of microstructural features. The enhancement in mechanical properties is due to the variation in microstructure. The presence of lamellar alpha + beta is noticed in the wall. This lamellar alpha + beta enhances the strength with reduction in the ductility by retarding dislocation movement. On analyzing the fractography results, it revealed morphologies such as dimples and void which proves the occurrence of ductile failure. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polytetrafluoroethylene (CF/PTFE) composites are known for their exceptional tribological performance when sliding against steel or cast iron in inert gas environments. Compared to experiments in humid air, about an order of magnitude lower wear rate and several times lower coefficient of friction have been reported for tests conducted in dry nitrogen and hydrogen. Moreover, trace moisture has been shown to affect the friction and wear significantly of this tribosystem, although a possible effect of oxygen cannot be ruled out due to uncertainties regarding the oxygen concentrations. While several studies have pointed out the environmental sensitivity of CF/PTFE, the understanding of the underlying mechanisms are very limited. The objective of this research is to investigate the individual and combined effect of oxygen and moisture on the tribological behavior of CF/PTFE sliding against steel. Additionally, this study aims to elucidate the underlying mechanisms that govern the environmental sensitivity of the system. Climate-controlled three-pin-on-disc experiments were conducted in nitrogen atmospheres at various concentrations of oxygen and moisture. The tribological results clearly demonstrate that both moisture and oxygen contribute to increased friction and wear. However, the adverse effect was much more pronounced for oxygen than moisture. A qualitative method was developed to estimate the tribofilm coverage on the CF/PTFE surface. Results showed strong correlation between high coverage of strongly adhered tribofilm and low wear rate. Moreover, a loosely adhered tribofilm was observed on top of the CF/PTFE surface in presence of moisture. FTIR analysis indicated that the loosely adhered tribofilm found in the moisture-enriched environment contained a significant amount of adsorbed water, which may explain the lower coefficient of friction in presence of moisture compared to oxygen. The adsorbed water in the loosely adhered tribofilm could be an indication of moisture-driven lubrication by the non-graphitic carbon in the tribofilm. [ABSTRACT FROM AUTHOR]

Multi-laser Additive Manufacturing systems hold great potential to increase productivity. However, adding multiple energy sources to a powder bed fusion system requires careful selection of a laser scan and inert gas flow strategy to optimize component performance. In this work, we explore four different laser scan and argon flow strategies on the quasi-static compressive mechanical response of Body Centered Cubic lattices. Three strategies employ a swim lane method where laser pathing tends to progress parallel to argon flow. Method one only uses a single laser while method two uses four, both with the laser path working against the argon flow. The third method uses four lasers, each operating in their own lane like the second method, but the laser pathing progresses with the argon flow. The fourth method has all four lasers operating in quadrants and the laser pathing trends against the argon flow. The single-laser strategy generally had the lowest mechanical responses compared to the other three strategies. A quadrant strategy generally had the highest quasi-static mechanical responses and was at least 25% greater in stiffness, yield force, ultimate force, and energy absorption when compared to the single laser strategy. However, the four-laser swim strategy where the laser pathing tends against the argon flow was found to be statistically similar to the quadrant strategy. It is hypothesized that spatter introduced onto the powder layer from the melt pool and particle entrainment may be worse for laser pathing which trends with the argon flow direction. Additionally, the additional energy added to the build volume helps to mitigate inter-layer cool time which reduces temperature gradients. This shows that multi-laser AM systems have an impact on part performance and potentially shows lattices built with multi-laser AM systems may have certain advantages over single-laser AM systems. [ABSTRACT FROM AUTHOR]

Noble gases are useful tracers for geochemistry, used to elucidate the origin and evolution of the solar system and planets. Noble gas analyses have been limited to bulk and spot analyses of solids and have yet to be developed for two- and three-dimensional imaging analysis. Recent developments in He isotope imaging using secondary neutral mass spectrometry are reviewed. The images have been fully quantified, and the spatial resolution has reached the nanoscale. The detection limit has been reduced to the level of ~ 10–3 cm3 STP g−1 (~ 1017 cm−3, ~ 1 ppma) for helium at lateral micrometer resolution. With this development, the concentration distribution of He in solids has been visualized as a map for the first time. [ABSTRACT FROM AUTHOR]

Hydrogen is troublesome in any periodic table classification. This being so it may as well be placed in a position that confers desirable attributes to the arrangement of the elements, while notionally recognising its lineage to the group 1 alkali metals and the group 17 halogens. Since the noble gases bridge the halogens and the alkali metals, and hydrogen encompasses the transition from the alkali metals to the halogens, there is more to the idea of hydrogen over helium. Hydrogen...seems to claim an exceptional position (Meyer 1870, p. 357) The real voyage of discovery consists not in seeking new lands but in seeing with new eyes (Proust 1927, p. 559) [ABSTRACT FROM AUTHOR]

This paper adopted the new process of double-sided oscillation laser autogenous backing welding and double-sided oscillation laser–TIG hybrid filling welding to achieve 80 mm thick SA-738Gr.B steel narrow gap welding in the horizontal position. The microstructure, mechanical properties, and residual stress of the welded joints in the as-welded (AW) state and in the post-weld heat treatment (PWHT) state were analyzed comparatively. The results show that because of the high-temperature tempering effect of PWHT, the microstructure of the welded joint is transformed into a high-temperature tempered microstructure with the increase in alloy carbide precipitation. The grains growth of the backing weld and the base material is obvious. The relative frequency of the high-angle grain boundary of the weld increases. Under the PWHT, the tensile strength of the welded joint decreases, and the residual stresses of the welded joint are redistributed and reduced significantly. [ABSTRACT FROM AUTHOR]

A theoretical analysis of a radiation amplifier based on metastable noble gas atoms excited by laser diodes in transverse pumping mode is presented. In the case when the amplified radiation reaches a sufficiently high intensity, the original equations allow a simple analytical solution, from which all the most important characteristics of the amplifier and the optimal parameters of both the working environment and the pump radiation, which ensure the most efficient operation of the amplifier, are easily found. [ABSTRACT FROM AUTHOR]

Inert gases, although widely used in various industries, can pose a risk of asphyxiation, making it crucial to detect and monitor their presence. However, creating sensors for inert gases is difficult because these gases have a very unreactive chemical nature, which means they don't readily interact with other substances. This work was carried out to investigate the transport properties of inert gas sensors based on palladium-clusters-decorated-graphene-sheets (Pd–Gr) using Density Functional Theory (DFT) based methodology. The sensors comprising Pd clusters Pdn (n = 2–5) decorated graphene were simulated to investigate the structural stability, adsorption, sensitivity, and electronic characteristics. The transport properties were studied using current–voltage (I–V) curves obtained via non-equilibrium Green's function (NEGF). The current appeared small at the start due to higher electrical resistance caused by charge transfer due to the adsorption of inert gases on the sensors. However, a voltage-dependent increase in the current took place afterward. The values of the resistance are found sensitive to the adsorption of the inert gases onto the sensors which helped to detect the gases. The energy difference of frontier molecular orbitals contributing to the conduction exhibited different responsive voltages which helped to points to the gas being adsorbed on the sensor. The Amsterdam Density Functional (ADF) package's BAND and DFTB modules were used to apply the linear combination of atomic orbitals (LCAO) approach throughout the whole computation process. The graphical user interface (GUI) was used to set up the input, and calculations with periodic boundary conditions were carried out. Built-in Slater-type orbitals (STO), TZ2P basis set and a hybrid functional B3LYP were used as the level of theory to establish the exchange correlation between electrons. The frozen core was adjusted to none and spin–orbit coupling was used to take relativistic factors into account and for all electron interactions. The adsorption energies were calculated which predicted that Pd2–Gr sensor has good sensitivity towards neon and xenon with − 0.363 eV and − 0.645 eV adsorption energy and 67% and 84% sensor response, respectively. The sensor Pd3-Gr appeared more effective in the detection of krypton gas having an adsorption energy of − 1.185 eV and 73% sensor response. Helium happened to be detected by Pd4–Gr Sensor with 91% sensor response and adsorption energy of − 1.194 eV. Similarly, Pd5–Gr Sensor is found more effective for sensing radon (− 0.669 eV) and argon (− 0.902 eV) gases with sensor response of 49% and 61% respectively. Pd6–Gr Sensor has least adsorption energy which indicates that the Pd6–Gr sensor is not a favorable sensor for sensing of inert gases. [ABSTRACT FROM AUTHOR]

To explore the mechanism of inhibiting spontaneous combustion of coal by mixed gases, the low-temperature oxidation characteristics of coal under different components of mixed gases were analyzed. ESR and FTIR experiments were used to investigate the effects of different gas mixtures on the activity of coal during low-temperature oxidation and the oxidation reaction of coal surface functional groups. The mechanism of chemical oxygen inhibition of mixed gas was studied by density functional theory. The results show that the larger the CO2 component in the mixed gas, the higher the ability to inhibit coal oxidation. The concentration of free radicals in coal under dry air condition is higher than that under inert mixed gas condition during oxidation heating at 30–230 °C. The oxidation ability of –CH3, –OH and oxygen-containing functional groups in the mixed gas reaction is inhibited. Through quantum chemistry calculation, it is found that the mixed gas increases the activation energy of free radicals and reduces the heat release of the reaction. This study provides theoretical reference for coal mine thermal disaster. [ABSTRACT FROM AUTHOR]

The isotopic composition (δ2H and δ18O) and unstable parameters (temperature, Eh, pH) of the natural waters in this area were obtained to clarify the features of the formation of the thermal water. The nitrogen thermal (72 °C) and relatively cold (20–25 °C) groundwater as well as surface water was studied in 2022. The isotopic composition of the surface water in the Kuldur River varies from δ18O≈−13.30‰ and δ2H≈−95.8‰ to δ18O≈−12.53‰ and δ2H≈−90.5‰ and fits on the approximation line δ2H = 7.14 × δ18O–1.2 (R2 = 0.91), which is close to the Local Meteoric Water Line (LMWL δ2H = 7.24 × δ18O + 0.5). Thermal groundwater has the isotope composition from δ18O≈−13.83‰ and δ2H≈−100.6‰ to δ18O≈−12.29‰ and δ2H≈−95.1‰ and it is approximated by equation δ2H = 3.23 × δ18O–56.2 (R2 = 0.84). The initial isotopic composition of the recharge water is about δ18O≈−14.1‰ and δ2H≈−102‰, which was found as intersection of the approximation line and LMWL. A comparison of the water temperature and its isotopic composition shows that thermal waters are most likely the result of a mixture of three components. The first end-member is the modern recharge water (it is obviously from tritium content), the second end-member is thermal fluid, and the third one is thawed permafrost, as the authors suggest. This assumption is supported by water from one of the observation boreholes noticeably shifts from the main area of the isotopic composition of the thermal water towards the isotopic enrichment. Apparently, this deviation is attributed to the isotopic fractionation during the groundwater freezing, when aquifer was turned into permafrost in last ice age, which is now thawing under the climate influence. The contribution of meltwater cannot yet possible to assess. Data on the tritium content and the isotopic composition of the dissolved noble gases makes it possible to estimate characteristics of the modern recharge water. Calculation gives an age of the modern component about 55 years and initial tritium concentrations of about 98 TU, which is fully consistent with field observations. [ABSTRACT FROM AUTHOR]

The energy deposited in resist during its exposure by ion beam was simulated for ions from a set of rare gases and for gallium. It was shown that the distribution of energy density can be approximated by the product of two Gaussian functions. One of them describes the lateral distribution of energy, the second the dependence on depth. The widths and centres of these Gaussian functions are determined by the energy length (also mentioned in the literature as "Range" or "mean length of trajectories"), the mass of ions and the average atomic number of resist. The obtained description would make it possible to estimate the size of the resist modified volume for any type of ion with energy of tens kiloelectronvolts. So it can be used for a priori estimates of resolution and performance, as well as for the choice of beam energy and ion type based on this. [ABSTRACT FROM AUTHOR]

Positron scattering from the noble gas atoms neon and argon is calculated using the single-center convergent close-coupling (CCC) method. Unlike previous CCC calculations, we have relaxed the frozen-core approximation by fully opening the outermost s and p shells, and find better agreement with experiment for excitation energies and dipole polarizability. We have used this improved structure model to calculate elastic, elastic differential, total, momentum-transfer, electron-loss, and total bound excitation cross sections. We have applied a complex model potential calculation, scaled to our single-center CCC results, to obtain direct ionization and positronium-formation cross sections for these systems. This complex model potential was also used to calculate results between the positronium-formation and ionization thresholds, giving complete results from 10 - 5 eV to 5000 eV. Overall, good agreement is observed with past theory and experiment for most transitions. [ABSTRACT FROM AUTHOR]

The non-consumable tungsten electrode plays a key-role in the tungsten inert gas (TIG) welding process, governing the behavior of the electrical arc that is essential for generating the necessary heat in welding. This study is focused on varying of electric parameters in the purpose to identify the appropriate conditions that promote electrode integrity. The post weld cathode analysis revealed that both the input current intensity and its frequency affect the overall morphology and microstructural and mechanical performance of the refractory electrode. Noticeable physical alterations occur with increased current, leading to larger grains and a reduction in microhardness values. In addition, it causes apparent defects such as perforation and superficial deformation. However, applying higher frequencies mitigates these defects significantly. Based on these findings, it seems crucial to take into consideration the interactive effect of current applied and its frequency to ensure better electrode conservation, thereby enhancing the efficiency of the welding process. [ABSTRACT FROM AUTHOR]

In the two-component relativistic density functional theory, the picture change error (PCE), which originates from insufficient transformation of operators, should be corrected. In this study, we examine the PCE in the fractional occupation number (FON) state based on the spin-free infinite-order two-component Hamiltonian. The PCE for the total and orbital energy changes is estimated with respect to the FON electrons of the highest occupied molecular orbital and 1s core orbital in noble gas atoms. PCE is significant in core orbitals in heavy elements but relatively small in light elements and valence orbitals. The delocalization error, which can be represented by the total energy deviation from the behavior of the exact energy, is overestimated by the lack of picture change correction of the two-electron operator and underestimated by that of the density operator. Corresponding to these results, the PCE influences the value of orbital energies and slope of orbital energy change to FON. [ABSTRACT FROM AUTHOR]

Germanium (Ge) is an attractive material for Silicon (Si) compatible optoelectronics, but the nature of its indirect bandgap renders it an inefficient light emitter. Drawing inspiration from the significant expansion of Ge volume upon lithiation as a Lithium (Li) ion battery anode, here, we propose incorporating Li atoms into the Ge to cause lattice expansion to achieve the desired tensile strain for a transition from an indirect to a direct bandgap. Our first-principles calculations show that a minimal amount of 3 at.% Li can convert Ge from an indirect to a direct bandgap to possess a dipole transition matrix element comparable to that of typical direct bandgap semiconductors. To enhance compatibility with Si Complementary-Metal-Oxide-Semiconductors (CMOS) technology, we additionally suggest implanting noble gas atoms instead of Li atoms. We also demonstrate the tunability of the direct-bandgap emission wavelength through the manipulation of dopant concentration, enabling coverage of the mid-infrared to far-infrared spectrum. This Ge-based light-emitting approach presents exciting prospects for surpassing the physical limitations of Si technology in the field of photonics and calls for experimental proof-of-concept studies. The authors proposed a Silicon technology-compatible approach to convert Germanium from an indirect bandgap to a direct bandgap via doping. This is done to expand the lattice to produce tunable effective tensile strain, aiming towards the on-chip light sources. [ABSTRACT FROM AUTHOR]

Laboratory research works on the separation of scale into components by extracting dehydrated scale are presented. Kerosene was used as a solvent. Dehydration was carried out by distillation with an inert gas. As a result, samples of dry scale, oil, and distilled water were obtained and analyzed. [ABSTRACT FROM AUTHOR]

Results are presented for a TEM laser system with a peak output power of ≥10 kW in several spectral ranges and with an improved design through the use of a combined gas mixture containing inert gases lasing on electronic transitions in addition to CO2 molecules. [ABSTRACT FROM AUTHOR]

It is noted that free sinusoidal oscillations in a classical mechanical oscillator are due to the mutual transformation of kinetic energy into potential energy. Known is an oscillator, in which free sinusoidal oscillations are accompanied by the transformation of the kinetic energy of an inert element into the same kinetic energy of another inert element. Elements with a different nature of reactivity are absent in such an oscillator. Such an oscillator is essentially monoreactive. The disadvantage of this oscillator is its imbalance due to the asymmetry of the structure, which may require additional vibration protection measures. This drawback can be avoided by using a symmetrical scheme with three loads. For the purposes of this work, it is convenient to use a flat three-coordinate system similar to the three-phase coordinate system used in electrical engineering. For an arbitrary vector R lying in the three-coordinate plane with the origin coinciding with the origin of coordinates, Theorem 1 is true. Coordinates , , of vector R form a regular triangle, the size of which does not change with an arbitrary rotation of vector R. Theorem 2. The middle of vector R is aligned with the center of the triangle . Half of vector R plays the role of a crank, which in real devices is needed to develop angular velocity and to impart the moment of force to compensate for dissipative losses. In a monoreactive harmonic oscillator with three loads, free sinusoidal oscillations of any given frequency can occur, which is determined solely by the initial conditions. [ABSTRACT FROM AUTHOR]

High harmonic generation is a phenomenon that occurs when an atom is subjected to a strong laser field. The laser field must have an intensity of at least 10 14 W / cm 2 to cause tunnel ionization, which releases an electron from the nucleus and allows it to gain energy by moving in the laser field. Upon recombining with the parent ion, the electron radiates its kinetic energy as photons in the XUV region. In this study, In order to find the optimal intensity of each atom, we first simulate and investigate the ionization probability of the noble gas atom. The simulation results show that the saturation intensity of tunnel ionization is about 3.8, 6, 8.1 and 12.5 × 10 14 W / cm 2 for xenon, argon, neon and helium gases, respectively. Using these results, we have been able to obtain the appropriate intensities to produce optimal attosecond pulses for each atoms. Then, according to the saturation intensity of gas ionization, we simulate the high-order harmonic spectrum in three intensities of 3, 5, and 8 × 10 14 W / cm 2 and investigate the effects of atomic and laser parameters on the cut-off point and plateau region of high harmonic generation spectrum. The simulation results show that the intensity and time profile of attosecond pulses are highly dependent on I P , and only the atoms that are in the range of tunnel ionization produced attosecond pulses. Also, our simulation results indicate that increasing the intensity leads to higher cut-off points and plateau regions for the harmonics. Furthermore, we found that helium had the highest cut-off point and plateau region at all three intensities, making it the most efficient noble gas for high harmonic generation. [ABSTRACT FROM AUTHOR]

Sprint interval training (SIT) increases peak oxygen uptake (V̇O2peak) but the mechanistic basis is unclear. We have reported that 12 wk of SIT increased V̇O2peak and peak cardiac output (Q̇peak) and the changes in these variables were correlated. An exploratory analysis suggested that Q̇peak increased in males but not females. The present study incorporated best practices to examine the potential influence of biological sex on the Q̇peak response to SIT. Male and female participants (n = 10 each; 21 ± 4 y) performed 33 ± 2 sessions of SIT over 12 wk. Each 10-min session involved 3 × 20-s 'all-out' sprints on an ergometer. V̇O2peak increased after SIT (3.16 ± 1.0 vs. 2.89 ± 1.0 L/min, η2p = 0.53, p < 0.001) with no sex × time interaction (p = 0.61). Q̇peak was unchanged after training (15.2 ± 3.3 vs. 15.1 ± 3.0 L/min, p = 0.85), in contrast to our previous study. The peak estimated arteriovenous oxygen difference increased after training (204 ± 30 vs. 187 ± 36 ml/L, p = 0.006). There was no effect of training or sex on measures of endothelial function. We conclude that 12 wk of SIT increases V̇O2peak but the mechanistic basis remains unclear. The capacity of inert gas rebreathing to assess changes in Q̇peak may be limited and invasive studies that use more direct measures are needed. [ABSTRACT FROM AUTHOR]

This paper proposes new combination of material and take on model evaluation in development of membrane anemometric gas flow sensor. We propose study of flow rate dependence for membrane-based thermal flow sensor composed with TaN/FeNi/TaN thermistors based on SiO2/Si3N4/SiO2 membrane. The purpose of this research is to develop a thermal flow rate sensor with advanced range of gas flow velocity measurement with increased accuracy and sensitivity. Currently presented as-is sensor is capable of measuring gas flow in the range from 150 to 300 L/min for low humidity preferably clean not reactive gases such as noble gases or air, supplied for clean room. In calculation the significant influence on the shape of the dependence of resistance on temperature was discovered from the heat capacity of the Si3N4 film on which the sensor is located. Observed dependence can serve as a justification for selecting film materials with lower thermal conductivity to increase the difference in resistance depending on the increase in gas flow, which will lead to a decrease in error and simplify signal detection. [ABSTRACT FROM AUTHOR]

Purpose: Neonatal sepsis is a systemic inflammatory infection common in premature infants and a leading cause of mortality. Argon is an emerging interest in the field of noble gas therapy. Neonates with severe sepsis are frequently mechanically ventilated creating an opportunity for inhalation therapy. We aimed to investigate argon inhalation as a novel experimental therapy in neonatal sepsis. Methods: Sepsis was established in C57BL/6 neonatal mice by a lipopolysaccharide intraperitoneal injection on postnatal day 9. Septic pup mice were exposed to room air as well as non-septic controls. In the argon group, septic pup mice were exposed to argon (70% Ar, 30% O2) for 6 h in a temperature-controlled environment. Results: At 6 h, survival was significantly enhanced when septic mice received argon compared to septic controls. Serum profiles of cytokine release were significantly attenuated as well as lung architecture restored. Conclusions: Our findings suggest that argon inhalation as a novel treatment for neonatal sepsis, reducing mortality and counteracting the acute systemic inflammatory response in the blood and preserving the architecture of the lung. This research can contribute to a paradigm shift in the treatment and outcome of neonates with sepsis. [ABSTRACT FROM AUTHOR]

Effectiveness of inhaled normoxic argon/oxygen gas mixture was tested with the participation of volunteers with good initial hearing prior to white noise exposure (preconditioning). The results of comprehensive audiometry including measurements of hearing threshold, delayed evoked otoacoustic emissions, distortion-product otoacoustic emissions, and short-latency auditory evoked potentials attested to the benefit of this method of otoprotection. [ABSTRACT FROM AUTHOR]

The most important structure types of nonmetals belonging to the VIII–IV groups and their importance for the development of the ideas about the composition and structure of the deep shells of the Earth and terrestrial-group planets are analyzed. The structural features of gas hydrates and their possible role in geological processes are considered. The structures of inert gases, hydrogen, and astrophysical ices in the Earth and other planets of the Solar system are presented in the light of new data. The modern concepts of the crystal chemistry of carbon polymorphs, genetic types of diamond, the indicator role of inclusions in its crystals, and conditions of its formation in nature and in model experiments are reviewed. [ABSTRACT FROM AUTHOR]

This paper investigates customized AA5083 and Al-Mg binary powders produced by gas atomization and assesses cold spray (CS) deposition of these materials with the evaluation of interface quality, deposition efficiency, porosity, and microhardness. While there has been extensive research progress on CS deposition of AA2024, AA6061, and AA7075, less attention has been given to CS 5xxx-series (Al-Mg) aluminum alloys. For the development and investigation of CS Al-Mg series alloys, AA5083 and customized Al-Mg binary powders were fabricated using a close-coupled inert gas atomizer, and those powders were sprayed using a high-pressure cold spray system to produce CS Al-Mg deposits. The microstructural characteristics of the powders, such as lattice constant and the formation of intermetallic networks, were affected by the Mg content of as-atomized powders. Selected CS parameters were able to produce highly dense CS deposits over a range of 1.7-5 wt.% Mg. The Mg content of as-atomized powders also influenced the hardness of the deposits and the DE while having no effect on porosity. The influence of Mg content on powder properties, CS process, and CS Al-Mg deposits has been discussed. [ABSTRACT FROM AUTHOR]

This paper presents the new geochemical isotope (Sr–Nd system, H2O, Cl) data obtained for basalt glasses of the Mid-Atlantic Ridge (MAR) sampled from six areas of the MAR axial zone between 31° and 12° N. The data are consistent with the existing ideas about large-scale geochemical segmentation of the MAR. It is shown that samples from predominantly serpentinite segments have a narrower range of variations of strontium isotopic composition (87Sr/86Sr = 0.7027–0.7032) in comparison with samples collected from the areas where the crustal section is dominated by basalts (87Sr/86Sr = 0.7024–0.7041). The variation ranges of the neodymium isotopic composition in these two groups of samples are almost identical (εNd = +4.9 to +10.9 and +5.9 to +11.6 in serpentinite and basalt segments, respectively), although, in general, serpentinite segments have a slightly more enriched composition. The wide variations of the neodymium isotopic composition and increased contents of Cl, H2O, and U, as well as increased K2O/TiO2 and La/Sm ratios, in samples from serpentinites can most probably be related to the participation of different geochemically heterogeneous sources in the magmatism of the MAR axial zone. The influence of enriched plume-type matter cannot be excluded in some segments. The isotopic composition of noble gases may shed light on the subject. [ABSTRACT FROM AUTHOR]

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The effect of irradiation with hydrogen, helium, nitrogen, and neon ions with an average energy of 0.8 keV on the surface morphology under the magnetron sputtering of a high-modular carbon fiber made of polyacrylonitrile is studied experimentally. In all cases, a whisker-like relief is formed on the surface. The greatest height of whiskers is obtained under irradiation with nitrogen and neon ions, while the lowest height and a lower density of whiskers is obtained under irradiation with hydrogen ions. Comparison with the irradiation of polyacrylonitrile carbon fiber with noble gas and nitrogen ions with energies of 10–30 keV shows that the whisker-like morphology complements the variety of types of ion-induced fiber surface morphology. The results obtained are discussed within the framework of existing models of the formation of ion-induced morphological elements on the surface of graphite-like materials. It is assumed that there is a threshold in the number of radiation-induced displacements created in the surface layer, leading to the observed qualitative difference in ion-induced morphology at low and high energies. The evaluations of the displacement profiles for the case of irradiation with hydrogen ions show several-fold fewer displacements than for other ions, which correlates with the observed differences in whiskering by selected ions and whisker-growth factors observed in the experiment performed. [ABSTRACT FROM AUTHOR]

Recently, noble gas has become a hot spot within the medical field like respiratory organ cerebral anemia, acute urinary organ injury and transplantation. However, the shield performance in cerebral ischemia–reperfusion injury (CIRI) has not reached an accord. This study aims to evaluate existing evidence through meta-analysis to determine the effects of inert gases on the level of blood glucose, partial pressure of oxygen, and lactate levels in CIRI. We searched relevant articles within the following both Chinese and English databases: PubMed, Web of science, Embase, CNKI, Cochrane Library and Scopus. The search was conducted from the time of database establishment to the end of May 2023, and two researchers independently entered the data into Revman 5.3 and Stata 15.1. There were total 14 articles were enclosed within the search. The results showed that the amount of partial pressure of blood oxygen in the noble gas cluster was beyond that in the medicine gas cluster (P < 0.05), and the inert gas group had lower lactate acid and blood glucose levels than the medical gas group. The partial pressure of oxygen (SMD = 1.51, 95% CI 0.10 ~ 0.91 P = 0.04), the blood glucose level (SMD = − 0.59, 95% CI − 0.92 ~ − 0.27 P = 0.0004) and the lactic acid level (SMD = − 0.42, 95% CI − 0.80 ~ − 0.03 P = 0.03) (P < 0.05). These results are evaluated as medium-quality evidence. Inert gas can effectively regulate blood glucose level, partial pressure of oxygen and lactate level, and this regulatory function mainly plays a protective role in the small animal ischemia–reperfusion injury model. This finding provides an assessment and evidence of the effectiveness of inert gases for clinical practice, and provides the possibility for the application of noble gases in the treatment of CIRI. However, more operations are still needed before designing clinical trials, such as the analysis of the inhalation time, inhalation dose and efficacy of different inert gases, and the effective comparison of the effects in large-scale animal experiments. [ABSTRACT FROM AUTHOR]