Search

As a high-energy density material, polymeric nitrogen has attracted considerable attention, while the exceptionally high synthesis pressure hinders its studies and applications. A significant discovery indicates that the insertion of noble gas elements can effectively reduce the synthesis pressure of polymeric nitrogen compounds. This work utilized the particle swarm optimization algorithm and first-principles calculations to extensively explore the stoichiometry of Xe–N compounds under high pressures. Two phases of XeN14, P6mm and P-62m, have been discovered, which are energetically more stable than the basic mixture of Xe and N2. Evidence of charge transfer between Xe and N was found, verifying that Xe plays a crucial role in forming polymeric nitrogen compounds. These two compounds are kinetically stable at pressures ranging from 50 to 200 GPa and exhibit semiconductor properties. A unique channel-like structure was discovered in the P6mm phase. The energy densities of P6mm and P-62m phases are 7.39 and 7.59 kJ/g, respectively, significantly exceeding those of TNT (Trinitrotoluene) and HMX (Octogen), indicating their potential as high-energy density materials. [ABSTRACT FROM AUTHOR]

We present a detailed study on the effects of oxygen on the photoluminescence properties of CdSe/CdS quantum dots (QDs). We investigated the role of oxygen by performing confocal measurements on thin films as well as on single particles while rapidly exchanging the gaseous environment between oxygen and an inert gas atmosphere. We found that the deionization of negatively charged particles by oxygen depends on both the excitation power and the shell thickness of the QDs. For QDs with thin shells, which exhibit strong photoluminescence blinking, we observed that the presence of oxygen affects both band-edge carrier blinking and hot-carrier blinking. [ABSTRACT FROM AUTHOR]

The influence of argon and helium on the rovibrational kinetics of carbon dioxide (CO2) and CO in low-temperature conversion plasma is investigated. With this objective, a combined experimental and computational study is conducted, applying quantum cascade laser infrared absorption spectroscopy to a pulsed DC CO2 glow discharge with varying noble gas admixture and modeling it with a two-term Boltzmann solver. Time-resolved rovibrational temperatures and dissociation fractions are presented, exhibiting an increase in rotational–vibrational non-equilibrium and an increasing CO2 conversion with argon (Ar) and helium (He) admixtures. Results are discussed in the context of energy transfer processes for collisions involving electrons, corroborated by electron-kinetic modeling, and heavy particle collisions. With noble gas addition, an increase in the electron number density, promoting excitation, and the high-energy tail of the electron energy distribution function are found. Penning ionization processes are proposed as an explanation for the increase in conversion, showing higher conversion for Ar due to the lower excitation thresholds and, therefore, larger state population. In the context of rovibrational kinetics, processes leading to the gain or loss of vibrational energy of CO2 are analyzed, pointing out subtle differences in, for example, relaxation rate coefficients between Ar and He. However, the cooling of the gas through conductive heat transfer is identified as the most important influence of the Ar and He admixture, as it keeps the relaxation rate for vibrational quenching low. [ABSTRACT FROM AUTHOR]

The thermophysical properties and elemental abundances of the noble gases in terrestrial materials can provide unique insights into the Earth's evolution and mantle dynamics. Here, we perform extensive ab initio molecular dynamics simulations to determine the melting temperature and sound velocity of neon up to 370 GPa and 7500 K to constrain its physical state and storage capacity, together with to reveal its implications for the deep interior of the Earth. It is found that solid neon can exist stably under the lower mantle and inner core conditions, and the abnormal melting of neon is not observed under the entire temperature (T) and pressure (P) region inside the Earth owing to its peculiar electronic structure, which is substantially distinct from other heavier noble gases. An inspection of the reduction for sound velocity along the Earth's geotherm evidences that neon can be used as a light element to account for the low-velocity anomaly and density deficit in the deep Earth. A comparison of the pair distribution functions and mean square displacements of MgSiO3–Ne and Fe–Ne alloys further reveals that MgSiO3 has a larger neon storage capacity than the liquid iron under the deep Earth condition, indicating that the lower mantle may be a natural deep noble gas storage reservoir. Our results provide valuable information for studying the fundamental behavior and phase transition of neon in a higher T–P regime, and further enhance our understanding for the interior structure and evolution processes inside the Earth. [ABSTRACT FROM AUTHOR]

This paper explores the emergence of topological interface states in one-dimensional locally resonant lattices incorporating inerters in both nearest neighbor (NN) and beyond-nearest neighbor (BNN) coupling. The investigation focuses on the unique wave propagation characteristics of these lattices, particularly the presence and behavior of interface states. The non-trivial topological behavior due to broken inversion symmetry within the unit cell of the locally resonant lattice is comprehensively investigated in the presence of inerters in NN and BNN coupling. The emerging interface states in the supercell analysis exhibit specific spatial and frequency localization properties due to inerter-based BNN interactions. Additionally, the study demonstrates the ability of inerter elements with weak inertance to control the frequency of interface states while maintaining the fundamental topological properties of the lattice. The identified topological interface states in lattices with BNN coupling present an opportunity for designing diverse devices, such as waveguides, filters, sensors, and energy harvesting systems. Overall, this research enhances our comprehension of topological phenomena in inerter-based locally resonant lattices with BNN interactions and introduces possibilities for creating robust and versatile devices based on topologically protected edge/interface states. [ABSTRACT FROM AUTHOR]

It is shown that the transport coefficients (self-diffusion, shear viscosity, and thermal conductivity) of the Weeks–Chandler–Andersen (WCA) fluid along isotherms exhibit a freezing density scaling (FDS). The functional form of this FDS is essentially the same or closely related to those in the Lennard-Jones fluid, hard-sphere fluid, and some liquefied noble gases. This proves that this FDS represents a quasi-universal corresponding state principle for simple classical fluids with steep interactions. Some related aspects, such as a Stokes–Einstein relation without a hydrodynamic diameter and gas-to-liquid dynamical crossover, are briefly discussed. Simple fitting formulas for the transport coefficients of the dense WCA fluid are suggested. [ABSTRACT FROM AUTHOR]

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

A comparison is made between the three principal methods for the analysis of neutron and x-ray diffraction data from noble gas fluids by direct Fourier transform. All three methods (standard Fourier transform, Lorch modification, and Soper–Barney modification) are used to analyze four different sets of diffraction data from noble gas fluids. The results are compared to the findings of a full-scale real-space structure determination, namely, Empirical Potential Structure Refinement. Conclusions are drawn on the relative merits of the three Fourier transform methods, what information can be reliably obtained using each method, and which method is most suitable for the analysis of different kinds of diffraction data. The mathematical validity of the Lorch method is critically analyzed. [ABSTRACT FROM AUTHOR]

Prussian blue analogues (PBAs) have been widely studied in aqueous zinc‐ion batteries (AZIBs) due to the characteristics of large specific surface area, open aperture, and straightforward synthesis. In this work, vanadium‐based PBA nanocubes were firstly prepared using a mild in situ conversion strategy at room temperature without the protection of noble gas. Benefiting from the multiple‐redox active sites of V3+/V4+, V4+/V5+, and Fe2+/Fe3+, the cathode exhibited an excellent discharge specific capacity of 200 mAh g−1 in AZIBs, which is much higher than those of other metal‐based PBAs nanocubes. To further improve the long‐term cycling stability of the V‐PBA cathode, a high concentration water‐in‐salt electrolyte (4.5 M ZnSO4+3 M Zn(OTf)2), and a water‐based eutectic electrolyte (5.55 M glucose+3 M Zn(OTf)2) were designed to successfully inhibit the dissolution of vanadium and improve the deposition of Zn2+ onto the zinc anode. More importantly, the assembled AZIBs maintained 55 % of their highest discharge specific capacity even after 10000 cycles at 10 A g−1 with superior rate capability. This study provides a new strategy for the preparation of pure PBA nanostructures and a new direction for enhancing the long‐term cycling stability of PBA‐based AZIBs at high current densities for industrialization prospects. [ABSTRACT FROM AUTHOR]

Leak proof tube-to-tube sheet joints are mandatory for the optimal operation and longevity of the shell and tube heat exchanger. Tube-to-tube sheet joints play a crucial role as fluid barriers, ensuring effective separation between the tube and shell side fluids within shell and tube heat exchangers. Nonconventional friction stir welding, known for imparting less residual stresses, is not commercially used for the fabrication of tube-to-tube sheet joints due to complex joint configuration and geometrical limitations. An extensive study on friction stir welding considering the geometrical parameters of tube-to-tube sheet arrangement is highly demanded. This research examined the mutual influence of radial clearance ranging from 0 mm to 0.5 mm and tube projection lying from 1 mm to 2 mm in friction stir welding of tube to tube sheet configuration on the pull-out strength, extension and, hardness at the stirring and fusion zones. Optimum radial clearance and tube projection for achieving high mechanical weld properties was estimated using multi-objective integrated Taguchi-PCA-GRA optimization. The result proves that the friction stir welded joint is capable of achieving joint strength close to the tungsten inert gas welded joint. The optimum parameters are 2 mm for tube projection and 0 mm for radial clearance to achieve maximum strength and weld penetration, while minimizing hardness at both stir zone and fusion zone. The findings of this research proved the adaptability of friction stir welding for the fabrication of tube-to-tube sheet joints with the right choice of tube projection and radial clearance. [ABSTRACT FROM AUTHOR]

The Apollo 16 regolith breccia sample suite provides a record of lunar regolith formation from the basin‐forming epoch (~3.9 Ga) through to a time of declining impactor flux (~2 Ga). These rocks have been characterized into three groups: the "ancient," "young," and "soil‐like" regolith breccias on the basis of their petrographic characteristics, and, in the case of the "ancient" and "young" regolith breccias, noble gas inventory. This study investigates the as‐yet unexamined noble gas records of the "soil‐like" regolith breccias to understand more recent regolith evolution processes that occurred at the Apollo 16 landing site. The range of gas concentrations measured for each noble gas in these samples is comparable to those previously reported for the local Apollo 16 soils. The "soil‐like" regolith breccias were found to be more gas rich than the gas poor "young" and "ancient" regolith breccias, consistent with them having formed from comparatively mature soil(s). Our results further confirm the scientific value of lunar regolith breccias and bulk regolith samples as probes of the impact history and the space environment of the lunar surface across a wide range of time. [ABSTRACT FROM AUTHOR]

Synthetic graphite of complex fractional composition was mixed with phenolic resin as a binder and pore-forming component. The mixtures were pressed and subsequently heat-treated to obtain porous matrices. The structural transformations of phenolic resin by heating up to 900 °C in oxygen and inert gas media were studied and the patterns of amorphization of fixed carbon formed on the walls of the pore system during carbonization were investigated. We found regularities in the changes in matrix volume density in the function of the open porosity and the average pore diameter. It is shown that, in order to obtain graphitized carbon matrices with a density of 1 g/cm3 and an open porosity of at least 50%, it is necessary to introduce no more than 20% of phenolic resin into the molding powder with an equal content of 60, 100 and 250 μm graphite fractions. This allows for high intensity and completeness of bulk silicon infiltration. [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]

This study aims to improve our understanding of some differences in odd and even chain-length alkanethiol self-assembled monolayers (SAMs) using infrared reflection absorption spectroscopy (IRRAS) and density functional theory (DFT). Xe, Kr, CH2Cl2, CD2Cl2, and CDCl3 were used experimentally to perturb the CH2 and CH3 stretches arising from the tail region of the SAM films and changes in position and intensity were monitored in the infrared. Using DFT methods, noble gases and CH2Cl2 were added to models of the SAM monolayers, and energies and vibrational spectra were calculated. It was observed that perturbing species affected the CH3 symmetric and asymmetric stretches on hexadecanethiol SAMs (an "even" SAM with a 16-carbon backbone) while on pentadecanethiol SAMs (an "odd" SAM with a 15-carbon backbone) both CH2 and CH3 symmetric and asymmetric stretches were affected. Films formed with shorter chain-length species, hexanethiol (even) and pentanethiol (odd), had less consistent results, likely due to more disorder in the alkanethiol chains from weaker van der Waals interactions. Adsorption energies for different perturbing species on the monolayers were higher for the hexanethiol than the pentanethiol. The vibrational spectrum of pentanethiol monolayers with adsorbed species mainly showed shifts to higher frequencies for CH2 and CH3 stretches; for hexanethiol, shifts to lower frequencies for CH2 stretches and higher frequencies for CH3 stretches were observed. Thus, the odd and even alkanethiol SAMs were affected differently by the perturbing species as observed both experimentally and computationally. [ABSTRACT FROM AUTHOR]

Excesses of cosmic-ray produced nuclei in individual components of meteorites indicate "pre-irradiation", either in the surface region of their parent bodies or as free-floating small particles in the early Solar System. We expand on our earlier work (Beyersdorf-Kuis et al., 2015) and report a study of cosmic-ray produced He and Ne in chondrules and "matrix" (i.e., matrix-dominated) material of several CR2 and CV meteorites as well as the highly primitive, unique, carbonaceous chondrite Acfer 094. In accordance with previous work, no evidence for pre-irradiation was found for CV3 Allende, while for CV3 Vigarano evidence for pre-irradiation is marginal at best. Also, the single chondrule from unique Acfer 094 that we studied has a cosmic ray exposure indistinguishable from the one we found for "matrix" material. Chondrules from Acfer 082 (CV) exhibit both excesses and deficits relative to "matrix", which points to pre-irradiation of not only chondrules, but also matrix material. A similar case may be Renazzo (CR2), where, however, the identification is complicated by the presence of abundant pre-solar Ne-E. A large number of chondrules (ten) were studied from CR2 El Djouf 001, which yielded slightly variable, small but consistent, excesses relative to "matrix", corresponding to "nominal" (i.e., irradiation by galactic cosmic rays in 4π geometry) excess ages of 1–2 Ma. Modelling suggests contributions from irradiation in the parent body regolith by solar cosmic rays (SCR) as well as galactic cosmic rays (GCR), where the latter dominates. Reevaluating the large variations previously identified in chondrules from QUE 99177, we suggest either a very different regolith history compared to that of El Djouf 001 or, more likely, pre-irradiation by, primarily, GCR in the early solar system as suggested previously. The case of solar-wind-rich NWA 852 (CR2) shows similarity to El Djouf 001 except for a much larger size of the effects. We suggest that the situation may be common among meteorites with a regolith origin. With independent information on the cosmic ray exposure age, which could be obtained by the study of cosmic-ray produced radionuclides, the individual parent body contributions may be disentangled, providing constraints on regolith dynamics. [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]

Ceramic refractory bubbling devices may be applied in the steel ladle to induce the flotation of non‐metallic inclusions to the slag phase. These inclusions have many origins along the steelmaking process and induce a detrimental effect on the mechanical properties of these metals. Therefore, the design of high‐performance ceramic plugs relies on understanding the fundamentals of non‐metallic inclusions captured by the gas bubbles. This study investigated the flotation dynamics of hydrophobic and hydrophilic hollow glass particles through experimentation using a water model and quantifying the particle concentration via light scattering. Both types of particles exhibited a comparable natural flotation removal rate, whereas a 40% increase for hydrophobic particles was observed when introducing 1.1 mm bubbles (at 25 NL/h) enhancing the efficiency from 43.1% to 65.2%. For hydrophilic particles, the efficiency increased from 59.1% to 86.2% when bubbles were injected into the system, whereas the removal rate decreased by 2.1‐fold. The consequence of the practice of inert gas purging to remove non‐metallic inclusions is also discussed. [ABSTRACT FROM AUTHOR]

• Two proposed hybrid isolators employ inerters to enhance the low-frequency isolation performance of the QZS-VI. • The resonance peaks of the proposed isolators get rectified and moved to the left on the amplitude-frequency spectrum. • The type I QZS-IE isolator can utilize slighter mass blocks to achieve better low-frequency isolation. • The type II QZS-IE isolator merely straightens the resonance peak without other opposite effect. The pursuit of enhanced low-frequency vibration isolation motivates the development of quasi-zero-stiffness vibration isolators (QZS-VIs), yet with inherent limitations. The nonlinear hardening stiffness may distort the resonance peak rightward, narrowing the isolation bandwidth. Additionally, the high sensitivity to excitation variations can exacerbate the rightward distortion and jumping phenomenon. In this study, two types of hybrid isolators (QZS-IE isolators) are developed by integrating inerter elements (IEs) with traditional QZS-VI to enhance isolation performance. Their distinct mass block configurations yield varied enhancement behaviors. The unified dynamic equation for the two QZS-IE isolators is derived using harmonic balance and arc-length methods, validated by Runge-Kutta. The analyses of stability and periodicity clarify their response characteristics. Subsequently, the study investigates the effects of geometry and excitation parameters, comparing the enhancements of the two QZS-IE isolators. The results manifest that the introduction of inerter elements improves low-frequency vibration isolation, suppressing peak transmissibility and reducing isolation beginning frequency. The type I QZS-IE isolator outperforms the type II QZS-IE and traditional QZS isolators in low-frequency isolation performance and excitation sensitivity. However, the high-frequency isolation performance of the type I isolator is hindered by the ascending transmissibility curve post anti-resonant frequency. The type II QZS-IE isolator rectifies resonance peak distortion while avoiding adverse effects. The different configurations of the inerter elements and the related attenuating strategies offer a guideline for diversified vibration isolation objectives. [ABSTRACT FROM AUTHOR]

This work aims to investigate the effect of N2/CO2 on the explosion behavior of premixed liquefied petroleum gas (LPG)-air in a half-open duct. Experiments were performed in a duct (L/D = 47.5) with the ignition end closed and the other end open. Firstly, the optimal explosion concentration of LPG was determined using the stepwise approximation method, secondly, the effects of different volume fractions (VFs) of N2/CO2 on the pressure dynamic process, flame propagation velocity, and explosion severity of LPG-air explosion were analyzed, and finally the inerting effects of N2 and CO2 were compared using the control variable method. The results show that the explosion pressure and flame propagation velocity reach a maximum when the VF of LPG is 4.8% (without inert gas), and two pressure peaks (the first pressure peak (P1) and the second pressure peak (P2)) are observed. When the VF of LPG is 4.8%, the maximum pressure and the average flame propagation velocity in the tube decrease and the explosion intensity inside and outside the duct was effectively mitigated as the VF of N2/CO2 increases, and the explosion is completely suppressed as the VF of inert gas reached 30%. P2 is significantly suppressed, and the maximum explosion pressure (Pmax) occurs at $${P_1}$$ P 1 when the VF of N2/CO2 is above 15%. The suppression effects of CO2 are more remarkable at a lower VF (below 18%), those of N2 are more significant at a higher VF (above 18%), and P1 also follows this rule. For a given volume fraction of inert gas, the suppression effect of N2/CO2 on the degree of explosion severity becomes more significant when approaching the optimal LPG explosion concentration (4.8%). [ABSTRACT FROM AUTHOR]

Affected by the occurrence conditions, the inclination angle of the goaf and the ground temperature change the caving structure and temperature rise environment of the goaf, which in turn affects the distribution range of the spontaneous combustion zone in the goaf. During the process of inert gas injection, the cooling and diffusion range of the inert gas determines the its inerting effect. In this paper, the temperature-programmed experiment was used to obtain the oxygen consumption rate of coal at different temperatures. Fluent simulation showed that when no inert gas was injected, the scope of the spontaneous combustion zone on the inlet side moved backward and expanded, while the gas in the gob on the return air side overflowed, and the spontaneous combustion zone The range becomes smaller; when inert gas is injected at low temperature, the influence of different inert gases (N2, CO2) on cooling and diffusion distribution is quite different, CO2 accumulates at the bottom of the goaf, and the influence range is larger; And the space inerting effect is better; the spontaneous combustion area is affected by the injection of inert gas, and there is a risk of secondary re-ignition when the inert gas injection ends. [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]

Inerters (ID) and Clutched Inerter Devices (CID) are a novel technology with demonstrated seismic control potential. However, the inherent nonlinearity and discontinuity of the clutching phenomena in CIDs can pose significant challenges for their accurate numerical modeling. In general, conventional existing methods either oversimplify the physics involved or are sensitive to the step size and thus are inherently unstable, demanding excessive numerical resources. Most relevant studies to date have focused on small‐scale systems with a limited number of inerters and have used simplified models due to the lack of analysis tools. At the same time, the Mixed Lagrangian Formulation (MLF), has proven to be a powerful tool for simulating non‐smooth dynamics phenomena. This paper presents an alternative way of modeling the behavior of CIDs in both MLF and conventional finite element method. We put forward an original formulation of the inerter element, clutching behavior, and the inerter‐related dissipation model, as well as their associated computational scheme in MLF and the equivalent construction in FEM. The newly proposed CID element in MLF is then implemented and validated through three examples, including a single degree of freedom system, a multi 10‐storey moment resisting frame (MRF), and a 10‐storey self‐centering concentrically braced frame (SC‐CBF) with multiple rocking sections. The results are compared to those from existing models used for clutching inerter and to the proposed FE model. Finally, the advantages of using the MLF framework and salient characteristics of the structures equipped with clutched inerters are discussed. The modeling strategy proposed in this work empowers researchers to simulate structures with a larger number of degrees of freedom, equipped with a considerable amount of inerter‐based devices, with reduced effort and improved computational performance. [ABSTRACT FROM AUTHOR]

The excessive main girder displacement responses of the large-span cable-stayed bridges during seismic events may precipitate collisions between the main girder and the approach bridge. The viscous dampers (VDs) have been extensively employed in the seismic response control of long-span bridges, yet their effectiveness is limited. To augment the seismic-induced vibration control performance of the VD, inerter element, negative stiffness (NS) element, and spring element have been incorporated into the VD to achieve energy dissipation capacity enhancement. The equations of motion for the simplified cable-stayed bridge-damper systems are established under stochastic seismic excitation, and the design parameters of inerter and NS-based damper are optimized by using the genetic algorithm. The seismic control performance of the VD and five types of dampers are systematically compared, demonstrating that these dampers can substantially enhance the main girder displacement mitigation performance in cable-stayed bridges. Owing to the NS characteristics attributes of the inerter element and NS element and the tuning effect of the spring element, the tuned viscous mass damper (TVMD) with NS achieves a 24.56% higher efficiency in control performance compared to the VD. [ABSTRACT FROM AUTHOR]

Based on DFT calculations (ωB97XD/def2‐SVP/SVPfit), the ability and mechanism of noble gas encapsulation by series of cryptophanes were investigated. The focus was set to study the influence of different functionalization groups placed at the “gates” of cryptophanes cavity entrance by which the energy criteria were chosen as a main indicator for selective encapsulation of noble gases. Chosen functionalization groups were CH3, OCH3, OH, NH2, and Cl, and the encapsulation process of these cryptophanes was compared to a cryptophane without any functionalization group on its outer rim. Those groups were selected based on their different chemical properties and based on their size which will subsequently put additional steric restrictions on the cavity entrance. Chosen functionalization groups, beside their steric influence on the energy barrier magnitude, influence also the gating process through its chemical nature by which they can put an additional stabilization on noble gases encapsulation transition states enhancing the encapsulation process. Objective of this study was clearly to get better insights on the influence of those functional groups on the whole encapsulation process of noble gases. Large‐size noble gases (Xe and Rn) from all noble gases are best accommodated in the cavities of selected cryptophanes, on the other hand these noble gases require to pass the highest energy barrier through the gating process. From the series of investigated cryptophanes, the cryptophane with the OCH3 functionalization group has been identified as the one with the best capabilities to host investigated noble gases, but on the other side this cryptophane puts the highest energy criteria required for the previous gating process. [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 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]

The sustenance of cellular detonation under weak confinement is studied through two-dimensional (2D) numerical simulations of hydrogen–oxygen mixtures surrounded by inert gas. The results show that in the weakly confined space, the cellular detonation with Chapman-Jouguet velocity can survive by increasing the width of the reactant layer and enhancing the reactivity of reactants, which ensures enough triple points and high reactivity in the reactant layer for detonation sustenance since transverse shocks cannot be regenerated and reinforced by boundary reflection. By adding ozone into the system and changing the width of the reactant layer, the relationship between induction length and detonation sustenance is established. It is found that the sustenance of cellular detonation in the weakly confined space is related to the ratio of the reactant layer width to the induction length. Ozone reactions can reduce the induction length and enhance reactivity, thereby promoting the generation of new transverse shocks and significantly improving the sustenance of cellular detonation in weakly confined space. [ABSTRACT FROM AUTHOR]

The Panel on Food Additives and Flavourings (FAF) provides a scientific opinion re‐evaluating the safety of the two food additives argon (E 938) and helium (E 939). Argon (Ar) and helium (He) are two noble gases, highly stable single atoms. Their chemical inertness is well known. Their physicochemical properties have served as a basis for their previous evaluations by SCF and JECFA, which have considered the use of these food additives safe even in the absence of a toxicological evaluation. No business operator or other interested party provided information in response to the call for data published by EFSA to support the re‐evaluation of these two food additives with respect to their identity and specifications, manufacturing process (including the identification and quantification of potential impurities) and how they are applied to food to exert their technological function. One business operator replied to the call for data issued by EFSA reporting use levels of E 938 as a packaging gas in one food category. Based on their physicochemical properties, both gases are considered by the Panel to be of low toxicological concern when used as food additives. No information was available on the potential presence of impurities of toxicological concern resulting from the manufacturing process(es) applied to the production of the food additives E 938 and E 939. The Panel however noted that a minimum purity of 99.0% is required to comply with existing specifications. The Panel concluded that the use of argon (E 938) and helium (E 939) as food additives does not raise a safety concern. The Panel recommended an amendment of the existing EU specifications to introduce the respective CAS numbers. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) are very suitable for extraction, drug delivery systems, and sensors due to their good selective adsorption ability, but the difficulty of eluting templates during synthesis and the limitation of application scenarios put higher demands on MIPs. Stimuli‐responsive MIPs (SR‐MIPs) can actively respond to changes in external conditions to realize various functions, which provides new ideas for the further development of MIPs. This paper reviews the multiple response modes of MIPs, including the common temperature, pH, photo, magnetic, redox‐responsive and rare gas, biomolecule, ion, and solvent‐responsive MIPs, and explains the mechanism, composition, and applications of such SR‐MIPs. These SR‐MIPs and the resulting dual/multiple‐responsive MIPs have good selectivity, and controllability, and are very promising for isolation and extraction, targeted drug delivery, and electro‐sensor. [ABSTRACT FROM AUTHOR]

The atmosphere-induced interference reduction device (AIRD) shows promise in mitigating interferences in inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The effectiveness of AIRD in reducing interferences caused by atmospheric gases such as H, C, N and O was evaluated by using argon (Ar) and helium (He) as shielding gases due to their inert properties. Krypton (82Kr) served as an internal standard for monitoring and correcting instrumental sensitivity drift. The shielding gas flow rate was optimized using gas dynamics simulations, revealing a threshold of 10 L min-1 for optimal interference reduction. Results indicate the superiority of He in reducing interferences, with a reduction of 32% for 12C+, 51% for 15N+, 56% for 16O+, 54% for 16O¹H¹H+, 51% for 40Ar140Ar16O+ compared to Ar.N+, and 42% for 4 Moreover, AIRD maintained low oxide yields even after shielding gas cessation, with oxide yield maintained at approximately 0.03% for 24 hours. Analyses of LA-ICP-MS coupled with AIRD demonstrate that ThO/Th can be reduced from 0.92% to 0.15% compared to normal analysis without AIRD. Experimental investigations further revealed that AIRD influenced elemental sensitivity, particularly with He as the shielding gas, with an ~25.7% enhancement observed in the signal intensity of 82Kr. [ABSTRACT FROM AUTHOR]

Uncovering the nature of dark matter microscopic particles is one of the most important disciplinary goals of physics and astronomy in the 21st century, and how to reduce background signals and environmental interference in dark matter experiments is one of the key factors to improve the sensitivity of the detector and to take the lead in obtaining significant detection results. High-purity nitrogen, as a crucial gas for detector purging, scintillator purification and pipe cleaning, among other things, contains the radioactive gases 85Kr and 81Kr in natural Kr, which emit β-rays that can interfere with the detection of dark matter signals. Therefore, it is necessary to measure the concentration of ultra-trace level Kr in high-purity nitrogen, and screen high-purity nitrogen complying with the standard for use in dark matter experiments. This study develops a novel analytical method to determine ultra-trace level Kr in highpurity nitrogen using a static noble gas mass spectrometer coupled with a newly designed sample processing system. A large amount of reactive gases from the original sample are removed by the largevolume high-temperature purification device, and then we explore a simple and iterative trapping method for Ar-Kr separation. This method improves the noble gas separation factor with the promise of ensuring recovery. The separated Kr is fed into a static vacuum mass spectrometer. The detection limit of this method for natural Kr is as low as 10-14 L L-1 with an uncertainty of about 8%. [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]

Although flash sintering (FS) is an effective method for rapidly preparing ceramics, FS of non-oxide ceramics at room temperature (RT) has not yet been achieved. In this study, we developed a feasible method for FS of SiC at room temperature (RT). A dog-bone-shape SiC sample prepared without using any sintering aid achieved a relative density of 96.5 % after sintering in a low-pressure Ar atmosphere for 60 s. Arc heating, which was constrained by the height of an alumina plate fixed above the sample, increased the conductivity of the sample, which then reached the stable stage of FS. The sintered sample exhibited a typical 6H–SiC crystal structure, which was consistent with that of the raw powder. The proposed FS method, based on constraining the arc using an alumina plate under a low-pressure inert gas atmosphere, provides a reference for developing further advanced RT FS strategies for non-oxide ceramics with low conductivities at RT. [ABSTRACT FROM AUTHOR]

This study investigates the dynamics of mass transfer between gas and liquid during the fuel scrubbing inerting process, utilizing a mixed inert gas (MIG) composed of CO2, N2, and trace amounts of O2. The goal is to lower oxygen concentrations in aircraft fuel tanks, thereby reducing the risk of explosions. The experiments were conducted on a fuel scrubbing inerting platform, where an MIG was utilized to deoxygenate aviation fuel. Changes in the oxygen concentration in the ullage (OCU) and the dissolved oxygen concentration in the fuel (DOCF) were measured during the scrubbing process. Validated by these experimental data, Computational Fluid Dynamics (CFD) simulations demonstrated the reliability of the model. The discrepancies between CFD predictions and experimental measurements were 4.11% for OCU and 5.23% for DOCF. The influence of the MIG bubble diameter, MIG flow rate, and fuel loading rate on DOCF, gas holdup (GH), and the oxygen volumetric mass transfer coefficient (OVMTC) was comprehensively examined. The results reveal that larger MIG bubble diameters lead to an increased DOCF but reduced GH and OVMTC. In contrast, a higher MIG flow rate decreases DOCF while boosting GH and OVMTC. Additionally, a greater fuel loading rate increases DOCF but decreases GH and OVMTC. These findings offer important insights for optimizing fuel scrubbing inerting systems, underscoring the necessity of selecting suitable operating parameters to enhance oxygen displacement and ensure aircraft safety. [ABSTRACT FROM AUTHOR]

The present work investigates the variation of the surface roughness due to the build position of specimens with respect to the inert gas flow direction and re-coater movement direction. Selective laser melting (SLM) method was used to study this effect using Inconel 718 as workpiece material. A total of 21 samples were placed equidistant from each other on the built plate to observe the effect of gas flow and re-coater movement. The effect of these parameters on the printed samples was analyzed in terms of the profile surface roughness parameter such as Ra and Rz in the build direction. The result showed that samples placed near the gas inlet and the re-coater starting position had larger roughness as compared to the samples placed further from the gas inlet and re-coater end position. The result showed that the profile average roughness parameter values varied from Ra = 5.02 µm to 14.7 µm and profile maximum height surface parameter varied from Rz = 47.61 µm to 118.3 µm for all the printed samples. Surface topography of the samples was also studied which showed common printing defects such as cracks, micropores, local solidified melt pools, and dimples. The study opens an avenue to explore and optimize the placement of the printing sample on the build plate with respect to the inlet gas flow and recoater movement directions for better surface roughness. [ABSTRACT FROM AUTHOR]

The active injection system was designed to study the explosion flame propagation behavior of premixed CH 4 /H 2 /air mixtures in the closed tube with inert gas injection. The injection of inert gases (N 2 , CO 2 , and air) was controlled by the injection time, t inject , which is set from 0 ms to 210 ms. The effects of injection disturbance and inert gas dilution on flame morphology, flame tip dynamics, and overpressure build-up have been investigated. Results show that the injection of inert gas into premixed CH 4 /H 2 /air flame wrinkles the early laminar flame, changing the flame structure. The increase in t inject shortens the flame propagation time and increases the maximum explosion pressure, but the maximum value is attained at t inject = 120 ms. The linear relationship between maximum explosion pressure and maximum flame tip velocity is presented. The addition of inert gas dilutes the fuel-air mixture, but the inert gas shows some inhibition effect on the turbulent explosion flame propagation at t inject > 120 ms. The injection disturbance plays a dominant role in the flame propagation process compared to inert gas dilutions. Finally, the effect of Darrieus-Landau and Rayleigh-Taylor instabilities on explosion flame propagation behavior has been examined. The injection of inert gas into premixed CH 4 /H 2 /air flames creates local turbulence, enhances flame instabilities, and provides positive feedback on the flame's acceleration and oscillation. • Effect of inert gas injection on premixed CH 4 /H 2 /air explosions is investigated. • The injection disturbance plays a dominant role in explosion flame propagation behavior. • The injection of inert gas shortens flame propagation time and increases the explosion pressure. • Effect of inert gas type and injection time on explosion parameters are confirmed. • Injecting inert gas into the explosion flame changes the DL and RT instabilities. [ABSTRACT FROM AUTHOR]

Hydrogen, which emits large amounts of heat and has harmless products, is considered a potential alternative fuel. However, its wide flammability range and low ignition energy make it hazardous during storage and transportation. Therefore, in the event of a hydrogen leak in a confined space, a certain amount of inert gas can be added to inhibit combustion. Nonetheless, the addition of inert gas can also lead to an increase in the initial pressure as well. The aim of this research is to analyze the characteristics of laminar flame propagation and the inherent instability of laminar flames composed of 30% H 2 -air under various initial pressures and different types or quantities of inert gas dilution. In the experimental setup, hydrogen and air are pressurized into a 20 L spherical chamber to create the required mixed gas, following which inert gases such as CO 2 , N 2 , and He are added to achieve the desired pressure levels. Initially, the study focuses on elucidating the impacts of different variables on parameters such as flame propagation speed, flame stretching rate, un-stretched flame propagation speed, Markstein Length, and un-stretched flame burning speed. Additionally, it delves into investigating the effective Lewis number, density ratio, and flame thickness under varying conditions to understand the mechanisms influencing inherent flame instability. The findings indicate that increasing p 0 or augmenting the amount of dilute gas mixing both exacerbate flame front instability and reduce the critical radius of the flame. Among the three admixed species, CO 2 addition exhibits the most significant effect. [Display omitted] • Experiments study on the inherent flame instability of H 2 -air with combined effects of p 0 and inert gas dilution. • For p 0 ≥ 150 kPa, CO 2 addition≥ 20%, or N 2 addition≥ 25%, the stretching rate enhances flame propagation speed. • Inert gas dilution alters the structure of the H 2 -air premixed flame front. [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]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries 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.)

Liquid steel atomization using close‐coupled nozzles is highly dependent on the relationship between momentum flux ratio, gas–liquid ratio, aspiration pressure, and operating pressure of inert gases. A strong correlation between these parameters and the final powder must be assumed. Understanding these parameters, their influence on the process, and their interactions with each other is indispensable for efficient powder production. In particular, the industrial application of close‐coupled atomization nozzles, which develop a thin pre‐film on the nozzle tip, is not yet fully understood. A model experiment is presented to investigate interactions between the flow conditions of the gaseous and liquid phases, focusing on recirculation phenomena inside the atomization zone. The experiments show the influence of liquid and gas flow conditions on the spray geometry and the liquid core length, as well as the strong dependence of the liquid mass flux on the gas flow. The aspiration pressure below the liquid nozzle is sensitive to gas pressure and has a major influence on the development of the liquid core and the pre‐film, as it increases the liquid mass flux. For practical application, the results confirm an optimal operating point of interacting system parameters, which leads to high‐quality atomization with minimal use of resources. [ABSTRACT FROM AUTHOR]

In this investigation, an effort was made to introduce Ag into the CeO2 fluorite crystal lattice to form Ce0.99Ag0.01O2-δ (ACRM) using an ammonium hydroxide-assisted co-precipitation method. The resulting powder obtained after the co-precipitation reaction, filtration, and drying was annealed at 800 °C in a muffle furnace to obtain crystalline ACRM. The phase composition and microstructure of the synthesized ACRM were analyzed using a powder X-ray diffractometer (PXRD) and a scanning electron microscope (SEM). The characterized ACRM powder was then subjected to multiple thermochemical thermal reduction (TR) and CO2 splitting (CDS) cycles using a high-temperature thermogravimetric analyzer (TGA). The TR step was conducted using Ar gas as an inert atmosphere, maintaining the temperature at 1400 °C for 60 min. Subsequently, the same powder was subjected to the CDS step by treating it with a gaseous mixture of 50% CO2 and Ar gas at 1000 °C for 30 min. ACRM displayed stable redox reactivity towards thermochemical CDS cycles by generating an average of 50.9 μmol of O2/g·cycle and 101.6 μmol of CO/g·cycle, respectively, over 10 thermochemical cycles. [ABSTRACT FROM AUTHOR]

Intense bombardment of solar system planets in the immediate aftermath of protoplanetary disk dissipation has played a key role in their atmospheric evolution. During this epoch, energetic collisions will have removed substantial masses of gas from rocky planet atmospheres. Noble gases are powerful tracers of this early atmospheric history, xenon in particular, which on Mars and Earth shows significant depletions and isotopic fractionations relative to the lighter noble gasses. To evaluate the effect of impacts on the loss and fractionation of xenon, we measure its ionization and recombination efficiency by laser shock and apply these constraints to model impact-driven atmospheric escape on Mars. We demonstrate that impact bombardment within the first 200 to 300 million years of solar system history generates the observed Xe depletion and isotope fractionation of the modern martian atmosphere. This process may also explain the Xe depletion recorded in Earth's deep mantle and provides a latest date for the timing of giant planet instability. [ABSTRACT FROM AUTHOR]

To obtain a successful product during additive manufacturing, the powder as a raw material must have the high quality. The purpose of this work is to investigate CrMnNi steel powders obtained by inert gas atomization with nickel content: 3, 6, and 9 wt% and to identify dependencies between the powder size and morphology, solidification structure, and change in chemical composition and thermophysical properties. Particle size distribution is measured by a laser scattering analyzer: d50 value are 82.02, 69.32, and 75.54 μm for powders with 3, 6, and 9 wt%, respectively. Surface tension (ST) measurements are made by maximum bubble pressure method: for steels with 3, 6, and 9 wt% at temperature 1500 °C, ST is 1.01, 1.07, and 1.15 mN m−1, respectively. It is found that the change in particle size affects the chemical composition, the content of the ferromagnetic phase and secondary dendritic arm‐spacing. Changes in the content of elements such as S, O, N, and Mn are determined, depending on the diameter of the particles. The influence of changes in content of S, O, and N on the thermophysical properties such as ST is investigated. [ABSTRACT FROM AUTHOR]

The creation of SiV−, GeV−, and SnV− are presented by the atmospheric annealing in the argon flow. Compared to high‐pressure annealing, in which gas cannot flow, atmospheric annealing with an inert gas flow not only causes less degradation of the sample surface but also has the advantage of reducing equipment cost and preparation time. Excessive annealing time has been shown to reduce the amount of centers created. The optimal annealing time that maximizes formations depends on the type of diamond sample and the implanted ions. Furthermore, inspired by the split‐vacancy structure of the group IV–V centers, atmospheric pre‐annealing at 600 °C to increase the amount of di‐vacancy is demonstrated, followed by annealing at 1800 °C for 1 min. A shorter duration of high‐temperature annealing is expected to qualitatively reduce stress and deterioration of the crystallinity of the diamond sample. [ABSTRACT FROM AUTHOR]

The preservation period afforded by cold storage of cells is short. However, the use of rare gases for cold storage as a means of extending the period of preservation would be highly beneficial.To examine the effect of temperature on the protective effect of cold storage of cells using pressurized dissolution of xenon gas, with particular focus on the inhibition of substance transport by viscosity.Human dermal fibroblast monolayers incubated in a culture dish for 48 h were used as a test sample, with culture medium used as a preservation solution. Samples were placed into a pressure-resistant vessel, which was pressurized with xenon gas at 0 or 0.5 MPa, and cells were stored at 0 to 5 °C for 18 h. Cell activity was evaluated by tetrazolium salt assay. The viscosity of the medium under pressurization at each storage temperature was estimated.The maximum protective effect against cell damage of cold storage with pressurized dissolution of xenon gas was observed at 4 °C. An increase in estimated viscosity by pressurization was correlated with increased cell activity at 4 °C.Analysis of the temperature dependence of the protective effect against cell damage of cold storage with pressurized dissolution of xenon gas revealed that the most effective temperature is 4 °C. The data also suggest that increased viscosity due to pressurization plays a role in the protective effect. [ABSTRACT FROM AUTHOR]

Elmshorn fell April 25, 2023, about 30 km northwest of the city of Hamburg (Germany). Shortly after the fall, 21 pieces were recovered totaling a mass of 4277 g. Elmshorn is a polymict and anomalous H3‐6 chondritic, fragmental breccia. The rock is a mixture of typical H chondrite lithologies and clasts of intermediate H/L (or L, based on magnetic properties) chondrite origin. In some of the 21 pieces, the H chondrite lithologies dominate, while in others the H/L (or L) chondrite components are prevalent. The H/L chondrite assignment of these components is based on the mean composition of their olivines in equilibrated type 4 fragments (~Fa21–22). The physical properties like density (3.34 g cm−3) and magnetic susceptibility (logχ <5.0, with χ in 10−9 m3 kg−1) are typical for L chondrites, which is inconsistent with the oxygen isotope compositions: all eight O isotope analyses from two different fragments clearly fall into the H chondrite field. Thus, the fragments found in the strewn field vary in mineralogy, mineral chemistry, and physical properties but not in O isotope characteristics. The sample most intensively studied belongs to the stones dominated by H chondrite lithologies. The chemical composition and nucleosynthetic Cr and Ti isotope data are typical for ordinary chondrites. The noble gases in Elmshorn represent a mixture between cosmogenic, radiogenic, and primordially trapped noble gases, while a solar wind component can be excluded. Because the chondritic rock of Elmshorn contains (a) H chondrite parent body interior materials (of types 5 and 6), (b) chondrite parent body near‐surface materials (of types 3 and 4), (c) fragments of an H/L chondrite (dominant in many stones), (d) shock‐darkened fragments, and (e) clasts of various types of impact melts but no solar wind‐implanted noble gases, the different components cannot have been part of a parent body regolith. The most straightforward explanation is that the fragmental breccia of Elmshorn represents a reaccreted rock after a catastrophic collision between an H chondrite parent body and another body with H/L (or L) chondrite characteristics but with deviating O isotope values (i.e. that of H chondrites), complete disruption of the bodies, mixing, and reassembly. This is the only straightforward way that the implantation of solar wind gases could have been avoided in this kind of complex breccia. The gas retention ages of about 2.8 Gyr possibly indicate the closure time after the catastrophic collision between H and H/L (or L) chondrite parent bodies, while the cosmic ray exposure age for Elmshorn, which had a preatmospheric radius of 25–40 cm, is ~17–20 Myr. [ABSTRACT FROM AUTHOR]

The exchange of carbon dioxide with methane in natural gas hydrates (NGHs) is one of the sustainable approaches for the sequestration of carbon dioxide in NGHs. However, the formation of mixed CH4─CO2 hydrates during CH4─CO2 exchange in NGHs reduces the rate of CH4─CO2 exchange in NGHs. It is reported that molecular level insights into CH4─CO2 exchange in NGHs using quaternary‐gas systems of CH4, CO2, and a mixture of flue (H2S and N2) and noble (Ne, Ar, Kr, and Xe) gases in heterogeneous medium using molecular dynamics simulation techniques. The sequestration of gases other than CH4 in the new hydrate cages besides the interface is the highest in CO2:H2S:Ar (2:1:1) system among all the reported quaternary‐gas systems. The results show that Ar enhances CO2 sequestration in NGHs in the presence of H2S rather than N2. The hydrate growth occurs due to the formation of dual hydrate cages. Among the methane molecules released from the hydrate slab in a binary‐gas (CH4─CO2) system, > 60 % of the released methane molecules reform new cages beside the interface. On the other hand, only ≈ 50 % of the released methane molecules reform new hydrate cages besides the interface in CO2:H2S:Ar (2:1:1) system. [ABSTRACT FROM AUTHOR]

Using a 50‐compartment Python‐coded mathematical lung model, we compared mixed venous blood flow (Q) distributions and arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) relationships in lungs modeled with log normal distributions (LND) of inspired (VI) versus expired (VA) alveolar gas volumes. In lungs with normal V/Q heterogeneity, Q versus VA/Q and Q versus VI/Q distributions were similar with either approach, and PaO2/FiO2 sequences remained indistinguishable. In V/Q heterogeneous lungs at high FiO2, VILND generated low Q versus VA/Q shoulders and some negative VA units, while VALND preserved Q versus VA/Q log normality by blood flow diversion from low VI/Q units. We managed VILND‐induced negative VA units either by shunt conversion (VI decreased to 0) or VI redistribution simulating collateral ventilation (VI increased till VA = 0). Comparing oxygen transfer: VALND > VILND (redistribution) > VILND (shunt). In V/Q heterogeneous lungs VALND and VILND (redistribution) regained near optimal oxygen transfer on 100% oxygen, while impairment persisted with VILND (shunt). Unlike VALND, VILND (redistribution) produced Q versus VA/Q distributions in V/Q heterogeneity compatible with multiple inert gas (MIGET) reports. VILND (redistribution) is a physiologically–based MIGET–compatible alternative to West's original VALND lung modeling approach. [ABSTRACT FROM AUTHOR]

We present a computational investigation on the structural arrangements and energetic stabilities of small-size protonated argon clusters, Ar   n H   + . Using high-level ab initio electronic structure computations, we determined that the linear symmetric triatomic ArH   + Ar ion serves as the molecular core for all larger clusters studied. Through harmonic normal-mode analysis for clusters containing up to seven argon atoms, we observed that the proton-shared vibration shifts to lower frequencies, consistent with measurements in gas-phase IRPD and solid Ar-matrix isolation experiments. We explored the sum-of-potentials approach by employing kernel-based machine-learning potential models trained on CCSD(T)-F12 data. These models included expansions of up to two-body, three-body, and four-body terms to represent the underlying interactions as the number of Ar atoms increases. Our results indicate that the four-body contributions are crucial for accurately describing the potential surfaces in clusters with n > 3. Using these potential models and an evolutionary programming method, we analyzed the structural stability of clusters with up to 24 Ar atoms. The most energetically favored Ar   n H   + structures were identified for magic size clusters at n = 7, 13, and 19, corresponding to the formation of Ar-pentagon rings perpendicular to the ArH   + Ar core ion axis. The sequential formation of such regular shell structures is compared to ion yield data from high-resolution mass spectrometry measurements. Our results demonstrate the effectiveness of the developed sum-of-potentials model in describing trends in the nature of bonding during the single proton microsolvation by Ar atoms, encouraging further quantum nuclear studies. [ABSTRACT FROM AUTHOR]

The Pohang Accelerator Laboratory X‐ray Free‐Electron Laser (PAL‐XFEL) operates hard X‐ray and soft X‐ray beamlines for conducting scientific experiments providing intense ultrashort X‐ray pulses based on the self‐amplified spontaneous emission (SASE) process. The X‐ray free‐electron laser is characterized by strong pulse‐to‐pulse fluctuations resulting from the SASE process. Therefore, online photon diagnostics are very important for rigorous measurements. The concept of photo‐absorption and emission using solid materials is seldom considered in soft X‐ray beamline diagnostics. Instead, gas monitoring detectors, which utilize the photo‐ionization of noble gas, are employed for monitoring the beam intensity. To track the beam position at the soft X‐ray beamline in addition to those intensity monitors, an X‐ray ionization beam position monitor (XIBPM) has been developed and characterized at the soft X‐ray beamline of PAL‐XFEL. The XIBPM utilizes ionization of either the residual gas in an ultra‐high‐vacuum environment or injected krypton gas, along with a microchannel plate with phosphor. The XIBPM was tested separately for monitoring horizontal and vertical beam positions, confirming the feasibility of tracking relative changes in beam position both on average and down to single‐shot measurements. This paper presents the basic structure and test results of the newly developed non‐invasive XIBPM. [ABSTRACT FROM AUTHOR]