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We investigate the non-local thermodynamic equilibrium (non-LTE, hereafter NLTE) analysis for Cu i lines with the updated model atom that includes quantum-mechanical rate coefficients of Cu + H and Cu+ + Hâˆ' inelastic collisions from the recent study of Belyaev et al. The influence of these data on NLTE abundance determinations has been performed for six metal-poor stars in a metallicity range of âˆ'2.59 dex ≤ [Fe/H] ≤ âˆ'0.95 dex. For Cu i lines, the application of accurate atomic data leads to a decrease in the departure from LTE and lower copper abundances compared to that obtained with Drawin’s theoretical approximation. To verify our adopted copper atomic model, we also derived the LTE copper abundances of Cu ii lines for the sample stars. A consistent copper abundance from the Cu i (NLTE) and Cu ii (LTE) lines has been obtained, which indicates the reliability of our copper atomic model. It is noted that the [Cu/Fe] ratios increase with increasing metallicity when ∼âˆ'2.0 dex < [Fe/H] < ∼âˆ'1.0 dex, favoring a secondary (metallicity-dependent) copper production. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of data on the cross sections of elastic and inelastic collisions of electrons with noble gases, alkali and other atoms. For the selected sets of experimental and theoretical data, optimal analytical formulas are found, and approximation coefficients are calculated. The obtained semi-empirical formulas reproduce the values of the transport (diffusion), excitation and ionization cross sections for noble gases. Much attention is paid to the ionization cross sections of metal atoms, which are often present as an impurity in gas-discharge plasma. The approximation formulas reproduce the values of the ionization cross sections for hydrogen, metal and other elements in a wide range of energies with accurate orders of errors of the available theoretical and experimental data. For some elements with a two-hump plot of the dependence of the ionization cross section on the collision energy, it is proposed to use a two-term formula that takes into account ionization from both external and internal shells. [ABSTRACT FROM AUTHOR]

The application of a modern solving algorithm or method of resolving dynamical equations for small projectile of finite sizes orbiting to be captured in a trapped zigzaging oscillations on orbit around the another large asteroid and in a further inelastic colliding scenario with him (using a formulation of the elliptic restricted three-body problem, ER3BP) is studied semi-analytically. Herein, two primaries MSun and mp (mp < MSun) revolve around their barycenter on Keplerian orbits with low eccentricities. A smaller body (projectile for attacking a large asteroid) is supposed to be a solid, almost symmetric ellipsoid, having the gravitational potential of the MacCullagh type. Our aim is to develop a previously introduced solving procedure and to investigate the updated dynamics of the projectile captured to a trapped dynamical resonance, thereby having the inelastic collision of a small projectile orbiting on quasi-stable elliptic orbits around the large asteroid, mp. [ABSTRACT FROM AUTHOR]

In this article, the calculation of ionization cross-section of N2 molecule by electron impact is reviewed. The work on ionization cross-sections from threshold to high (10 KeV) incident electron energies are calculated and their applications are discussed. To find exact values of total ionization cross-sections for the N2 molecule, a semi-empirical approach of Jain and Khare (1976) is adopted which is a modification to eliminate the error factors, and then it is compared with the existing experimental and/or theoretical data which gives satisfactory results. [ABSTRACT FROM AUTHOR]

The analytical accuracy is often seriously affected by the self-absorption effect in laser-induced breakdown spectroscopy (LIBS). To investigate the self-absorption temporal evolution, time-resolved LIBS was adopted to analyze K, Ca, Na, and Mg element lines from the soil. The self-absorption coefficients of analyzed element lines in LIBS were calculated and investigated. To physically understand the mechanism of self-absorption, the evolution of the plasma image after Abel inversion, plasma temperature, and electron number density in time-resolved plasma were studied. The results show that the self-absorption effect was weaker at the early stage of the plasma because the emission intensity of plasma from the inner layer to the outer layer is high, and the plasma temperature is high with fewer low-energy particles. And less energy loss is caused by inelastic collision with air particles. The consequences of this work provide a convenient approach for reducing the self-absorption effect in LIBS and a deeper understanding of the mechanism of self-absorption evolution. [ABSTRACT FROM AUTHOR]

We numerically and theoretically investigated the elliptic and vortex solitons, and their dynamical stabilities in a magnetized dusty plasma. By using the Petviashvili method, a type of completely localized solitons, which are also confirmed analytically, is found numerically. Numerical results indicate that the amplitude is proportional to its velocity and inverse proportional to the nonlinear interaction strength. The linear stability analysis shows that these solitons are always linearly stable, which agrees well with the nonlinear dynamic evolution. Finally, we find that both elastic and inelastic collisions exist when two localized solitons collide. It is an elastic one when the collision occurs between a localized soliton and a stable line soliton. However, a series of localized solitons will be excited if a localized soliton and an unstable line soliton collide, suggesting that inelastic collisions also exist. This finding may be helpful to understand the nonlinear phenomena in magnetized dusty plasma. [ABSTRACT FROM AUTHOR]

The paper considers a model of a vertical double pendulum, which includes two balls suspended on rigid non-deformable threads to one centre of the suspension. For the proposed system of pendulums, differential equations of motion and conditions for collision of balls have been recorded. When simulating the motion of the pendulums, the central collision of the balls has been considered for various options of the motion of the suspension point: the suspension point is motionless; the suspension point oscillates in the vertical direction; the suspension point makes rotational motions in the vertical plane. Meanwhile, various conditions for the central collision between the balls have been considered: a perfectly inelastic collision; a perfectly elastic collision; a collision with transformation of collision energy (partially elastic collision). The results of numerical simulation are consistent with the behaviour of pendulums in real physical models, which makes it possible to simulate an elastic collision between balls when studying their acceleration in auto-balancing devices. [ABSTRACT FROM AUTHOR]

HCS+ ions have been detected in several regions of the interstellar medium (ISM), but an accurate determination of the chemical-physical conditions in the molecular clouds where this molecule is observed requires detailed knowledge of the collisional rate coefficients with the most common colliders in those environments. In this work, we study the dynamics of rotationally inelastic collisions of HCS+ + H2 at low temperature, and report, for the first time, a set of rate coefficients for this system. We used a recently developed potential energy surface for the HCS+–H2 van der Waals complex and computed state-to-state rotational rate coefficients for the lower rotational states of HCS+ in collision with both para - and ortho -H2, analysing the influence of the computed rate coefficients on the determination of critical densities. Additionally, the computed rate coefficients are compared with those obtained by scaling the ones from HCS+ in collision with He (an approximation that is sometimes used when data is lacking), and large differences are found. Furthermore, the approximation of using the rates for the HCO+ + H2 collision as a rough approximation for those of the HCS+ + H2 system is also evaluated. Finally, the complete set of de-excitation rate coefficients for the lowest 30 rotational states of HCS+ by collision with H2 is reported from 5 to 100 K. [ABSTRACT FROM AUTHOR]

In this paper we discuss exclusive reactions whose analysis can be used to receive direct indication of diquark existence. We make estimations of diquark scattering process measurement in inelastic proton–proton collisions. It was shown that putting special restrictions over kinematics and particles in the final state of the it will be possible to enhance potential diquark contribution to scattering up to 10 . We present qualitative characteristics of process with diquark and ways to distinguish it from quark scattering in model-independent way. [ABSTRACT FROM AUTHOR]

It is well-recognized that granular media under rapid flow conditions can be modeled as a gas of hard spheres with inelastic collisions. At moderate densities, a fundamental basis for the determination of the granular hydrodynamics is provided by the Enskog kinetic equation conveniently adapted to account for inelastic collisions. A surprising result (compared to its molecular gas counterpart) for granular mixtures is the failure of the energy equipartition, even in homogeneous states. This means that the partial temperatures T i (measuring the mean kinetic energy of each species) are different to the (total) granular temperature T. The goal of this paper is to provide an overview on the effect of different partial temperatures on the transport properties of the mixture. Our analysis addresses first the impact of energy nonequipartition on transport which is only due to the inelastic character of collisions. This effect (which is absent for elastic collisions) is shown to be significant in important problems in granular mixtures such as thermal diffusion segregation. Then, an independent source of energy nonequipartition due to the existence of a divergence of the flow velocity is studied. This effect (which was already analyzed in several pioneering works on dense hard-sphere molecular mixtures) affects to the bulk viscosity coefficient. Analytical (approximate) results are compared against Monte Carlo and molecular dynamics simulations, showing the reliability of kinetic theory for describing granular flows. [ABSTRACT FROM AUTHOR]

Amorphous TiTaNbZr multi-element alloy (Multi-principal elements alloys, MPCA) films were prepared by magnetron sputtering. The impact of 6 MeV Au ion irradiation with different temperatures (room temperature, 623 K, and 773 K) on the microstructure and mechanical properties of amorphous films was investigated. The findings indicate that when Au ion irradiation is administered at room temperature, the transformation of initially amorphous films into crystalline structures occurs. Furthermore, an increase in irradiation dose leads to enhanced crystallinity and growth in grain size. This is mainly due to cascade collisions between ion irradiation and alloy atoms, which promote atomic rearrangement, crystal nucleation, and growth. With the increase of irradiation temperature, there is no discernible defect structure under the irradiation condition at 623 K. Meanwhile, due to T < 0.3 T m (T m ≈ 2443 K), the crystallization behavior is mainly related to the Au ion energy deposition. The inelastic collision predominates at the initial stage. The crystal 20 nm away below the surface has a single-phase body-centered cube structure, and the elastic collision increases with the depth to form a biphase BCC structure. Similar grain size also increases with the increase of irradiation depth. Additionally, the hardness of the film remains unchanged at high temperatures and high radiation doses; its expansion rate is only 2 % due to the growth of grain boundaries and the self-healing mechanism. These results show that TiTaNbZr MPCA still has strong self-healing ability under high temperatures coupled with heavy ion irradiation, indicating excellent radiation resistance. • Under the three temperature conditions, the amorphous to biphase BCC structure of TiTaNbZr MPCA films was transformed by Au ion irradiation. • By studying the energy deposition of implanted Au ions, the underlying mechanism driving the grain size and phase structure change with irradiation depth was elucidated. • The effect of structural transformation on mechanical properties was investigated. [ABSTRACT FROM AUTHOR]

We report measurements of rate coefficients at T ≈ 600 K for rotationally inelastic collisions of NaK molecules in the 2(A)1∑+ electronic state with helium, argon, and potassium atom perturbers. Several initial rotational levels J between 14 and 44 were investigated. Collisions involving molecules in lowlying vibrational levels (v = 0, 1, and 2) of the 2(A)1∑+ state were studied using Fourier-transform spectroscopy. Collisions involving molecules in a higher vibrational level, v = 16, were studied using pump/probe, optical-optical double resonance spectroscopy. In addition, polarization spectroscopy measurements were carried out to study the transfer of orientation in these collisions. Many, but not all, of the measurements were carried out in the "single-collision regime" where more than one collision is unlikely to occur within the lifetime of the excited molecule. The analysis of the experimental data, which is described in detail, includes an estimate of effects of multiple collisions on the reported rate coefficients. The most significant result of these experiments is the observation of a strong propensity for ΔJ = even transitions in collisions involving either helium or argon atoms; the propensity is much stronger for helium than for argon. For the initial rotational levels studied experimentally, almost all initial orientation is preserved in collisions of NaK 2(A)1∑+ molecules with helium. Roughly between 1/3 and 2/3 of the orientation is preserved in collisions with argon, and almost all orientation is destroyed in collisions with potassium atoms. Complementary measurements on rotationally inelastic collisions of NaCs 2(A)1∑+ with argon do not show a ΔJ = even propensity. The experimental results are compared with new theoretical calculations of collisions of NaK 2(A)1∑+ with helium and argon. The calculations are in good agreement with the absolute magnitudes of the experimentally determined rate coefficients and accurately reproduce the very strong propensity for ΔJ = even transitions in helium collisions and the less strong propensity for ΔJ = even transitions in argon collisions. The calculations also show that collisions with helium are less likely to destroy orientation than collisions with argon, in agreement with the experimental results. [ABSTRACT FROM AUTHOR]

A direct simulation Monte Carlo (DSMC) method is applied to model collisions between He buffer gas atoms and ammonia molecules within a buffer gas cell. State-to-state cross sections, calculated as a function of the collision energy, enable the inelastic collisions between He and NH3 to be considered explicitly. The inclusion of rotational-state-changing collisions affects the translational temperature of the beam, indicating that elastic and inelastic processes should not be considered in isolation. The properties of the cold molecular beam exiting the cell are examined as a function of the cell parameters and operating conditions; the rotational and translational energy distributions are in accord with experimental measurements. The DSMC calculations show that thermalisation occurs well within the typical 10-20 mm length of many buffer gas cells, suggesting that shorter cells could be employed in many instances--yielding a higher flux of cold molecules. [ABSTRACT FROM AUTHOR]

Small satellites embedded in Saturn's ring – Daphnis and Pan – open a clear gap. Observations by the Voyager and Cassini spacecrafts have revealed various striking features of the gap structure, such as the density waves, sharp edge, and vertical wall structure. In order to explain these features in a single simulation, we perform a high-resolution (N ∼ 1 0 6 − 1 0 7 ) global full N-body simulation of gap formation by an embedded satellite considering gravitational interactions and inelastic collisions among all ring particles and the satellite, while these features have been mostly investigated separately with different theoretical approaches: the streamline models, 1D diffusion models, and local N-body simulation. As a first attempt of a series of papers, we here focus on the gap formation by separating satellite migration with fixing the satellite orbit in a Keplerian circular orbit. We reveal how the striking gap features – the density waves, sharp edge, and vertical wall structure – are simultaneously formed by an interplay of the satellite-ring and ring particle–particle interactions. In particular, we propose a new mechanism to quantitatively explain the creation of the vertical wall structure at the gap edge. Inelastic collisions between ring particles damp their eccentricity excited by the satellite's perturbations to enhance the surface density at the gap edge, making its sharp edges more pronounced. We find the eccentricity damping process inevitably raises the vertical wall structures the most effectively in the second epicycle waves. Particle–particle collisions generally convert their lateral epicyclic motion into vertical motion. Because the excited epicyclic motion is the greatest near the ring edge and the epicycle motions are aligned in the first waves, the conversion is the most efficient in the gap edge of the second waves and the wall height is scaled by the satellite Hill radius, which are consistent with the observations. • The observed clear gap is reproduced with a global N-body simulation. • The sharp edge is enhanced due to the inelastic collisions between ring particles. • Particle-particle collisions inevitably raises the vertical wall structure. [ABSTRACT FROM AUTHOR]

We begin by introducing a non-isospectral Lax pair, from which we derive a non-isospectral integrable Kaup–Newell hierarchy. The new general solutions for the non-isospectral integrable Kaup–Newell hierarchy are obtained through the inverse scattering transform (IST) method. Finally, we obtain the soliton solutions of a reduced non-isospectral integrable equation from non-isospectral integrable Kaup–Newell hierarchy. For 1-soliton solution, we obtain the explicit expression and analyze the dynamical behavior of soliton solution; for 2-soliton solutions, we verify that collisions between soliton solutions are inelastic collisions. The significant difference of the paper from the works finished by other authors (such as Ning et al., 2004 [11,12]; Li et al., 2008, 2010, 2012) lies in except for the spectral parameter λ being higher order, not one-order of λ. [ABSTRACT FROM AUTHOR]

The characteristics of Alfvén waves propagating in a direction oblique to the ambient magnetic field in a stellar wind environment are discussed. A kinetic formulation for a magnetized dusty plasma is adopted considering Maxwellian distributions of electrons and ions, and immobile dust particles electrically charged by absorption of plasma particles and by photoionization. The dispersion relation is numerically solved and the results are compared with situations previously studied where dust particles were not charged by photoionization, which is an important process in a stellar wind of a relatively hot star. We show that the presence of dust causes the shear Alfvén waves to present a region of wavenumber values with zero frequency and that the minimum wavelength for which the mode becomes dispersive again is roughly proportional to the radiation intensity to which the dust grains are exposed. The damping rates of both shear and compressional Alfvén waves are observed to decrease with increasing radiation flux, for the parameters considered. For the particular case where both modes present a region with null real frequency when the radiation flux is absent or weak, it is shown that when the radiation flux is sufficiently strong, the photoionization mechanism may cause this region to get smaller or even to vanish, for compressional Alfvén waves. In that case, the compressional Alfvén waves present non-zero frequency for all wavenumber values, while the shear Alfvén waves still present null frequency in a certain interval of wavenumber values, which gets smaller with the presence of radiation. [ABSTRACT FROM AUTHOR]

In this paper, the dynamics of the higher-order soliton solutions for the coupled mixed derivative nonlinear Schrödinger equation are investigated via generalized Darboux transformation. Given a pair of linearly independent solutions of the Lax pair, the one- to three-soliton solutions are obtained via algebraic iteration. Furthermore, two and three solitons are respectively displayed via numerical simulation. Moreover, the dynamics of solitons are illustrated with corresponding evolution plots, such as elastic collisions, inelastic collisions, and bound states. It is found that there are some novel phenomena of interactions among solitons, which may provide a theoretical basis for studying optical solitons in experiments. [ABSTRACT FROM AUTHOR]

Carbon nano-onions (CNO) are multilayered fullerenes. They exhibit good electrical conductivity and large surface area, being of interest for several optoelectronic applications. However, it is still an open question what synthesis routes can be used to convert them into diamonds. Here, we used fully atomistic reactive (ReaxFF) molecular dynamics simulations to study the dynamics and structural transformations of CNO structures under high-velocity impacts against a fixed and rigid substrate. The aim of this study is to propose a new synthesis route, based on the mechanical impact of CNO, that can be exploited in the conversion of onions to diamonds. Our results indicated three regimes formed after the CNO impact: slightly deformed CNO (quasi-elastic collision, below 2.0 km/s), collapsed CNO (inelastic collisions, between 3.0 and 5.0 km/s) forming a diamondoid-like core, and fragmented CNO yielding linear atomic carbon chains (above 5.0 km/s). We also discussed the dynamical reconfiguration of carbon-carbon bonds during the collision process. The impact of CNO yielded sp 3-like bond types for all the used initial velocities. At intermediate velocities (between 3.0 and 5.0 km/s), the inelastic collision forms diamondoid-like cores by converting a substantial quantity of sp 2-like bonds into sp 3-like ones. [Display omitted] [ABSTRACT FROM AUTHOR]

Inertia-dominated droplet impact transfers momentum to a dry flat target within a short span of time t characterized by (droplet diameter D)/(impact speed U). We investigate experimentally how impact force dynamics change when a droplet hits a thin liquid film of thickness H, less than or approximately equal to the droplet diameter, atop the flat target. Impact force and morphology are recorded simultaneously by piezoelectric force sensing and high-speed video imaging. Compared with a dry surface, the force of droplet impact on a thin liquid film is found to follow the same initial t U / D scaling and reach a slightly higher peak value, but at a significantly later time. Modeling the impact process as a perfect inelastic collision between the droplet and a liquid column of height equal to the film thickness yields the proper timescale (H + D) / U to characterize temporal evolution of the impact force near the inertial peak and through its subsequent exponential decay. The impact crater penetration depth developing within the thin film over the same time span is also found to collapse to a self-similar form based on this characteristic timescale, which attests to the validity of the inelastic collision model in capturing the underlying impact flow physics. [ABSTRACT FROM AUTHOR]

An electrostatic ion thruster, modelled on Busek's BIT-3 [5], is simulated numerically using the open-source software "Starfish". It is assumed that the thruster is in vacuum conditions propelling a CubeSat in low Earth orbit. Iodine is chosen here as the propellant under test. The results from modelling this relatively recent new fuel are compared to those of the standard propellant of xenon. The plasma in the ion thruster and the associated electric fields are simulated using a particle-based kinetic code in which the hybrid approach of Particle in Cell and Direct Simulation Monte Carlo methods has been used. In modelling these flows, elastic and inelastic collisions can occur involving charge and momentum exchanges. Such collision models use a number of assumptions, e.g., concerning the collisional cross-section area, and in this paper, we present results where the physico-chemical modelling is improved reducing the level of assumptions used. Results are also presented concerning the numerical methods used for the iterative convergence scheme, stochastic sampling, and the importance of the constraints for the mesh size and timestep. It is found that the most appropriate timestep is one which enables both the CFL condition and the highest frequency to be captured. The mesh size affects the choice of the solver being used; the largest the cell sizes the greater the assumption of quasi-neutral flow and thus areas of non-neutrality (such as in the surrounding shealth may be treated inadequately. The subsequent effects on the plume and the thrust produced of using different approaches in modelling the electron temperature distribution are also evaluated to produce a more rigorous modelling methodology. [ABSTRACT FROM AUTHOR]

Measurements of K ∗ (892) 0 resonance production via its K + π - decay mode in inelastic p+p collisions at beam momenta 40 and 80 GeV / c ( s NN = 8.8 and 12.3 GeV ) are presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The template method was used to extract the K ∗ (892) 0 signal. Transverse momentum and rapidity spectra were obtained. The mean multiplicities of K ∗ (892) 0 mesons were found to be (35.1 ± 1.3 (stat) ± 3.6 (sys)) · 10 - 3 at 40 GeV / c and (58.3 ± 1.9 (stat) ± 4.9 (sys)) · 10 - 3 at 80 GeV / c . The NA61/SHINE results are compared with the Epos1.99 and Hadron Resonance Gas models as well as with world data. The transverse mass spectra of K ∗ (892) 0 mesons and other particles previously reported by NA61/SHINE were fitted within the Blast-Wave model. The transverse flow velocities are close to 0.1–0.2 of the speed of light and are significantly smaller than the ones determined in heavy nucleus-nucleus interactions at the same beam momenta. [ABSTRACT FROM AUTHOR]

The study of the production of nuclei and antinuclei in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper, the production of protons, deuterons and 3 He and their charge conjugates at midrapidity is studied as a function of the charged-particle multiplicity in inelastic pp collisions at s = 5.02 TeV using the ALICE detector. Within the uncertainties, the yields of nuclei in pp collisions at s = 5.02 TeV are compatible with those in pp collisions at different energies and to those in p–Pb collisions when compared at similar multiplicities. The measurements are compared with the expectations of coalescence and Statistical Hadronisation Models. The results suggest a common formation mechanism behind the production of light nuclei in hadronic interactions and confirm that they do not depend on the collision energy but on the number of produced particles. [ABSTRACT FROM AUTHOR]

Inelastic processes in collisions of boron atoms and cations with hydrogen atoms and anions, namely mutual neutralization, ion-pair formation, excitation, and deexcitation, a total of 56 processes, are investigated. The partial cross sections and rate coefficients are calculated in the ranges of collision energies –100 eV and temperatures 1000–10 000 K, respectively. Quantum calculations are performed within the asymptotic approach for the electronic structure and the multichannel formula for the nuclear dynamics. The largest rate coefficient is shown to correspond to the mutual neutralization process with a value of cm s . The data obtained will allow the photospheres of stars to be modeled under conditions of departures from local thermodynamic equilibrium with a higher accuracy than the previous calculations based on the classical Drawin formula. [ABSTRACT FROM AUTHOR]

A simulation of cluster formation in granular media is conducted under the Coriolis effect. In a situation of a rotary coordinate system with the fixed angular velocity, clusters are generated in granular media in virtue of inelastic collisions and friction between particles. The scale of a cluster is evaluated by the characteristic length, which is defined through the Fourier transform for the particle density function. It is discovered that the characteristic length and the angular velocity of the rotary coordinate system follow two different power laws in two different length scales. [ABSTRACT FROM AUTHOR]

The Larsen–Borgnakke (L–B) model is most widely used to redistribute relaxation energies in direct simulation Monte Carlo (DSMC) method; the relaxation energies in an inelastic collision are determined beforehand and redistributed by sampling from the equilibrium distributions (not locally equilibrium distributions) of these energies that are appropriate to this collision. The present concern focuses on how to redistribute the selected energies when they have been determined to require relaxation. When certain energies are determined to require relaxation and redistribution in an inelastic collision, the hierarchical method and the serial or sequential method are used to complete the L–B procedure. Although the hierarchical method is theoretically accurate, it needs to complete the integration of the joint energy distribution function, so it is not applicable when the energy distribution function has a complex form or contains more than one discontinuous energy. Hence, researchers turn to the serial or sequential method, but the rationality proof of this method implies an assumption of locally thermal equilibrium, so it is obviously not appropriate in the DSMC method usually applied to hypersonic nonequilibrium flows. Then, a new method of redistributing relaxation energies to complete the L–B procedure is proposed, which does not include any integration process; the original form of the energy distribution function is used directly, so it can be expected to have excellent adaptability, especially for complex cases such as energy redistribution of reaction products. The effectiveness, efficiency, and extensive applicability of the method are proved by multiple examples. [ABSTRACT FROM AUTHOR]

4FGL J0822.8–4207 is a point source found in the 4FGL-DR2 catalogue by the gamma-ray observatory Fermi -LAT and has no known association. We carry out X-ray observations of 4FGL J0822.8–4207 to help understand its nature. We explore two scenarios for the origin of 4FGL J0822.8–4207 . In the first case, we study the possibility that cosmic rays from the supernova remnant (SNR) Puppis A, seen nearby in the sky, reach the dense gas at the location of the source and produce the gamma-rays through inelastic proton–proton collisions. We apply a standard model for particle diffusion in the interstellar medium and derive the required physical parameters. We find that this scenario for the gamma-rays is possible if the gas is located at a distance that is not higher than ∼40 pc from Puppis A, unless the SNR is older than 7 kyr or the diffusion coefficient is higher than typical Galactic values, and relatively low-energy cosmic rays are currently escaping from the SNR. In the second scenario, we consider the protostellar jet HH219 as the origin of the GeV source and find the very interesting possibility that particles could be accelerated up to energies of at least several TeV in HH219. This would make this system the first known of its kind to produce gamma-ray emission extending up to hundreds of GeV without any apparent cut-off and an excellent laboratory to study the process of particle acceleration. [ABSTRACT FROM AUTHOR]

This paper aims at studying the inelastic Boltzmann equation without Grad's angular cutoff assumption, where the well-posedness theory of the Cauchy problem is established for the Maxwellian molecules in a space of probability measure defined by Cannone and Karch [Commun. Pure Appl. Math. 63, 747–778 (2010)] via Fourier transform and the infinite energy solutions are not a priori excluded. The key strategy is to construct a brand new geometric relation of the inelastic collision mechanism to extend the result of Cannone and Karch from moderate singularity of the non-cutoff collision kernels to strong singularity and simultaneously handle more general restitution coefficients. Moreover, we extend the self-similar solution to the Boltzmann equation with infinite energy shown by Bobylev and Cercignani [J. Stat. Phys. 106, 1039–1071 (2002)] to the inelastic case by using a constructive approach, which is also proved to be the large-time asymptotic steady solution with the help of an asymptotic stability result in a certain sense. [ABSTRACT FROM AUTHOR]

The paper presents an analysis of data on the cross sections of elastic and inelastic collisions of electrons with noble gas atoms. The transport (diffusion) cross section and the excitation and ionization cross sections are considered. Optimal analytical formulas are found for the selected sets of experimental and theoretical data, and approximation coefficients are selected for them. The obtained semi-empirical formulas make it possible to reproduce the cross sections in a wide range of collision energies from 0.001 to 10 000 eV with an accuracy of several percent. [ABSTRACT FROM AUTHOR]

The coexistence and interaction of a granular liquid‐like phase (emulsion) and a gas‐like phase (bubbles) in fluidization is a spontaneous symmetry‐breaking dissipative state, contributing to excellent mixing behavior in fluidized beds. In the present study, a universal granular state equation to describe the phase coexistence at far away from the critical point is developed by taking both the inelastic solid collision and asymmetrical instability into consideration. Besides, a cold‐flow experiment using particles of the Geldart's A group at 0.1–1 MPa pressure is performed to verify the granular state equation, where the solid volume fraction (εs) and solid pressure (ps) are obtained by a dual optical probe and a special pressure transducer, respectively. Based on both theoretical analysis and experimental study, a phase diagram is produced to serve as a useful guide for the design and operation of efficient fluidized‐bed reactors. [ABSTRACT FROM AUTHOR]

Building on our previous work on NO + Ar, this paper presents a complete set of orientation measurements and quantum mechanical calculations for the NO + Kr collision system, including both spin-orbit conserving and changing collisions, and both side-on (x-axis) and end-on (z-axis) orientations. While many of the trends observed in the oriented differential and integral scattering distributions, as well as in the spin-orbit branching fractions, are similar to the ones seen previously for NO + Ar, a direct comparison with the Ar data reveals subtle differences in the scattering dynamics, which we rationalise with the more extended attractive regions on the NO + Kr potential energy surfaces. High-impact parameter collisions that lead to low scattering angles in the spin-orbit conserving manifold are particularly sensitive to the topology in the attractive parts of the potential, whereas more impulsive, low-impact parameter trajectories, which sample the repulsive parts of the potential, produce very similar features in the oriented differential cross sections for the Ar and Kr systems, especially for spin-orbit changing collisions. [ABSTRACT FROM AUTHOR]

The production of K S 0 mesons in inelastic p+p collisions at beam momentum 158 GeV / c ( s NN = 17.3 GeV ) was measured with the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicity of K S 0 was determined to be 0.162 ± 0.001 (s t a t.) ± 0.011 (s y s.) . The results on K S 0 production are compared with model predictions (EPOS 1.99, SMASH 2.0, PHSD and UrQMD 3.4 models) as well as with published world data. [ABSTRACT FROM AUTHOR]

We investigate an averaging process that describes how interacting agents approach consensus through binary interactions. In each elementary step, two agents are selected at random and they reach compromise by adopting their opinion average. We show that the fraction of agents with a monotonically decreasing opinion decays as e âˆ' αt , and that the exponent α = 1 2 âˆ' 1 + ln ln 2 4 ln 2 is selected as the extremum from a continuous spectrum of possible values. The opinion distribution of monotonic agents is asymmetric, and it becomes self-similar at large times. Furthermore, the tails of the opinion distribution are algebraic, and they are characterized by two distinct and nontrivial exponents. We also explore statistical properties of agents with an opinion strictly above average. [ABSTRACT FROM AUTHOR]

Particle-in-cell, direct simulation Monte Carlo simulations reveal that ion-acoustic instabilities excited in presheaths can cause significant ion heating. Ion-acoustic instabilities are excited by the ion flow toward a sheath when the neutral gas pressure is small enough and the electron temperature is large enough. A series of 1D simulations were conducted in which neutral plasma (electrons and ions) was uniformly sourced with an ion temperature of 0.026 eV and different electron temperatures (0.1 eV–50 eV). Ion heating was observed when the electron-to-ion temperature ratio exceeded the minimum value predicted by linear response theory to excite ion-acoustic instabilities at the sheath edge ( T e / T i ≈ 28). When this threshold was exceeded, the temperature equilibration rate between ions and electrons rapidly increased near the sheath so that the local temperature ratio did not significantly exceed the threshold for instability. This resulted in significant ion heating near the sheath edge, which also extended back into the bulk plasma; presumably due to wave reflection from the sheath. This ion-acoustic wave heating mechanism was found to decrease for higher neutral pressures, where ion-neutral collisions damp the ion-acoustic waves and ion heating is instead dominated by inelastic collisions in the presheath. [ABSTRACT FROM AUTHOR]

Lucidity is obtained by understanding the differences between kinematic and radiative heat transfer and their relationships to temperature. Differences become apparent when one evaluates the utilitarian temperature associated with closed systems and compares that to temperatures measured in open systems. Acceptance, requires the realization that the sciences founded upon closed system experimentation is not always ideal for formulating open system physics. Temperatures measured in open systems that are dominated by anisotropic radiation often become non-sensible, e.g., those in Earth's upper atmosphere. [ABSTRACT FROM AUTHOR]

The effect of orientation of the NO(X) bond axis prior to rotationally inelastic collisions with Ar has been investigated experimentally and theoretically. A modification to conventional velocity-map imaging ion optics is described, which allows the orientation of hexapole state-selected NO(X) using a static electric field, followed by velocity map imaging of the resonantly ionized scattered products. Bond orientation resolved differential cross sections are measured experimentally for a series of spin-orbit conserving transitions and compared with quantum mechanical calculations. The agreement between experimental results and those from quantum mechanical calculations is generally good. Parity pairs, which have previously been observed in collisions of unpolarized NO with various rare gases, are not observed due to the coherent superposition of the two j = 1/2, Ω = 1/2 Λ-doublet levels in the orienting field. The normalized difference differential cross sections are found to depend predominantly on the final rotational state, and are not very sensitive to the final Λ-doublet level. The differential steric effect has also been investigated theoretically, by means of quantum mechanical and classical calculations. Classically, the differential steric effect can be understood by considering the steric requirement for different types of trajectories that contribute to different regions of the differential cross section. However, classical effects cannot account quantitatively for the differential steric asymmetry observed in NO(X) + Ar collisions, which reflects quantum interference from scattering at either end of the molecule. This quantum interference effect is dominated by the repulsive region of the potential. [ABSTRACT FROM AUTHOR]

The intensity profiles of the bands of the first and second positive N2 systems and the infrared atmospheric and atmospheric O2 systems were calculated based on models of the electronic kinetics of triplet states of molecular nitrogen and singlet states of molecular oxygen for the middle Earth's atmosphere in the case of the precipitation of high-energy protons into the Earth's atmosphere during the ground-level enhancement (GLE) (no. 69) on January 20, 2005. Calculations have shown that there is a significant contribution from the quenching of the B3Πg state during molecular collisions over nearly all of the considered altitude range of 20–80 km. The kinetics of O2 singlet states at altitudes of the middle atmosphere during proton precipitation is considered. Both direct excitation by high-energy particles and intermolecular processes of electron-excitation transfer are taken into account. It is shown that the quenching of the state during inelastic molecular collisions leads to a significant decrease in the intensities of the bands of the atmospheric system at the heights of the middle atmosphere. [ABSTRACT FROM AUTHOR]

The potential energy surface describing the interaction of methylene (CH 2 ) in its ground X ~ 3 B 1 electronic state with molecular hydrogen has been calculated through explicitly correlated coupled cluster theory with inclusion of single, double, and (perturbatively) triple excitations [RCCSD(T)-F12a] and a correlation-consistent aug-cc-pVTZ basis. The calculated points for various geometries of the CH 2 –H 2 complex were fit to a functional form suitable for use in time-independent quantum scattering calculations of cross sections for collision-induced transitions between CH 2 rotational levels. The well depth D e of the CH 2 –H 2 complex was found to equal 92.1 cm − 1 in a planar geometry and intermolecular separation R = 6.55 a 0 . A representative set of cross sections is presented and compared with cross sections for the corresponding transitions in methylene induced by collisions with helium. [ABSTRACT FROM AUTHOR]

This paper investigates the one-dimensional planar piston problem in dilute granular-gaseous mixture using both analytical and numerical approaches. Starting from the Euler equations of the two-fluid model, a one-way coupling model for dilute granular flow was derived assuming that the piston speed is higher than the sound speed of the granular phase, but much smaller than that of the gaseous phase—which results in a shock wave propagating in the granular phase. It was shown that the dissipation terms of this model—the drag force and inelastic collisions—affect the shock wave structure. A reference analytical solution for fully elastic particles assuming that the linear drag is the only dissipation mechanism predicted a shock wave structure that is similar to ideal molecular gas but decays exponentially with time. The nonlinear drag component resulted in decreasing velocity and density behind the shock while the temperature increases, in an opposite trend to the effect of inelastic collisions. It was shown that the combined effects of both nonlinear drag and inelastic collisions could result in either two regimes depending on the values of their corresponding parameters. [ABSTRACT FROM AUTHOR]

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The time evolution of a homogeneous bidisperse granular suspension is studied in the context of the Enskog kinetic equation. The influence of the surrounding viscous gas on the solid particles is modeled via a deterministic viscous drag force plus a stochastic Langevin-like term. It is found first that, regardless of the initial conditions, the system reaches (after a transient period lasting a few collisions per particle) a universal unsteady hydrodynamic regime where the distribution function of each species not only depends on the dimensionless velocity (as in the homogeneous cooling state) but also on the instantaneous temperature scaled with respect to the background temperature. To confirm this result, theoretical predictions for the time-dependent partial temperatures are compared against direct simulation Monte Carlo (DSMC) results; the comparison shows an excellent agreement confirming the applicability of hydrodynamics in granular suspensions. Also, in the transient regime, the so-called Mpemba-like effect (namely, when an initially hotter sample cools sooner than the colder one) is analyzed for inelastic collisions. The theoretical analysis of the Mpemba effect is performed for initial states close to and far away from the asymptotic steady state. In both cases, good agreement is found again between theory and DSMC results. As a complement to the previous studies, we determine in this paper the dependence of the steady values of the dynamic properties of the suspension on the parameter space of the system. More specifically, we focus our attention on the temperature ratio T 1 / T 2 and the fourth degree cumulants c1 and c2 (measuring the departure of the velocity distributions f1 and f2 from their Maxwellian forms). While our approximate theoretical expression for T 1 / T 2 agrees very well with computer simulations, some discrepancies are found for the cumulants. Finally, a linear stability analysis of the steady state solution is also carried out showing that the steady state is always linearly stable. [ABSTRACT FROM AUTHOR]

The scattering cross-sections and corresponding rate coefficients for rotationally inelastic collisions of 12 C 2 − ( 2 Σ g + ) with H 2 ( 1 Σ g + ) are presented over a broad range of cold-trap temperatures. They have been calculated using quantum scattering theory that employs a new ab initio potential energy surface. The rate coefficients for the inelastic processes in the anionic partner are used to model the thermalisation dynamics of 12 C 2 − using H 2 as a buffer gas, a trap partner which is found here to be far more efficient than the typical buffer gas He and even more so than when using Ar as a partner gas. The microscopic physics underlying these findings is discussed in some detail. We additionally compute and discuss 12 C 2 − quadrupole transitions by spontaneous emission and use the newly computed rates to show that the anion's rotational levels should be in local thermal equilibrium at typical interstellar conditions. [ABSTRACT FROM AUTHOR]

We present a combined experimental and theoretical study on the rotationally inelastic scattering of heavy water, D2O, with normal-H2. Crossed-molecular beam measurements are performed in the collision energy range between 10 and 100 cm−1, corresponding to the near-threshold regime in which scattering resonances are most pronounced. State-to-state excitation cross-sections are obtained by probing three low-lying rotational levels of D2O using the REMPI technique. These measurements are complemented by quantum close-coupling scattering calculations based on a high-accuracy D2O–H2 interaction potential. The agreement between experiment and theory is within the experimental error bars at 95% confidence intervals, leading to a relative difference of less than 7%: the near-threshold rise and the overall shape of the cross-sections, including small undulations due to resonances, are nicely reproduced by the calculations. Isotopic effects (D2O versus H2O) are also discussed by comparing the shape and magnitude of the respective cross-sections.