Rotational Levels Research Articles

Ro-vibrational Spectrum of Linear Dialuminum Monoxide (Al2O) at 10 μm.

Dialuminum monoxide, Al2O, has been investigated in the laboratory at mid-IR wavelengths around 10 μm at high spectral resolution. The molecule was produced by laser ablation of an aluminum target with the addition of gaseous nitrous oxide, N2O. Subsequent adiabatic cooling of the gas in a supersonic beam expansion led to rotationally cold spectra. In total, 848 ro-vibrational transitions have been assigned to the fundamental asymmetric stretching mode ν3 and to five of its hot bands, originating from excited levels of the ν1 symmetric stretching mode and the ν2 bending mode. The measurements encompass 11 vibrational energy states (v1 v2l v3). The ro-vibrational transitions show spin statistical line intensity alternation of 7:5, which is caused by two identical aluminum nuclei of spin I = 5/2 at both ends of the centrosymmetric molecule of structure Al-O-Al. The less effective cooling of vibrational states in the supersonic beam expansion allowed measurement of transitions in excited vibrational states at energies of 1000 cm-1 and higher, while rotational levels within vibrational modes exhibited thermal population, with rotational temperatures around Trot = 115 K. Molecular parameters for 11 vibrational states were derived, including rotation and centrifugal distortion constants and l-type doubling constants for the states (v1 v2l v3) = (0 11 0) and (0 11 1) and an l-type resonance between the states (0 20 0) - (0 22 0) and (0 20 1) - (0 22 1). From the experimental results, rotational correction terms and the equilibrium bond length re were derived. The measurements were supported and guided by high-level quantum-chemical calculations that agree well with the derived experimental results.

High Frequency Electromagnetic Radiation Stimulates Neuronal Growth and Hippocampal Synaptic Transmission

Terahertz waves lie within the rotation and oscillation energy levels of biomolecules, and can directly couple with biomolecules to excite nonlinear resonance effects, thus causing conformational or configuration changes in biomolecules. Based on this mechanism, we investigated the effect pattern of 0.138 THz radiation on the dynamic growth of neurons and synaptic transmission efficiency, while explaining the phenomenon at a more microscopic level. We found that cumulative 0.138 THz radiation not only did not cause neuronal death, but that it promoted the dynamic growth of neuronal cytosol and protrusions. Additionally, there was a cumulative effect of terahertz radiation on the promotion of neuronal growth. Furthermore, in electrophysiological terms, 0.138 THz waves improved synaptic transmission efficiency in the hippocampal CA1 region, and this was a slow and continuous process. This is consistent with the morphological results. This phenomenon can continue for more than 10 min after terahertz radiation ends, and these phenomena were associated with an increase in dendritic spine density. In summary, our study shows that 0.138 THz waves can modulate dynamic neuronal growth and synaptic transmission. Therefore, 0.138 terahertz waves may become a novel neuromodulation technique for modulating neuron structure and function.

Amino-acid classification based on terahertz absorption spectroscopy with Gaussian process and maximum likelihood

The rotational and vibrational energy levels of numerous biomolecules lie in the terahertz (THz) band, which makes THz spectroscopy a viable option for biosensing and monitoring the chemical processes such as the formation of hydrogen bonds. However, classifying the fingerprint THz spectra of various molecules has constantly challenged real-world applications. Here, a machine learning model based on a discrete Gaussian process and maximum likelihood estimation (DGPML) for classifying an ensemble of 20 amino acids is proposed. The model demonstrates a prediction accuracy of 99.5% in the presence of scattering noise and various experimental conditions and is able to distinguish spectra without significant absorption peaks. Compared to the conventional Gaussian process classifier, which generally exhibits less time and space complexity than neural-network models, DGPML requires 99% less training time and achieves 1530 times faster processing speed with around 0.29 million parameters. Regarding the DGPML, a database that encloses the THz absorption spectrum and its covariance matrix, which describes the deviation of the absorption spectrum under various experimental conditions, is designed. Due to the compact size and high efficiency of the proposed model, it has the potential to power the THz chemical sensor in the future.

Optimization of response function on hydromagnetic buoyancy-driven rotating flow considering particle diameter and interfacial layer effects: Homotopy and sensitivity analysis

Alumina is one of the modern era and most utilized ceramic materials. One example of an electrical insulating substance is alumina. It has an enhanced temperature, chemical stability and higher thermal conductivity. It is mostly used in medical, industry, household items, military purposes, production of batteries and electrical parts. Therefore, the authors have formulated a mathematical model of the three-dimensional magnetohydrodynamic mixed convective flow of a nanofluid containing Alumina nanoparticles past a stretching surface. Preliminary assumptions bound the nanofluid flow to be rotational, electrically conducting, dissipative, buoyancy driven, thermally heated and convective. An important investigation based on the effects of nanoparticle diameter and nanolayer of the nanofluid makes the novelty of this investigation. The modeled problem is solved with a homotopic approach, which is suitable for the solution of the highly nonlinear differential equations and has quick convergence. The outcomes of the present analysis are shown with the help of Tables and Figures. The outcomes showed that the higher resistive force at the sheet surface caused by the higher solid volume fraction (varies from 1% to 4%), diminishes the primary velocity, while escalates the secondary velocity. Additionally, the greater solid volume fraction (which ranges from 1% to 4%) raises the thermal conductivity of the nanofluid flow, resulting in an increasing conduct in the thermal function. The enhancing nanolayer to base fluid conductivity ratio (which ranges from 1.1 to 65.25), results in an increase in both velocities and thermal functions, gives the nanofluid flow a higher thermal conductivity. Additionally, the local Nusselt number and skin friction increase as a result of the higher thermal conductivity. The primary velocity and temperature are reduced due to the decrease in thermal and momentum boundary layer thicknesses brought on by the rising nanoparticle diameter (which ranges from 1 nm to 50 nm). The rate of heat transfer is significantly achieved at the higher levels of the volume fraction and radiation factor while heat source is at lower level. The friction rate at the surface is dominant at higher level values of magnetic and volume fraction factor and medium level of rotation factor. The transport of heat has highest sentivity at the middle level of thermla radaition and volume fraction of the nanoparticle and low level of heat source, while the highest sensitivity of friction factor is observed at the middle level of thermal rotation and high level nanoparticle volume fraction and magnetic factor.

Robust Nuclear Spin Entanglement via Dipolar Interactions in Polar Molecules.

We propose a general protocol for on-demand generation of robust entangled states of nuclear and/or electron spins of ultracold ^{1}Σ and ^{2}Σ polar molecules using electric dipolar interactions. By encoding a spin-1/2 degree of freedom in a combined set of spin and rotational molecular levels, we theoretically demonstrate the emergence of effective spin-spin interactions of the Ising and XXZ forms, enabled by efficient magnetic control over electric dipolar interactions. We show how to use these interactions to create long-lived cluster and squeezed spin states.

Millimeter wave spectroscopy of propynal isotopologues and structure determination

Rotational transitions of propynal (HCCCHO) have been measured in the 150–900 GHz region by millimeter wave spectroscopy and in the far infrared region by high resolution FTIR spectroscopy using a synchrotron source. For the parent isotopologue, assignment of MMW transitions up to very high quantum numbers (J = 100, Ka = 25) reveals evidence of extensive perturbations in the ground vibrational state due to Fermi-asymmetry resonance with an excited vibrational state. A fit to nearly 3000 ground state transitions yields effective constants that are suitable for describing relatively unperturbed rotational levels up to Ka = 13. Over 1000 transitions were assigned and fitted for each singly substituted 13C species and nearly 400 transitions for the 18O variant. Re-analysis of literature data on deuterated species, aided by centrifugal distortion constants from hybrid density functional theory calculations at the B2PLYP/aug-cc-pVTZ level, provides a further set of rotational constants. This allows determination of a Rm(2) structure for propynal with the following geometry: r(C≡C) = 1.2066(15), r(CC) = 1.4486(14), r(CO) = 1.2087(10), r(C­H ald) = 1.1069(8), r(C­Hacet) = 1.0578(13), θ(CCC) = 176.71(22), θ(OCC) = 123.23(7), θ(HCCald) = 114.43(31), θ(HCCacet) = 178.45(16). A new Rs structure was also derived.

Collision excitation of nitrous acid (HONO) by helium: isomerization effect

ABSTRACTWe generated new 3D-potential energy surfaces (3D-PESs) for the cis-HONO–He and trans-HONO–He weakly bound complexes along the intermonomer coordinates. We used the explicitly correlated Coupled Clusters with single, double, and perturbative triple excitations (CCSD(T)-F12) approach for the electronic structure computations, where the atoms were described using the aug-cc-pVTZ basis set. Then, we derived analytical forms for each PES. These PESs exhibit different shapes and present strong anisotropies. After quantum close-coupling scattering calculations for the lower rotational levels (up to ${9}_{2,7}$), and the coupled-states approximation for higher levels (up to ${22}_{1,22}$) using these PESs, we derived the collisional excitation cross sections of cis-HONO and trans-HONO by He for total energies 0.1 ≤ E ≤ 900 cm−1 and the rate coefficients for kinetic temperatures T ≤ 100 K. Our work shows that the collision data of cis-HONO and trans-HONO are different mainly because of the different 3D-PESs since the rotational energy structures of both isomers are very similar. Also, computations show that the data of the non-detected cis-HONO are as large as those of the detected trans-HONO isomer. They confirm the large values for the detected transition 52,4 → 41,3 of trans-HONO. Therefore, our work strongly suggests revisiting radiative transfer calculations to determine accurately the population of the rotational levels of these isomers. Our work should help astrophysicists for the detectability of such nitrogen oxide molecules and for the possible formation mechanisms and isomerization pathways specificities.

Role of the Cohen-Fano interference in recoil-induced rotation.

We study the rotational dynamics induced by the recoil effect in diatomic molecules using time-resolved two-color x-ray pump-probe spectroscopy. A short pump x-ray pulse ionizes a valence electron inducing the molecular rotational wave packet, whereas the second time-delayed x-ray pulse probes the dynamics. An accurate theoretical description is used for analytical discussions and numerical simulations. Our main attention is paid to the following two interference effects that influence the recoil-induced dynamics: (i) Cohen-Fano (CF) two-center interference between partial ionization channels in diatomics and (ii) interference between the recoil-excited rotational levels manifesting as the rotational revival structures in the time-dependent absorption of the probe pulse. The time-dependent x-ray absorption is computed for the heteronuclear CO and homonuclear N2 molecules as showcases. It is found that the effect of CF interference is comparable with the contribution from independent partial ionization channels, especially for the low photoelectron kinetic energy case. The amplitude of the recoil-induced revival structures for the individual ionization decreases monotonously with a decrease in the photoelectron energy, whereas the amplitude of the CF contribution remains sufficient even at the photoelectron kinetic energy below 1eV. The profile and intensity of the CF interference depend on the phase difference between the individual ionization channels related to the parity of the molecular orbital emitting the photoelectron. This phenomenon provides a sensitive tool for the symmetry analysis of molecular orbitals.

Microscopic theory of Raman scattering for the rotational organic cation in metal halide perovskites

A gap exists in the microscopic understanding the dynamic properties of the rotational organic cation (ROC) in the inorganic framework of the metal halide perovskites (MHP) to date. Herein, we develop a microscopic theory of Raman scattering for the ROC in MHP based on the angular momentum of a ROC exchanging with that of the photon and phonon. We systematically present the selection rules for the angular momentum transfer among the three lowest rotational levels. We find that the phonon angular momentum that arises from the inorganic framework and its specific values could be directly manifested by Stokes (or anti-Stokes) shift. Moreover, the initial orientation of the ROC and its preferentially rotational directions could be judged in Raman spectra. This study lays the theoretical foundation for the high-precision resolution and manipulation of molecular rotation immersed in the many-body environment by Raman technique.

Using an expert system to assess biodiversity in life cycle assessment of vegetable crops

Biodiversity loss in agricultural landscapes due to intensification of agriculture and degradation and loss of semi-natural habitats is a major issue that life cycle assessment (LCA) methods intend to address. No current LCA method is able to assess and compare impacts on the biodiversity of vegetable production systems as a function of farming practices and the local context. Based on a literature review and consultation with experts, the SALCA-BD expert system, originally designed to assess impacts on the biodiversity of cropland and grassland at field, rotation, and farm levels, was adapted to vegetable production systems. SALCA-BD is based on an inventory of the habitats found on a farm and a list of practices that can be implemented in these habitats. We distinguished an open field and a greenhouse as two distinct “level I” habitats, as a habitat’s openness favours the exchange of species with surrounding habitats. These two habitats were subdivided into “level II” habitats that corresponded to vegetable crops. Given the many types of vegetables, we used a clustering method to create a few categories that grouped vegetables that had similar potential to host biodiversity. We created a category for intercropped vegetables for fields in which multiple vegetables are grown at the same time, which is common on microfarms. We tested the expert system at field and farm levels using scenarios and a farm case study. We quantified effects of changes to individual practices and practice intensities at the field level on biodiversity. The results highlighted the importance of semi-natural habitats for preserving biodiversity, in addition to low-intensity practices, which indicates that assessment at the farm level is more informative than that at the field level. Because it considers habitats and practices in detail, SALCA-BD is useful for assessing biodiversity at field and farm levels and for comparing farming systems with the same land use and type of management (organic or conventional), which other LCA methods for assessing biodiversity cannot do. Field size, which is a driver of biodiversity, is considered indirectly only when semi-natural habitats are included. As SALCA-BD does not consider impacts of the background system, combining SALCA-BD with comprehensive methods for assessing impacts on biodiversity is a promising perspective for more complete assessment.

KINEMATIC ANALYSIS OF HIP JOINT MODIFICATIONS IN SWITCH LEAP: COMPENSATORY MECHANISMS DUE TO REDUCED MOBILITY IN THIS AREA

ABSTRACT. Artistic gymnastics include a series of artistic elements where the joints’ mobility represents an essential factor for the accuracy of the execution in both beam and floor routines. The reduced mobility is responsible for the occurrence of compensatory movements. This type of repetitive and long-term compensations can damage the joints involved in execution of an accurate switch leap element. The aim of the study was to analyze the compensatory mechanisms due to reduced mobility in the hip joint that can occur during the execution of a switch leap. 6 female gymnasts (8-10 years) from C.S.S.1 Timisoara have been analyzed when they executed switch leap on the floor. The kinematic analysis was carried using inertial sensors for movement tracking technology. The evaluated parameters were: leg separation angle (LSA), lateral pelvic tilt (LPT) and pelvic rotation (PR). The data revealed a LSA of 137.5± 2.239° which corresponds to the second level of penalty (0.30 points). The compensatory movements were revealed by the level of LPT and pelvic rotation. Depending on the front leg, the compensatory tilt, represented by the elevation of the hip joint, was found on the right or left part accordingly. Regarding the pelvic rotation, this is performed in the backward direction on the same part with the tilt. The kinematic analysis of the switch leap element provides supplementary data that can be taken into consideration by the gymnasts and coaches during the training period in order to reduce the risk of injuries and the risk of falling from the beam.

Influence of elite rotation on authoritarian resilience

ABSTRACT This article proposes the use of the indicator of elite rotation to deepen the understanding of the phenomenon of authoritarian cooptation. The high frequency of changes in the ruling coalition can have a twofold effect on authoritarian regimes. On the one hand, it makes it possible to include new leaders in the ruling coalition in a timely fashion, remove potential opponents and maintain loyalty among the nobility. On the other hand, constant rotation creates a situation of high uncertainty and deprives some elites of access to previously received benefits. This study offers an empirical test of these assumptions: an analysis of all authoritarian regimes that existed between 1968 and 2010 (as well as all dictators who ruled between 1968 and 2008) leads to the conclusion that a low level of elite rotation generally contributes to the resilience of authoritarian regimes and leaders.

Quantum state-resolved molecular dipolar collisions over four decades of energy.

Collisions between cold polar molecules represent a fascinating research frontier but have proven hard to probe experimentally. We report measurements of inelastic cross sections for collisions between nitric oxide (NO) and deuterated ammonia (ND3) molecules at energies between 0.1 and 580 centimeter-1, with full quantum state resolution. At energies below the ~100-centimeter-1 well depth of the interaction potential, we observed backward glories originating from peculiar U-turn trajectories. At energies below 0.2 centimeter-1, we observed a breakdown of the Langevin capture model, which we interpreted in terms of a suppressed mutual polarization during the collision, effectively switching off the molecular dipole moments. Scattering calculations based on an ab initio NO-ND3 potential energy surface revealed the crucial role of near-degenerate rotational levels with opposite parity in low-energy dipolar collisions.

Topological Charges of Periodically Kicked Molecules.

We show that the simplest of existing molecules-closed-shell diatomics not interacting with one another-host topological charges when driven by periodic far-off-resonant laser pulses. A periodically kicked molecular rotor can be mapped onto a "crystalline" lattice in angular momentum space. This allows us to define quasimomenta and the band structure in the Floquet representation, by analogy with the Bloch waves of solid-state physics. Applying laser pulses spaced by 1/3 of the molecular rotational period creates a lattice with three atoms per unit cell with staggered hopping. Within the synthetic dimension of the laser strength, we discover Dirac cones with topological charges. These Dirac cones, topologically protected by reflection and time-reversal symmetry, are reminiscent of (although not equivalent to) that seen in graphene. They-and the corresponding edge states-are broadly tunable by adjusting the laser strength and can be observed in present-day experiments by measuring molecular alignment and populations of rotational levels. This paves the way to study controllable topological physics in gas-phase experiments with small molecules as well as to classify dynamical molecular states by their topological invariants.

Biomechanical Stability of Lateral Ulnar Collateral Ligament Reconstruction and Repair of the Elbow: The Role of Ligament Bracing on Gap Formation and Stabilization

Background: Augmented (internal braced) lateral ulnar collateral ligament (LUCL) repair has been biomechanically compared with reconstruction techniques in the elbow. However, LUCL repair alone has not yet been compared with augmented repair and reconstruction techniques. Hypothesis: Internal bracing of LUCL repair would improve time-zero stabilization regarding gap formation, stiffness, and residual torque as compared with repair alone and reconstruction techniques to restore native elbow stability. Study Design: Controlled laboratory study. Methods: Overall, 24 cadaveric elbows were used for either internal braced LUCL repair (Repair-IB) or single- and double-strand ligament reconstruction with triceps (Recon-TR) and palmaris longus tendon graft (Recon-PL), respectively. Laxity testing in external rotation was consecutively performed at 90° of elbow flexion on the intact, dissected, and repaired conditions and with the previously assigned techniques. First, intact elbows were loaded to 7.0-N·m external torque to evaluate time-zero ligament rotations at 2.5, 4.0, 5.5, and 7.0 N·m. Rotation-controlled cycling was performed (total of 1000 cycles) for each surgical condition. Gapping, stiffness, and residual torque were analyzed. Finally, these and 8 additional intact elbows underwent torque-to-failure testing (30 deg/min). Results: The dissected state showed the highest gap formation and lowest peak torques (P < .001). While gap formation of Repair-IB (P < .021) was significantly lower than that of repair without internal bracing at all rotation levels, gaps of Recon-PL were similar to and Recon-TR were significantly higher than those of Repair-IB except for the highest torsion level. Residual peak torques at specific rotation angles between native state and Recon-TR (α2.5), Recon-PL (α4.0), and Repair-IB (α5.5) were similar; all other comparisons were significantly different (P < .027). Torsional stiffness of Repair-IB was significantly higher at all rotation angles measured. Analysis of covariance showed significantly less gap formation over residual peak torques for Repair-IB (P < .001) as compared with all other groups. The native state failure load was significantly higher than Recon-PL and Recon-TR failure loads, with similar stiffness to all other groups. Conclusion: Repair-IB and Recon-PL of the LUCL showed increased rotational stiffness relative to the intact elbow for restoring posterolateral stability to the native state in a cadaveric model. Recon-TR demonstrated lower residual peak torques but provided near-native rotational stiffness. Clinical Relevance: Internal bracing of LUCL repair may reduce suture-tearing effects through tissue and provide sufficient stabilization for healing throughout accelerated and reliable recovery without the need for a tendon graft.

Spectroscopic investigation of atmospheric pressure ‘micro-plasma needle’

Plasma-based sterilization at atmospheric pressure in plasma needle configuration is a recently developing technique that has numerous applications in heat-sensitive materials and enhances biosensor properties. In this study, the capacitively coupled He–O2/Ar and He–N2/Ar mixtures [Formula: see text]-plasma at atmospheric pressure is characterized to find out the optimum condition of plasma-based sterilization for plasma needle. Trace rare gas actinometry based on optical emission spectroscopy has been used to estimate the [O] and [N] atomic densities as a function of discharge parameters i.e., applied pulsing voltage, gases concentration and different flow rates. Ar-1line Ar[Formula: see text] at 750 nm, N-I line [Formula: see text] at 746.8 nm and O-I line [Formula: see text] at 844.6 nm is used to determine the atomic densities of oxygen [O] and nitrogen [N]. Using the Boltzmann plot, the rotational temperature of He–N2/Ar and He–O2/Ar was calculated from the rotational levels of the “first negative system” (FNS) [Formula: see text]. The temperature of the gas increases as the pulsed DC power increases, but it drops as the gas flow rate in the mixture increases. The actinometric results show that both densities increase with applied pulsing voltage and molecular concentration of oxygen and nitrogen. Moreover, it is also observed that emission intensity ratios ([Formula: see text] and [Formula: see text]) also increase with an increase in applied pulsing voltage but they decrease with an increase in flow rate. Based on these results, it is suggested that the optimum conditions, in terms of [O] and [N] atomic densities, for plasma-based sterilization in needle configuration are 4% oxygen and nitrogen concentration at 4 kV applied pulsing voltage and 100[Formula: see text]SCCM flow rate.

Concentration on the market of audit services provided to publicly listed companies: Evidence from Poland

Abstract Paper’s objectives The main purpose of the article was to identify the level of concentration on the market of audit services provided to public companies listed on the Warsaw Stock Exchange. The additional aim of the article was to identify the level of rotation among companies providing audit services to public companies listed on the Warsaw Stock Exchange. Methods applied The research conclusions were formulated based on the analysis of 3,960 annual reports prepared in the years between 2011 and 2019 by companies listed on the Warsaw Stock Exchange. Findings The study found that over the years from 2011 to 2016 the concentration (measured by BIG4, CR4, CR8, and 10KAP indicators) on the market of auditing services provided to public companies increased. However, as of 2017, this concentration began to decline. This demonstrates the effectiveness of the new regulations on the audit market. In the analyzed period, eight audit firms, referred to in the article as “leading”, provided their services to an average of &gt;62% of public companies. Their share in the market of auditing services varied from sector to sector. At the turn of 2016 and of 2017, a significant increase in the level of rotation on the market of audit services provided to public companies was observed. This level varied from sector to sector. Originality/value The literature on the subject has not yet presented a comprehensive analysis of the impact of EU directives on the structure of the Polish market of audit services provided to public companies. This issue is a research gap, which has been filled in this article.

Fuzzy-Quantized Elliptical Target Encircling Control of Quadrotors With Arbitrary-Time Convergence

This article addresses a fuzzy-quantized elliptical target encircling control of quadrotors with arbitrary-time convergence, consisting of translational and rotational designs. At the translational level, an arbitrary-time elliptical guidance rule is designed to empower quadrotors to move along the predefined elliptical path within a prescribed settling time free from initial conditions. At the rotational level, a fuzzy-quantized attitude regulation protocol is developed to stabilize the attitude deviation, where a quantized fuzzy logic is artfully constructed to online recover uncertainties via updating weights with finite states scheduled by a hysteresis quantizer, greatly reducing signal transmission burden. Finally, the overall system stability is demonstrated via input-to-state stable principle, while not only simulations but also experiments are given to verify the efficacy of suggested approach.

Pre- and During-Pandemic Financial Standing of Companies in Poland Ranked According to the Type of Business Activity

Abstract Subject and purpose of work This paper seeks to examine how the COVID-19 pandemic affected the financial standing of companies classified according to the type of their business activity. Materials and methods This paper is based on aggregate data on businesses operating in Poland in the period 2017–2021, grouped according to the type of business activity. The data was published by the Central Statistical Office GUS in Poland. The company status was investigated using the calculated values of diagnostic indicators (return on assets, current financial liquidity, level of debt, stock rotation, and growth in sales). These indicators were normalized with the zero unitarization method to construct a synthetic indicator. The synthetic indicator was then used to generate business rankings. Results The vast majority of the examined companies proved to be profitable. In 2020, the profitability and sales revenue of the businesses concerned were found to deteriorate slightly. There has been a downward trend in the rankings for companies operating in the accommodation and catering sector and the manufacturers of petroleum products. Pharmaceutical companies were the businesses that improved and topped the rankings. Conclusions The pandemic had a strong negative impact on businesses operating in the market sector of accommodation and catering. The producers of refined petroleum products were also affected. The producers of pharmaceuticals benefited most during the pandemic. There are no clear indicators as to the impact of the pandemic on other types of businesses.

Collisional excitation of HCNH+ by He and H2: New potential energy surfaces and inelastic rate coefficients.

Protonated molecules have been increasingly detected in the interstellar medium (ISM), and usually astrochemical models fail at reproducing the abundances derived from observational spectra. Rigorous interpretation of the detected interstellar emission lines requires prior calculations of collisional rate coefficients with H2 and He, i.e., the most abundant species in the ISM. In this work, we focus on the excitation of HCNH+ induced by collision with H2 and He. Therefore, we first calculate ab initio potential energy surfaces (PESs) using the explicitly correlated and standard coupled cluster method with single, double, and non-iterative triple excitation in conjunction with the augmented-correlation consistent-polarized valence triple zeta basis set. Both the HCNH+-H2 and HCNH+-He potentials are characterized by deep global minima of 1426.60 and 271.72 cm-1, respectively, and large anisotropies. From these PESs, we derive state-to-state inelastic cross sections for the 16 low-lying rotational energy levels of HCNH+ using the quantum mechanical close-coupling approach. The differences between cross sections due to ortho- and para-H2 impacts turn out to be minor. Using a thermal average of these data, we retrieve downward rate coefficients for kinetic temperatures of up to 100K. As it could be anticipated, differences of up to two orders of magnitude exist between the rate coefficients induced by H2 and He collisions. We expect that our new collision data will help to improve the disagreement between abundances retrieved from observational spectra and astrochemical models.