This work presents the results of measurements of the hyperfine structure for electronic levels belonging to odd-parity configurations of the terbium atom with high quantum number J. Laser spectroscopy with laser-induced fluorescence detection was used. The hyperfine structure of 80 terbium lines was recorded in three spectral regions. The hyperfine structure constants were determined for 47 levels

As energy issues gain prominence, the technology of regulating thermal radiation through phase change materials has garnered significant attention. However, fabrication challenges and monofunctionality plague the current technologies. So, we suggest a three-layer thin-film metasurface structure made of the phase-change material Ge2Sb2Te5(GST) and the metals Ge and Ag. This structure can change the

We have used convolutional neural network in a classification task to track the radius evolution of levitating evaporating microdroplets of pure diethylene glycol, diethylene glycol-water-polystyrene microparticles suspension, dipropylene glycol-water mixture and dipropylene glycol-water-silica nanoparticles suspension. We discretized a wider radii range into short radii segments, labeled them with

Under increasing stress due to climate change, cities are looking for ways to mitigate its impacts. In warmer climates, they face the prospect of higher air temperatures in summer compared to historical averages due to the urban heat island effect. An approach intended to address this problem is the application of “cool pavement” treatments (CPT) to city streets to make them more reflective to sunlight

We report the results of semi-empirical calculations of the fine structure (fs) and the hyperfine structure (hfs) for the odd-parity level system of the niobium ion (Nb II), using all available experimental data. The calculations performed showed, in most cases, a very good agreement, within the experimental uncertainty or slightly above it, between the total of 156 experimental hfs A values and the

The low-lying electronic states of LiIn+, which has remained unexplored both experimentally and theoretically until now, are investigated in this work from a theoretical perspective. By employing the multireference configuration interaction method, we have successfully characterized the molecular geometries, electronic structures and vibrational levels of Λ-S electronic states of the cation associated

Physics-informed neural networks have emerged as powerful tools for addressing complex forward and inverse problems governed by partial differential equations (PDEs). By embedding PDEs into the neural network’s loss function through automatic differentiation, PINN enables efficient evaluation at scattered spatio-temporal residual points. In this study, PINN methods are applied to solve integro-differential

Highly-charged tin ions (Sn HCIs) are key sources of extreme ultraviolet (EUV) radiation used in advanced nanolithography. This work presents a comprehensive study of energy levels, transition rates, and oscillator strength for Sn XIV-XXI, calculated using relativistic configuration interaction (RCI) and relativistic many-body perturbation theory (RMBPT) methods within the flexible atomic code (FAC)

The polarization of whitecap-covered regions significantly influences the accuracy of ocean polarization remote sensing and the parameter retrieval based on polarization information. In this study, a vector radiative transfer model based on the geometric structure of whitecap is proposed to calculate the reflectance and the degree of linear polarization (DoLP) of whitecap-covered regions. The whitecap-covered

The lower accuracy for line positions obtained using variational calculations (VCs) compared to effective Hamiltonian approaches is the main drawback in the VC methodology. The ability of VCs to make predictions for all the bands up to dissociation, treat several isotopologues at once and to incorporate first principle ab initio methods makes VCs the preferred method of constructing molecular line

An important problem for numerous applications in physics and chemistry is the precise quantitative determination of spectroscopic parameters of the MSiH4 (M= 28, 29, 30) molecules which is solved on the basis of high accurate experimental data and of sets of symmetrized vibrational functions and tetrahedral splitting parameters for the XY4 (Td symmetry) molecules recently derived in analytical form

Radiative transfer is essential in astronomy, both for interpreting observations and simulating various astrophysical phenomena. However, self-consistent line radiative transfer is computationally expensive, especially in 3D. To reduce the computational cost when utilizing a discrete angular discretization, we use a comoving frame interpretation of the radiative transfer equation. The main innovation

The spectroscopic rotational, centrifugal distortion and splitting parameters as well as the rotational structure of the ground vibrational state of the AsH3 molecule are improved considerably in comparison with the analogous information known in the literature by new precise infrared FTIR experimental data and an improved effective Hamiltonian for a symmetric vibrational state of the C3v symmetry

In this paper, we report new quantum Full Widths at Half Maximum (FWHM) intensities for 24 spectral lines corresponding to various nitrogen and oxygen ions, including 13 N IV, 4 N V and 7 O IV lines. The majority of the spectral lines examined were recently identified in the CASPEC and UVES spectra of the O(He) star JL9, which is a hot hydrogen-deficient pre-white dwarf (pre-WD). These recent findings

This study employs laser-locked cavity ring-down spectroscopy to investigate 15 weak 12C16O transitions in the near-infrared, corresponding to the P and R branches of the (3-0) band with rotational quantum numbers J ranging from 25 to 35. Most spectra were recorded at low pressures (below 1333 Pa), where Doppler broadening dominates, and collision broadening is mainly driven by speed-dependent interactions

The propagation of light that undergoes multiple-scattering by resonant atomic vapor can be described as a Lévy flight. Lévy flight is a random walk with heavy tailed step-size (r) distribution, decaying asymptotically as P(r)∼r−1−α, with α<2. The large steps, typical of Lévy flights, have its origins in frequency redistribution of the light scattered by the vapor. We calculate the frequency redistribution

Spectroscopic networks, based on rovibrational line-center measurements found in 10/5 literature sources, are presented for the triply substituted carbon dioxide isotopologues 17O13C18O/17O13C17O (738/737, according to a well-established shorthand notation followed in this study). For 738/737, the spectroscopic networks contain 2058(1488)/1831(1349) measured(unique) transitions, belonging to 25/22

Aircraft are the best tool to measure irradiance (incoming radiant energy) at different levels within the atmosphere and locations. However, to ensure precise evaluation of geophysical parameters, such as atmospheric heating rates, from airborne irradiance measurements, corrections for aircraft motion and for the non-level sensor placement are needed. Combined airborne irradiance measurements from

Combustion temperature and gas concentration are important parameters for understanding combustion status. Two types of signals including spontaneous emission and absorption signals are usually used for combustion temperature and gas concentration measurement. In this work, a combined method utilizing both spontaneous emission and absorption signals is proposed for combustion detection. The integrated

We report the second generation of Ames N2O IR line lists, ABG-IMRHT for room-temperature and Ames-2000K for high temperature applications. The ABG-IMRHT line list utilized a new potential energy surface (PES), B1b, refined from a refit of Schröder’s Comp I PES [10.1515/zpch-2015–0622] with σrms = 0.006 cm-1 for all reliable 14N216O levels in HITRAN2020 [10.1016/j.jqsrt.2021.107949], and a new dipole

Using a high-resolution dual-comb spectrometer based on quantum cascade lasers, we have measured line shape parameters of CH4 transitions broadened by CO2 in the ν4 vibrational band. 8 spectra were recorded at room temperature for total pressures ranging from 25 mbar to 700 mbar. The line shape parameters were determined by fitting 4 different theoretical profiles to the experimental methane line shapes

Line-by-line databases such as HITRAN enable the simulation of high-resolution molecular absorbance and emission spectra, which are indispensable for the development and application of spectroscopic diagnostics. Multiple tools reported in the literature have been built to assist with calculating absorbance and emission spectra based on line-by-line data. However, the available tools lack the essential

Broadening coefficients and high-order line-shape parameters, including the speed dependence of the line width, Dicke narrowing and first-order line-mixing parameters, are predicted for N2-broadened CO2 lines over a temperature range from 100 K to 1000 K using requantized molecular dynamics simulations (rCMDS). By employing an intermolecular potential, classical equations of motion, and a requantization

This paper reports on an experimental and theoretical study of line shape parameters for ν1-band nitrous oxide lines diluted in a bath of nitrogen. The measurements were performed at room temperature using a high-resolution mid-infrared dual-comb spectrometer. The collisional broadening coefficient and its speed-dependence were determined by adjusting the Voigt and speed-dependent Voigt profiles to

Transitions of ND2H have been detected in the high-resolution spectra of 14ND3 recorded in the region 60 − 1515 cm−1, using the Bruker IFS 125 Fourier transform spectrometer located at the synchrotron far-infrared beamline, Canadian Light Source. In this study we report on the observation and analysis of transitions to and between the s, a inversion levels of the v2 = 1 and v4a = 1 states for ND2H

Aerosol particles suspended in the atmosphere naturally aggregate to form various morphologies, which significantly impact atmospheric radiation transmission. This paper investigates the impact of particle mixing states on the scattering phase function of chain-like atmospheric aerosol aggregates using the Generalised Multiparticle Mie (GMM) method. The scattering properties of dust aerosol particles

High-optical-absorbance coatings are key contributors to the conversion of photons into heat for industrial applications, particularly in thermophotovoltaic (TPV) systems. Carbon nanotubes (CNTs) remain a promising material for these applications due to their exceptional melting point, superior optical absorbance, and efficient thermal emittance properties. Here we present CNTs arrays subjected to

Observation of the atomic oxygen fine structure line at 2.06 Terahertz from an orbiting limb sounder serves as a compelling platform for the characterization of neutral winds in the lower thermosphere and ionosphere (LTI, ∼110–250 km). The precision of wind measurements retrieved from this prospective instrument class are directly linked to the rest frequency of this targeted transition as determined

Atomic selective ionization processes provide critical ionization probability and isotopic selectivity in laser isotope separation. Aimed at the general principles of transition cross sections and ionization probabilities under various atomic hyperfine structures and laser parameters, and the optimization of atomic multi-channel photo-excitation and ionization processes of non-zero nuclear spin isotopes

1H-perfluorohexane and perfluoro-2-methyl-2-pentene are polyfluoroalkyl and perfluoroalkyl substances, respectively. Such substances are of general interest due to their ubiquity in industry and adverse health effects. To our knowledge, perfluoro-2-methyl-2-pentene has not been measured before in the infrared, and a single measurement of 1H-perfluorohexane exists. This work provides infrared absorption

Spectroscopic properties of the Se2+ cation are studied using high-level ab initio methods. Scalar relativistic (SR) corrections, core-valence (CV) electron correlation and spin-orbit coupling (SOC) effects are taken into account. The potential energy curves (PECs) of 19 Λ-S states and 52 Ω states generated from the Λ-S coupling scheme are obtained at the multireference configuration interaction plus

A Fortran code for fast computation of the reflection matrix of light for a semi-infinite discrete random medium in the case of oblique incidence of light on the boundary of the medium is described. It is assumed that the medium is homogeneous, isotropic and mirror symmetric and the waves propagating between the scatterers of the medium are spherical. The reflection matrix is the sum of two components

The oxygen (O2) A-band is used to determine the airmass in ground- and space-based remote sensing measurements because O2 is well-mixed in the Earth’s atmosphere and its column-integrated amount fraction on a dry-gas basis is nearly constant. Because biases in the retrieved airmass propagate to measurements of target species, low-uncertainty spectroscopic parameters are essential for increasingly precise

In this work, we propose a novel three-dimensional semi-empirical formula for the estimation of K-shell X-ray fluorescence cross sections for a wide range of elements 16≤Z≤92 based on the database of the experimental values published between 1985 and 2023 for photons spanning from 5.46 to 123.6 keV (over 3300 data). This approach employs an analytical dependent on the atomic number Z and the energy

A Surface Integral Equation (SIE) method has been implemented to analyze light scattering by arbitrarily shaped solid dielectric particles. Specifically, the Poggio–Miller–Chang–Harrington–Wu–Tsai formulation is discretized using the Galerkin method, employing Rao–Wilton–Glisson basis functions. The numerical solution is further accelerated through the application of the high-frequency Multilevel Fast

In this paper, the range of low-frequency microwave radar going through sand storms is numerically investigated with considering the attenuation and backscattering of charged sand grains along the link. It was found that strong sandstorms can reduce the range of microwave radar, which is reduced by < 5 % for radars at the L and S bands when the visibility is larger than 50 m; while with the visibility

High accurate ro-vibrational spectra of 12CD4 were measured in the pentad region with a Bruker IFS125 HR Fourier transform infrared (IR) spectrometer at an optical resolution of 0.003 cm−1 and different pressures and optical path-lengths. The analysis of 1264 experimental absolute transition strengths belonging to all nine ro-vibrational sub-bands of the 12CD4 pentad was performed using the Voigt profile

Absorption cross-sections at room temperature have been derived for two non-cyclic organic molecules cyanopropyne (CH3C3N) and isobutyronitrile (i-C3H7CN), and have been proposed for the 2024 update of the high-resolution transmission molecular absorption database (HITRAN). The gas phase infrared spectra of pure cyanopropyne and isobutyronitrile have been recorded at room temperature between 160 and

It has been recently demonstrated that the electromagnetic beam shape coefficients gn,Xm (X=TM or TE) which encode the structure of structured light beams may be expressed in terms of scalar, more specifically acoustical, beam shape coefficients. Because the technique used to obtain the relevant expressions relied on the properties of what is known as the finite series method, the aforementioned expressions

Here, we propose a graded hybridization strategy for the enhancement of radiative heat transfer, which is based on the heterostructure consisting of multilayer graded SiO2 gratings and black phosphorus (BP). In the near-field region, this graded hybridization strategy exhibits an advantage in radiative heat transfer capabilities when compared with conventional multiple surface plasmon polaritons (SPPs)

The spectrum of the Cd+6 ion excited in a vacuum spark and recorded with high resolution was studied in the range 170–320 Å. About 390 spectral lines of the 4p64d6 − (4p64d55p + 4p64d54f + 4p54d7) transitions were identified for the first time. All but one energy levels of the ground term configuration 4p64d6 were established. It also resulted in the determination of 171 and 36 levels of the 4p64d55p

16O12C17O is the fourth most abundant isotopologue of carbon dioxide. As part of this study, a total of 16223 rovibrational transitions, 9822 unique ones, measured for the ground electronic state of CO2, were collected from 31 articles, corresponding to the limited wavenumber range of 634–12727 cm−1. The measured transitions span the polyads P=0−17, where P=2v1+v2+3v3, and v1, v2, and v3 are the normal-mode

The atmospheric radiative transfer simulator ARTS is a software for computing atmospheric absorption, scattering, the transfer of radiation through an atmosphere, and sensor characteristics. It is written in C++ and can simulate remote sensing observations and radiative energy fluxes. The article describes version 2.6 of the software. There are numerous changes compared to the last ARTS publication

In this paper, we present libraries of simulated Raman spectra of di- and triatomic gaseous species relevant for reactive flows in high-temperature environments such as flames, ranging from 1 to 2500 K. The libraries encompass the most abundant isotopologues for key species, including CO ▪ . Simulation methodologies and results were primarily drawn from and validated in previous studies, with additional

A study of vibrational excitations of the OCS molecule in the framework of a polyad conserving local algebraic model is presented. The description starts establishing the Hamiltonian in configuration space in terms of normal modes and later on translated into an algebraic representation by introducing the bosonic realization for harmonic oscillator. Then a canonical transformation to local operators

Nitrous oxide is a long-lived greenhouse gas. Its isotopic composition provides valuable insights into sources and sinks, and about the mechanisms of formation. A major challenge in the spectroscopic analysis of the isotopocule compositions is the availability of accurate spectroscopic parameters, particularly for the minor 15N isotopocules. In this work, we introduce high-resolution spectroscopic

The new room temperature 12C16O2 line list (CDSD-2024-PI) is presented. This semi empirical line list contains the calculated line parameters (positions, intensities, air- and self-broadened half-widths, exponents of temperature dependence of air-broadened half-widths, and air pressure induced shifts). The reference temperature is 296 K, and intensity cutoff is 10-30 cm-1/(molecule cm-2). More than

We use a dual electro-optic comb system (EOOFC) and a differential chirped-pulse down conversion technique to study the R(6) manifold of the 2ν3 band (1645 nm) of methane at low pressure (< 1 kPa). In the frequency domain, the EOOFC method magnifies of the temporal dynamics of the system and due to of the 6-component asymmetric line shape, is shown to give unique amplitude and phase spectra that depend

In hot and dense plasma of solar and stellar interiors, Coulomb potentials between the nucleus and electrons are screened due to the complicated many-body interactions, resulting in significant alterations in atomic structures and dynamic properties of the embedded ions as well as the macroscopic transport properties, such as opacities. Here, the photoionization dynamics of the n ≤ 2 states of hydrogen-like

Nighttime light pollution is gaining significant interest in the scientific community and the public due to its harmful effects on human health, ecosystems, and leisure activities. Recently, many countries worldwide have been retrofitting their streetlights with light emitting diodes (LEDs) to enable smart street lighting while reducing energy use for street lights. However, little is known about the

Satellite missions are considering the atmospheric O2 band at 1.27 µm to determine the air-column. A prerequisite of these demanding atmospheric applications is an accurate knowledge of the spectroscopy of this band, in particular of the line profiles and their temperature dependence. In the present work, fifty-five transitions of the 1.27 µm band of O2 have been studied with a cavity ring down spectrometer

Accurate emissivity measurement is essential for characterizing metasurfaces with highly directional thermal radiation. Traditional Fourier-transform infrared (FTIR) spectroscopy, particularly when using focusing optics, introduces measurement artifacts due to divergence angle effects, leading to underestimated emissivity and angular deviations. This study investigates the use of FTIR-based infrared

This study presents a novel methodology for retrieving the temporal evolution of a single physical parameter throughout the course of measurements conducted with imaging-FTIR systems. Rather than operating in the spectral domain, the proposed approach performs parameter fitting directly in the interferogram (i.e., the time or Optical Path Difference (OPD) domain). The method is based on a linearization

Atmospheric sounding from a space instrument usually leads to solving some inverse problem to retrieve a vertical number density profile of a particular constituent like ozone. The paper starts to consider the total number of calls to the forward model that are necessary to iteratively process a large ensemble of observations. For a comparable computational effort, it can be useful to generate a large

This paper presents the design, validation, and application of a new optically accessible gas cell capable of supporting high-pressure and high-temperature environments. The new cell enabled spectroscopic studies to be performed at pressures up to 200 atm and temperatures up to 1300 K. The cell was manufactured from a nickel alloy material to allow for high-temperature operation. Long sapphire rods

Polarization imaging has drawn significant attention from the research fraternity for decades due to its prominent imaging capabilities across multidisciplinary fields. Polarization imaging is based on the study of vectorial properties of light and associated vectorial transformations resulting from light-matter interaction. The range of polarization imaging and its applications is so broad that it

The high levels of nocturnal artificial light emissions from urban areas induce adverse effects on the environment and human health. Having adequate monitoring provides information for planning public policies and measuring their degree of achievement. Consequently, there is a need for optimal designing or redesigning of Light-Pollution Monitoring Networks focused on sensing the most impacting regions