THE STUDY OF CURVES OF THE TRANSIENT CURRENT IN POLYTETRAFLUOROETHYLENE BY MEANS OF FOURIER ANALYSIS

Experimental transition current curves for polytetrafluoroethylene after exposure to high-energy ionizing radiation are obtained. The transient current curves in irradiated polytetrafluoroethylene are analyzed based on the discrete Fourier transform. It is shown that there is an intense maximum of dielectric absorption in the infralow frequency region. This maximum is characterized by abnormally large values of the dielectric increment, permittivity, and the dielectric loss factor. It is concluded that the volume polarization of the irradiated polytetrafluoroethylene is uniform. The polarization observed in this frequency range is associated with the activation of migration of trapped charge carriers within microscopic regions.

ExoMol line list – XXXIV. A rovibrational line list for phosphinidene (PH) in its $X\, {}^3\Sigma ^-$ and $a\, {}^1\Delta$ electronic states

ABSTRACT A rovibronic line list for the ground (X 3Σ−) and first excited (a 1Δ) states of phosphinidene, 31PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data is used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm−1. The nuclear Schrödinger equation is solved using these PECs plus Born–Oppenheimer and spin splitting correction terms. Line intensities and Einstein A coefficients are computed using ab initio dipole moment curves for X–X and a–a transitions. The resulting LaTY line list, which contains 65 055 transitions for 2528 rovibronic states up to 24 500 cm −1 and J = 80, is used to simulate spectra in emission and absorption for a range of temperatures. The line list is made available in electronic form at the CDS and ExoMol data bases.

Experimental transition probabilities for 4p – 4d spectral lines in V II

Aims. We aim to measure lifetimes of levels belonging to the 3d3(4F)4d subconfiguration in V II, and derive absolute transition probabilities by combining the lifetimes with experimental branching fractions.Methods. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge lamp, recorded with a Fourier transform spectrometer.Results. We report lifetimes for 13 levels at an energy around 73 000 cm−1. Absolute transition probabilities of 78 lines are derived by combining the lifetimes and branching fractions. The experimental values are compared with theoretical data from the literature.

Numerical and experimental transition results evaluation for a morphing wing and aileron system

ABSTRACTA new wing-tip concept with morphing upper surface and interchangeable conventional and morphing ailerons was designed, manufactured, bench and wind-tunnel tested. The development of this wing-tip model was performed in the frame of an international CRIAQ project, and the purpose was to demonstrate the wing upper surface and aileron morphing capabilities in improving the wing-tip aerodynamic performances. During numerical optimisation with ‘in-house’ genetic algorithm software, and during wind-tunnel experimental tests, it was demonstrated that the air-flow laminarity over the wing skin was promoted, and the laminar flow was extended with up to 9% of the chord. Drag coefficient reduction of up to 9% was obtained when the morphing aileron was introduced.

Band head spin assignment of superdeformed bands in 133Pr using two-parameter formulae

The two-parameter formulae viz. the power index formula, the nuclear softness formula and the VMI model are adopted to accredit the band head spin [Formula: see text] of four superdeformed rotational bands in [Formula: see text]. The technique of least square fitting is used to accredit the band head spin for four superdeformed rotational bands in [Formula: see text]. The root mean deviation among the computed transition energies and well-known experimental transition energies are attained by extracting the model parameters from the two-parameter formulae. The determined transition energies are in excellent agreement with the experimental transition energies, whenever exact spins are accredited. The power index formula coincides well with the experimental data and provides minimum root mean deviation. So, the power index formula is more efficient tool than the nuclear softness formula and the VMI model. The deviation of dynamic moment of inertia [Formula: see text] against the rotational frequency is also examined.