Study of the HO dipole moment and polarisability vibrational dependence by the analysis of rovibrational line shifts.

The study of the HO dipole moment μ and polarisability α vibrational dependence is based on the comparison of experimental and calculated line shifts induced by argon, nitrogen, and air pressure in different HO vibrational bands. Obtained dependence α on the stretching vibrations is in good agreement with the existing ab initio calculations in the literature, but the dependence α on the bending vibration is quite different. To clarify the dependence of μ and α on the bending vibration, the shifts of selected HO lines of the 4ν, 5ν, and 6ν bands induced by argon, hydrogen and helium pressure are measured with the help of a Bruker IFS HR 125 spectrometer at room temperature with a spectral resolution of 0.

Isotopic and symmetry breaking effects on phosphine spectra under H → D substitutions from variational calculations.

Variationally computed infrared spectra in the range [0-5000] cm are reported for the deuterated PHD and PHD molecules from accurate potential energy and dipole moment surfaces initially derived for the major isotopologue PH( ). Energy level and line intensity calculations were performed by using a normal-mode model combined with isotopic and symmetry transformations for the H → D substitutions. Theoretical spectra were computed at 296 K up to = 30 and will be made available through the TheoReTS information system (http://theorets.

Modification of the Ceramic Implant Surfaces from Zirconia by the Magnetron Sputtering of Different Calcium Phosphate Targets: A Comparative Study.

In this study, thin calcium phosphate (Ca-P) coatings were deposited on zirconia substrates by radiofrequency (RF) magnetron sputtering using different calcium phosphate targets (calcium phosphate tribasic (CPT), hydroxyapatite (HA), calcium phosphate monobasic, calcium phosphate dibasic dehydrate (DCPD) and calcium pyrophosphate (CPP) powders). The sputtering of calcium phosphate monobasic and DCPD powders was carried out without an inert gas in the self-sustaining plasma mode. The physico-chemical, mechanical and biological properties of the coatings were investigated.

Highly excited vibrational levels of methane up to 10 300 cm: Comparative study of variational methods.

In this work, we report calculated vibrational energy levels of the methane molecule up to 10 300 cm. Two potential energy surfaces constructed in quite different coordinate systems with different analytical representations are employed in order to evaluate the uncertainty of vibrational predictions. To calculate methane energy levels, we used two independent techniques of the variational method.

[The role of changes in the structure of water and water-based systems in the mechanism of combined action of the magnetic field and natural therapeutic factors].

The application of the dielectrometric technology in the combination with the resonance method and thermometry has been shown to provide an insight into a variety of factors including the influence of the magnetic field of the permanent magnets on the structure of water and water-containing systems. It was found that the magnetization of both distilled water and «Karachinskaya» mineral water increase their structuredness. Magnetization changes the biological properties of therapeutic peloids by virtue of a change in the structure of water and, accordingly, the structuring of the water fraction of therapeutic muds.

[Photoacoustic spectroscopy evaluation of the impact of smoking on the composition of exhaled air in patients with bronchopulmonary diseases].

Aim: To investigate the impact of smoking on the air exhaled by patients with chronic obstructive pulmonary disease (COPD) and asthmatics, by applying photoacoustic spectroscopy.

Subjects And Methods: The exhaled air absorption spectra (EAAS) were analyzed in healthy volunteers and patients with COPD and asthmatics, by applying an ILPA-1 CO2 laser photoacoustic gas analyzer. The procedure based on the calculation of an integrated estimate (IE) of the state of the object was used to assess the findings.

Full-Dimensional Potential Energy and Dipole Moment Surfaces of GeH Molecule and Accurate First-Principle Rotationally Resolved Intensity Predictions in the Infrared.

Nine-dimensional potential energy surface (PES) and dipole moment surface (DMS) of the germane molecule are constructed using extended ab initio CCSD(T) calculations at 19 882 points. PES analytical representation is determined as an expansion in nonlinear symmetry adapted products of orthogonal and internal coordinates involving 340 parameters up to eighth order. Minor empirical refinement of the equilibrium geometry and of four quadratic parameters of the PES computed at the CCSD(T)/aug-cc-pVQZ-DK level of the theory yielded the accuracy below 1 cm for all experimentally known vibrational band centers of five stable isotopologues of GeH, GeH, GeH, GeH, and GeH up to 8300 cm.

Interferometric Laser Scanner for Direction Determination.

In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.

Resummation of divergent perturbation series: Application to the vibrational states of H2CO molecule.

Large-order Rayleigh-Schrödinger perturbation theory (RSPT) is applied to the calculation of anharmonic vibrational energy levels of H2CO molecule. We use the model of harmonic oscillators perturbed by anharmonic terms of potential energy. Since the perturbation series typically diverge due to strong couplings, we apply the algebraic approximation technique because of its effectiveness shown earlier by Goodson and Sergeev [J.

First predictions of rotationally resolved infrared spectra of dideuteromethane ((12)CH2D2) from potential energy and dipole moment surfaces.

We report the variationally computed infrared spectrum of (12)CH2D2 using our recent potential energy and dipole moment methane surfaces, which have been initially derived in the irreducible tensor representation adapted to the tetrahedral symmetry of the major isotopologue (12)CH4. The nuclear motion calculations are accomplished by combining the normal-mode Eckart-Watson Hamiltonian with isotopic and symmetry transformations. Our direct vibrational calculations are compared to the 93 observed band centers up to 6300 cm(-1).

An efficient method for energy levels calculation using full symmetry and exact kinetic energy operator: tetrahedral molecules.

A simultaneous use of the full molecular symmetry and of an exact kinetic energy operator (KEO) is of key importance for accurate predictions of vibrational levels at a high energy range from a potential energy surface (PES). An efficient method that permits a fast convergence of variational calculations would allow iterative optimization of the PES parameters using experimental data. In this work, we propose such a method applied to tetrahedral AB4 molecules for which a use of high symmetry is crucial for vibrational calculations.

Does the "reef structure" at the ozone transition state towards the dissociation exist? New insight from calculations and ultrasensitive spectroscopy experiments.

Since the discovery of anomalies in ozone isotope enrichment, several fundamental issues in the dynamics linked to the shape of the potential energy surface in the transition state region have been raised. The role of the reeflike structure on the minimum energy path is an intricate question previously discussed in the context of chemical experiments. In this Letter, we bring strong arguments in favor of the absence of a submerged barrier from ultrasensitive laser spectroscopy experiments combined with accurate predictions of highly excited vibrations up to nearly 95% of the dissociation threshold.

A new accurate ground-state potential energy surface of ethylene and predictions for rotational and vibrational energy levels.

In this paper we report a new ground state potential energy surface for ethylene (ethene) C2H4 obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82,542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters.

Accurate first-principles calculations for 12CH3D infrared spectra from isotopic and symmetry transformations.

Accurate variational high-resolution spectra calculations in the range 0-8000 cm(-1) are reported for the first time for the monodeutered methane ((12)CH3D). Global calculations were performed by using recent ab initio surfaces for line positions and line intensities derived from the main isotopologue (12)CH4. Calculation of excited vibrational levels and high-J rovibrational states is described by using the normal mode Eckart-Watson Hamiltonian combined with irreducible tensor formalism and appropriate numerical procedures for solving the quantum nuclear motion problem.

Laser monitor for non-destructive testing of materials and processes shielded by intensive background lighting.

A single-pulse imaging laser projection system (laser monitor) is proposed for real-time monitoring high-speed processes shielded by the intensive background lighting. The brightness temperature of the lighting can reach thousands or even tens of thousands of degrees, which makes it difficult to observe the processes with the naked eye. The estimates of limiting temperatures show that the use of the proposed instrument allows to view the objects when the equivalent brightness temperature of the background lighting is up to 45,000 K.

A laser photoacoustic analysis of residual CO₂ and H₂O in larch stems.

Every so often, the results obtained from investigations into the effects of varying environmental conditions on the tree growth rate at the same sites and on the change in the carbon balance in plants, using traditional methods, are found to differ widely. We believe that the reason for the ambiguity of the data has to do with failure to account for the role of the residual CO2 (and H2O) in the tree wood exhibiting a climate response. In our earlier work, the results of a laser photoacoustic gas analysis of CO2 and H2O vacuum-desorbed from disc tree rings of evergreen conifer trees were presented.

Backscattering by hexagonal ice crystals of cirrus clouds.

Light backscattering by randomly oriented hexagonal ice crystals of cirrus clouds is considered within the framework of the physical-optics approximation. The fine angular structure of all elements of the Mueller matrix in the vicinity of the exact backward direction is first calculated and discussed. In particular, an approximate equation for the differential scattering cross section is obtained.

Transformation of light backscattering phase matrices of crystal clouds depending on the zenith sensing angle.

Problems encountered in the interpretation of results of laser sensing of crystal clouds are considered. The parameters characterizing the cloud particle orientation are determined through the backscattering phase matrix elements. It is demonstrated how these parameters are related to the probability density of particle distribution over the spatial orientation angles.

Backscattering reciprocity for large particles.

The backscattering reciprocity theorem is considered for large particles as compared with the incident wavelength particles of arbitrary shape. It is shown that, in the specific case of faceted particles, this theorem is provided by the appearance of pairs of conjugate backscattered beams. A parameter characterizing a deviation of any approximation from the reciprocity theorem is proposed, and it is used for estimation of reliability for the physical-optics approximation.

Backscattering Mueller matrix for quasi-horizontally oriented ice plates of cirrus clouds: application to CALIPSO signals.

A general view of the backscattering Mueller matrix for the quasi-horizontally oriented hexagonal ice crystals of cirrus clouds has been obtained in the case of tilted and scanning lidars. It is shown that the main properties of this matrix are caused by contributions from two qualitatively different components referred to the specular and corner-reflection terms. The numerical calculation of the matrix is worked out in the physical optics approximation.

Increase in laser beam resistance to random inhomogeneities of atmospheric permittivity with an optical vortex included in the beam structure.

The role of the vortical phase in the initial structure of the wave field of a laser beam propagating in the turbulent atmosphere in statistical regularities of beam wandering is studied. It is found that in the near diffraction zone the variances of wandering of the vortical beam and the fundamental Gaussian beam turns out to be identical, if the initial radius of the Gaussian beam is equal to the radius of the ring intensity distribution of the vortical beam. In the far diffraction zone, the vortical beam wanders more slightly than the Gaussian beam with the same effective radius of the initial intensity distribution does.

Remote monitoring of emission activity level from NPP using radiofrequencies 1420, 1665, 1667 MHz in real time.

The Fukushima nuclear accident showed the importance of timely monitoring and detection of radioactive emissions released from enterprises of the nuclear fuel cycle. Nuclear power plants (NPP) working continuously are a stationary source of gas-aerosol emissions which presented in a ground surface layer persistently. Following radioactive emission, untypical effects can be observed, for example: the occurrences of areas with increased ionization, and increased concentration of some gases caused by photochemical reactions.

An acousto-optical sensor with high angular resolution.

The paper introduces a new laser interferometry-based sensor for diagnosis of random media by means of high accuracy angle measurements and describes the results of its development and testing. Theoretical calculations of the dependence of the range of the laser interferometer on laser beam parameters, device geometry, and atmospheric turbulence characteristics are reported. It is demonstrated that at moderate turbulence intensities corresponding to those observed most frequently in turbulent atmosphere at moderate latitudes and with low interference contrast values, the performance range of the laser interferometer-based device exceeds 5 km.

Modeling technique of capacitive discharge pumping of metal vapor lasers for electrode capacitance optimization.

To estimate optimum gas discharge tube (GDT) electrode capacitance of metal vapor lasers (MVLs) pumped by a longitudinal capacitive discharge, we offer to use series connection of capacitors to the electrodes of a conventionally pumped GDT with inner electrodes. It has been demonstrated that the maximum output power in CuBr lasers is obtained when the capacitances of high-voltage and ground electrodes are equal. When using a model circuit an average output power reaches 12 W that suggests the possibility of generating high average output power (>10 W) in MVLs pumped using a capacitive discharge.