Search results for "Spectroscopy."

Atomic physics, optical technologies, and medical physics: Abstracts book, 16.-17.02.2023., Riga

2023

81h International Scientific Conference of the University of Latvia Section ‘Atomic physics, optical technologies and medical physics’ will be held by Institute of Atomic Physics and Spectroscopy (IAPS) on 16-17.02.2023. The section will present the recent results, achieved by IAPS researchers and the IAPS partners in the following research fields: optical phenomena in gas, liquid, solid state and biological samples, optical methods for diagnostics, chemical analysis and optical sensor technologies, quantum optics and telecommunication, modelling, novel nanomaterials and their biomedical applications. Total 23 abstracts.

Atomic physics, optical technologies and medical physics, 10-11.02.2022.,Riga

2022

80th International Scientific Conference of the University of Latvia Section ‘Atomic physics, optical technologies and medical physics’ will be held by Institute of Atomic Physics and Spectroscopy (IAPS) on 10-11.02.2022. The section will present the recent results, achieved by IAPS researchers and the IAPS partners in the following research fields: optical phenomena in gas, liquid, solid state and biological samples, optical methods for diagnostics, chemical analysis and optical sensor technologies, quantum optics and telecommunication, modelling, novel nanomaterials and their biomedical applications. Total 27 abstracts.

Influence de la symétrie et de la taille de la molécule adsorbée sur le processus d'adsorption des composés éthyléniques sur une zéolithe de topologi…

2005

This manuscript lies within the scope of the understanding of the stepped isotherm observed during adsorption, on MFI zeolites, of some organic compounds which have a similar size to that of the pore opening of zeolite. During this work, the process of adsorption of ethylene and tetramethylethylene is initially studied by gravimetry and then by in situ infrared spectroscopy. This last technique enables to follow simultaneously the modifications of the adsorbent and the adsorbate. The analysis of these data lets suppose that the step in adsorption isotherm can be explained by taking account simultaneously of the symmetry and the size of the admolecule. In addition to the infrared bands chara…

Quantum-chemical determination of Born–Oppenheimer breakdown parameters for rotational constants: the open-shell species CN, CO+ and BO

2013

The quantum-chemical protocol for computing Born-Oppenheimer breakdown corrections to rotational constants in the case of diatomic molecules is extended to open-shell species. The deviation from the Born-Oppenheimer equilibrium rotational constant is obtained by considering three contributions: the adiabatic correction to the equilibrium bond distance, the electronic contribution to the moment of inertia requiring the computation of the rotational g-tensor, and the so-called Dunham correction. Values for the Born-Oppenheimer breakdown parameters of CN, CO+, and BO in their (2)sigma(+) electronic ground states are reported based on coupled-cluster calculations of the involved quantities and …

Multiple scattering approach for two-electron resonant emission studied by angle-resolved coincidence spectroscopy.

2008

International audience; We have developed a generalization of the multiple-scattering formalism to deal with Auger-photoelectron coincidence spectroscopy APECS in the solid state. We have merged the exact atomic treatment of the angular correlations between the two electrons and the single-particle approach, on which the multiplescattering description of condensed matter relies. This allows the recovering, even in extended systems, of the entangled form of the electron-pair wave function characterizing the coincidence angular diffraction pattern. In the atomic limit our formalism correctly reproduces the cross section, as calculated within the statistical-tensors approach, usually employed …

Decorated pottery study: Analysis of pigments by x-ray absorbance spectroscopy measurements

2007

Characterization of pigments on decorated pottery fragments has been fully carried out by nondestructive x-ray absorbance spectroscopy (XAS). The samples were a series of pottery shards excavated from the archeological site of Caltagirone (Sicily, Italy), a well-known ceramic production center. Aesthetical criteria and morphological observations allowed us to attribute the samples to quite different historical periods, starting from the 18th century B.C. up to the 16th century A.D. An extensive time interval led us to suppose that different materials and techniques were used for the production of the ceramic paste and also for the preparation of pigments. XAS measurements were performed at …

Buffer-gas-free mass-selective ion centering in Penning traps by simultaneous dipolar excitation of magnetron motion and quadrupolar excitation for i…

2012

A new excitation scheme of the radial ion-motional modes is introduced for Penning-trap ion-cyclotron-resonance experiments. By simultaneous dipolar excitation of the magnetron motion and resonant quadrupolar excitation for the conversion between magnetron motion and cyclotron motion, a mass-selective recentering of the ions of interest is performed while all other (contaminant) ions are ejected from the trap. This new technique does not rely on the application of a buffer gas as presently used [G. Savard, St. Becker, G. Bollen, H.-J. Kluge, R.B. Moore, Th. Otto, L Schweikhard, H. Stolzenberg, U. Wiess, Physics Letters A 158 (1991) 247] and will thus prevent charge-exchange reactions and da…

Response of AGATA segmented HPGe detectors to gamma rays up to 15.1MeV

2013

WOS: 000314826000009

Fibrillation of Human Serum Albumin at physiological pH is inhibited by oxidation

2014

Corrosion and wear resistance of coatings produced on AZ31 Mg alloy by plasma electrolytic oxidation in silicate-based K2TiF6 containing solution: Ef…

2022

Abstract In this research, plasma electrolytic oxidation coatings were prepared on AZ31 Mg alloy in a silicate-based solution containing K2TiF6 using bipolar and soft sparking waveforms with 10, 20, and 30% cathodic duty cycles. The coatings displayed a net-like surface morphology consisted of irregular micro-pores, micro-cracks, fused oxide particles, and a sintered structure. Due to the incorporation of TiO2 colloidal particles and the cathodic pulse repair effect, most of the micro-pores were sealed. Long-term corrosion performance of the coatings was investigated using electrochemical impedance spectroscopy during immersion in 3.5 wt.% NaCl solution up to 14 days. The coating grown by t…