National Aviation Academy

About: National Aviation Academy is a based out in . It is known for research contribution in the topics: Laser & Dipole. The organization has 92 authors who have published 93 publications receiving 189 citations.

Competing magnetic and structural states in multiferroic YM n 2 O 5 at high pressure

Abstract: The magnetic, structural, and vibrational properties of $\mathrm{YM}{\mathrm{n}}_{2}{\mathrm{O}}_{5}$ multiferroic have been studied by means of neutron, x-ray powder diffraction, and Raman spectroscopy at pressures up to 6 and $30\phantom{\rule{0.28em}{0ex}}\mathrm{GPa}$, respectively. Application of high pressure, $Pg1\phantom{\rule{0.28em}{0ex}}\mathrm{GPa}$, leads to a gradual suppression of the commensurate and incommensurate antiferromagnetic (AFM) phases with a propagation vector $q=(1/2,0,{q}_{z}\ensuremath{\sim}1/4)$ and appearance of the commensurate AFM phase with $q=(1/2,0,1/2)$. This observation is sharply contrasting to general trend towards stabilization of commensurate AFM phase with $q=(1/2,0,1/4)$ found in other $R\mathrm{M}{\mathrm{n}}_{2}{\mathrm{O}}_{5}$ compounds upon lattice compression. At $P\ensuremath{\sim}16\phantom{\rule{0.28em}{0ex}}\mathrm{GPa}$ a structural phase transformation accompanied by anomalies in lattice compression and pressure behavior of vibrational modes was observed. The comparative analysis of high-pressure and $R$-cation radius variation effects clarified a role of particular magnetic interactions in the formation of the magnetic states of $R\mathrm{M}{\mathrm{n}}_{2}{\mathrm{O}}_{5}$ compounds.

Ground state magnetic properties of odd neutron dy isotopes

Abstract: Using the quasiparticle phonon nuclear model (QPNM) and taking into account the spin–spin interaction, the effects of the spin polarization on spin gyromagnetic factors (gs) as well as the intrinsic magnetic moments (gK) of the deformed odd neutron 155-165Dy isotopes were studied. The calculated values of gs and gK are in fair agreement with the experiment as well as with other microscopic calculations. Our calculations indicated that because of the core polarization, the gs factors of the nucleons in the nucleus reduce noticeably from its free nucleon value and the spin–spin interactions play an important role in the explanation of the quenching of the gs factors. A very good reproduction of the phenomenological quenching of gs factor from its free values is obtained for 155-165Dy.

The ground-state magnetic moments of odd-mass Hf isotopes

Abstract: In this paper the Quasiparticle-Phonon Nuclear Model (QPNM), based on QRPA (Quasiparticle Random Phase Approximation) phonons, has been utilized to investigate spin polarization effects on the groundstate magnetic properties such as intrinsic magnetic moment (g K ) and effective spin gyromagnetic factor (g . ) of odd-mass deformed 165–179Hf isotopes with K > 1/2. Investigations of the spin polarization effects of the even core on the magnetic moments show that the spin gyromagnetic factors (g s ) of the nucleons in the nucleus differ noticeably from the corresponding values for free nucleons and that the spin-spin interactions play an important role in the re-normalization of g s factors of the odd-mass 165–179Hf isotopes. In addition, some theoretical predictions are presented for the magnetic moments of 165Hf, 167Hf, and 169Hf, whose ground state magnetic moments haven’t been experimentally determined yet.

A micropixel avalanche phototransistor for time of flight measurements

Abstract: This paper presents results of studies of the silicon based new micropixel avalanche phototransistor (MAPT). MAPT is a modification of well-known silicon photomultipliers (SiPMs) and differs since each photosensitive pixel of the MAPT operates in Geiger mode and comprises an individual micro-transistor operating in binary mode. This provides a high amplitude single photoelectron signal with significantly shorter rise time. The obtained results are compared with appropriate parameters of known SiPMs.

LIDAR for remote sensing of contaminations on water and earth surfaces taking place during oil-gas production

Abstract: Remote sensing of contaminations on water and earth surfaces (oil spills, films) taking place during oil-gas extraction is an interesting and actual problem. This problem may be solved by using different methods of optical spectroscopy, including: •Raman scattering; •light induced breakdown spectroscopy (LIBS); •fluorescence spectroscopy. Fluorescence Light Detection and Ranging (LIDAR) LIDARs are successfully used for remote sensing of chemical and biological substances at atmosphere. A new laser induced fluorescence (LIF) KA-14 LIDAR system for detecting of oil spills on the sea surface was employed at the National Aviation Academy of Azerbaijan. LIDAR’s parameters are as follows: •laser CFR 200- type QUANTEL, λ = 355 nm, beam O = 5.35 mm, f = 20 Hz, pulse duration τ = 7 ns, pulse power 60 mJ; •diameter of Newtonian- type telescope is 200 mm; •collimator expansion of the laser beam diameter- not less than 3; •angle range of telescope measurements relative to horizon: from -20 to +20 degree; •spectral range of measurements: from 380 to 750 nm, number of spectral channels- 32; •maximum range of measurements- not less than 250 m. This LIDAR is the first performing these kind of research not only on the Azerbaijan beach of Caspian sea, but also on the earth places of Absheron peninsula, where oil-gas production takes place. We hope that the performance of LIDAR will have an International recognition and will make noticeable input on the International Research of Caspian sea surfaces.