Armenian National Academy of Sciences

About: Armenian National Academy of Sciences is a government organization based out in Yerevan, Armenia. It is known for research contribution in the topics: Population & Laser. The organization has 4090 authors who have published 4042 publications receiving 40828 citations. The organization is also known as: Armenian National Academy of Sciences & NAS RA.

Derivatives of condensed thienopyrimidines: Synthesis and anticonvulsant and tranquilizer activity of hydrochlorides of pyrano[4′,3′:4,5]thieno[3,2-e]imidazo[1,2-a]pyrimidines

Abstract: New methods for the synthesis of 4-substituted 6,7-dihydro-7,7-dimethyl-5-oxo-9H-pyrano-[4′,3′: 4,5]-thieno[3,2-e]imidazo[1,2-a]pyrimidines and their hydrochlorides are developed. The anticonvulsant and tranquilizer properties of newly synthesized compounds have been studied.

Detection of very-high-energy gamma-ray emission from the vicinity of PSR B1706-44 and G343.1-2.3 with H.E.S.S

Abstract: The gamma-ray pulsar PSR B1706-44 and the adjacent supernova remnant (SNR) candidate G343.1-2.3 were observed by H.E.S.S. during a dedicated observation campaign in 2007. As a result of this observation campaign, a new source of very-high-energy (VHE; E > 100 GeV) gamma-ray emission, HESS J1708-443, was detected with a statistical significance of 7 sigma, although no significant point-like emission was detected at the position of the energetic pulsar itself. In this paper, the morphological and spectral analyses of the newly-discovered TeV source are presented. The centroid of HESS J1708-443 is considerably offset from the pulsar and located near the apparent center of the SNR, at RA(J2000) = 17h08m11s +/- 17s and Dec(J2000) = -44d20' +/- 4'. The source is found to be significantly more extended than the H.E.S.S. point spread function (~0.1 deg), with an intrinsic Gaussian width of 0.29 deg +/- 0.04 deg. Its integral flux between 1 and 10 TeV is ~ 3.8 x 10^-12 ph cm^-2 s^-1, equivalent to 17% of the Crab Nebula flux in the same energy range. The measured energy spectrum is well-fit by a power law with a relatively hard photon index Gamma = 2.0 +/- 0.1 (stat) +/- 0.2 (sys). Additional multi-wavelength data, including 330 MHz VLA observations, were used to investigate the VHE gamma-ray source's possible associations with the pulsar wind nebula of PSR B1706-44 and/or with the complex radio structure of the partial shell-type SNR G343.1-2.3.

Ball milling-induced reduction of MoS2 with Al

Abstract: The ball milling-induced reduction of MoS2 by Al has been investigated. Although this is a highly exothermic reaction that, based on its thermodynamic properties, should progress as a self-sustaining process, ignition could not be achieved by ball milling. In order to identify the reason, XRD, particle size distribution, SEM, and DTA measurements were carried out on a series of samples milled for different durations. It was found that the largest composite agglomerates broke up due to the presence of a fine dispersion of MoS2 particles. SEM also revealed that the grains are packed rather loosely within the agglomerates. These results indicate that a self-sustaining process can take place only if large and well-compacted composite particles are present.