Currently, the most actively developing area in the field of permanent magnets is development of those based on compounds of rare-earth metals with transition metals. This is due to their unique magnetic properties that surpass those for ferrite and lithium magnets by several factors and makes them irreplaceable with utilization in aero and automobile building, robot technology, computers, etc. Among all of the compounds of iron with rare-earth elements, the greatest iron content and, consequently, highest saturation magnetization applies to R2Fe17 compounds (R is rare-earth element). Regimes are studied for nitriding alloy powders (Sm0.9Zr0.1)Fe-17 and Sm-2(Fe0.9Co0.1)(17) in a nitrogen atmosphere with excess pressure of 15 kPa and temperature of 440-450A degrees C. Dependences are established for phase composition and main magnetic parameters of nitriding regime.

Recent results of the GRAAL experiment and simulation of meson photoproduction on nuclei are presented.

The study of meson photoproduction on the nucleon is a very important tool to complete the puzzle of baryon excited states. GRAAL aim is the measurement of cross sections and of beam asymmetries for all the photonuclear reactions accessible in the energy range from 600 MeV up to 1.5 GeV. In the following preliminary results of the Sigma beam asymmetry for omega photoproduction on the free proton in Hydrogen and on the quasi-free nucleon in Deuterium are shown. GRAAL is the first experiment in which both the charged and the radiative decay of omega meson are studied. Since the beam asymmetry is independent of the decay mode, the comparison of the results from the two channel allows an important check on data consistency. Results on the free proton are in good agreement with theoretical prediction from Zhao model and confirm the presence of P(13)(1720) state. The analysis performed for the radiative decay is applied to the process of. photoproduction on the quasi free nucleon in Deuterium.

Corrosion resistance of hard magnetic Sm2Fe17N3 materials is studied. It is shown that addition of cobalt (up to 8 wt.%) makes it possible to improve corrosion resistance of these materials by 20-25% without reducing their magnetic properties. It is established that additional treatment of Sm2Fe17N3 powder with organosilicon liquid GKZh 136-41 makes it possible to improve corrosion resistance by a factor of 2-3.

Experimental data of the GRAAL Collaboration on the total cross sections for photoabsorption on deuterium and carbon targets at gamma-ray energies in the range between 600 and 1500 MeV are presented. The experiment was performed in a beam of photons obtained by the method of the Compton backscattering of laser photons at the electron storage ring of the European Synchrotron Radiation Facility (ESRF, Grenoble, France) by using a wide-aperture detector covering a solid angle close to 4 pi. The total photoabsorption cross sections were determined by two independent methods: by subtracting the emptytarget background and by summing partial cross sections for meson photoproduction. The total cross sections for photoabsorption on quasifree protons and neutrons are shown to agree both in magnitude and in shape within a 5% precision of the measurements. In contrast to data previously available in the literature, both cross sections show distinctly the F (15)(1680) resonance at a photon energy of about 1 GeV. Data obtained in the present experiment for the cross sections for photoabsorption on a free and a bound nucleon are compared. This comparison reveals a substantial role of two-nucleon correlations in estimating the nuclear-medium effect on meson photoproduction.

We present the analysis of data performed in order to identify the events of the gamma + n -> pi(-) + p reaction obtained by bombarding a liquid Deuterium target with a polarised. beam of 0.55-1.5 GeV at the Graal-experiment. We show the effect of different kinematic and hardware constraints used to reduce the contamination coming from the concurrent reaction channels. By the simulation we estimate the contamination degree due to the other reaction channels so we can test the reliability of our method. We describe a new three-dimensional cut based on the Fermi momentum reconstruction and its effect on the suppression of the concurrent double charged pion photoproduction. We present the preliminary beam asymmetry Sigma of the pi(-) fotoproduction off quasi-free neutron up to about theta(c.m.), (pi-) = 165 degrees together with some theoretical multipolar analysis. For a comparison we also report the data present in literature on the same reaction for E(gamma) -850-1740 MeV and theta(c.m.), (pi-) <= 105 degrees.

Eta-meson photoproduction on protons, neutrons, and light nuclei is reviewed. New results obtained for photoproduction on protons and neutrons at the GRAAL facility are analyzed in detail. The experiment in question was performed in a gamma-ray beam that was obtained by means of Compton backscattering of laser photons on electrons at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). A comparative analysis of data on the differential cross sections and the asymmetries for eta-meson photoproduction allowed us to reveal some special features and to study the mechanisms of eta-meson photoproduction on nucleons in detail. Data available from the literature on eta-meson photoproduction on light nuclei are discussed in detail. Results that suggest the existence of bound states (etamesic nuclei) are presented. Particular attention is given to the newmethod of "taggedmesons," which, according to the GRAAL experiment and to simulated results, makes it possible to study thoroughly the interaction of unstable mesons with intranuclear nucleons.

The gamma p -> eta'p reaction was studied near the threshold, in the 1.44 GeV > E(gamma) < 1.55GeV energy range with the tagged photons of the former GRAAL experiment. The two neutral decays gamma gamma(Gamma(i)/Gamma = 2.10 +/- 0.12%) and pi(0)pi(0)eta(Gamma(i)/Gamma = 20.7 +/- 1.2%) were analized and preliminary results of the beam asymmetry were extracted together with the invariant masses.

The results of qualitative and quantitative changes in phase composition as well as microstructure changes of amorphous Co69Fe4Cr4Si12B11 microwires at three stage crystallization process of are presented. After first and second stages the amount of crystalline Co-phase was 36 wt%. To study magnetization of the alloy during heating, exposure and cooling a unique vibration magnetometer with a chemical microreactor was used. The unique vibration magnetometer was used for low inertia real-time measurements under controlled atmosphere. The Curie temperatures of phases formed in the crystallization process were determined. Based on the analysis of magnetization kinetic curves, nucleation and growth mechanisms were established on the stage of primary crystallization. It was found that a one-dimensional mechanism is responsible for the growth of Co-based crystals and leads to the formation of a specific needle-shaped structure. At the second crystallization stage of a metastable phase with a Co23B6 structure type was formed. The Curie temperature of this phase was 165 degrees C. (C) 2018 Elsevier B.V. All rights reserved.

Sathamangalam Ranga Iyengar Srinivasa (Raghu) Varadhan was born in Chennai (then Madras). He received his Bachelor's and Master's degree from Presidency College, Madras, and his PhD from the Indian Statistical Institute in Kolkata, in 1963. That same year he came to the Courant Institute, New York University as a postdoc, and remained there as faculty member throughout his career. He has received numerous prizes and recognitions, including the Abel Prize in 2007, the US National Medal of Science in 2010 and honorary degrees from the Chennai Mathematical Institute, Duke University, the Indian Statistical Institute, Kolkata and the University of Paris.

We study the Sigma(s) - Sigma(s) as a possible di-baryonic molecule in the potential model framework. We approximated the binding mechanism mainly as One Boson Exchange (OBE) plus screen type Yukawa potential. We predict the Sigma(s) - Sigma(s) bound state molecule with I/(J(P))=3D0(0(+)) and 0(1(+)) possible quantum numbers.