Photolysis of Neptunium Ions in Acetic Acid Solutions

Radiochemistry - Photochemical reactions involving Np(VI) and Np(V) in 0.5–17.3 M CH3COOH (HAc) solutions have been studied. It was found that irradiation with UV light causes reduction of...     

Np(VI) Reduction with Diformylhydrazine in Perchloric Acid Solutions

Radiochemistry - The stoichiometry of the reaction of Np(VI) with diformylhydrazine N2H2(CHO)2 (DFH), in 0.01 and 0.1 M HClO4 solutions was studied by spectrophotometry. At an excess of Np(VI), 1...     

Synthesis and structure of dodecamolybdates of tetravalent cerium,thorium, uranium,neptunium, and plutonium

A series of isostructural compounds of the composition Na₇H[EMo₁₂O₄₂]·12H₂O, where E(IV) = Ce, Th, U, Np, or Pu, were synthesized and structurally characterized. In the [EMo₁₂O₄₂]^8– heteropolyanion (HPA), the central E(IV) atom is surrounded by six Mo₂O₉ groups, each constituted by two octahedra sharing a common face. The coordination polyhedron (CP) of the central atom is a weakly distorted icosahedron with the mean E(IV)–О bond lengths of 2.498, 2.529, 2.500, 2.490, and 2.488 Å for Ce, Th, U, Np, and Pu, respectively. In the structure of the compounds Na₇H[EMo₁₂O₄₂]·12H₂O, there are two crystallographically independent sodium atoms: Na(1) and Na(2). The oxygen surrounding of the Na(1) atom is formed by the terminal oxygen atoms of two heteropolyanions adjacent along [001], and its coordination polyhedron is an octahedron. The surrounding of the Na(2) atom (a six-vertex polyhedron) is formed by three terminal oxygen atoms of three Mo₂O₉ groups belonging to the same HPA and by three water molecules. The coordination polyhedra of the Na(2) atoms are linked with each other via common oxygen atoms of O_w(2) water molecules to form a chain “winding” around the 3₁ screw axis. The heteropolyanions and Na⁺ cations in the crystal form a framework constructed in a fashion characteristic of Dexter–Silverton type anions, with the coordination via three terminal oxygen atoms of three Mo₂O₉ groups. Excess negative charge of HPA is compensated by the proton localized on one of the six bridging O atoms. In the Mo₂O₉ doubled octahedra, the Mo–O bonds with the О atoms bonded to E(IV) and forming the edge of the common face are sensitive to the kind of the central atom.     

Estimating Synergetic Openness of Industrial Enterprise Management Systems

The problem of comprehensive assessment of available enterprise management systems from implementation and application viewpoint is discussed. The degree of information system’s synergetic openness, which described system’s ability to respond to external users’ requests by means of built-in self-organization mechanisms and tools, is offered as an integrated quality index. This complex index depends of partial factors, describing system’s adaptability and integrability. With the help of comprehensive assessment the available ERP systems are compared, and the need in taking into account industrial user’s specific features during system selection is demonstrated.     

A Method for Determination of Alcohol Content in Dielectric Liquids by a Longitudinal-Slot Waveguide

A new method is proposed to determine the content of alcohol in dielectric liquids. The method is based on measuring the attenuation of a wave propagating in a rectangular waveguide with a longitudinal slot in its narrow wall, immersed in a liquid under test. The propagation constant of the H ₁₀ mode in such a waveguide is calculated numerically for various parameters of the medium and the waveguide. It is shown that the attenuation of the wave depends on the parameters of the dielectric medium outside the waveguide. Experiment is carried out on two different types of waveguide at frequencies from 29 to 37 GHz with a solution of ethyl alcohol in water as the external medium. The results of the measurements show that the method can be used for the on-line measurement of alcohol concentration during fermentation.     

Construction of the welded body of vehicles from aluminium alloys

The theory of thermal processes, developed by N.N. Rykalin, is used for calculating the cooling rate, the temperature in heating and the width of quenched grooves in surface quenching with the electric arc. The results confirm that high-quality surface quenching of the components can be carried out without additional cooling of the surface with water.