Optical loss of metal coated optical fibers at temperatures up to 800°C

Temperature band of ordinary telecommunication optical fibers is −60...85°C. The developing fiber optic sensors which can work at higher temperatures, required to develop metal coated optical fibers. The Purpose of the work is a researching additional optical loss of copper alloy coated optical fibers which were drawn from low hydroxyl group contamination preforms at temperatures 20...800°C. It is reached that metal coated optical fiber worked at temperature 700°C for 7 hours, while the optical losses changed from 2 to 3 dB/km at the wavelength of λ = 1300 nm. It is not observed intensive growth of optical losses on hydroxyl groups at 800°C, which was observed in metal coated optical fiber when it was heated at 700°C.     

Polymerization characteristics of a dye of anthraquinone

A technical dye of the anthraquinone type was analyzed by GPC, mass spectroscopy, and elemental analysis. Along with the polymerizable component, N-[4-amino-3-methoxyanthraquinonyl-(1)] methacrylamide (I), it contained a saturated admixture, N-[4-amino-3-methoxyanthraquinonyl-(1)]-2-chloro-2-methylpropionamide (II). The homopolymerization of I was carried out, and admixture II was isolated and characterized. The copolymerization of the dye with styrene and methyl methacrylate was verified, and the retardation effect of II on the polymerization of these monomers was evaluated.     

New aspects in the microstructure of YBCO melt-textured high-Tc superconductors

The microstructure and phase constitution of bulk textured YBCO samples prepared by the modified MTG method in the longitudinal temperature gradient have been investigated. We found the existence of an unusual phase between stacked platelets. Microanalysis shows that this phase may be characterized as Y-143. This phase forms ellipsoid-like particles with a typical size about 0.05–2 which can play the role of effective pinning centers. The reason for the phase formation is discussed. We assume that this phase exists commonly in melt-textured samples prepared in the temperature field gradient.     

New aspects in the microstructure of YBCO melt-textured high-T c superconductors

The microstructure and phase constitution of bulk textured YBCO samples prepared by the modified MTG method in the longitudinal temperature gradient have been investigated. We found the existence of an unusual phase between stacked platelets. Microanalysis shows that this phase may be characterized as Y-143. This phase forms ellipsoid-like particles with a typical size about 0.05–2μ which can play the role of effective pinning centers. The reason for the phase formation is discussed. We assume that this phase exists commonly in melt-textured samples prepared in the temperature field gradient.     

An adaptive system for the automatic control of systems for compensating the reactive power of substations

An algorithm for the adaptive control of systems for compensating the reactive power of substations is developed and programmed. The algorithm is based on the fact that a specified voltage level on the controlled buses can be set up in accordance with a certain overall reactive power, which must be compensated at the substation to maintain this voltage level. The substation can be represented by a proportional section, described by a transfer function, defined by the mode of operation of the network and the composition of the working equipment.     

The first ribbed functionalized tris-dioximate clathrochelates with inherent hydroxyl substituents: Synthesis, spectra and X-ray structure

The controlled hydrolysis of the dichlorine-containing iron(II) clathrochelate FeBd₂(Cl₂Gm)(BF)₂ precursor (where Bd²⁻ and Cl₂Gm²⁻ are α-benzyldioxime and dichloroglyoxime dianions, respectively) afforded the hydroxy-containing clathrochelate derivatives with the hydroxyl substituent inherently bound to the ribbed chelate fragment of the macrobicyclic ligand. The triethylammonium and tetra-n-butylammonium salts of the clathrochelate [FeBd₂(OClGm)(BF)₂]⁻ anion have been characterized using elemental analysis, MALDI-TOF mass spectrometry, IR, UV–Vis, ⁵⁷Fe Mössbauer and ¹H, ¹³C{¹H}, ¹¹B and ¹⁹F NMR spectroscopies, and X-ray crystallography. The X-ray structural data for this deprotonated anion showed strong delocalization of its negative charge into the clathrochelate framework.     

Preservation of diagnostic information in the synthesis of EKG signals of the Frank orthogonal system from those recorded by the standard lead system: The Washington Code criteria

The problem of synthesizing Frank orthogonal lead system signals from those recorded by the standard lead system is considered, to answer the important practical question: can the synthesized EKG signals be used in practice for their diagnostic classification in terms of the Washington Code?