Quantitative estimation of stabilizers in petroleum and its compounds using a model reaction

The possible application of a kinetic model for the quantitative estimation of the inhibiting ability of natural compounds of unknown composition and structure has been studied. The antioxidative ability of several petroleums and their high-molecular weight components has been quantitatively estimated. Petroleums of different types possess an inhibiting activity, which is mainly determined by their tar components. In their antioxidative ability these substances equal and sometimes even surpass the activity of known commercial stabilizers.

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Relationship between the forced elasticity limit and the structure for amorphous-crystalline polymers

The structural features of polyethylene composites stabilized with a highly dispersed mixture of Fe and FeO have a complex effect on forced elasticity. A study was carried out on the dependence of the forced elasticity limit of the samples on the density of the fluctuational network of molecular engagements and extent of crystallinity during stretch testing at from 293 to 393 K.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2143–2145, September, 1990.     

Comparative Characterization of Relaxed Organic–Inorganic Hybrid Perovskite Structures Using Molecular Dynamic Simulation and X-ray Diffraction Data

Materials based on organic–inorganic hybrid perovskites MAPbX₃ (X = I, Cl, or Br) having unique adsorption characteristics have been considered. Theoretical investigation data obtained by molecular modeling and results of X-ray diffraction measurements of the hybrid organic–inorganic perovskite structures based on methylammonium lead trichloride in different temperature ranges have been analyzed.Z     

Measurement of the fluctuational grid parameters of molecular engagements upon the introduction of a highly dispersed mixture of Fe and FeO into a polymer

The Introduction of a highly dispersed mixture of Fe and FeO into amorphous-crystalline and amorphous polymers leads to microstructural changes, leading to an increase in the molecular engagement grid and change in the polymer properties. The most likely reason for the microstructural changes of the polymer compositions studied is a magnetic interaction of the iron and ferrous oxide particles with the polymer matrix.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1915–1917, August, 1990.     

Voltammetric Determination of Sulfide Ions

Procedures were proposed for the voltammetric determination of S^2– at a mercury-film electrode. They are based on the oxidation of S^2– at –0.79 to –0.80 V and on the reduction of HgS, the product of the oxidation of S^2–, at –0.76 to –0.96 V in a 1 M NaOH solution. The anodic and cathodic currents are linear functions of S^2– concentration in the ranges from 1 × 10^–5 to 1 × 10^–4 M and from 2 × 10^–6 to 1 × 10^–4 M, respectively.     

The b \to X_s \gamma rate and Higgs boson limits in the constrained minimal supersymmetric model

New NLO calculations have become available using resummed radiative corrections. Using these calculations we perform a global fit of the supergravity inspired constrained minimal supersymmetric model. We find that the resummed calculations show similar constraints as the LO calculations, namely that only with a relatively heavy supersymmetric mass spectrum of (1 TeV) the b– Yukawa unification and the rate can coexist in the large scenario. The resummed calculations are found to reduce the renormalization scale uncertainty considerably. The low scenario is excluded by the present Higgs limits from LEP II. The constraint from the Higgs limit in the plane is severe, if the trilinear coupling at the GUT scale is fixed to zero, but is considerably reduced for . The relatively heavy SUSY spectrum required by corresponds to a Higgs mass of GeV in the CMSSM. Received: 14 February 2001 / Revised version: 22 March 2001 / Published online: 29 June 2001     

Erratum to: Optical Gain of 1550-nm-Range Multiple-Quantum-Well Heterostructures and Limiting Modulation Frequencies of Vertical-Cavity Surface-Emitting Lasers Based on Them

Optics and Spectroscopy - 10.1134/S0030400X18080143