Algorithm for identifying parameters of the dynamic system of an aircraft

The parameter identification problem for the nonlinear dynamic system of a sufficiently general form, in which the multipolynomial approximation algorithm processes measured data, is considered. To show the efficiency of the algorithm, an example of parameter identification for a nonlinear dynamic system with non-differentiable right-hand side is given and the identification problem for aerodynamic parameters of aircraft pitching motion is solved.     

Algorithm for identifying parameters of the dynamic system of an aircraft. II

The problem of identification of aerodynamic parameters of IL-96-300 aircraft by processing digital information on its longitudinal and lateral motion provided by on-board measurement complex according to real flight data (longitudinal motion) and results of mathematical simulation (lateral motion) is studied. The problem of algorithmic parameter identification for the nonlinear dynamic system, whose model corresponds to the control system of a modern maneuvering aircraft, is considered.     

Effect of propionitrile nitramine salts on the thermal decomposition of HMX

The thermal decomposition of HMX with additives of metal salts of propionitrile nitramine is studied. The process goes with acceleration by a complex mechanism, in which the interaction of HMX with propionitrile imine and its oligomer formed in the reaction plays an important role. The initial rate of HMX decomposition correlates with the mass fraction of the anion in the salt. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 5, pp. 74–77, September–October, 2000.     

Low-temperature catalytic decomposition of hydrogen sulfide on metal catalysts under layer of solvent

When hydrogen sulfide decomposition {2 H₂S ? 2 H₂?+?S₂^(gas)} is carried out in the flow regime at room temperature on metal catalysts placed in a liquid capable of dissolving H₂S and sulfur, the reaction equilibrium can be significantly (up to 100%) shifted to the right yielding the desired product – hydrogen. The process efficiency was demonstrated using aqueous solutions of monoethanolamine (MEA), sodium carbonate, which is widely used in industry for H₂S absorption from tail gases, and aqueous hydrazine as examples. IR and Raman spectroscopy data demonstrated that sulfur obtained in the solutions is in the form of diatomic molecules. DFT calculations showed that diatomic sulfur forms weakly bound coordinative complexes with solvent molecules. Some problems related to sulfur accumulation and recovery from the solvents are discussed.     

Effect of Metal Formiates and Oxalates on HMX Decomposition

Metal formiates and oxalates applied onto HMX increase the initial rate and decrease the induction period of thermal decomposition of HMX. The activity of sodium oxalates, which contain crystal water, is much lower than that of anhydrous formiates of the same metals. The possible reasons of the catalytic effect of the additives on the thermal decomposition of are discussed.     

Low Temperature Catalytic Decomposition of Hydrogen Sulfide into Hydrogen and Diatomic Gaseous Sulfur

A new catalytic reaction of hydrogen sulfide decomposition is discovered, the reaction occurs on metal catalysts in gas phase according to equation $$2{\text{H}}_{2} {\text{S}} \leftrightarrow 2{\text{H}}_{2} + {\text{S}}_{2}^{{({\text{gas}})}}$$ 2 H 2 S ? 2 H 2 + S 2 ( gas ) to produce hydrogen and gaseous diatomic sulfur, conversion of hydrogen sulfide at room temperature is close to 15 %. The thermodynamic driving force of the reaction is the formation of the chemical sulfur–sulfur bond between two hydrogen sulfide molecules adsorbed on two adjacent metal atoms in the key surface intermediate and elimination of hydrogen into gas phase. “Fingerprints” of diatomic sulfur adsorbed on the solid surfaces and dissolved in different solvents are studied. In closed vessels in adsorbed or dissolved states, this molecule is stable for a long period of time (weeks). A possible electronic structure of diatomic gaseous sulfur in the singlet state is considered. According to DFT/CASSCF calculations, energy of the singlet state of S₂ molecule is over the triplet ground state energy for 10.4/14.4 kcal/mol. Some properties of gaseous diatomic sulfur are also investigated. Catalytic solid systems, both bulk and supported on porous carriers, are developed. When hydrogen sulfide is passing through the solid catalyst immersed in liquid solvent which is capable of dissolving sulfur generated, conversion of hydrogen sulfide at room temperature achieves 100 %, producing hydrogen in gas phase. This gives grounds to consider hydrogen sulfide as inexhaustible potential source of hydrogen—a very valuable chemical reagent and environmentally friendly energy product.     

Investigation of industrial UV radiation sources for automatic composition analyses

Conclusions On the basis of the results obtained, the gas discharge sources DKSSh-200 and SVD-120A can be recommended for use in automatic photoabsorption analyzers under the obligatory proviso of construction of the instrument according to the two-channel setup.For the determination of concentrations of substances with maximal optical densities for radiation of wavelengths 254, 297, 313, 365, 405 m it is preferable to use the lamp SVD-120A; for the remaining parts of the ultraviolet spectrum from 200–400 m the xenon gas discharge lamps DKSSh-200 give greater possibility of separating parts of the spectrum during operation with interference filters.One should draw attention to the stabilization of radiation sources, since instability of radiation, especially with respect to the intensity of the spectral components, can lead to considerable difficulties in operation.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 50–52, March, 1968.     

Kinetics and mechanism of thermal decomposition of HMX with metal cupferronate additives

The kinetic features of the thermal decomposition of HMX with metal cupferronate additives, in which the nucleophilic detachment of a proton in HMX by a phenylnitric-oxide anion-radical plays an important role, are established. The logarithms of the rate constants for the decomposition of HMX correlate with the ratio of the charge of the metal cation in the cupferronate to its radius, which indicates a different reactivity of the anion-radical owing to the polarizing effect of the cation. Translated fromFizika Goreniya i Vzryva, Vol. 35, No. 3, pp. 52–56, May–June 1999.