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activation (Δ G ≠ ), self-accelerating decomposition temperature ( T SADT ), adiabatic time-to-explosion ( t ), critical temperature of hot-spot initiation ( T cr, hot-spot ), and characteristic drop height of impact sensitivity ( H 50 ) are important
Abstract
The solubility of two n-alkanes in commercial organic liquids, such as diesel fuel and jet fuel represent a problem to industry, because they precipitate in an unpredictable fashion. First we calculated the metastable enthalpy and entropy of fusion of the low temperature forms of the n-alkanes. We analyzed the solubility of alkanes n-C22H46, n-C23H48, n-C24H50 and n-C28H58 in ethylbenzene, m-xylene, n-heptane and gas oil. All systems seem to be close ideal, possibly with a slight positive deviation. We analyzed the solubility at constant temperature of the ternary system solvent C22H46-C24H50, C23H48-C24H50, C13H28-C16H34, C20H42-C22H46, C20H42-C24H50 and C20H42-C28H58, and looked at cloud points in various ternary systems. When the difference in the number of carbon atoms in the two alkanes is small, four or less, a metastable solid solution precipitates from the solvent. If the difference in the number of carbon atoms is six or more, the ‘equilibrium’ phases, or at least phases with low solubility precipitate.
Abstract
Differential enthalpy analyses were performed on the binaryn-alkane systemn-C24H50-n-C26H54 with a Setaram DSC111 calorimeter of Tian Calvet type. The measurements provided enthalpy data from 260 to 260 K onn-tetracosane,n-hexacosane and 19 binary mixtures. An analytical expression, derived from the Einstein model, is proposed for every pure phase in its temperature domain, to represent the variation in the enthalpy with temperature. A general expression for the enthalpy as a function of temperature and composition is also given.
Studies on energetic compounds
IV. Thermal explosion of ring-substituted arylammonium perchlorates
Thermal and explosion characteristics of ring(mono) substituted arylammonium perchlorates (RSAP) are studied by DTA, impact and friction sensitivity measurements. Exothermic decomposition temperature (T d) from DTA curves and impact sensitivity data (h 50%) were found to be linearly related to the Hammett substituent constant (σ+,σ−) andpK a values of the corresponding arylamines. A reaction scheme, based on the formation of reaction intermediates during decomposition and explosion, accounting for the products, is proposed which, involves proton transfer as the rate determining process and evolution of ammonia. It seems that oxidation-reduction reactions between the arylamine/substituted benzene and HClO4 or its decomposition products cause explosion.
Thermal behaviour and electro-optical properties of a series of liquid crystals based on palladium complexes with mixed ligands
Schiff bases and N-benzoyl thioureas
.62–1.30 (m, 18H), 0.89 (t, 3 J = 6.5 Hz, 3H). IR (cm −1 ): 2226w(ν C≡N ); 1601, 1580s(ν C=N ); 1538, 1495, 1416vs(ν CN+CS ), 1249vs(ν CN ). 2a. Yield 72%, yellow crystals. Anal. Calcd for C 48 H 44 N 4 O 4 PdS: C, 65.6; H, 5.0
.00 550 °C (12 h) 50.00 MoO 3 , + 50.00 In 2 (MoO 4 ) 3 6 75.00 25.00 Stage II: In 2 (MoO 4 ) 3 a
– ∞ ) ng/mL*h 324.1 ± 54.2 176.1 ± 19.7 b MRT (0– t ) h 5.0 ± 0.8 3.1 ± 0.2 b
Metal complexes of fenoterol drug
Preparation, spectroscopic, thermal, and biological activity characterization
.95 68.00 [Mn(FEN) 2 (H 2 O) 2 ]·2H 2 O C 34 H 50 MnN 2 O 12 Brown (70) >300 38.11 (37.90) 5.32 (5.50) 5.11 (5
chromatography separation, limonin (C 26 H 30 O 8 ) and β-sitosterol (C 29 H 50 O) were extracted from the seeds and pulp of Citrus suavissima Hort. ex Tanaka , respectively [ 5 ]. Their structures were identified by spectral analysis ( 1 H NMR, 13 C NMR, DEPT
found (ng mL −1 , mean ± SD) Precision (%RSD) Accuracy (%) Bench top (up to 9 h) 5.0 4.7 ± 0
