Synthesis, Crystal Structure and Thermolysis of Cadmium Perchlorate Complex with Hexamethylenetetramine

The complex of cadmium perchlorate, [Cd(HMTA)2(H2O)4](ClO4)2•2H2O was synthesized by the reaction with hexamethylenetetramine (HMTA). C, H, N analyses, FT-IR, and X-ray crystallography were used to characterize the obtained complex. TG in the static air, simultaneous thermogravimetry-derivative thermogravimetry (TG-DTG), and differential scanning calorimetry (DSC) in streaming nitrogen atmosphere were evolved for thermal decay of prepared cadmium complex. To evaluate the reaction with quick warming, explosion delay measurements were attempted. The model-free isoconversional and model-fitting kinetic methodologies were applied to isothermal TG data for kinetic examination of the complex's thermal decomposition. At higher temperatures, the complex explodes to synthesize highly thermally stable residue most closely resembles cadmium oxide.

Микровзрывная фрагментация группы неоднородных капель топлив

The results of experimental studies of the processes of micro-explosive fragmentation of two-component (diesel fuel – water) droplets upon heating in a high-temperature medium are presented. The experiments were carried out with a group of 10-30 falling drops in a tubular muffle furnace. Micro-explosion delay times are studied. It was shown that the mutual arrangement of the droplet group significantly affects the integral characteristics of the investigated process. Limit distances (from 8 to 10 radii) between the droplets are established at which the characteristics of the micro-explosion are similar to those recorded in experiments with single droplets.

Common envelope to explosion delay time of Type Ia supernovae

ABSTRACT I study the rate of Type Ia supernovae (SNe Ia) within about a million years after the assumed common envelope evolution (CEE) that forms the progenitors of these SNe Ia, and find that the population of SNe Ia with short CEE to explosion delay (CEED) time is ≈few × 0.1 of all SNe Ia. I also claim for an expression for the rate of these SNe Ia that occur at short times after the CEE ($t_{\rm CEED} \lesssim 10^6 {~\rm yr}$), which is different from that of the delay time distribution (DTD) billions of years after star formation. This tentatively hints that the physical processes that determine the short CEED time distribution (CEEDTD) are different (at least to some extent) from those that determine the DTD at billions of years. To reach these conclusions I examine SNe Ia that interact with a circumstellar matter (CSM) within months after explosion, so-called SNe Ia-CSM, and the rate of SNe Ia that on a time-scale of tens to hundreds of years interact with a CSM that might have been a planetary nebula, so-called SNe Ia inside a planetary nebula (SNIPs). I assume that the CSM in these populations results from a CEE, and hence this study is relevant mainly to the core-degenerate (CD) scenario, the double-degenerate (DD) scenario, the double-detonation (DDet) scenario with white dwarf companions, and to the CEE-wind channel of the single-degenerate (SD) scenario.

An experimental study of smelt-water interaction in the recovery boiler dissolving tank

A laboratory apparatus was constructed to simulate the operating conditions of recovery boiler smelt dissolving tanks and used to systematically study the interaction between molten smelt droplets and water. Experiments were performed on synthetic smelt made of 80 wt% Na2CO3 and 20 wt% NaCl at 800°C, 900°C, and 1000°C. The results show that upon contact with water, some smelt droplets explode immediately and break into small pieces, some require a delay time to explode, and others solidify without exploding. The probability of explosion strongly depends on water temperature and to some extent, smelt temperature. At a given smelt temperature, there exists a water temperature range below which explosion always occurs (the lower critical water temperature) and above which there is no explosion (the upper critical water temperature). The lower critical water temperature decreases with increasing smelt temperature, while the upper critical water temperature remains the same at 82°C in all cases. Up to this upper critical water temperature, both the explosion delay time and explosion intensity increase with increasing water temperature. The data was used to construct a Smelt-Water Interaction Temperature (SWIT) diagram that can predict if a molten synthetic smelt droplet will explode in water at different smelt and water temperatures.

Kinetics of Thermolysis of Nickel(II) Perchlorate Complex with n-Propylamine

Complex of nickel perchlorate with n-propylamine has been synthesised with molecular formula [Ni(n-pa)3(ClO4)(H2O)]ClO4. It has been characterised by elemental analysis, thermogravimetry, UV-VIS, and IR spectroscopic data. Thermal properties have been investigated by thermogravimetry (TG) in static air and by simultaneous thermogravimetry-derivative thermogravimetry-differential thermal analysis (TG-DTG-DTA) in flowing nitrogen atmosphere. Kinetics of thermolysis has been analysed applying model-fitting and model-free isoconversional method on isothermal TG data recorded at five different temperatures. To observe the response of complex towards fast heating, explosion delay time has been recorded at various temperatures and kinetics of explosion has been studied using these data.