Thermal behaviour of succinic acid, sodium succinate and its compounds with some bivalent transitions metal ions in dynamic N2 and CO2 atmospheres
Thermal stability and thermal decomposition of succinic acid, sodium succinate and its compounds with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA) in nitrogen and carbon dioxide atmospheres and TG-FTIR in nitrogen atmosphere. On heating, in both atmospheres the succinic acid melt and evaporate, while for the sodium succinate the thermal decomposition occurs with the formation of sodium carbonate. For the transition metal succinates the final residue up to 1180 oC in N2 atmosphere was a mixture of metal and metal oxide in no simple stoichiometric relation, except for Zn compound, where the residue was a small quantity of carbonaceous residue. For the CO2 atmosphere the final residue up to 980 oC was: MnO, Fe3O4, CoO, ZnO and mixtures of Ni, NiO and Cu, Cu2O.
A
comparative study on the thermal decomposition of some transition metal carboxylates
AbstractThermal
decomposition of transition metal malonates, MCH2C2O4⋅xH2O and transition metal
succinates, M(CH2)2C2O4⋅xH2O (M=Mn,
Fe, Co, Ni, Cu, Zn) has been studied employing TG, DTG, DTA, XRD, SEM, IR
and Mössbauer spectroscopic techniques. After dehydration, the anhydrous
metal malonates and succinates decompose directly to their respective metal
oxides in the temperature ranges 310–400 and 400–525°C, respectively.
The oxides obtained have been found to be nanosized. The thermal stability
of succinates have been found to be higher than that of the respective malonates.
Anaesthetic aspects of bronchial fistula.
SINCE the term bronchial fistula can, from the practical point of view, be applied to any abnormal connection between the inside of the intrathoracic respiratory system and the outside, it includes a very wide assortment of cases. Fistulae vary in their acuteness and duration from a few minutes up to thirty years or more (Huizinga and Smelt, 1950), and in their consequences from the rapidly fatal to the almost insignificant. Although the anaesthetic management of these cases falls mainly within the province of those working in specialized units, any anaesthetist may be caught unawares from time to time. Quite apart from this consideration the subject is well worth discussing because of its intrinsic interest and because it has probably called for as much anaesthetic ingenuity and resourcefulness as any other subject within the specialty.