APPLICATION OF SUPERSONIC RADIATION WAVE MODELS TO FLAMES SPECIFICATION IN RECIPROCATOR

Some relations between various auto- and soliton models are investigated. Common features in the problem formulation of combustion, supersonic radiation wave propagation and moving of soliton wave on soundings are revealed. Realization of the known mathematical solutions for wave flame structure characterization in the reciprocating motor grain is proved

INFORMATION MODELING AND SYSTEM DYNAMICS INTERPRETATION OF CONVENTIONAL ENGINES

An original improvement of modern information models of conventional engine is proposed. Within the model all internal as well as external processes related to engine are integrated to a general system. Additional procedure to simulate nitric oxide kinetics in a combustion chamber is elaborated. The problem of exhaust toxicity is solved in relation to partial engine loads. Compared to prototypes the model enables to estimate engine toxicity appreciably more precise

Morphological Changes in the Dental Pulp of Experimental Animals in the Treatment of Acute Partial Pulpitis using Modern Materials

Aim. To study the morphological changes in the tooth pulp of experimental animals when modelling acute partial pulpitis using calcium silicate modified with light-cured resin and calcium hydroxide.Materials and methods. An experimental model of acute partial pulpitis was applied including the formation of a cavity on the lingual surface of the tooth, which corresponded to advanced caries in terms of depth, followed by a slight perforation up to the tooth pulp with a sharp probe. This model of acute partial pulpitis was reproduced for 32 teeth in four sexually mature rams. The teeth were extracted together with the surrounding sockets 15, 30 and 90 days after the modelling of pulpitis, followed by their fi xation in 10% solution of neutral formalin. Decalcification was performed in 25% solution of Trilon B. The material was poured into celloidin; histological sections were stained with hematoxylin and eosin according to Masson’s trichrome procedure.Results. The histological examination of pulp from the main group (calcium silicate modified with light-cured resin) revealed the formation of a biological barrier from secondary dentin in the area of the cavity and perforation up to the pulp chamber on the 90th day after the experiment started. The tooth pulp revealed no signs of an inflammatory process. On the 90th day after the experiment started, no pronounced morphological changes in the main substance and dentinal tubules in the area of the cavity walls were noted in the coronal pulp of experimental animals from the comparison group (calcium hydroxide). A focal chronic inflammatory process was noted in the tooth pulp.Conclusion. It was established that the use of calcium silicate modified with light-cured resin in the experimentally created model of acute partial pulpitis was accompanied by the formation of a biological barrier and a well-developed zone of reparative dentin in the area of the cavity and perforation up to the pulp chamber, as compared to the group where calcium hydroxide was used. Thus, the study results confirmed the efficay of using calcium silicate modified with light-cured resin within the biological method for treating acute partial pulpitis, which shortens the functional recovery of tooth pulp