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  • Author: Żaneta Grzywacz x
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Abstract

It is justified thatproblems related to the changes in structural and mechanical properties of plastic material and influence of structural elements of equipment and modes of implementation of the for-mation process on them are considered detail, taking into account empirical data, theoretical dependencies and results of physical experiments. It was established that during the mechanical influence of rollers with grooves on a structured dispersion plastic material in the node of injection of the molding machine, internal shear, and shearing deformation have a preponderant value. Accordingly, the productivity of machines is determined mainly by the structural parameters of the working bodies geometry, kinematics, and contact area. It is shown that increasing the pressure in the plastic material causes a decrease in its volume, but the relationship between pressure and volume has a nonlinear character. It has been established that regardless the variety of flour from which the plastic material was prepared for bagels, its moisture content and the duration of fermentation reduced viscosity of the effective plastic material along with the increase of the shear stress. The paper describes the refined rheological model of the Bingham body deformation, which develops instantaneously, and the velocity of the common elastic deformation in the dough is a simultaneous function of stresses and temperatures, which are close to exponential ones.

Abstract

The size of all sensible heat balance components in livestock building varies in time, because it depends on time-varying weather factors. On the example of two buildings, sensible heat balance was shown on a daily basis. Measurements carried out in winter and spring in two livestock buildings with usable attics included measurements of air temperature and humidity inside and outside, air velocity in ventilation channels, and wind speed. Measuring devices were designed to record the results of measurements at intervals of 300s. During each such time interval, sensible heat losses by ventilation, heat losses by permeation through the barrier construction, and the amount of sensible heat produced by the animals were calculated. The results of measurements were shown in graphs. The study is important for the development of animal livestock building.