This paper deals with the mechanical macro and microdamage arising in the process of threshing and separating of grain in combine harvester. In our study, data from experiment conducted on a stand with eight-drum threshing device were used. Because the macro and microdamage are evidently interdependent, so their separate investigation doesn’t give full image of the situation. Adequate tool of description of dependent features is the multivariate analysis of variance. (MANOVA). In this paper the two-variate model of the four way cross classification with interaction is used. Moreover we give the explicit form for some block matrices relating the particular effects and some projection operators. At the end we present multivariate analysis of variance and conclusions.

As a result of the analysis of the work process of a safety device mechanism a mathematical model was for mulated. It was a model of a dynamic force F_x protecting a cultivating tool from overload and realized by safety device mechanism. The selected sort of the safety device mechanism was based on a spring-loaded accumulator (with a single screw spring) using kinematics of a four-bar linkage with a second-class lever. It can be used both to protect working elements and for central protection of cultivating tools. On the strength of the model it was found that an overload force F_x – brought to resistance horizontal component appliced at a share point of a cultivating tool – occured as a function of 24 different (specified in the article) parameters of work process of the cultivating tool protected in that way. The parameters can be assigned to two subsets: to constructional parameters (defined – regarding the value – univocally by the construction) and using parameters (whose values follow from using conditions) of the cultivating tool. Some formulae for computer simulation of these parameters’ influence on the value of a force F_x were given.

The aim of this work was such definition of the values of constructional parameters of work process of a selected safety device protecting a cultivating tool (e.g. plough body) from overload to be able to obtain the least difference between protecting forces: a force realized by a safety device F_x and a force expected by a user F_xo. The task was limited to the search for the minimal value of objective function, which described that difference and it was realized with the method of nonlinear optimization using the software package Mathcad. As a criterion of optimization, an error mean-square between functions of the mentioned forces F_x and F_xo in defined ranges of working depth h of a cultivating element and a regulation parameter r of the force value was assumed. To define selectively fragments of variation of objective function significant for realized process (following from rank of selection of values of overload forces) variation ranges of parameters h and r were digitized. Values of force F_xo were given in a table but for a force F_x a mathematical model from part I of this work was used, which among other things defined a set of parameters of work process of a safety device, which influenced its value and admissible values of the parameters. Constructional parameters were divided into two subsets: constant parameters X_Ks (sssumed values, following from assignment of a safety device and cultivating tool) and matched parameters X_Kd (matched values as a result of realized optimal synthesis). Two limitations were introduced: necessary condition of obtainment of para-uelism of a frame of a cultivating tool to soil surface during its cultivation and not large force (max 6 kN) on an adjusting nut allowing to change easily (by a user) the value of overload force according to using conditions. Algorithm of selection of desired values was given. Assumed and matched values of parameters of safety device work process were shown in a table and realization of optimal synthesis was illustrated in the work.

This paper presents the estimation of blanching and vacuum freezing processes of vegetable material, originating from parsley, based on measurements of kinetics of water absorption with weighting-displacement method. The investigations was passed on blanching and both blanching and vacuum freezing samples. Blanching process was conducted using hot water at temperature 95°C during 30 s, 3 min i.e. 15 min. Vacuum – chamber with vegetable material contain, evacuated by means vacuum pumps to vacuum freezing was used. During vacuum freezing process change of mass and temperatures of investigated material was registered. The results of measurements shows that blanching time has essential influence on kinetics of water absorption by investigated vegetable material.

Important criterion evaluating of agricultural machines is threat, which they create on the environment, after they are taken out of use. Generally approve of way managing them is recycling, which reduce destructive impact on the environment. About susceptibility of machine to recycling we should think and evaluated her in process of construction. For evaluating the susceptibility to recycling is using different methods. In work we made evaluating the susceptibility of machines to recycling using structural method. The researches show, that structural method gives results more adequate to reality in comparison with mass method.

One of the ways of the utilisation of chromium-free tannery wastes may be their processing into organic fertilisers. Two methods are taken into consideration: methane fermentation and composting. It has been found that alongside gas recovery, methane fermentation of chromium-free tannery wastes allows to obtain material that is dewatered in different degree, with various, but always high, content of fertilising components. The final properties are determined by the kind of wastes (proportions in which various wastes have been mixed), and by conditions of the process. The paper offers a preliminary fertilising characteristics of various sludges and sludge liquids. The results confirm that it is possible to obtain biologically stable fertilising products of big, or even very big, fertilising value from nasty chromium-free tannery wastes.

In previous studies (part I) it has been established that methane fermentation of chromium-free tannery wastes results in partly stabilised post-fermentation sludges, rich in nitrogen and phosphorus. This part of the investigations have confirmed that in view of the quality of fertilising material, the composting of post-fermentation sludges is most beneficial; and composting of non-fermented wastes is less beneficial. The sludges from short fermentation (only partly stabilised) and after prolonged fermentation were subjected to composting. The composting of sludges allowed to obtain material, rich in basic fertilising components and organic soil-forming components. The paper shows that it is possible to reduce the arduousness of direct composting (with the omission of fermentation) of chromium-free tannery wastes. The dependence of the quantity of basic fertilising and soil-forming components in the obtained material on the applied processing conditions has been shown.

The aim of the paper is to investigate a computer identification algorithm for determining the time-varying shear and bulk modulus of linear viscoelastic materials based on experimentally obtained stress and strain uniaxial relaxation functions of an cylindrical specimens of the tested material is proposed. On the first stage of the identification procedure the models of the uniaxial relaxation functions are determined and next, on the second stage, the shear and bulk modulus are computed. It is proved that if four parameter Maxwell models are used to approximate the uniaxial relaxation functions, then the shear and bulk modulus can be given as a linear combination of exponential functions and multiple convolution integrals of original and modified Bessel functions. For least squares identification of uniaxial relaxation functions by positive sums of exponentials the Prony's method is applied. Applying the scheme proposed the time-dependent shear and bulk modulus of the beet sugar root samples are computed using discrete time-measurements of the force relaxation of an unconfined and of a laterally constrained cylindrical specimens of the material obtained in double independent stress relaxation tests.

Experiments on drying of malt wort have been carried out in countercurrent laboratory spray drier APV ANHYDRO LAB1. The proces was conducted at the temperature of drying medium 137–140°C, at concentration of raw material 30% dry substance. The final moisture content of dry product was 2.8–4.0%. The mean volumetric diameter of atomized of malt wort was 30.5 μm. The influence of stream of air on the value of moisture flux, dry product flux from unit volume of drying chamber, and thermal efficiency have been determined.

The aim of this work is the statement if an initial subjecting corn seeds to the magnetic field stimulation influences on differences in a distribution structure of modulus of longitudinal elasticity of stacks of corn sprouted from this seeds. Often applied in ecological problems Gini coefficient was used to a compare the modulus of elasticity. The usage of confidence intervals was proposed to determine the significance differences of modulus of elasticity to state about influence of magnetic field stimulation to corn seeds. Confidence intervals were constructed by the bootstrap method.

In this paper the possibilities of application artificial intelligence to forecast electric energy monthly sales to rural receivers were presented. There were three models which were built on the basis of determinate chaos theory, artificial neural networks and fuzzy set theory. Calculations proved that artificial neural networks are good enough to forecast the demand for the supplies of electricity. Fuzzy Takagi-Sugeno model is competetive in comparison with neural model and worth recommending to forecasting.