An urgent problem is drying and processing of the wet dispersed waste, obtained in the production of food products, which can then be efficiently used as a fertiliser, for feeding livestock or as biofuel. A new design of a vibrating fluidised bed dryer has been developed, which, with low energy consumption, provides a pre-set productivity and the required final moisture content. The process of vertical oscillations of the body of a vibration dryer, together with the food waste contained in it, is analysed analytically, the necessary equivalent scheme is built, on the basis of which differential equations of the vertical oscillations of the body are compiled, their analytical solutions are obtained, and a numerical calculation is performed on a PC using the developed program. Rational parameters of the vibration dryer, providing vibroboiling of the mass of the food waste, have been determined: the body mass m = 250 ... 510 kg; the debalance mass md = 10… 15 kg; the number of revolutions of the debalance electric motor nd = 1950 ... 2650 rpm ∙ min ∙¹; maximum stiffness of the support springs Cₚ = 8∙10⁵ N∙m–¹; the diameter of the centre of mass of the debalances dd = 0.01 m. In addition, as a result of the thermophysical theoretical and experimental studies of the vibration drying process, the following optimal design and technological parameters of the vibration dryer were obtained: the heat transfer area Sₜ.ₚ.ₙ= 4.15 m²; the radius of the heating pipe rₜ= 0.1 m; the length of the heating pipe lₜ = 3 m; the number of heating pipes nₜ= 50; the heat transfer coefficient Kₚ= 2500; the final temperature of the dried waste tₒ₂ = 100 ºС.

An urgent problem is drying and processing of the wet dispersed waste, obtained in the production of food products, which can then be efficiently used as a fertiliser, for feeding livestock or as biofuel. A new design of a vibrating fluidised bed dryer has been developed, which, with low energy consumption, provides a pre-set productivity and the required final moisture content. The process of vertical oscillations of the body of a vibration dryer, together with the food waste contained in it, is analysed analytically, the necessary equivalent scheme is built, on the basis of which differential equations of the vertical oscillations of the body are compiled, their analytical solutions are obtained, and a numerical calculation is performed on a PC using the developed program.

The kinetics of plasma nitriding of CoCr alloy below temperatures of nitrides formation and mechanisms of nitrogen penetration are analyzed by proposed kinetic modeling in this article. Proposed nitrogen diffusion model is based on the trapping – detrapping (TD) model and developed taking into account the effect of the concentration dependent diffusivity of nitrogen, nitrogen adsorption on the surface of alloy and surface swelling process. The model indicates the influence of chromium atoms to nitrogen atoms diffusivity. The model consists of time and depth dependent diffusion, which is described by a partial differential equation, and it is solved by using Crank – Nicolson finite difference method. By fitting of experimental nitrogen depth profiles, it is shown that nitrogen diffusion coefficient varies with nitrogen concentration according to Einstein-Smoluchowski relation. Nitrogen depth profiles in plasma nitrided medical grade CoCr alloy (ISO 5831 – 12) at T = 400 °C for 1, 4 and 20 hours calculated on the basis of this model are in good agreement with experimental nitrogen profiles. Furthermore, the swelling process is showed and analyzed, derived the dependency of swelling rate on nitriding duration – the swelling rate is inversely proportional to the square root of nitriding duration. The obtained diffusion coefficient value and the swelling process rates satisfy the experimental data form Ref. The derived model explains physical processes during plasma nitriding and allows obtaining nitrogen depth profiles for any requisite nitriding duration.

The kinetics of plasma nitriding of CoCr alloy below temperatures of nitrides formation and mechanisms of nitrogen penetration are analyzed by proposed kinetic modeling in this article. Proposed nitrogen diffusion model is based on the trapping – detrapping (TD) model and developed taking into account the effect of the concentration dependent diffusivity of nitrogen, nitrogen adsorption on the surface of alloy and surface swelling process. The model indicates the influence of chromium atoms to nitrogen atoms diffusivity. The model consists of time and depth dependent diffusion, which is described by a partial differential equation, and it is solved by using Crank – Nicolson finite difference method. By fitting of experimental nitrogen depth profiles, it is shown that nitrogen diffusion coefficient varies with nitrogen concentration according to Einstein-Smoluchowski relation. Nitrogen depth profiles in plasma nitrided medical grade CoCr alloy (ISO 5831 – 12) at T = 400 °C for 1, 4 and 20 hours calculated on the basis of this model are in good agreement with experimental nitrogen profiles. Furthermore, the swelling process is showed and analysed, derived the dependency of swelling rate on nitriding duration – the swelling rate is inversely proportional to the square root of nitriding duration. The obtained diffusion coefficient value and the swelling process rates satisfy the experimental data form Ref. The derived model explains physical processes during plasma nitriding and allows obtaining nitrogen depth profiles for any requisite nitriding duration.

Sourdough plays an important role in quality assurance, especially during developing wholegrain wheat bread products. The value of barley and hull-less barley grains is determined by the low lipid and high carbohydrate (starch and resistant starch) content, balanced amino acid profile, dietary fibre and phenolic compounds. During germination (24 h) the amount of sugar, amino acids and vitamins increase in the grains. Therefore, it could be optimal environment for microbiota growth in sourdough. The goal of the research was to find optimal technological parameters and to study microorganism growth dynamic during the fermentation of sourdough with germinated hull-less barley. The study was performed using three steps of fermentation, with different temperature and time parameters. At each step pH, dynamics of lactic acid bacteria (LAB), yeast-like fungi and total plate count (TPC) growth were determined using standard methods. The results of the study showed that the optimal fermentation conditions for the first stage are 48 h and 26 ± 1 °C, for the second stage 8 h and 26 ± 1 °C and for the third stage 20 h and 28 ± 1 °C. During fermentation of the sourdough, the pH 3.91 is reached, LAB 8.8 log₁₀ CFU g⁻¹, and the yeast-like fungi 8.7 log₁₀ CFU g⁻¹ was determined. Obtained data show that more than 80 bacteria and 50 microscopic fungal species were detected in hull-less barley flour, but after germination their diversity decreased and in the germinated hull-less barley sourdoughs dominated species were Pediococcus pentosaceus.

Sourdough plays an important role in quality assurance, especially during developing wholegrain wheat bread products. The value of barley and hull-less barley grains is determined by the low lipid and high carbohydrate (starch and resistant starch) content, balanced amino acid profile, dietary fibre and phenolic compounds. During germination (24 h) the amount of sugar, amino acids and vitamins increase in the grains. Therefore, it could be optimal environment for microbiota growth in sourdough. The goal of the research was to find optimal technological parameters and to study microorganism growth dynamic during the fermentation of sourdough with germinated hull-less barley. The study was performed using three steps of fermentation, with different temperature and time parameters. At each step pH, dynamics of lactic acid bacteria (LAB), yeast-like fungi and total plate count (TPC) growth were determined using standard methods. The results of the study showed that the optimal fermentation conditions for the first stage are 48 h and 26 ± 1 °C, for the second stage 8 h and 26 ± 1 °C and for the third stage 20 h and 28 ± 1 °C. During fermentation of the sourdough, the pH 3.91 is reached, LAB 8.8 log10 CFU gE−1, and the yeast-like fungi 8.7 log10 CFU gE−1 was determined. Obtained data show that more than 80 bacteria and 50 microscopic fungal species were detected in hull-less barley flour, but after germination their diversity decreased and in the germinated hull-less barley sourdoughs dominated species were Pediococcus pentosaceus.

An Induction motor reliability survey at an egg processing plant shows that almost 50% of the total motor failures are fan induction motors. Visual investigations of the faulty fan motors show that the main cause of the induction motor failure is air gap eccentricity. In this study, experimental tests are performed on a 1.1kW three-phase induction motor to detect air gap eccentricity and overheating of the induction motor. Heating tests show that end shield housing temperature reaches 100°C with blocked air flow from the fan, which can reduce the lifespan of the bearing. Dimension measurements of the end shield housing show that the dimensions of both tested motors back-end shields are larger than ISO tolerance grade limit. It leads to a loose fit between the housing and bearing, causing air gap eccentricity. Also, both motor back end shield housing has an out-of-round condition leading to an unbalanced magnetic pull. To detect the air gap eccentricity caused by too loose of a fit between housing bore and bearing, current Park’s vector approach is used. To measure three phase current, Hall Effect current transducers, a digital oscilloscope is used and Matlab software to process the measurement data. Results show that Park’s vector approach can be used to detect the air gap eccentricity caused by too loose a fit between bearing and housing. Therefore, the Park’s vector approach can be used to diagnose air gap eccentricity and analyse the type of the air gap eccentricity.

An induction motor reliability survey at an egg processing plant shows that almost 50% of the total motor failures are fan induction motors. Visual investigations of the faulty fan motors show that the main cause of the induction motor failure is air gap eccentricity. In this study, experimental tests are performed on a 1.1kW three-phase induction motor to detect air gap eccentricity and overheating of the induction motor. Heating tests show that end shield housing temperature reaches 100°C with blocked air flow from the fan, which can reduce the lifespan of the bearing. Dimension measurements of the end shield housing show that the dimensions of both tested motors back-end shields are larger than ISO tolerance grade limit. It leads to a loose fit between the housing and bearing, causing air gap eccentricity. Also, both motor back end shield housing has an out-of-round condition leading to an unbalanced magnetic pull. To detect the air gap eccentricity caused by too loose of a fit between housing bore and bearing, current Park’s vector approach is used. To measure three phase current, Hall Effect current transducers, a digital oscilloscope is used and Matlab software to process the measurement data. Results show that Park’s vector approach can be used to detect the air gap eccentricity caused by too loose a fit between bearing and housing. Therefore, the Park’s vector approach can be used to diagnose air gap eccentricity and analyse the type of the air gap eccentricity.