Hydrodynamic cavitation damages the apparatus by intensive cavitational erosion of the elements in a hydro system. Being acquainted with the mechanisms of effect, hydrodynamic cavitation can be used to intensify technological processes in different industrial areas. The aim of the present work is to investigate the possibilities using hydrodynamic cavitation for wastewater treatment from an urban treatment plant. To intensify the purifying process series of trials, at different levels of intensity of the electrical field in the zone of cavitation, were performed. Additionally presented, the electrical field assists in forcing the process of silver ions separation with the purpose of microbiological purification of the flowing water. Here we present the results of experimental studies conducted at various times and electrical fields intensity. These trials substantiate the idea of the microbiological purification of wastewaters via hydrodynamic cavitation and represent a huge range of opportunities for applying this method in various industrial fields. The basic criterion that supports our statement is the enormous drop of the microbe number by increasing the cavitation treatment time.

The energy efficiency of household refrigerating appliances was measured according to EN TSO15502. A Liebherr TKP 1650 built-in Domestic refrigerator is used to determine the influence of the capillary pipe geometry. The temperatures at the injection site of the refrigerant, the inlet and outlet of the evaporator receiver were measured. The obtained results show that there is no universal optimal geometry of the capillary pipe. There is no element of the refrigeration cycle whose change has no effect on the refrigerant flow rate passing through the capillary pipe. A change in the geometry of capillary pipe affects all other components of the refrigeration cycle and can greatly improve or impair the efficiency of the refrigerator. The potential for switching from one to two different geometries of the capillary pipe is approximately 8% improvement in energy consumption. Possible implementation should take into account the potential savings - 8% and the life cycle of the particular appliance (- 15 years). For the particular measured device, the consumption per year is about 75kWh, which should take into account that the device itself has a low volume and low energy consumption.

Many plant extracts selected for their high in vitro antibacterial activity in microbiological media have a far lower in situ antibacterial activity in foods. This is likely due to interactions of plant antimicrobial molecules with food components such as proteins or dispersed fat at the expense of their interaction with target unwanted bacteria. Gaillac red wine powder and Cinnamon cassia essential oil were selected for their in vitro antibacterial activity against Staphylococcus aureus CNRZ3 and Listeria innocua LRGIA 01, respectively. In order to assess their potential application to the preservation of raw meat or dairy products, respectively, their antibacterial activity was tested in Mueller Hinton broth (MHB) supplemented with up to 20% beef meat proteins to mimick raw beef meat protein content and in TSB, skimmed, semi-skimmed and whole milk, respectively. Supplementation of MHB with beef extract proteins annihilated the antibacterial activity of Gaillac red wine powder as well as of resveratrol, a stilbene polyphenol present in red wine. The comparison of the anti-Listeria innocua activity of C. cassia essential oil in TSB 1% (w/w), skimmed, semi-skimmed and whole milk led to the conclusion that its antibacterial activity was significantly reduced in the presence of milk fat globules but not significantly by milk proteins. Complexified microbiological media or liquid foods such as sterilized milk with various milk fat contents might thus be valuable tools for the rapid screening of antibacterial plant extracts of interest for perishable foods preservation.

The possibilities for low-temperature heat pump and conventional drying of blueberries during preliminary osmotic dehydration was studied. A full factor experiment of type 22+3 was performed. The kinetics of the process during variation of the main mode parameters: inlet temperature and thickness of the drying layer (load on the scaffolding) was studied. The curves of the drying process U = f (τ) and the curves of the drying speed dU / dτ = f (U) were constructed. The influence of the regime parameters on the drying time was established. Regression models of the drying coefficient during the second period of drying were presented.