Evaluation of impact of the Covid-19 pandemic on rental housing prices in the city of Brno between 2020 and 2021

The aim of the paper is an application of the basic principles in determining rental housing prices and factors that may affect them. In the experimental part, an analysis of rental housing in the city of Brno is performed for the 2020 – 2021 period affected by the covid-19 pandemic. The analysis is processed for individual city districts and divided according to apartment layout. Finally, all outputs are compared and the real estate market development is determined with a focus on the biggest changes and their occurrence.

MONITORING OF MONOLITHIC OVERLAP WITH PRESTRESSED BEAMS

A method for monitoring the stress-strain state of building structures has been developed. A technical inspection of monolithic slab structures using electronic beacons for crack control was carried out. The basis of the monitoring system of monolithic reinforced concrete structures is a fiber-optic technology based on the control of changes in the parameters of the light wave. For the experimental part, a scheme for testing fiber-optic sensors has been developed.

ANALYSISOF FULL VALUE FEEDING OF MARAL STAGS IN WINTER AND SPRING

The productivecharacteristics of marals largely depend on the level, full value and balance of feeding. Provided these factors are taken into account, marals maximize their genetic potential. The experimental part of the study was carried out on the farm of the SPK PZ “Abayskiy”of the Ust-Koksinskiy District of the Republic of Altai in 2020. The research goal was to evaluate the full value of feeding maral stags in winter and spring period. It was found that the best energy feed was oat grain which contained 0.9 energetic feed units. When evaluating the mineral composi-tion, it may be seen that legume hay is superior to other forages in terms of calcium content. Oat grain contains larger amount of phosphorus, haylage –larger amount of magnesium. The maral stag diet usedin the SPK PZ “Abayskiy”contains mainly cereals (oats). As a result, in terms of energy nutritional value, it exceeds the upper threshold of the standard by 23%. There is phosphorus deficit by 5.2%. The content of digestible protein, sugar and carotene is higher than in the standard by 1.2, 8 and 69%, respectively. It has been found that on a daily basis, roughage (legume hay) is the largest part of the diet -7 kg per head; there is less succulent forage (silage) and less concentrates (oats). It should be noted that this diet for maral stag during the stall period requires adjustment; if possible, the proportion of hay in the diet should be re-duced; the diet should include enriched mineral supple-ments of natural origin.

ANALYSIS OF MECHANICAL VIBRATION OF A SERVOMOTOR USING VIBROMETRY

The servomotor must ensure resistance to the environment (mechanical vibration, humidity, temperature) in which it will be operated. It is the vibration that is one of the important monitored parameters that allow obtaining initial information about the operational status of the equipment. Exceeding the preset limits adversely affects the service life and reliability of the components. The experimental part is focused on recording and analyzing the magnitude of vibration acceleration, through frequency spectrum and its comparison with the envelopes of frequency spectrums. The obtained graphical dependencies from the experiments are a suitable basis for the assessment of the objective state.

Anatomical cutting of gutted carcases of broiler chickens of the Smena-9 cross

The creation of a new cross “Smena-9” is aimed at reducing import dependence in the production of poultry products. In order to assess the meat raw material potential, morphological indicators of gutted carcasses of broiler chickens of the Smena-9 cross and individual parts were determined. The research used 5 carcasses of broilers from a batch of 38 days of age, weight, g: 1457.80; 1487.50; 1508.10; 1548.20; 1567.0. Separate parts – chest, thighs, drumsticks, legs and wings were anatomically divided into their components [muscles, skin, fat and bones with a residual lump]. The results of the experimental part of the research are reduced to average indicators: the average weight of a gutted carcass, individual parts and their components. It was found that the yield of the breast part is 36.0% [meat tissue 30.9%], the yield of the drumsticks – 29.9% [thighs – 16.45%, legs – 13.45%], wings – 10.75%, while flesh makes up 30.9%, 24.9%, and 7.8%, respectively, which exceeds the same indicators of domestic crosses. It was determined that the total yield of the breast and legs of the Smena-9 cross [65.9%] is higher by 5.3% for carcasses weighing 1600 g and by 8.8% for carcasses weighing 1850 g; for flesh, the excess is 5.8% and 5.2%, respectively. The obtained results serve as the basis for the development of normative documentation for parts of carcasses and their components of the Smena-9 cross and a system for assessing the effectiveness of equipment for cutting and deboning by the degree of approximation of the results of its operation to similar indicators for anatomical cutting and deboning.

Electrochemical Synthesis of Unique Nanomaterials in Ionic Liquids

The review considers the features of the processes of the electrochemical synthesis of nanostructures in ionic liquids (ILs), including the production of carbon nanomaterials, silicon and germanium nanoparticles, metallic nanoparticles, nanomaterials and surface nanostructures based on oxides. In addition, the analysis of works on the synthesis of nanoscale polymer films of conductive polymers prepared using ionic liquids by electrochemical methods is given. The purpose of the review is to dwell upon an aspect of the applicability of ILs that is usually not fully reflected in modern literature, the synthesis of nanostructures (including unique ones that cannot be obtained in other electrolytes). The current underestimation of ILs as an electrochemical medium for the synthesis of nanomaterials may limit our understanding and the scope of their potential application. Another purpose of our review is to expand their possible application and to show the relative simplicity of the experimental part of the work.

Experimental Assessment if Changes in Structural Steel Composition by Progressive Technology Cutting

The submitted paper deals with the issue of change in structure, hardness and thermally affected zone of the samples of a toothed wheel part produced by technology of cutting by plasma, laser and water jet. The cutting process by laser and plasma technology causes intensive thermal affection of material and change in structure and microhardness in the cutting area referred to as thermally affected zone. The paper describes three material cutting technologies of the toothed wheel part. The experimental part contains description of experimental sample preparation, its hardness measurement and examination of structure along with further evaluation through graphs and photo documentation of structures.

Perovskite Single Crystals for Energy Conversion of Solar Radiation

Experimental part describes synthesis, structural and optical properties of MAPbBr3 single crystals and electrical characterization of the Au/MAPbBr3/Au light-sensitive assembly. Its parameters (responsivity, external quantum efficiency and specific detectivity) are calculated based on the spectral and switching (on/off) current responses. The material is further discussed as a detector and a possible active component for photovoltaic panels.

Ultrasonic-Assisted Brazing of Titanium Joints Using Al-Si Based Fillers: Numerical and Experimental Process Design

The ultrasonic-assisted brazing process was studied both numerically and experimentally. The ultrasonic brazing system was modeled by considering the actual brazing conditions. The numerical model showed the distribution of acoustic pressure within the filler and its variations according to the gap distance at different brazing temperatures. In the experimental part, brazing joints were studied and evaluated under multiple conditions and parameters. Although either the initial compression load or the ultrasonic vibration (USV) can initiate the interaction at the interface, the combined effect of both helped to produce joints of a higher quality with a relatively short brazing time, which can be further optimized in terms of their mechanical strength. The effect of the Si content on the joint interface, and the effect of the brazing conditions on the microstructures were studied and discussed.

The component composition of the essential oil from Laurus nobilis L. unripe fruits harvested in Ukraine

Aim. To study the qualitative composition and the quantitative content of the essential oil components from Laurus nobilis L. unripe fruits.Results and discussion. In the essential oil from Laurus nobilis L. unripe fruits 31 compounds were determined; among them 28 substances were identified. A high content was characteristic for spatulenol (1947.1 mg/kg) and betulenol (925.3 mg/kg).Experimental part. The raw material for obtaining the essential oil (unripe fruits) of Laurus nobilis L. was harvested in November 2017 in Alushta and the village of Rybalskoe, Crimea. The component composition of the essential oil of the unripe fruits from Laurus nobilis L. was studied and the constituents of the essential oil were identified by chromato-mass spectrometry using an Agilent Technology 6890N chromatograph. The component composition of the essential oil was revealed by comparing the results obtained with data from the NIST 02 mass spectrum library (more than 174.000 substances).Conclusions. The component composition of the essential oil from Laurus nobilis L. unripe fruits harvested in Ukraine has been studied. Taking into account the set of the biologically active compounds found in the essential oil of Laurus nobilis L. it can be argued that further pharmacognostic studies of fruits of this plant as the medicinal raw material with the predicted pharmacological activity (e.g., antimicrobial and skin cleansing) are promising.