Kyiv National University of Trade and Economics

The theoretical description of two bivalent metals (with the examples of nickel and cadmium), electrochemical removal, and determination by phenolic conducting polymer has been described. In this system, the conducting polymer acts in both aromatic and overoxidized forms, providing efficient metal cation removal. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis, and its investigation confirms the efficiency of the phenolic conducting polymers for cadmium and nickel removal and immobilization into the polymer phase, where they are used in a composite. This is the keystone for the use of this process as a part of waste management and circular economy.

People desire friends who have qualities such as similarity, the ability to provide support, opportunities for socialisation, assistance in achieving self-serving goals and access to potential mates. In the current study, we aimed to examine the degree of overlap between the friends people consider ideal and those they actually have. Using a sample of 6224 participants from 12 countries, we found that, across five dimensions of friendship, ideal and actual friendships considerably overlapped and ideal preferences were significant and strong predictors of actual friendships. Still, the overlap between ideal and actual friendships was not complete; rather, a small deficit emerged, with participants getting less of what they wanted. These results were consistent across the 12 countries in our sample. We also found significant effects of the Dark Triad personality traits on several dimensions of friendship.

The Alpine and Yogurt craft hard cheeses made from unpasteurized goat milk are studied in this paper. The task under consideration is to define the authenticity criteria for the Alpine and Yogurt craft goat cheeses made from unpasteurized milk during maturity process. Consumers' orientation towards healthy eating leads to an increase in the supply of craft cheeses made from unpasteurized goat milk on the market, which involves assessing their quality, safety, and establishing authenticity criteria. Such indicators include the fatty acid composition and quality of milk fat lipids. The fatty acid composition of the cheeses has been analyzed using gas chromatography. The lipid structure of both cheeses contained 15 fatty acids (11 saturated and 4 unsaturated). The share of saturated fatty acids increased by 4.04–4.44% at the 18th month of maturity of the Yogurt cheese and at the 6th month of maturity of the Alpine cheese. During the maturity process, the proportion of polyunsaturated fatty acids in the Alpine cheese increased by 1.60–2.07%; in the Yogurt cheese by 1.24–2.35%. In both cheeses, the basis of ω-3 and ω-6 polyunsaturated fatty acids was linolenic and linoleic; their ratio ranged from 1:4.26 to 1:2.31. The ripened Alpine and Yogurt cheeses were characterized by the highest indices of thrombogenicity and atherogenicity, in contrast to old-ripened cheeses, in which these indices decreased against the background of an increase in the indices of hypocholesterolemic/hypercholesterolemic acids and healthy fat. The delta nine desaturase index (C14) during maturity period of the Alpine cheese decreased by 0.010–0.011; in the Yogurt cheese, on the contrary, it increased by 0.054–0.026 units. The fatty acid composition of goat craft hard cheeses could be a justification for devising criteria for their authenticity and nutritional value

Purpose of the article. The article considers key issues of digital advertising effectiveness, including the relationship between costs and profitability in the process of scaling advertising campaigns. The research methodology is comprised of a systematic method, comparative analysis, and theoretical methods (analytical-synthetic, classification, systematisation, and generalisation). Results. The article considers contemporary trends in the development of digital advertising in the context of scaling. The present study analyses the relationship between a decrease in ROAS (return on advertising costs), an increase in costs and an increase in net profit. It was determined that a decline in return on advertising spend (ROAS) when scaling advertising campaigns is a common occurrence. This is due to the fact that the efficacy of the campaign may be diminished due to market saturation and the necessity to expand the target audience. While attracting users who are less knowledgeable about the product or brand may be more costly, it is nevertheless essential in the context of scaling advertising campaigns. It has been demonstrated that an increase in advertising costs does not necessarily result in a proportional increase in profit from these advertising campaigns. The necessity for informed management decisions to optimise digital advertising is well-documented, and this process involves conducting campaign audits to identify new opportunities, personalising advertising communications and using A/B testing to determine the most effective combinations, and personalising advertising to find new target audience segments. Practical implications. The study demonstrates that scaling digital advertising is a pivotal stage for any business if costs are optimised to maintain a high level of profitability. Value/Originality. The article proposes an innovative approach to the effectiveness of advertising in terms of scaling, which takes into account the expansion of campaigns to new audience segments, the expansion of advertising channels and strategies, the modelling and forecasting of ROI (return on investment) and ROAS for each stage of scaling in order to predict a possible decrease in effectiveness and adjust the strategy over time. It also focuses on the value of the product for the client.