A possibility to reduce costs incurred in both product manufacturing and energy consumption constitutes energy-efficient consumption at industrial enterprises. Manufacturers operating in various economic sectors adopt similar conceptual models of energy consumption, which allows developing a universal solution for modeling such processes. The central problem of modeling lies in finding an adequate objective function based on a sufficient set of parameters and characteristics of the efficiency of an enterprise's power circuit. The article justifies the performance indicators of industrial enterprises' power supply systems. The literature review proves that economic feasibility of energy efficiency is especially obvious if a massive modernization program is implemented. The estimates produced indicate that the largest portion of the potential energy savings is attributed to implementation of energy-saving projects in industrial buildings and other structures. We present a mathematical model designed to perform a comparative analysis of technical and economic features of two modernization scenarios of the heat and power supply system of an industrial enterprise circuit. Performing a simulation calculation based on performance aspects of Russian companies, the paper outlines the advantages of integrated modernization and analyzes the influence of various factors. The results reveal that there is an inverse correlation between specific heat consumption of buildings under thermal modernization and the length of the thermal network. As specific energy consumption in the thermal modernization scenario increases, the payback period for capital investments decreases. The effect of this dynamics is virtually proportional. Compared with total costs for various heat sources, the share of capital costs differs significantly; however, the share of running costs is dominant for all types of units. At the same time, the length of an enterprise's heat circuit weakly affects the payback period of capital costs.

Introduction The mainstay of management for locally advanced rectal cancer is chemoradiotherapy followed by surgical resection. Following chemoradiotherapy, a complete response may be detected clinically and radiologically (cCR) prior to surgery or pathologically after surgery (pCR). We aim to report the overall complete pathological response (pCR) rate and the reliability of detecting a cCR by conventional pre‐operative imaging. Methods A pre‐planned analysis of the European Society of Coloproctology (ESCP) 2017 audit was performed. Patients treated by elective rectal resection were included. A pCR was defined as a ypT0 N0 EMVI negative primary tumour; a partial response represented any regression from baseline staging following chemoradiotherapy. The primary endpoint was the pCR rate. The secondary endpoint was agreement between post‐treatment MRI restaging (yMRI) and final pathological staging. Results Of 2572 patients undergoing rectal cancer surgery in 277 participating centres across 44 countries, 673 (26.2%) underwent chemoradiotherapy and surgery. The pCR rate was 10.3% (67/649), with a partial response in 35.9% (233/649) patients. Comparison of AJCC stage determined by post‐treatment yMRI with final pathology showed understaging in 13% (55/429) and overstaging in 34% (148/429). Agreement between yMRI and final pathology for T‐stage, N‐stage, or AJCC status were each graded as ‘fair’ only (n = 429, Kappa 0.25, 0.26 and 0.35 respectively). Conclusion The reported pCR rate of 10% highlights the potential for non‐operative management in selected cases. The limited strength of agreement between basic conventional post‐chemoradiotherapy imaging assessment techniques and pathology suggest alternative markers of response should be considered, in the context of controlled clinical trials.

Labour migration is one of the most important socio-economic development indicators. The problem of a steady decline in the working-age population size has changed a role of migration that has an active impact on the human potential development. With the help of an empirical example from the Eurasian Economic Union (EEU), this research paper presents specifics of labour migration. A review of literary sources points out to an ambiguous impact of a number of factors on dynamics of migration flows, employment, and unemployment. Correlation-regression modelling of migration processes for the EEU in various configurations has resulted with the following. First, a revealed direct relationship between a natural growth (decline) in the population, a number of vacant jobs and the population migration indicator. Second, researchers have established an inverse dependence between GDP per capita, consumer price index, minimum wage, unemployment rate, and population migration indicator. Thirdly, they have shown that a direction of migrant flows depends on such factors, as GDP per capita, number of vacant jobs and minimum wage. Results of the analysis show that an increasing difference between an average wage in the region and across the EEU, and minimum standard of living leads to decreasing numbers of migrants from a particular region of the EEU. In the EEU, for the population main reasons for employment abroad include unemployment in rural areas, no regular income, and lower wages compared to neighbouring countries. The discussion explains an essence of contradictory consequences of the labour migration impact on a development of national economic systems in terms of the completed academic and empirical research. In this regard, it is reasonable to consider labour migration as a global economic phenomenon and this needs further research in terms of factors that influence it.

Renewable energy has become a promising way to meet growing energy needs in the society. However, operation of power supply systems based on renewable energy sources (RES) depends on a number of uncontrolled factors. This imposes certain restrictions on applications and causes applicationrelated challenges. At this point, the search for the best combination of applied energy sources has been still a key issue. Methodological approaches to the solution to this problem are diverse. The idea of our research is the application of tools from economics and mathematics to measure the best mutual substitution of energy resources in the production facility local power supply system. Authors have considered the possible application of RES through the example of the Russian-based production facility typical in terms of average power consumption and size. Authors chose a solar power plant as a RES. From the simulation results, authors conclude that when using RES, in terms of gross figures, there is about 20-25% less consumption. This makes it possible to achieve the balanced energy consumption from traditional sources throughout a production cycle. Our calculations have showed that, depending on the seasonal prevalence, it is possible to reduce average daily costs for power (in case of compensation from RES) by about 15.75% in the first season, 37.04% in the second season, and 25.44% in the third season. As for time period, in the second season, in the half-peak period (43.68%), we achieve the highest saving, while the lowest saving in the half-peak period of the first season (1.22%). Thus, the application of the solar power plant as a part of the local power supply system of the production facility makes it possible on average to achieve the 13% less energy consumed from centralized sources. It is safe to say that the application of combined sources of power in local power supply systems of production facilities is economically feasible to compensate for peak and half-peak loads. Authors have concluded that the potential of RES at the enterprise might be only developed as that of an additional energy resource and full substitution is impossible.

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On the go is the development and adaptation of an individual target for Bulgaria, in order to increase the share of RES energy, according to the EU common vision for leadership in the implementation of renewables to 32% in the gross final consumption by 2030. The technological progress, the easy applicability and feasibility of the projects, as well as the geographic and climatic specifics of Bulgaria, makes photovoltaic Bulgaria's main candidate for leading technology in this process. With net specific production of 1323kWh/annual per installed kWp, price levels of PV technology of €1360kWp and Levelized cost of energy (LCOE) below €0.12kWh for 20 years time frame, households in Bulgaria are at a stage where photovoltaic projects should be developed as an alternative to the grid supply