Table of Contents

  • Innovative role of the regional educational system: Response to the challenges of the new economy

    pg(s) 47-49

    Industry 4.0 has a significant impact on the economic and social sphere of society. Changes in the economic system give rise to a number of social risks associated primarily with the labor market, occupational structure and employment. In the article the social risks of the digital economy, identifies threats and challenges to the education sector are systematized. Contradictions of the functioning of educational institutions are described. The innovative role of the educational system, which it can play in regional development, is defined. Innovative approaches to the development of the education system based on existing experience are proposed.

  • Generational motivation differences at the R&D centers: Gen Y and Gen Z

    pg(s) 50-53

    There often seem to be differences in work values between employees (and managers) who are from different generation. There has been a continuing debate about the extent to which Gen Yers and Zers are motivated by similar values and processes as those from earlier generations, who were already in the workplace when earlier studies were conducted. An associated question might be whether Gen Yers (many of whom are now working as junior and middle managers) and Zers that work on R&D center subscribe to similar motivational techniques and theories as those managers who were born in an earlier generation. Although there has been a great deal of speculation and opinion regarding the motivation of the Generation Y and Z that work on R&D center, there has been relatively little formal research.

  • Diverse individual value-sets among entrepreneurs in Europe: A comparative analysis

    pg(s) 54-57

    The paper examines the relevant value-sets of entrepreneurs in Europe. As both approaches, i.e. the perspective of Economics, which is interested in ideal entrepreneur mentalities, and Sociology that rather takes entrepreneurs’ ethically-morally significant roles into its main focus, are addressing epistemological and praxis-related aspects, then this paper highlights the importance of values as ontological foundations to these features. From the various value-theories Shalom H. Schwartz’s concept about Basic Human Values is applied as a framework. Schwartz distinguishes ten types of values, which are interrelated based on a twofold axes. The empirical part starts with a differentiation of entrepreneur-groups by cluster analysis based on the individualistic values. Then the collectivist values are invoked in order to draw up more comprehensive profiles about the primarily identified groups. Finally additional variables contribute to the clarification of these profiles.

  • Model of assessment of level of potential possibilities of the technology applied by the enterprise

    pg(s) 58-59

    In this paper authors cover the problem of creation of automated control systems for the production technology which will provide the given ranges of values of various properties of metallurgical products is considered. For a solution it is offered all properties to lead to a comparable look, having entered a concept of potential of properties. The general vector of technological variables is offered to be defined by finding of rational values of variables for target function which is equal to the general level of potential of properties in the corresponding time frame.

  • Plate heat exchanger design: a case study for ventilation systems of small residences

    pg(s) 60-65

    In this study, a plate heat exchanger (PHE) was designed to meet the ventilation requirements in a small dwelling by performing heat recovery. In the Taguchi analysis performed by selecting three-level four effective parameters, L9 orthogonal array was used. In the analysis, the optimal levels of the design variables were determined by using Computational Fluid Dynamics (CFD) results in order to maximize the combined thermal and hydrodynamic effectiveness (CTHE) selected as the performance parameter. The CTHE was defined as the multiply of thermal effectiveness and flow effectiveness of the PHE. The 3-dimesional CFD models of the PHE were designed to include the effects of the local change in the flow cross-section, which will occur at the inlet-outlet of the air flow channels. Thermal and hydrodynamic computation of PHE models were obtained by finite volume software. In Taguchi analysis, design variables and levels that maximize CTHE: sub-channel number-6, channel height-3 mm, average air flow rate-2 m/s and plate material is paper. When the CTHE predicted from Taguchi analysis was compared with that solution of the CFD model generated using the optimized design and operating parameters, the difference was determined to be less than 1%. In addition, in order to calculate the CTHE based on the design variables, a mathematical equation was obtained in a 90% confidence interval.

  • An innovative approach for repairing of corroded reinforced concrete industrial structures in aggressive environment by high-tech hybrid reinforced sprayed concrete with capillary crystalline admixture

    pg(s) 66-69

    Solvay Sodi JSC, Devnya, Bulgaria, is the biggest calcite soda production plant in Europe. It is built in 1974 and it works in three-shift production regime up to present days. The exploitation environment is highly influenced by numerous factors, acting corrosively on main reinforced concrete structures – active atmospheric processes (in continental type moderate climate), sea water born chloride-aerosols, as well chemical attack caused by carbon dioxide and nitric acid, presented in the air in form of evaporation. The most reinforced concrete structures need urgent remedial measures to restore the load-bearing capacity of its components.
    The “light soda” silos are reinforced concrete facilities (cylindrical shells) which repair has to be executed during continuous production process. The options for repair of these structures and restoration of their load bearing ability by specially designed innovative high-tech hybrid reinforced sprayed concrete, containing capillary crystalline admixture, are discussed in the report.
    The in-situ tests and wide-range comparative studies are carried out, covering basic physical and mechanical structural characteristics of the proposed sprayed concrete for wet spraying and another one – based on proportioned dry ready mix.
    The original scientific results concerning strength-deformation properties, phase composition and structure of hardened sprayed concrete, directly related to the durability in aggressive environment, are obtained by X-ray diffraction (XRD), differential thermal analysis (DTA), mercury porosimetry, low temperature gas adsorption (BET-method) and computer X-ray tomography.
    The static and dynamic analysis of the structure is performed using the test results obtained and the fully specified engineering solution
    has been presented to restore the load-bearing capacity of the structures with a guaranteed service life of at least 50 years.

  • Membrane distillation using solar energy – membrane modification

    pg(s) 70-72

    The desalination is an important technological process applied not only to obtain drinking water, but also for wastewater treatment from e.g. dyes, textile and mining industry. In this process, membrane processes such as reverse osmosis, pervaporation, electrodialysis and membrane distillation are quite commonly used. This work focuses on membrane distillation. The research was carried out in order to produce membranes absorbing solar radiation, to use this energy in the distillation process. Membranes were produced using the phase inversion method from polysulfone polymer at various proportions of ingredients to select the optimal blend composition. The fabricated membranes were investigated to assess wettability, maximum pore size and execute preliminary tests of the membrane distillation process.

  • Reefer container power supply and supervision system onboard railway wagons

    pg(s) 73-76

    Concerns about greenhouse gas emissions and environment protection in general, lead to application of new, eco-friendly solutions in almost all areas of human activities. Today, transportation is in the focus of many researchers since transport units generate substantial emissions locally as well as globally. Turning to electricity powered transportation units seems to be a logical step if global power production transitions to renewable energy sources (large hydro, wind, solar, biomass, etc). This paper demonstrates a technical solution applicable to reefer containers railway transport, as an alternative to road transport with conventional trucks or railway transport with diesel gen-sets. In fact, reefer containers are frequently used to transport sensitive goods. Therefore, containers must be almost constantly supplied with electric power to maintain desired ambient parameters (temperature, humidity, number of air changes per hour, etc.). An innovative technical solution which provides suitable power supply to reefer containers aboard wagons has been developed and tested in real-life conditions. Electrical power is drawn from the locomotive’s single-phase, head-end-power line (usually 1500 Vac, 1500 Vdc or 3000 Vdc), available at the locomotive, or on wagons with electric installation. Throughout the paper, the developed static converter system suitable for transforming single-phase 1500 Vac, into three-phase 400 Vac, 50 Hz is presented. Furthermore, a dedicated communication system is developed which enables users to perform supervision of transported goods (temperature and relative humidity) and track the reefer container onboard railway wagons.

  • Power systems emulator based on DCS

    pg(s) 77-79

    Research, optimization and practical implementation of optimization processes in power subsystems of power plants, heating plants and industrial plants present a relatively complex task that is nowadays unimaginable without powerful specialized tools of computer support. The paper presents a power systems emulator concept (a tool for the design and application processes involving power systems) that is based on decentralized control systems (DCS) standardly used today. Basic principles of modular design of the emulator along with an example of its implementation based on the Siemens SIMATIC-S7 DCS system are presented.

  • Simulation-driven design and optimization of a new two-coil crucible induction furnace using the Altair Flux3D® software

    pg(s) 80-83

    A new two-coil crucible induction furnace with a lateral coil connected to the one-phase electric power supply and a bottom coil connected to a capacitor bank with an appropriate value of the capacity is able to realize a desired balance between the induction heating of the lateral face and of the bottom face of the furnace bath. The evaluation of the optimum value of the capacity, which corresponds to the same mean value of the induced power density on the respective faces, represents an example of simulation-driven optimal design. Finite element models are used to study many variants of the new furnace related the number of turns of the two coils and related the diameter of the furnace bath for imposed bath volume.

  • Transportation of liquefied fuel gas in containers

    pg(s) 84-86

    Transportation from receiving terminals and condensed fuel gas production plants is accomplished by sea, railway and road transport using the standard (ISO) tank-containers, dedicated tanks and cryogenic semi-trailers.
    Recently, the 20 ft and 40 ft tank containers, optimally adapted for multimodal transport have become commonplace.
    The use of cryogenic semi-trailers with vacuum-perlite, polyurethane, multi-layer and combined insulation with a capacity of up to 54,000 liters of condensed fuel gas allows for creating a flexible and elastic delivery system to the market.