International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This study proposes a mathematical model for design and optimization of a hydrogen supply chain, covering all stages of the life cycle – feedstocks, production, storage, distribution, end-use in the transport sector. The developed methodology integrates different hydrogen production technologies and takes into account environmental, economic and social impacts in order to identify the most efficient and sustainable configuration. The focus in this work falls on hydrogen production by steam reforming of methane and hydrogen production by electrolysis of water in hydrogen refueling stations. The mathematical model is formulated in terms of MILP programming and can be solved using the GAMS software product. The aim is to find an optimal balance between economic efficiency, environmental sustainability and social impact by using weighted coefficients (weights). The proposed concept provides a decision-making tool for planning hydrogen infrastructure in line with European decarbonization and sustainable transport goals.

Solar energy is a cornerstone in the transition towards sustainable and renewable energy sources. Enhancing the efficiency of solar cells is critical to maximizing energy capture and utilization. One promising approach to improve solar cell performance is the application of self-cleaning coatings. This research work explores the enhancement of the energy efficiency of solar cells through the application of a SiO2/WO3-B5 self-cleaning coated film. These coatings not only help in maintaining the cleanliness of the solar cell surfaces but also contribute to better light absorption and reduced reflection losses, ultimately leading to higher energy output.

This study proposes a mathematical pathway to achieve sustainable design and resource-friendly management of a biodiesel supply chain produced from dairy waste scum. In the work, the features of a combined biodiesel/dairy supply chain are outlined and a set of design and management tools is developed, which is formulated in MILP terms. The optimization criterion is defined in terms of economic sustainability and environmental assessment data is applied as part of it. The purpose of the defined mathematical model is to obtain optimal operating conditions of the considered combined supply chain. A test example based on a case study from Bulgaria was considered. The results of the toolbox implementation can be used as a decision-making tool.

Furniture made of corrugated cardboard is environmentally friendly, cheap and allow a construction of complex geometry in design and ergonomics of wide application. They may have functional value, art direction, etc. The application of advanced technological means which support the design process of furniture made of cardboard allows optimization of the complete process of creating a sustainable design.