Entrepreneurship and Sustainability Issues is a peer-reviewed journal which publishes original research papers and case studies

Cereal straw is a biomaterial with great potential: about 144 million tons of biomass are grown annually in Europe. For any use of straw (fertilizer, biofuel, etc.), efficient chopping technology, i.e., the reliable and efficient operation of mobile or stationary choppers, is the key factor for further success. Since most of the straw is chopped at harvest time, the subject of the study is the wear of the combine’s chopping knives. Six blades of different materials and designs were tested under realistic conditions during wheat and rapeseed harvesting on 180 ha. The influence of hardness, composition, cutting edge angle, and position in the chopper on knife wear was analyzed. The study showed that the blades with the highest cutting edge hardness (568 ± 11 HV) and the lowest cutting edge angle (20.9°) had the lowest wear. The highest hardness of the induction hardened knives was due to the 0.42% carbon content of the steel. The study confirmed that wear was inversely proportional to the hardness of the cutting edge (the harder the cutting edge, the lower the wear) and directly proportional to the angle of the cutting edge (the higher the angle, the greater the wear). The SEM study showed that part of the tooth surface of the blades was covered by permanent deposits of the material to be shredded. This wear was not caused by the interaction between straw and blade but by microabrasive particles that contaminated the straw.

Entrepreneurship and Sustainability Issues is a peer-reviewed journal which publishes original research papers and case studies

Sapropel was used as a biodegradable material for water treatment. Sapropel is a sedimentary layer of a mix of organic and inorganic substances accumulated in the bottoms of lakes for thousands of years. It is a jelly-like homogeneous mass and has properties of sorption. Sapropel is used as a biosorbent and an environment-friendly fertiliser, and it is used in building materials and in the beauty industry as well. In water, there are abundant various solutes that may cause a risk to human health. Such substances include fluorides, nitrates and lead in different sources of water. The goal of this investigation is to explore and compare the efficiencies of removal of different pollutants (fluorides, nitrates and lead) from aqueous solutions upon using sapropel as a sorbent. In this research, various doses of sapropel (0.1, 0.5, 1, 5, 10, 20, 50, 100 and 200 g/L) and various mixing times (15, 30, 60, 90 and 120 min) were used for removal of fluorides, nitrates and lead from aqueous solutions. It was found that the maximum efficiency (up to 98.57%) of lead removal from aqueous solutions by sapropel was achieved when the minimum doses of it (0.1 and 0.5 g/L) were used. The most efficient removal of fluorides (64.67%) was achieved by using 200 g/L of sapropel and mixing for 120 min. However, sapropel does not adsorb nitrates from aqueous solutions.

Entrepreneurship and Sustainability Issues is a peer-reviewed journal which publishes original research papers and case studies

The manufacture of automotive parts using progressive stamping tools demands high precision and efficiency to meet industry standards. This research explores integrating quality monitoring techniques, focusing on load sensors and tonnage monitoring, to enhance the production process. Progressive tools, which perform multiple operations within a single press cycle, are critical for maintaining dimensional accuracy and minimizing defects. This research examines the correlation between real-time load sensor data and the tonnage applied during stamping, aiming to detect anomalies and deviations that may define part quality. By analyzing variations in tool loads and press tonnage, this research identifies patterns that allow the user to connect the applied force with the observed part quality and could help to determine potential issues such as instability of force or part dimensions, tool wear or improper alignment. The results of this research demonstrate that incorporating advanced monitoring systems into progressive stamping processes does not only improve part quality but also extends tool life and reduces downtime. The proposed approach provides a robust framework for ensuring reliability and efficiency in the production of automotive components, aligning with the industry demand for high-quality, cost-effective manufacturing solutions.