In recent years, an increasing trend towards replacement of conventional fossil-based plastics with bio-based plastics was noticed, i.e., production of plastics partly or fully made from biomass is rapidly expanding. Currently, bio-based and biodegradable plastics have a very small market size, approximately only 1% of all plastics produced. However, the forecast of the global bioplastics production capacities predicts an increase from approximately 2.417 million tonnes in 2021 to approximately 7.593 million tonnes in 2026, more than three times the current capacity. Therefore, it is necessary to assess the challenges and identify the barriers for bio-based and biodegradable plastics for waste management and to evaluate the effectiveness of current plastic waste management strategies for the efficient waste management of bio-based and biodegradable plastics. The main barriers and motivators of the biodegradable and biodegradable plastics market that have been identified include macroeconomic factors, regulatory factors, technological factors, and social factors. The bio-based and biodegradable plastics have to be separately collected and treated under mostly controlled, regulated conditions. However, currently, there are no legal provisions providing for the separate collection of bio-based plastics, leading to their disposal with either hazardous waste, conventional plastics, or municipal waste. Since the effective plastic waste management strategy relates to good performance in each step of the waste management process, bio-based and biodegradable plastic waste management could, therefore, be based on an effective strategy for the management of plastic waste. However, there is a need for standardizing waste collection systems and creating a harmonized waste collection infrastructure, which would lead to effective sorting of bio-based plastic waste.

The reliability of the wind turbine blade (WTB) evaluation using a new criterion is presented in the work. Variation of the ultrasonic guided waves (UGW) phase velocity is proposed to be used as a new criterion for defect detection. Based on an intermediate value between the maximum and minimum values, the calculation of the phase velocity threshold is used for defect detection, location and sizing. The operation of the proposed technique is verified using simulation and experimental studies. The artificially milled defect having a diameter of 81 mm on the segment of WTB is used for verification of the proposed technique. After the application of the proposed evaluation technique for analysis of the simulated B-scan image, the coordinates of defect edges have been estimated with relative errors of 3.7% and 3%, respectively. The size of the defect was estimated with a relative error of 2.7%. In the case of an experimentally measured B-scan image, the coordinates of defect edges have been estimated with relative errors of 12.5% and 3.9%, respectively. The size of the defect was estimated with a relative error of 10%. The comparative results obtained by modelling and experiment show the suitability of the proposed new criterion to be used for the defect detection tasks solving.

This research utilizes Ultrasonic Guided Waves (UGW) to inspect corrosion-type defects in steel pipe walls, providing a solution for hard-to-reach areas typically inaccessible by traditional non-destructive testing (NDT) methods. Fundamental helical UGW modes are used, allowing the detection of defects anywhere on the pipe’s circumference using a limited number of transducers and measurements on the upper side of the pipe. Finite element (FE) modeling and experiments investigated generating and receiving UGW helical waves and their propagation through varying corrosion-type defects. Defect detection is based on phase delay differences in the helical wave’s signal amplitude peaks between defective and defect-free regions. Phase delay variations were noted for the different depths and spatial dimensions of the defects. These results highlight the phase delay method’s potential for NDT pipeline inspection.

The applications of ultrasonic Lamb waves are becoming more and more frequent and diverse in industrial fields. These waves are used in non-destructive testing (NDT), structural health monitoring (SHM), for the assessment of the quality of materials, etc. However, due to the unusual properties of these waves, new or adapted signal processing methods are necessary to use for the analysis of such wave signals. Based on the requirements of ISO 17025, the work presents the methodology for verification of the signal processing methods used to reconstruct the dispersion curves of the phase and group velocities of Lamb waves. The key sequence of the mathematical and experimental stages, which must be passed to evaluate the reliability of the methods are developed. The present methodology includes the algorithm to optimally quantify the uncertainty, as to avoid additional testing, saving cost and time. The main characteristics and sources of the uncertainties, that mainly affect the accuracy of the obtained results are identified, analyzed, and presented. New standards for certification testing, inspection, and monitoring can be developed more easily and quickly based on the provided methodology in the future.

This study presents two simple physiotherapy programs that were implemented for five weeks and showed positive changes in balance, coordination, and motor skills in kindergarteners with ASD. Physiotherapy programs in a gym and games on a smart board with balance plates and an unstable base were applied to improve the physical condition of children with ASD. Thirty children with ASD (4–6 years old) attending special needs kindergarten were enrolled in the study. Three tests were used to assess participants’ physical condition before and after the study: the modified Berg Balance Scale, the Imbalance Coordination Sample, and the Bruininks–Oseretsky Motor Proficiency Test (BOTMP). The resulting mean change, calculated from each group’s scores, shows that the participants who received physical therapy sessions at the smart board had the greatest change of 1.58 points. It shows that the opportunity to play games on a smart board motivates children with ASD to work harder; therefore, it is a simple and easy way to engage children in different types of physical exercise. A slightly smaller change of 1.51 was obtained in the group that received gym sessions. However, working in the gym was more psychologically challenging for the children with ASD due to their lack of desire and motivation. Both methods are relatively simple and easy to apply at home; therefore, parents can make a significant contribution to improving children’s physical condition and that can be an effective tool to assist these individuals with activities in daily life.