The presented proceedings include selected articles from the 4th International Conference on Science and Technology Applications (ICoSTA). The edition presents research results and engineering solutions on actual issues in areas of structural mechanics, nuclear reactor exploitation and thermal energy equipment design, measurement methods and sensors applications, methods and algorithms of data and image processing, materials for biomedical engineering, modern biotechnologies and technologies for environmental protection and plant cultivation, waste and biomass conversion technologies, as well as quality control and failure analysis in power plant equipment. The publication will be helpful to specialists in mechanical engineering, biomedicine, power energy production, information technologies and engineering measurements, environmental engineering and agriculture.