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Biodiesel is produced from renewable energy sources, it is biodegradable, non-toxic, CO2 neutral (it does not contribute to the greenhouse effect), and its use contributes to reducing the emission of harmful substances in urban areas. Most of the biodiesel properties are similar to those of mineral diesel, and it can be used as a substitute for mineral diesel or in a mixture with it. In internal combustion engines, the mixture of diesel and biodiesel significantly improves lubricity compared to conventional diesel and reduces wear and extends the life of the engine. However, larger amounts of biodiesel in the mixture result in a deterioration of low- temperature properties, which is usually prevented by the addition of additives. This is particularly important because European regulations for diesel fuel are moving in the direction of increasing proportions of biodiesel in diesel fuel, which represents a challenge for meeting low-temperature properties using current commercial additives. In our research, we synthesized a polymer additive by radical polymerization from methacrylate monomers and examined the influence of the additive on the low-temperature properties of non-additivated diesel fuel, biodiesel and their mixtures. The synthesized additive had a positive effect on the low-temperature properties of the tested samples and extended the temperature range of their possible use by up to 30 °C.

Biodiesel as fatty acid methyl ester is well recognized as a biofuel and is often considered to improve energy security and reduce the impact of fuel on climate change. It is regularly blended with diesel up to 7 vol% and those blends are still considered diesel (EN 590). Biodiesel is produced from vegetable oil, animal fat or their waste counterparts and methanol. Due to the possibility of using different bio alcohols obtained from fermentation processes, research interest is turning towards longer alcohols like ethanol and butanol. In our research we synthetized different biodiesel using long chain alkyl alcohols and tested the application properties of their two and three components blends. An improvement in lubricity and no degradation in low temperature properties are observed for all blends when comparing them to diesel.

Metal and rubber springs have been used for many years in various industries, but when it comes to applications in the food or pharmaceutical industry where the processes are validated, many additional requirements such as use at elevated temperatures and the possibility of sterilization, exposure to various chemicals (alkaline and acidic), alcohol, active components and very small particles limit the use of many classic springs. In this case, silicone meets many requirements and also has a great advantage because it is characterized by resistance to high temperatures, more than 250 °C. However, the question of durability under dynamic loads arises, ie its mechanical properties after a long period of operation as a spring. The paper compares rubber and silicone material as a spring element dynamically loaded for 7 days at room temperature on tensile properties. Tests have shown that the tensile strength of rubber decreases, while that of silicone increases. However, with regard to obtaining even better properties, an attempt was made to make a spring consisting of a metal spring in which rubber is pressed inside and silicone on the outside so that it can be further sterilized and facilitate validation for the food and pharmaceutical industry.

Composite materials have their wide range of application in automotive industry. Vehicle efficiency in public transportation, among others, have been achieved by using fibre reinforced plastics in interior design but as structural elements as well. This paper proposes a concept solution for a V shaped structural floor element of a passenger module in a city bus. CAD model of floor structural element has been designed from which, in later phases, construction of composite floor will be optimized and designed. For optimal design and strength an FEM model of structural element was made and compared with the real structural element produced from hybrid fibre reinforced polyester composite. For comparison of FEA and real load, structural element was tested under the flexural load and displacement was measured using a GOM Tritop optical measurement system. Compassion showed that difference between real measurement and FEA for maximal displacement is only 11.7%.

The oldest process of additive manufacturing is based on the crosslinking of liquid photopolymers using a light source, the socalled group Vat photopolymerization. This first procedure is called stereolithography (SLA), and more recently it has expanded to digital light processing (DLP), mask stereolithography (MSLA), continuous liquid interphase printing (CLIP) procedures that differ in the mode of illumination. The processes have many advantages, but one of the biggest disadvantages is the need for post curing after processing. The paper describes the MSLA procedure and the influence of the post curing time in the UV chamber on the tensile properties. The experiment plan was analyzed in the software Design Expert using analysis of variance. From the analysis it can be concluded that an increase in the post curing time leads to an increase in tensile strength of 53% and tensile modulus of 120%, but post curing reduces the elongation/strain by 64% and changes the color of the product.