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The goal of the study was to investigate the effect of different amounts of the CuO nanoparticles used as additive in the coolant on the power and efficiency of the analyzed SI engine. The temperature gradients in the engine body and its components were obtained using the elaborated model of the heat exchange in engine cooled with different fluids. The simplified model of combustion was used to estimate the temperature and power values generated during the combustion process in the engine under given load and speed values. The efficiency of the engine was estimated using the model taking into account various resistances generated during the operation of a given type of engine. The obtained changes in the engine power and efficiency resulted from the changed composition of the engine coolant were presented.

Nowadays, it is commonly strived to achieve the highest efficiency of internal combustion engines and the longest possible inter-repair millage conditioned by low wear of engine components. This needs the reduction of the friction and wear intensity for the mating surfaces of engine components. This is commonly achieved by using the right oil, its additives and coating the surface with protective layers. Various nanoparticles, such as TiO2, ZrO2, CuO can be added to the base oil to change lubricating properties and creating so-called nano-oils. Parallelly, mating engine surfaces are often covered with very thin DLC coatings. Lubrication of DLC-coated surfaces with nano-oil can create both positive and negative synergy effects. The goal of the present review is to recognize the state-of-art in terms of existing types of DLC coatings and techniques for their application, types of nanoparticles dispersible in engine oils and the tendency to create a synergistic effect in contact zones.

Cooling is one of the most important processes conditioning proper operation of combustion engines. The development of the higher-power engines entails greater thermal loads, in which in turn require an increased cooling. The use of nanofluids (NFs) with admixture of metallic or nonmetallic nanoparticles (NPs) promises a potential platform for miniaturization of heat exchangers and/or lower energy consumption. This is attributed to an extended surface area related to NPs in the fluid, which allows for increase of thermal conductivity and a considerable increase of the heat transfer coefficient of the fluid with NPs. Their thermo-physical properties, such as particle size, stability, viscosity, dispersion, heat dissipation efficiency, zeta potential and thermal conductivity and also their behavior under different amount in the base fluid are systematically investigated from the point of view of the choice of the best candidate for coolant applied in modern engines.

The scope of the study is limited to the period of closing valve, but phenomena existing in the antecedent phase influence conditions in the contact between seats. Friction type in such contact varies from mixed to boundary or even dry one, depending on the amount of oil and wear debris wherein. The operational conditions for inlet and outlet valve are different because of temperature in contact and deposition of carbon deposits. The complexity the phenomena in contact zone, including valve rotation makes difficult the modeling of friction. The valve rotation is considered only in macro scale and the other displacements of seats in micro and macro scale. The initial shape of seats resulted from grinding and lapping process varies during impacting and abrasion wear.

Conditions of the bacterial battery have been presented in the article. The models of different design configurations of bacterial battery and its assembly with electric circuit has been elaborated. The obtained values of voltage and currents obtained in such models has been compared with the case of similar circuit using lithium-ion battery and presented in the paper.