The aim of the paper was to discuss different effects, such as, among others, agglomeration of selected nanoparticles, particularly those from zirconia, on the tribological behavior of lubricants. The explanation of the difference between the concepts of ‘aggregation’ and ‘agglomeration’ for ZrO₂ nanoparticles is included. The factors that influence such an agglomeration are considered. Classification and thickeners of grease, the role of additives therein, and characteristics of the lithium grease with and without ZrO₂ additive are discussed in the paper. The role of nanoparticles, including those from ZrO₂ utilized as additives to lubricants, particularly to the lithium grease, is also discussed. The methods of preparation of ZrO₂ nanoparticles are described in the paper. The agglomeration of ZrO₂ nanoparticles and methods to prevent it and the lubrication mechanism of the lithium nanogrease and its tribological evaluation are also discussed. Sample preparation and a ball-on disc tester for investigating of spinning friction are described. The effect of ZrO₂ nanoparticles agglomeration on the frictional properties of the lithium grease is shown. The addition of 1 wt.% ZrO₂ nanoparticles to pure lithium grease can decrease the friction coefficient to 50%. On the other hand, the agglomeration of ZrO₂ nanoparticles in the lithium grease can increase twice the friction coefficient relative to that for the pure grease.

To fulfill the need to limit automotive emissions, reducing vehicle weight is widely recommended and achieved in many ways, both by the construction of individual elements of the vehicle and by the selection of light materials, including Al alloys. Connecting these elements with each other and with elements made of iron alloys can be realized, inter alia, by welding or stir welding. However, the quality of the welds obtained varies widely and depends on many design, operational, and environmental factors. The present study focused on a review of various welding techniques used to join both similar and dissimilar Al alloys utilized in the automotive industry, the effect of various process parameters on weld quality, and the phenomena observed in such welds. The research methodology was based on the analysis of the content of articles from main databases. Apart from capturing the current state of the art, this review evaluates reaching the possible highest joint quality and welding process disadvantages such as porosity, poor surface quality, a tendency toward hot cracking, and low ductility for the Al alloys applied in the automotive industry.

The amount of hybrid vehicles and their contribution have increased in the global market. They are a promising aspect for a decrease in emissions. Different tests are used to determine the factors of such emissions. The goal of the present study was to compare the emissions of two hybrid vehicles of the same manufacturer: the plug-in version and the HEV version (gasoline + electric engine). These vehicles were chosen because they comprise the largest market share of hybrid cars in Poland. The exhaust emission tests were conducted in the WLTC tests on a chassis dynamometer and under real traffic conditions. Simultaneous testing on a dyno and under real driving is the most adequate test to assess the environmental aspects of vehicles—especially hybrids. The combustion engines of the tested vehicles were supplied with gasoline containing 5% biocomponents. The emissions, including CO₂, CO, NO_x, THC and PNs, were measured in accordance with the European Union procedure. According to the latter, the resistance to motion of the chassis dyno was adjusted to the road load, allowing the hybrid vehicles to move in electric mode and allowing the dynamometer to operate in energy recovery mode. The obtained emissions of CO₂, CO, NO_x and THC in the case of the plug-in hybrid vehicle were lower by 3%, 2%, 25%, and 13%, respectively, compared to the case of HEV. Fuel consumption in the case of the plug-in hybrid vehicle was lower by 3%, and PN was lower by 10% compared to the case of HEV (WLTC). In real driving conditions, the differences were more pronounced in favour of the plug-in vehicle: CO₂ emissions in the RDE test were 30% lower, NO_x emissions were 50% lower, and PN was 10% lower. An increase in emissions was only observed for CO₂ emissions—the plug-in vehicle’s on-road emissions were 6% higher compared to the HEV. The obtained emissions for FC and PN varied with actual velocity values due to competitive driving between a combustion engine and an electric motor, as well as existing acceleration and deceleration events during the test and other factors.

This work concerns non-pressure granulation of mineral materials used for the production of agricultural fertilizers for soil deacidification. In order to expand the product range of Nordkalk Poland sp. z o. o. located in Poland, the granulation conditions of the gypsum–lime mix were examined with the use of various granulation methods. The processed mixture was Jurassic lime flour mined in the Sławno mine (Poland) and waste gypsum (sulfogypsum) obtained from the largest coal-fired power plant in the EU, Bełchatów Power Plant (Poland). This paper presents the results of the optimization of the gypsum–lime fertilizer granulation process. The results of the study of granulation of gypsum–lime mixture realized in one-stage technology in a disc granulator were compared with the effects of two-stage agglomeration. During the research, a mixture (in a 1:1 ratio) of waste sulfogypsum and lime flour was used. Such a weight ratio provides maximum use of the sulfogypsum waste while maintaining good mechanical properties of the granulate. The granulated bed was moistened with a lignosulfonate solution. The process was carried out periodically. After the experiment, the grain composition of the granulate obtained was determined and tests were performed to determine the strength of the product. The test results were compared with analogous ones obtained during granulation with the use of molasses (waste from sugar production). The results obtained were verified during a trial carried out on an industrial scale.

Existing methods of determining vehicle velocity based on measurements of body deformation have been based on linear models. This means that the linear relationship between the equivalent energy speed (EES), which is a measure of the kinetic energy lost during the collision of cars, and the value of the ratio C_s, representing the average value of the body deformation, has been sought. The aim of this publication is to present a nonlinear and innovative quick method, or its simpler form, using linearisation in the seven consecutive ranges, for determining EES on the basis of the averaged deformation ratio C_s. The most critical factor for this analysis has been the coefficient b_k, representing the slope of the linear relationship. Its fixed value is appropriate only for the rare case of a linear response of a system of cars interacting during a collision with the internal forces generated in the collision, and carrying out the work of deformation. In a more general case, the assumption of a fixed value of the coefficient b_k, based on the tables for each class of vehicles, can lead to an EES estimation error greater than 30%. This results in a significant difference between the calculated speed and actual speed. The use of a nonlinear model can be a better solution but, on the other hand, it can result in an increase in computation time due to a very small iteration time step and problems of solution convergence due to computation instability. The innovative compromise for such a situation has been the use of linear estimation with different slopes for each of the consecutive seven ranges, which together contain values of the deformation ratio C_s from 0.24 to 0.7. With such an assumption, and using the polynomial regression equations to calculate the b_k coefficient, the authors have obtained an improvement in the accuracy of EES estimation with an error of 2%. Additionally, this enables the use of a quicker computation algorithm.

Various vibrating screens are often applied in various industries, e.g., mining, agriculture, and others. The complex shapes of the screen trajectories in the oscillating motion strongly affect the best processing properties of such machines. One of the possible methods for obtaining such complex shapes is the application of double-frequency vibrators on such screens. The goal of the present study was to analyze the dynamical behavior of the prototype sifter sieve elaborated. The simulation model of such a sifter sieve and the research stand for studies on its sifter trajectories were elaborated. Simulations of sifter motion were conducted, and their results were compared with those obtained from measurements on the research stand. The recommendations as to the frequency ratio of vibrators enabling obtaining a high complexity of sieve movement have been formulated and included in the paper. Particularly, the multiple of the value equal to one third for the ratio of angular velocities under their reverse synchronization for two rotary vibrators exciting the screen analyzed was the best among all analyzed values of such a ratio.