The paper presents a static lateral stability of a sub-compact tractor MT8-070 Mini in relation to a safe tractor operation. Axle weight distribution of the tractor was measured to calculate the vertical and longitudinal coordinates of a centre of gravity (COG). Experiments were aimed at the tractor equipped with no and four levels of rear wheel ballast weights (30.5, 61, 91.5 and 122 kg) at standard and extended overall width on tyres. A static overturning angle was calculated and experimentally measured when the tractor with right wheels touching the ground was in a state of unstable equilibrium. Comparing the experimental data with ISO 16231-2 (2015), the differences were 2.57%, 2.80%, 3.04%, 3.42% and 3.88% in the case of the standard overall width on tyres and 2.40%, 2.61%, 3.11%, 3.67% and 3.99% in the case of the extended overall width on tyres at 0, 30.5, 91.5 and 122 kg of the rear wheel ballast weight. Considering the vertical tyre deformation and the lateral shift of the tyre, the differences decreased to 0.95%, 1.11%, 1.29%, 1.85% and 1.42% (standard overall width on tyres) and 0.91%, 1.18%, 1.69%, 2.27% and 2.57% (extended overall width on tyres). The length of a rubber lug of a tyre contact patch did not change when the tractor was inclined at various ballast weights and did not affect the static overturning angle calculation according to ISO 16231-2 (2015). Results showed higher static overturning angle experimentally measured in comparison with calculated according to ISO 16231-2 (2015) due to the tyre deformation. Limiting the tractor operation on the basis of the static overturning angle calculated according to ISO 16231-2 (2015) avoids the tractor usage under dangerous operation conditions.

In general, energy loss reduction via the interaction of tires with the ground improves tractor traction performance when a drawbar pull is generated. This paper is examines the driving wheels with steel spikes for a tractor equipped with modern radial tires. An improved design of the spike device that allows for the change between an active and inactive position of the spikes is presented. The traction performance of a compact articulated tractor with the spike device was tested on a grass plot with two soil moisture contents (SMC). The highest difference in the drawbar pull in the range from 14.2% to 40.5% and from 17.1% to 36.8% was reached by the spikes in the active position in comparison with the tires without spikes, which were at the slip range from 45% to 5% in the case of the low SMC when the test tractor was in the 3rd and 1st gear. The motion resistance difference between the spikes in the active position and the tires without spikes was 11.8% and 2.5% at the low and medium SMC, respectively. At the low and medium SMC, the highest tractive efficiency of 0.765 (0.721) and 0.757 (0.731) was reached by the spikes in the active position when the test tractor was in the 1st (3rd) gear in comparison with 0.736 (0.7) and 0.723 (0.708) in the case of the tires without spikes. The results indicated that the spike device allowed for the improvement of tractor tractive performance.

This scientific article deals with cyclic corrosion testing of bimetallic joints in order to describe the influence of different surface treatment as a protection against galvanic corrosion on bimetallic materials. Multi-material body parts joined with advanced manufacturing technologies are used to achieve the required car properties. Metallic materials have different values of electronegativity and joining increases the risk of corrosion. Different types of coatings are used to prevent galvanic corrosion, but each increases investments and costs. Galvanic corrosion affects the lifecycle of the car. Cyclic corrosion testing provides replicable results to estimate the range of corrosion in a real environment. Test specimens from different materials were riveted and treated with various surface treatments. The method and design of samples preparation is unique and reflects the reality more than current methods. It has not yet been published in any literature. The corrosion test was performed for 6 weeks. Samples were subjected to a salt mist with temperatures of 25 °C and 50 °C, wetting and drying phases. The samples were evaluated according to the standard EN ISO 4628-1:2016. Microscopic and energy-dispersive analysis were performed. Tests have shown considerable galvanic corrosion on uncoated samples. On the samples with ecoated surface galvanic corrosion was not recorded.

Tractor rollover is a very common occupational accident in agriculture. Rear-wheel-drive tractors, which are often used worldwide without a cab, pose the greatest risk to human health and life in case of an overturn. Therefore, this study focuses on operational factors influencing tractor stability on slopes, with regard to the use of rollover protective structures (ROPSs). The static lateral and longitudinal stability of a standard rear-wheel-drive tractor and a modified one enhanced against rollover were compared. The comparison considered the improved geometric dimensions of the modified tractor and its axle load distribution. The influence of ROPS and ballast weights on slope stability of the experimental tractors was evaluated. The modified tractor achieved higher lateral overturning angles in all configurations compared to the standard tractor (from 22.1% to 30.1%). Maximum longitudinal overturning angle reached 37.21° for the modified tractor and 33.32° for the standard tractor (double rear ballast weight). Applying ballast weight to the front and rear of the tractor, the study proposed compensating for the decrease in the tractor stability caused by ROPS, while simultaneously improving longitudinal stability.

A new method has been proposed for detecting the potential adulteration of extra virgin olive oil with processed sunflower oil. This method is based on analysing the laser-induced fluorescence (LIF) spectra of samples. The technique involves measuring the intensity ratio of three specific fluorescence peaks within the 650–750 nm region of the spectra, which are attributed to chlorophyll derivatives. The samples are excited with a 460 nm blue laser in an offset configuration. The results obtained indicate that the relative intensity ratio of these characteristic chlorophyll peaks is consistently correlated with the percentage of oil adulteration. A parameter named the chlorophyll relative intensity (CRI) number has been introduced, which is based on the relative intensity ratios of the chlorophyll peaks in the LIF spectra of the extra virgin olive oil sample. The CRI function demonstrates a linear relationship with the adulteration percentage up to 80%, with a high regression coefficient ( R ² ) value of 0.9984. This method can be applied accurately when the original fluorescence spectra of unadulterated extra virgin olive oil are known, and it can provide valuable information about the source of unknown oil samples.