Milan Helexa

Dr. Milan Helexa

Technical University in Zvolen, Faculty of technology

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 February 2022 in Applied Sciences
Verified
Journal Article
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MHMilan Helexa
Milan Helexa
JKJán Kováč
Ján Kováč
Jozef KrilekJozef Krilek
Jozef Krilek
JMJán Melicherčík
Ján Melicherčík
KTKuvik Tomáš
Kuvik Tomáš
The article deals with measuring the rolling resistance of two tires Mitas TS04 6.00-16 6PR and Mitas TS05 10.0/75-15.3 10PR on a concrete surface. The measurement was performed in a soil test channel which had to be adjusted for the given purpose. The tires were compared with each other based on the results of the rolling resistance coefficient calculation. The obtained individual values were approximated by linear functions and subsequently subjected to a statistical analysis—a test of the agreement of the regression coefficients of the two basic sets. The results of this analysis showed that there is no statistically significant difference in the values of the achieved rolling resistance coefficients of the monitored tires, although there are differences between them in geometric dimensions and load capacity. The achieved results are basically confirmed by the results of other authors, especially by the fact that on a solid surface the values of the achieved rolling resistances can be reduced by increasing the inflation pressure of the tire. This increase cannot be spontaneous; however, it is always a compromise among the resistances achieved, the life of the tire and its adhesive properties.

10 August 2024 in Forests
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Journal Article
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MHMilan Helexa
Milan Helexa
Jozef KrilekJozef Krilek
Jozef Krilek
Ján Kováč,Ján Kováč,
Ján Kováč,
KTKuvik Tomáš
Kuvik Tomáš
Vladimír MancelVladimír Mancel
Vladimír Mancel
Radoslav MajdanRadoslav Majdan
Radoslav Majdan
Many literature sources state that radial ply tires achieve lower rolling resistance values than cross ply tires. From a certain point of view, radial ply tires are gentler on the ground than cross ply tires. The effort was therefore to experimentally verify this statement for two radial ply and cross ply tires similar in shape and size. The work deals with the diagnostics of rolling resistance levels achieved by radial ply and cross ply tires on selected forest soil under the laboratory conditions of a soil test channel. BKT 210/95 R16 Agrimax RT 855 and Özka 7.50-16 8PR KNK 50 were chosen as radial ply and cross ply tires, respectively, and had approximately the same dimensions. The soil in the soil test channel can be characterized as a loamy sand with an average moisture content of 30% and an initial bulk density of 1445.07 kg·m−3. Another monitored parameter was the diagnostics of changes in soil density caused by tire movement in order to assess the degree of soil compaction. From the results of the work, it follows that there is no statistically significant difference between radial ply and cross ply tires in terms of the achieved levels of rolling resistance on the soil. The observed tires also caused intense compaction of the soil in the soil test channel, especially at higher tire pressures and higher vertical loads. The analysis of the results also shows that changes in tire pressure in both tires cause more energy loss and soil compaction than changes in the vertical load.

17 April 2026 in Agronomy
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Journal Article
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MMMiroslav Mojžiš
Miroslav Mojžiš
Radoslav MajdanRadoslav Majdan
Radoslav Majdan
EMEva Matejková
Eva Matejková
ZTZdenko Tkáč
Zdenko Tkáč
KKKatarina Kollarova
Katarina Kollarova
MHMilan Helexa
Milan Helexa
Despite various technical measures, the soil is negatively affected by the passage of agricultural machinery. This study presents soil resistance measured by a horizontal on-the-go soil resistance force sensor and a vertical penetrologger on a medium-plasticity clay loam (41% particles < 0.01 mm, organic matter 5.43%) in Krakovany village (Western Slovakia). The field has been managed using a no-till system since 2013, with no seedbed preparation performed since 2017. In-track data after multiple passes of a tractor were compared with out-track data. The results indicate that the most significant increase in horizontal soil resistance force occurred after the first pass, with each subsequent increase being smaller than the previous one. The no-till field showed the smallest percentage increase in soil resistance force after one tractor pass compared to conventionally tilled fields previously studied using the same methodology in the same soil region. Out-track SRF reached values similar to those of the conventionally tilled field after harvest. Vertical penetration resistance showed the lowest increase at depths of 9 to 25 cm in the no-till field compared to tilled fields. The highest values were observed at a depth of 9 cm, whereas at 25 cm, the values approached their minimum in comparison with tilled fields. These findings suggest that long-term no-till management may contribute to reducing machinery-induced soil compaction compared to conventional tillage.