Background/Aim: To evaluate the effect of curing light parameters (intensity, duration, and distance of curing tip) on the depth of cure of conventional resin-based composite. Material and methods: Cylindrical specimens made of nanohybride resin-based composite are cured with 12 different curing protocols, combined with 3 different light intensities (300, 650, and 1100 mW/cm²), 2 distances of curing tip (0 and 8 mm), and 2 exposure times (20 and 40 seconds). The specimens were measured after scraping the uncured composite material according to the ISO 4049 standard. The depth of cure was calculated by dividing the length of the remaining composite by 2. Data were analyzed using: Levene's test and Multivariate Analysis-of-variance (MANOVA). The level of significance was set at P<0.05. Results: The highest depth of cure (3.332 mm) was observed for curing protocol 1100mW/cm²/0mm/40s. The lowest depth of cure had specimens cured with curing protocol 300 mW/cm²/8mm/20s (2.034mm). MANOVA showed a significant influence of the distance of the curing tip (P=0.014; P=0.001) regardless of light intensity and duration of exposure time. Exposure time was a significant factor (P=0.009) when cured from different distances. Although higher light intensity produced a higher depth of cure, light intensity was not a significant factor. Conclusions: The depth of cure can be increased by reducing the distance of the curing tip, when it is possible. At a distance of 8 mm, the depth of cure can be increased by a longer exposure time, regardless of curing light intensity.

Proper nutrition is important for the healthy growth and development of preschool children. During this period, they undergo rapid physical, cognitive, and emotional changes, making it essential to provide both the necessary nutrients to support their overall development and hygienically safe foods. Maintaining high sanitary and hygienic standards in preschool food facilities requires a comprehensive approach that integrates regulatory compliance, facility design, staff training, and effective sanitation practices. By prioritizing these standards, preschools can provide a safe and healthy environment that supports the well-being and development of preschool children. Regulatory requirements form the backbone of sanitation standards in preschools. These guidelines are often established by public health authorities and childcare regulators, setting out minimum standards for cleanliness, food handling, and facility maintenance. Adherence to these regulations ensures that preschools provide a safe and healthy environment for children. Essential components include proper kitchen design, adequate ventilation, pest control measures, and accessible handwashing facilities. Assessing the effectiveness of hygiene practices in preschools involves a multi-pronged approach, including regular inspections, health monitoring, feedback collection, staff training assessments, and incident analysis. By continuously evaluating and improving hygiene practices, preschools can provide a safe and healthy environment for children.

We consider the machinability of the material as a technological feature that expresses the ability of the material to remove the maximum number of shavings from its machined surface in the minimum time with satisfactory processing quality, with as little cutting force as possible and as little tool wear as possible. The aim of the experimental research in this work is to examine the significance of the influential kinematic parameters of the roughness of the machined surface, i.e. of wood density (ρ), feeding speed (s’) and the number of spiral cutting knices (z) in the process of planning massive wood on the roughness of the newly created processing surface, which will vary in 14 trials, of which 6 are repetitions in the central point of the compositional plan, where the roughness parameter Ra is obtained as an output value, and the analysis of experimental data from the point of view of possible achievement of a better quality of the processed surface. The obtained mathematical model is essentially applicable and can be used to optimize the machinability parameters in the planning process of solid wood, and the experimental results can be used in further research into other parameters of the machinability of solid wood in the planning process.

Paper presents comparative analysis of experimental and analytical results of mechanical properties on truss members. Deformations are experimentally determined on the model of plexiglass truss, using six strain gauges. Strain gauges are measuring the deformation of truss members at the pre-defined measuring points. Knowing modulus of the elasticity and Hooke’s law, it is possible to calculate the stress values. The experimental stress values will be compared with the values obtained by the software and the results will be analyzed.

This study investigates the influence of ultraviolet (UV) radiation on the mechanical properties of Fused Deposition Modeling (FDM) 3D printed materials, specifically polycarbonate (PC) and polylactic acid (PLA) specimens. The research involves conducting experiments on five test specimens of each material exposed to UV radiation and comparing their mechanical properties to those of five control specimens that remain unexposed. The results reveal a significant mean difference between the mechanical properties of the control and UV-exposed materials. UV radiation caused a decrease in tensile strength for the PC material, while the PLA material exhibited an increase in tensile strength. The impact of UV radiation on PLA was more substantial compared to PC. Flexural strength testing showed an enhancement in strength for the UV-treated materials, with UV treatment having a greater influence on the flexural strength of PLA compared to PC. The mechanical properties of PLA were more significantly impacted by UV radiation than those of PC. The study findings suggest that PC and PLA materials exhibit different responses to UV exposure, which may have implications for their practical applications. Further research is needed to fully understand the underlying mechanisms governing these divergent responses and to optimize the performance of each material under UV radiation.

This study aims to investigate the influence of thermal modification (TM) on the physical and mechanical properties of wood. For this purpose, the experimental part focused on selected influential parameters, namely temperature, residence time, and density, while the four-point bending strength is obtained as the output parameter. The obtained experimental data are stochastically modeled and compared with the model created by genetic programming (GP). The classical mathematical analysis obtained treatment parameters in relation to the maximum bending strength (T = 187 °C, t = 125 min = 0.780 g/cm3) and compared with the results obtained by genetic algorithm (GA) (T = 208 °C, t = 122 min, and = 0.728 g/cm3). It is possible to obtain models that describe experimental results well with stochastic modeling and evolutionary algorithms.

Sedentary lifestyle and physical inactivity are some of the leading risk factors for cardiovascular diseases and total mortality. The aim of this study was to examine the effects of dosed physical exercise on the nutritional status of recreational athletes. In this study, we included 50 respondents of both sexes between the ages of 18 and 55, who engage in recreational physical exercise, were included in the study. All subjects had their body mass and height measured before the start of exercise and after three months, based on which the body mass index (BMI), waist circumference, and body fat percentage were determined. The exercise was carried out according to the plan 3 times a week for 75 minutes and combined anaerobic training (45 minutes) and aerobic training (30 minutes). The average body weight of all subjects at the beginning of the study was 81.74 kg, while at the end it was 80.16 kg. The average body weight of men at the end of the study was 1.95 kg less than the initial value, while it was 0.71 kg less for women. There is a statistically significant difference in BMI, waist circumference and fat percentage in the total number of respondents at the beginning and at the end of the study. Regular physical activity and exercise have a positive effect on BMI, waist circumference and body fat percentage, showing the importance of exercise in the prevention of obesity and chronic non-communicable diseases.