This paper presents the laboratory test stand that is used for experimental validation of underground power cable system models. Determination of temperature distribution in the vicinity of the cable is the main goal of the study. The paper considers a system of three power cables, situated in the in-line arrangement, and buried in sand. Three electrical heaters of special construction are used in order to simulate the heat flux that is generated in the power cables during their operation. The test stand is designed to be placed in a thermoclimatic chamber, which allows testing the system in various thermal conditions when the ambient temperature changes by 20 °C to 30 °C. Numerical computations of the steady-state temperature fields are performed using the finite element method.

The study aimed to determine the effect of acute, one-time physical effort performed under different environmental temperature conditions on erythrocyte deformability in healthy young men. This exploratory randomized parallel-group study involved 30 men randomly assigned to an experimental group exercising at −10 °C in a climatic chamber and a control group exercising under thermoneutral outdoor conditions. Erythrocyte deformability was assessed using the elongation index (EI), reflecting erythrocyte elasticity and the ability to pass through microcirculation vessels. Participants performed an incremental 20 m shuttle run test. Venous blood samples were collected before and immediately after exercise, and erythrocyte deformability was analyzed using a Lorrca analyzer across a shear stress range of 0.30–60.00 Pa. A two-factor repeated-measures analysis of variance was applied. An increase in EI after exercise was observed in both groups, predominantly at higher shear stress values, indicating enhanced erythrocyte deformability under conditions of increased shear forces. However, the magnitude of post-exertion changes differed between groups. At lower shear stress levels (0.30 Pa and 0.58 Pa), EI tended to decrease after exercise. These findings indicate that a single bout of physical effort influences erythrocyte deformability, while the potential effects of cold exposure on this response remain uncertain and warrant further investigation.

Maintaining temperature stability within the cold chain is critical to preventing food spoilage and financial loss. Insulated containers (coolboxes) using eutectic plates are widely employed to maintain passive cooling during transport. However, mechanical wear, seal damage, or improper latching can lead to microclimatic fluctuations inside the container, compromising product safety. This paper presents a non-invasive method for the automatic detection and classification of the technical state of coolboxes (fully functional, conditionally functional, and faulty) based on internal temperature and humidity measurements collected via wireless IoT sensors. Experimental trials conducted in a controlled climatic chamber simulating real-world operations demonstrate that micro-temperature gradients and heating rates allow for the early detection of seal degradation and incomplete door closures before critical thermal thresholds are violated. Specifically, the results confirm that uncompressed or damaged seals accelerate internal heating rates by up to 60%, and the diagnostic algorithm successfully classifies technical states with high sensitivity based on a degradation index threshold (∆Q ≤ 10% for fully functional, 10% < ∆Q ≤ 30% for conditionally functional, and ∆Q > 30% for faulty units). The proposed diagnostic framework supports predictive maintenance and improves overall cold-chain traceability.

Background: Exercise in the cold is an attractive option for many athletes. Erythrocyte aggregation, as one of the main rheological parameters, constitutes an important indicator of microcirculation and oxygen transport capacity in the human body. Acute exercise and environmental cold may alter erythrocyte aggregation. We compared immediate hematological, aggregation, metabolic, and hormonal responses to progressive shuttle run exercise in a cold chamber and outdoors. Methods: This exploratory parallel-group analysis included 30 young healthy male students allocated to exercise in a climatic chamber at −10 °C (n = 15) or outdoors at 18 °C (n = 15). Blood was collected before and immediately after exercise. Group × time interactions were assessed using repeated-measures ANOVA and within-group comparisons used Bonferroni adjustment. Results: Erythrocyte amplitude of aggregation (AMP) showed a significant group × time interaction (p = 0.0014). In the paired analysis, the between-group difference in AMP change was −3.24 au (pointwise 95% CI −5.12 to −1.36). Lactate showed a nominal interaction (p = 0.016). Within the experimental group, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, aggregation index (AI) and lactate increased, whereas AMP and aggregation half-time (T½) decreased (all p < 0.001). Estimated plasma-volume change did not differ significantly between settings. Conclusions: Exercise in the cold-chamber setting was associated with a greater reduction in the optical aggregation amplitude. Further studies are needed to clarify the contribution of temperature and the physiological significance of these changes.