The aim of the research described in this article was to optimize the basic sulphur process of lignin removal from the raw radially cut basswood (Tilia Cordata) pieces of various thicknesses. Lignin removal took place chemically in several consecutive steps in which the influence of individual parameters was investigated (solutions of NaOH + Na ₂ SO ₃ , KOH + Na ₂ SO ₃ , its concentrations, time of leaching, efficacy of whitening agents, effect of sample washing between individual baths, etc.). Through experiments, it was found that the change of fresh NaOH + Na ₂ SO ₃ solution during the experiment had no significant effect. In contrast, skipping the washing of the samples with boiling distilled water after the hydroxide bath had a significant effect on the rate and efficiency of lignin removal with H ₂ O ₂ in the following step. When comparing the lignin removal efficiency of NaOH + Na ₂ SO ₃ and KOH + Na ₂ SO ₃ , the delignification process was clearly demonstrated to be more effective using the KOH + Na ₂ SO ₃ solution. Application of the above-mentioned procedures has helped to streamline the lignin removal process from solid basswood.

Electricity is the most important form of household energy and one of the most important forms of energy for industry and transport. Electrical distribution in construction and transport is almost exclusively implemented using electrical cables. One of the unresolved problems associated with electrical cables is the release of smoke and the resulting reduction of visibility in case of fire in the area. In this study, a new approach was developed to assess the reduction of visibility in an area affected by an electrical cable fire. This approach is based on the determination of the critical ratio of smoke volume (in the smoke layer and exhausted from the fire compartment) to the length of the burning cable, through which the visibility of reflective and illuminated signs was reduced to a lower limit value (a standard of 10 m). The input data for this approach was the extinction area of the smoke released from one meter of burning cable and the length of the cables in the area. This approach was used to test two power cables (CHKE-V J3x1.5 and CHKE-R J3x1.5) and one signal cable J-H(St)H 1 × 2 × 0.8 with the B2_ca, s1, d1, a1 fire reaction class. The smoke extinction area of the examined cables was determined using a cone calorimeter at a heat flux of 50 kW/m². The obtained data showed that in order to maintain a visibility of 10 m for reflective signs, the critical ratio of smoke volume to length of burning cable was 7.5 m³/m. For illuminated signs, the critical ratio was 2.8 m³/m. The relationship between burning length and visibility allows the calculation of visibility in the fire compartment affected by cable fire only from cables length.

In order to manage the Construction Safety in a professional and due manner, it is of the key importance to have in place an Occupational Health and Safety Management System, consisting, similarly as a house project, of correct foundations as preparation, planning, procurement, properly set up rules and contractual relations, especially if a site of approx. 5,000 daily manpower is of a concern. Pillars of safe construction follow, i.e. education and training, inspections, communication and, last but not least, human behaviour. The purpose of the following article is to introduce the Human Behaviour Improvement Tools applied in the NPP Mochovce, completion process of Units 3&4, focusing on the implementation and the observance of the OH&S rules.