## 2 Materials and Methods
The finished installation is shown in Figure 2.  
After the explosion, the follower of the gas analyzer for sampling was placed in a special hole, the principle of operation of which was to automatically perform measurements for some time with the results being displayed and saving them in the device's memory. Then, after each explosion, the chamber was ventilated and treated with a special cleaning compound. The determination of the mass concentrations of nitrogen oxides released from the explosion of the model composition without the addition of a filler was a series of experimental explosions with averaging of the data obtained. At the second stage of the study, experiments were carried out to confirm the effectiveness of the use of catalysts for reducing nitrogen oxide emissions using the same laboratory setup. The fillers were: magnesium carbonate (MgCO\({}_{3}\)), calcium carbonate (CaCO\({}_{3}\)) and zinc carbonate (ZnCO\({}_{3}\)). Each of the selected fillers was used in studies to determine the  
Figure 1: Explosion chamber (photo by the author [PERSON]). Figure 2: Laboratory setup for measuring the concentration of nitrogen oxides (photo by the author [PERSON]). effectiveness of the application in order to reduce NOx emissions. The fillers had the same dispersion and the same percentage in the composition of the sample, which was carried out by particle analysis of substances using an A-30 particle analyzer. At the preparatory stage before the study, the reagents were preliminarily degradation in size and have been dried in a thermal chamber at a temperature of 50 \({}^{\circ}\)C for 12 h.  
To complete the study of the effect of using catalysts as part of a contoured stemming on nitrogen oxide emissions, in addition to conducting an experiment with a model explosive, it is necessary to carry out field experiments with a real explosive. The investigated explosive was pentaerythnitol tetranitrate (PETN), a chemical compound (CH\({}_{2}\)ONO\({}_{2}\))\({}_{4}\)C, a blasting explosive with high sensitivity to impacts, a white crystalline powder with a molar mass of 316.25 g/mol and an oxygen balance of 10.12%. To determine the amount of nitrogen oxides in the explosion products, an explosion chamber with a carrying capacity of 5 L was used, and a GANK-4 gas analyzer with an installed chemical cassette to determine the concentration of nitrogen oxides was used as a device for measuring the concentration of nitrogen oxides of the explosive under study (Figure 3). A steel mortar with a diameter of 100 mm and a height of 100 mm was placed in an explosion chamber. A hole with a diameter of 6 mm and a depth of 60 mm was drilled in the center of the mortar. An electric igniter placed in the lower part of the borehole was used as an initiator. Pentaerythnitol tetranitrate weighing 1.02 g was placed in the charged part of the hole (36 mm). Quartz sand (21 mm) was used as part of the contoured stemming. The installation is shown in Figure 3.  
Further, after conducting experiments without adding catalysts to pentaerythnitol tetranitrate, laboratory studies were carried out using zinc carbonate to determine the concentrations of nitrogen dioxide in explosion products in order to prove, on a practical level, the effectiveness of using highly active catalysts as a way to reduce the concentrations of poisonous gases.