Andrei Szollosi-Mota

While polyurethane acoustic foam is widely used in entertainment settings for sound absorption, it poses a considerable fire risk when exposed to sparks from pyrotechnic devices. Even though fountain-type pyrotechnic devices are often perceived as producing “cold sparks”, the ignition potential of a single incandescent particle remains insufficiently quantified. This study experimentally investigates the ignition capacity of a fountain-type pyrotechnic article on pyramidal polyurethane acoustic foam under controlled conditions. Three dedicated experimental configurations were developed: (i) ignition probability tests at various distances, (ii) scaled configuration tests reproducing realistic installation geometry, and (iii) high-speed visualization of single incandescent particle interaction with the foam surface. For the first two configurations, ignition probabilities of 20% and 22.2% were obtained. High-speed recordings showed two distinct interaction mechanisms: particle fragmentation and ricochet, which did not result in ignition; partial penetration with localized melting, volatile release, and gas-phase ignition when residual thermal energy (about 0.5–1 J) was retained. The results demonstrate that even isolated single incandescent particles generated under realistic conditions can initiate the combustion of polyurethane acoustic foam. These findings challenge the “cold spark” safety perception and provide quantitative evidence that particle–induced ignition represents a significant fire hazard in enclosed environments where combustible acoustic materials and pyrotechnic effects coexist. The findings in this paper have direct implications for safety regulations in entertainment venues.

When fine particles known as flammable powders are suspended in the air under specific circumstances, they have the potential to explode. There could be many serious fatalities, injuries, and structural damage as a result of a dust explosion. By being aware of the flammability parameters and the physico-chemical analysis for flammable powders and taking additional protective measures as a result of the occurrence of these kinds of catastrophic mixes, the risk of such incidents can be decreased. The goal of this study was to determine the flammability characteristics of two combustible powders, magnesium and aluminum powder. These characteristics included the lowest ignition temperature of the dust cloud and dust layer as well as certain physicochemical studies of the composition.

Agricultural waste is found in abundance in the environment, whether it is the plant itself represented by the stem, leaf or seeds that have been peeled or other waste. By drying and crushing the residues from the plants, organic powders will be formed with a variable granulation and humidity. Through the processing of oilseeds such as sunflower seeds, significant amounts of waste from seeds result. Seed shells resulting from technological processes crumble, forming fine powders, whose granulations are different. A certain percentage will be 63μm or smaller and if those fine powders are mixed with air can form clouds with explosive properties. The purpose of this paper was to determine the minimum ignition layer and cloud temperatures. Experimental determination of flammability parameters is particularly important in order to take the proper safety measures so that accidents can be avoided.

The aim of this paper was to determine the concentration of heavy metals in dust samples by the method of analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) and to assess the degree of pollution of the studied areas. The dust samples studied and subjected to analytical analyzes were collected from the vicinity of industrial areas and urban areas of localities in the Jiu Valley, a monoindustrial area. The main heavy metals determined were: Cu, Zn, Pb, Ni, Cr, Co etc. Dust particles depending on their origin can be inorganic or organic. The samples were collected from the urban areas and from the vicinity of the industrial areas.

The analysis of the samples collected from residential areas and the proximity of the industrial areas of Jiu Valley was carried out by means of induced coupled plasma optical emission spectrometry (ICP-OES) after acid processing and mineralization of the samples. The pollution level has increased once with the industrial development and acceleration of urbanization processes in the human society. Of the pollutant-generating substances, heavy metals are of particular importance. The purpose of this paper is to highlight level of pollution by heavy metals using moss (inferior plants) in order to determine the degree of bioaccumulation. From the pollution point of view, zinc, cadmium and lead are of particular relevance, but the effects of other heavy metals have also been studied. The pollution effects last for a long time in waste dumps, areas polluted with heavy metals from fuel combustion processes, fossil fuels a.s.o. The analysis of the samples collected from residential areas and the proximity of the industrial areas of Jiu Valley was carried out by means of induced coupled plasma optical emission spectrometry (ICP-OES) after acid processing and mineralization of the samples.

The dust cloud is the main form of existence of combustible dust in the production area and together with the existence of effective ignition sources are the main causes of dust explosions in production processes. The minimum ignition temperature has an important role in the process of selecting the explosion-protected electrical equipment when performing the explosion risk assessment of combustible dusts. The heated surfaces are able to ignite the dust clouds that can form in process industry. The oil products usually contain hydrogen sulfide and thus on the pipe walls iron sulfides can form, which can be very dangerous from health and safety point of view. In order to study the influence of the pyrophoric sulfide over the minimum ignition temperature of combustible dusts for this work were performed several experiments on a residue collected from the oil pipes contaminated with commercially iron sulfide.