W niniejszej pracy zbadano wpływ gazu Browna (HHO), gazowej mieszaniny wodoru i tlenu wytwarzanej w procesie elektrolizy wody, na zużycie oleju napędowego w małym silniku o zapłonie samoczynnym. Badania eksperymentalne przeprowadzono na stacjonarnym agregacie prądotwórczym pracującym w różnych warunkach obciążenia elektrycznego, z różnymi prędkościami przepływu gazu HHO dostarczanego do układu dolotowego silnika. Zużycie paliwa mierzono grawimetrycznie i analizowano w odniesieniu do obciążenia silnika oraz stosunku HHO do oleju napędowego. Wyniki pokazują, że dodatek HHO może zmniejszyć zużycie oleju napędowego, szczególnie przy wyższych obciążeniach silnika, z zaobserwowaną redukcją do około 4% w optymalnych warunkach. Jednakże zapotrzebowanie na energię elektrolizera potrzebnego do wytwarzania HHO znacznie przekracza uzyskane oszczędności paliwa. Można stwierdzić, że pomimo mierzalnej poprawy sprawności spalania, stosowanie systemu HHO zasilanego z instalacji elektrycznej pojazdu jest nieuzasadnione energetycznie i ekonomicznie.
Despite a long-term decline in the total number of road accidents in Poland, pedestrian safety remains a serious public health concern. Pedestrians continue to account for a substantial share of fatalities and serious injuries, with careless entry onto the roadway and illegal crossing being the dominant behavioral causes. This study investigates regional differences in pedestrian-caused road accidents across all 16 Polish provinces between 2018 and 2024. The analysis is based on official police accident statistics and applies descriptive statistics, normalized safety indicators (accidents per population and fatalities per accident), and correlation analysis to assess relationships between accident causes and their consequences. The results show strong regional differentiation. Highly urbanized provinces such as Mazowieckie and Śląskie record the highest absolute number of pedestrian accidents, while eastern provinces, including Lubelskie and Podkarpackie, exhibit significantly higher fatality rates per accident despite lower incident counts. Behaviors such as lying or sitting on the roadway are associated with the highest accident-to-incident ratios (up to 75%) and the highest mortality levels, reaching 50% of accidents. The findings demonstrate that accident frequency alone does not adequately reflect pedestrian safety and highlight the need for region-specific preventive measures. The results may support evidence-based regional road safety policies aimed at reducing pedestrian fatalities.
Wastewater is contaminated liquids discharged from homes and industrial plants. A wastewater treatment plant is a complex of basic technological facilities directly used for wastewater treatment, along with auxiliary facilities located on a shared site, necessary for supplying electricity and water, creating appropriate operating conditions, and maintaining the treatment plant. Brewing industries produce wastewater with high organic loads, characterized by high values of parameters such as BZT5 and ChZT. For this reason, these plants typically have their own wastewater treatment systems or cooperate with local municipal wastewater treatment plants. There is growing interest in energy recovery in this industry, for example, through the use of biogas generated during treatment processes, which contributes to cost reduction and a reduction in pollutant emissions. However, the variable composition and load of wastewater remain a challenge, as does the need to properly combine mechanical, biological, and chemical methods to reduce waste volume and its environmental impact. Preparations containing surfactant compounds are used to clean these types of industrial installations. The work was supplemented with an analysis of the content of anionic and nonionic surfactants. Their levels in wastewater—both raw and treated—can be determined using dedicated cuvette tests and the MBAS (for anionic surfactants) and BiAS-thio (for nonionic) methods. The assessment of treatment plant efficiency was based on the pollution reduction index, comparing the content of specific parameters before and after treatment, and the permissible pollutant values in treated wastewater discharged to surface waters.
The shipbuilding industry in Poland, Europe and the United States has been struggling in the 21st century with asymmetric competition from Asia. For several renowned shipyards – including those in Gdansk – identifying pathways for development and creating innovative solutions has become essential for survival. This article presents the dilemmas and research outcome that form part of the preparation for a project aimed at developing an innovative solution grounded in nature-based technologies supported by artificial intelligence. The project on efficient water management for planned production processes in the shipyard constitutes one component of the broader EcoTech initiative, which addresses a wider set of developmental needs of the shipbuilding sector, particularly in Gdansk. This article tackles the challenge of holistically identifying the wide spectrum of developmental conditions as well as the methodological responsibility guiding research and development activities intended to generate breakthrough solutions with business significance.
We analyze the formation of the boundary layer and point to its affinity for diffusion. Based on Prandl'swork, we discuss the properties of the boundary layer and its transition to the vortex state. We also describe theways to reduce the unfavorable effects of the boundary layer encountered in nature.
