The Application of the ‘K-Nearest Neighbour’ Method to Evaluate Pressure Loss in Water Supply Lines

Water supply systems are complex engineering structures; certainly, the most important part is the water distribution network. The design of this element requires calculations and many analyses to arrive at the best solution. The main task of the calculation is to determine the flow rates through pipes, to determine pressure losses, height of tanks, pressure required in the supply pumping station, pressure levels in the individual nodes of the network. Correct execution of the calculations requires careful evaluation of the results obtained and accuracy in the solutions applied. The issue of controlling the results of calculations is difficult to present in algorithmic form as these are mainly based on the experience and knowledge of the designer. Classes of decisions describing the problems of pressure loss in the pipework were established in order to evaluate the results of calculations. Numerical experiments were carried out in this paper to show how the ‘K-nearest neighbour’ method can be used to evaluate pressure loss in water pipes

Gospodarka odpadami w ramach regionu płockiego – deklaracje mieszkańców

The text of the article pertained to waste management in local government in the region of Płock. In my article described were changes to waste management after 1 July 2013, as well as methods of comparing local governments.Tekst artykułu dotyczy gospodarki odpadami w samorządzie w regionie płockim. W artykule opisano zmiany w gospodarce odpadami po 1 lipca 2013 r., a także metody porównywania samorządów

The Influence of Water Quality Change on the Corrosion Process in Galvanized Pipes of Fire Protection Installations

The article presents the results of an investigation of water composition and quality in sprinkler installations, as well as the influence of temperature changes on the corrosion process. The physical and chemical components of the water were measured to ascertain the influence of its properties on the corrosion process in a wet pipe sprinkler system operating in significantly changing ambient temperature conditions. The article presents the results of measurements of the wall thickness of galvanized pipes and changes in the chemical composition of water occurring under the influence of variable ambient temperature. The range and variability of temperatures corresponded to the seasons of the year: spring and summer in a temperate climate. Changes in the corrosive aggressiveness of water were assessed using the Langelier saturation index (LSI), the Ryznar stability index (RSI), and the general acidity intensity index (I). The tests revealed that the tap water used demonstrated strong corrosive properties for galvanized pipes. The calculated indices showed the tendency of water to cause corrosion (−1.1 > LSI < 1.0; RSI = 7.1–12.8). The chemical parameters that significantly influenced the corrosion of galvanized pipes are chloride (Cl−), sulphate (SO42−), and bicarbonate (HCO3−) ions. An important factor contributing to the intensification of corrosion is the roughness and heterogeneity of the pipe surface

The Influence of Water Quality Change on the Corrosion Process in Galvanized Pipes of Fire Protection Installations

The article presents the results of an investigation of water composition and quality in sprinkler installations, as well as the influence of temperature changes on the corrosion process. The physical and chemical components of the water were measured to ascertain the influence of its properties on the corrosion process in a wet pipe sprinkler system operating in significantly changing ambient temperature conditions. The article presents the results of measurements of the wall thickness of galvanized pipes and changes in the chemical composition of water occurring under the influence of variable ambient temperature. The range and variability of temperatures corresponded to the seasons of the year: spring and summer in a temperate climate. Changes in the corrosive aggressiveness of water were assessed using the Langelier saturation index (LSI), the Ryznar stability index (RSI), and the general acidity intensity index (I). The tests revealed that the tap water used demonstrated strong corrosive properties for galvanized pipes. The calculated indices showed the tendency of water to cause corrosion (−1.1 > LSI −), sulphate (SO42−), and bicarbonate (HCO3−) ions. An important factor contributing to the intensification of corrosion is the roughness and heterogeneity of the pipe surface

The effectiveness of selected decontamination techniques in the process of decontamination of chemical protection suits used by chemical rescue units in Fire Service

The paper presents research of the process of decontamination of chemical protection suits. The results of the research show the effectiveness of selected decontamination techniques. In experiments took into account the influence of the contaminant, the time of decontamination, the type of the decontamination agent and the use of mechanical support in removing the contaminant. The research has shown how to minimize the negative action of hazardous substances on protective clothing and show the problem of the possibility of secondary contamination. They demonstrate the impact of each factors on the quality of decontamination and showed that small changes in the process of decontamination significantly affect the safety of the rescuer. The key to effective decontamination is the synergy effect of the studied parameters. This approach will allow efficient and effective execution of the decontamination process, minimize the risk of contact between rescuers and the contaminant and prevent secondary contamination

Properties of Particulate Matter in the Air of the Wieliczka Salt Mine and Related Health Benefits for Tourists

This study aimed to evaluate the mass concentration of size-resolved (PM1, PM2.5, PM4, PM10, PM100) particulate matter (PM) in the Wieliczka Salt Mine located in southern Poland, compare them with the concentrations of the same PM fractions in the atmospheric air, and estimate the dose of dry salt aerosol inhaled by the mine visitors. Measurements were conducted for 2 h a day, simultaneously inside (tourist route, passage to the health resort, health resort) and outside the mine (duty-room), for three days in the summer of 2017 using DustTrak DRX devices (optical method). The highest average PM concentrations were recorded on the tourist route (54–81 µg/m3), while the lowest was in the passage to the health resort (49–62 µg/m3). At the same time, the mean outdoor PM concentrations were 14–20 µg/m3. Fine particles constituting the majority of PM mass (68–80%) in the mine originated from internal sources, while the presence of coarse particles was associated with tourist traffic. High PM deposition factors in the respiratory tract of children and adults estimated for particular mine chambers (0.58–0.70), the predominance of respirable particles in PM mass, and the high content of NaCl in PM composition indicate high health benefits for mine visitors

Heart Rate Variability and Accelerometry as Classification Tools for Monitoring Perceived Stress Levels—A Pilot Study on Firefighters

Chronic stress is the main cause of health problems in high-risk jobs. Wearable sensors can become an ecologically valid method of stress level assessment in real-life applications. We sought to determine a non-invasive technique for objective stress monitoring. Data were collected from firefighters during 24-h shifts using sensor belts equipped with a dry-lead electrocardiograph (ECG) and a three-axial accelerometer. Levels of stress experienced during fire incidents were evaluated via a brief self-assessment questionnaire. Types of physical activity were distinguished basing on accelerometer readings, and heart rate variability (HRV) time series were segmented accordingly into corresponding fragments. Those segments were classified as stress/no-stress conditions. Receiver Operating Characteristic (ROC) analysis showed true positive classification as stress condition for 15% of incidents (while maintaining almost zero False Positive Rate), which parallels the amount of truly stressful incidents reported in the questionnaires. These results show a firm correspondence between the perceived stress level and physiological data. Psychophysiological measurements are reliable indicators of stress even in ecological settings and appear promising for chronic stress monitoring in high-risk jobs, such as firefighting