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The purpose of the article was to analyse the reliability, maintainability, and availability estimates of firefighting and rescue engines. Analysing the reliability parameters of heavy firefighting and rescue vehicles over time requires knowledge of their failures. In this article, failure data from the six years of maintenance of ten heavy firefighting and rescue vehicles from ten were analysed in relation to two main subsystems. Reliability analysis was performed and the best-fit distribution was found, with the parameters calculated. For both subsystems, the chassis combined with the cabin and the superstructure, the 2P-Weibull distribution was identified as the most suitable fit. The availability and maintenance indicators for each vehicle and the individual subsystems were calculated. It was clearly defined that there exists a significant difference between the two subsystems analysed in terms of failure characteristics, as well as maintainability and availability parameters. [ABSTRACT FROM AUTHOR]

This year marks the 20th anniversary of the publication by the Institute of Mother and Child in Warsaw of a document establishing the Polish standards for preventive health care of school-age children and adolescents by general practitioners, which are still in force today. Since then, their health status and the health risk factors have changed. Polish society and its expectations of health care are also different. The Polish economy has grown, and the proportion of the public budget spent on health care has increased. The current system of preventive health care for young people seems to be facing a problem. Over the past decade, the percentage of children and adolescents attending preventive medical visits in Poland has decreased by approximately 30%. During well-care visits, doctors commonly avoid selected physical examinations and sensitive topics, such as sexuality or mental health. It appears that most young people visit doctors only because they falsely believe that check-up visits are mandatory and usually rate the experience negatively. The co-authors of this paper conclude that there is a need for a broad debate on the Polish standards of preventive health care for adolescents and their possible reform, which would lead to their adaptation to the challenges of modern times and the opportunities offered by the progress of medical science and technology. The selection of topics is subjective and certainly does not cover all aspects requiring attention. The authors’ intention is to contribute to further discussion rather than to provide a basis for conclusions or postulates. [ABSTRACT FROM AUTHOR]

The objective of the study was to carry out an analysis of changes in mechanical properties of polymer composites in conditions of thermal load. Such an analysis may allow an initial verification of possibilities of deploying new composites in production of fire helmet shells. The reference material chosen for testing was the Ultramid composite, which is currently used for the production of fire helmet shells. In addition three different materials were selected that contained reinforcement by glass fibres bearing the trade name of Tarnamid, which are not used in manufacturing of shells. Testing was conducted in conditions of quasi-static load, during which compressive tests were performed. Mechanical loads were applied at different levels of thermal exposure, which was to simulate presence in fire conditions. Results of tests indicated that the Tarnamid composites are characterised by better compressive strength and rigidity determined on the basis of the Young module value than Ultramid PA66 GF25 used in the production of head protective shells. It has also been proven that thermal loads contribute to significant degradation in strength and rigidity of tested materials, which affects adversely protective properties of the helmet.

This study was undertaken to analyze the influence of nozzle type on a mass spray density. The results indicated that the most uniform droplet distribution and spraying area was observed for the impact nozzle P 54. The highest mass spray density and the lowest spraying were noticed for the spiral nozzle TF 6. The high values of mass spray density for TF 6 nozzle were associated with the high K-factor value and the low spray angle. The results also showed that the construction of spiral nozzles influence the stream structure. The value of average mass spray density was twice as low for CW-50 F nozzle compared to TF 6.

Featured Application: The results of the study could improve the practical use of sorbents and neutralizers during chemical rescue operations. Undertaking effective and prompt action during chemical events is an important measure in preventing the spread of contamination. Studies have shown that despite very high surface activity of nanocrystalline metal oxides, their use does not reduce the fire hazard for hydrocarbon spills and alcohols more effectively than commonly used sorbents during fire rescue operations. Other limitations of specimens containing nanocrystalline oxides have also been proven, such as the maximum absorption similar to commonly used specimens, as well as high costs of conducting the acid neutralization process without increasing the level of safety of operations. Results obtained allowed the determination of proposed principles of effective and economically appropriate application of nanocrystalline metal oxides in rescue units. [ABSTRACT FROM AUTHOR]

The article examines how United Nations and Human Rights Treaty Body Review was foreseen as a chance to re-evaluate the system that monitors countries' compliance with international human rights obligations. It mentions about need of multilateralism with great mobilization for the rights, voice and leadership of women and girls.

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The article presents results of experimental studies on mechanical properties of the polymer-composite material used in manufacturing firefighting helmets. Conducted studies included static and impact strength tests, as well as a shock absorption test of glass fiber-reinforced polyamide 66 (PA66) samples and firefighting helmets. Samples were subject to the impact of thermal shocks before or during being placed under a mechanical load. A significant influence of thermal shocks on mechanical properties of glass fiber-reinforced PA66 was shown. The decrease in strength and elastic properties after cyclic heat shocks ranged from a few to several dozen percent. The average bending strength and modulus during the 170 degree Celsius shock dropped to several dozen percent from the room temperature strength. Under these thermal conditions, the impact strength was lost, and the lateral deflection of the helmet shells increased by approximately 300%. Moreover, while forcing a thermal shock occurring during the heat load, it was noticed that the character of a composite damage changes from the elasto-brittle type into the elasto-plastic one. It was also proved that changes in mechanical and elastic properties of the material used in a helmet shell can affect the protective abilities of a helmet. [ABSTRACT FROM AUTHOR]

This study aimed to determine the relative densities of populations of particles emitted in fire experiments of selected materials through direct measurement and parametrization of size distribution as number (NSD), volume (VSD), and mass (MSD). As objects of investigation, four typical materials used in construction and furniture were chosen: pinewood (PINE), laminated particle board (LPB), polyurethane (PUR), and poly(methyl methacrylate) (PMMA). The NSD and VSD were measured using an electric low-pressure impactor, while MSD was measured by weighing filters from the impactor using a microbalance. The parametrization of distributions was made assuming that each distribution can be expressed as the sum of an arbitrary number of log-normal distributions. In all materials, except PINE, the distributions of the particles emitted in fire experiments were the sum of two log-normal distributions; in PINE, the distribution was accounted for by only one log-normal distribution. The parametrization facilitated the determination of volume and mass abundances, and therefore, the relative density. The VSDs of particles generated in PINE, LPB, and PUR fires have similar location parameters, with a median volume diameter of 0.2–0.3 µm, whereas that of particles generated during PMMA burning is 0.7 µm. To validate the presented method, we burned samples made of the four materials in similar proportions and compared the measured VSD with the VSD predicted based on the weighted sum of VSD of raw materials. The measured VSD shifted toward smaller diameters than the predicted ones due to thermal decomposition at higher temperatures. [ABSTRACT FROM AUTHOR]

Purpose: For splinting or designing adhesive bridges, reconstructive composite structures with increased mechanical properties owing to embedded reinforcement fibres are used. The aim of this article was to determine the influence of glass and aramid fibres on the mechanical strength of composites reinforced with these fibres., Methods: Two polymer-ceramic microhybrid materials: Boston and Herculite were tested. Three types of reinforcement fibres were used: aramid (Podwiązka) with a single layer weave, a single layer weave glass fibre (FSO) and triple layer weave glass fibre (FSO evo). Tests were conducted in accordance with the requirements of ISO 4049:2009. The following material types were chosen for research: Boston, Boston + Podwiązka, Herculite, Herculite + Podwiązka, Herculite + FSO and Herculite + FSO evo. The scope of research included: flexural strength B, bending modulus of elasticity εB and work to failure of the reinforced composite Wfb. Additionally, microscopic observations of fracture occurring in samples were made., Results: In comparison: the Herculite (97.7 MPa) type with the Herculite + FSO evo (177.5 MPa) type was characterized by the highest strength. Fibre reinforcement resulted in decreasing the elasticity modulus: Herculite + reinforcement (6.86 GPa; 6.33 GPa; 6.11 GPa) in comparison with the Herculite (9.84 GPa) and respectively Boston + reinforcement (10.08 GPa) as compared with the Boston (11.81 GPa)., Conclusions: Using glass fibres increases flexural strength of the test composites. Using aramid fibres does not change their strength. The elasticity modulus of the reinforced reconstructive structures decreases after application of either type of fibres. However, their resistance to the crack initiation increases.