This article presents the results of testing the sound pressure level and sound power level of the experimental 3PW-KPF1-24-40-2-776 high-pressure gear pump. Acoustic tests were conducted in an reverberation chamber. The results of the acoustic power tests indicate good acoustic parameters of the tested high-pressure unit.
This paper summarises the results of motion analysis of a platform mechanism with a monolith design. A four-link planar mechanism was engineered in which the platform positioning is effected via one passive link and two eccentric links actuated by stepper motors. The prototype of the device was fabricated following a computation procedure based on the classical mechanism and machine theory and FEM calculations. Testing performed on the model and on the real device revealed the presence of two points on the platform for which the resultant of two independent perpendicular displacements implemented by two stages can be obtained for small values of angular displacement.
This paper presents changes observed in the green areas in the city of Sopot. Analyses of Sopot archival materials, both cartographic and graphic, provided grounds for an assessment of changes and transformations in that respect starting from the 19th century. These analyses covered all the spa town protection zones A, B and C. This study also focuses on the aspect related with the primary function served by the spa town within the city. The city was also investigated in terms of the considerable cultural value frequently associated with green areas, since Sopot is an architectural gem of historical value. The analysis empasised the positive effect of green areas on the health resort character of the city. Green areas in the spa town of Sopot were analysed applying the comparative method. For this purpose maps and city maps were investigated. Additionally, the study is also based on archival graphic materials collected from the dawnysopot.pl website, as well as recent field studies (Świeczkowska, 2017).
Authors present a short review of selected natural-origin zeolite materials. This article discusses the structure, classification and ability to modify natural zeolites, along with examples of their potential applications as adsorbents or catalysts.
European cities are centuries-old connections of social and cultural interrelations in which the history and heritage of generations have formed a specific model of collective life and culture. The nature, prestige and signs of urban life in these cities are best indicated by their public spaces and their structure and inclusion in the urban tissue. Being presentable areas as well as places of social intercourse and activity, public spaces form multipurpose areas which establishe the city’s cultural landscape. Simultaneously, the game for urban areas in the city and related economic interests, and market all activities promoting the city’s image and interfering with the city’s structure, pose a threat to the sensible development of the most valuable parts of the urban space. Globalisation processes contribute to the unification and standardisation of any forms of life, including space. The need for maintaining the continuity of urban tissue requires that its historical traces be cultivated. In this context, the contemporary role of the Old Canal area for downtown Bydgoszcz and its influence on the development of the city’s cultural landscape are part of the current strategies for the culture-forming regeneration of urban space.
This paper presents the practical application of fracture mechanics in investigating the possibility of crack propagation in a brake calliper bracket mounted in a vehicle bogie. The extended finite element method available in the Abaqus software was used. This method allows the modelling of material damage and its propagation independently of the finite element mesh. Damage can arise in any area of finite elements without changing the mesh. Numerical simulation of crack propagation was performed in order to analyse how crack changes as a result of the location change of damage initiation.
This article presents the results of a durability test of a prototype low-pulsation pump. Hydraulic measurements conducted during the test enabled visualisation of the behaviour of the unit in working conditions. The test was conducted according to a strict factory standard, which states that pump performance parameters cannot decrease by more than 8% during durability testing. The material presented in this publication is the result of a study within the project entitled The development of innovative gear pumps with a reduced level of acoustic emission. The solution developed as part of the project has been successfully implemented for a series of gear pumps consisting of twenty-two units. Among other awards, the product won the Gold Medal at the 10th International Fair of Pneumatics, Hydraulics, Drives and Controls, Kielce 2017.
The research aim was to analyse the influence of velocity and size of markers on the accuracy of motion capture measurement utilising image processing with the use of OpenCV. On the basis of the obtained results, the usefulness of the applied measurement method in studying the kinematics of the human body while driving operating a wheelchair was determined. This article presents the test results for a low-budget motion capture measurement system for testing the kinematics of the human body in a single plane. The tested measuring system includes a standard activity camera Xiaomi Yi4K, expanded polystyrene markers with printed ArUco codes, and original software for marker position detection developed by the author. The analysis of the measurement method with regard to its applicability in biomechanical studies has highlighted several key factors: the number of measuring points, measurement accuracy expressed as a relative error and the limit velocity at which the marker trajectory is correctly represented. The article shows that the limit velocity of the marker is 2.2 m/s for 50x50 mm markers and 1.4 m/s for 30x30 mm markers. The number of measured points ranged from 233 to 2,457 depending on the marker velocity. The relative error did not exceed 5% for the marker velocities and thus provided a correct representation of its trajectory.
The threat to health and social life resulting from the spread of the Sars-CoV-2 coronavirus causing the COVID-19 disease has influenced people’s awareness of the need to maintain appropriate hygiene conditions in every area of life. The use of public bathrooms and toilets has also become a controversial topic. The aim of the study was to investigate the risks associated with the use of bathrooms, taking into account the potential risk of coronavirus infection. Another goal was to analyse and indicate the possibilities of protection as well as the application of design solutions in order to maintain appropriate hygienic and healthy conditions in these spaces. As a result of the research, factors and precautions that should be taken into account in the process of designing and implementing these facilities were identified. Design possibilities were examined in the field of the functional and spatial arrangement of bathrooms, and the selection of material solutions, elements of equipment, fittings and technical installations with a particular emphasis on potential threats related to bacteria and viruses, including coronavirus in public bathrooms. Design criteria for bathrooms have been defined, taking into account potential health and social life hazards and the possibility of their elimination thanks to the use of available knowledge, modern technology and innovation.