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 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.
Introduction. The structure of the human body may vary greatly, depending on a number of factors, sociodemographic ones in particular. An analysis of the body composition makes it possible to assess the existing differences and provides broader insight into the multidimensional changes occuring to the human body.
Aim. An investigation of the relationship between selected sociodemographic factors and body composition in an open population of Rzeszów residents.
Material and methods. The study was performed on a group of 101 adults, aged 30-83. Their body composition was examined using bioimpedance analyzer BIA-101 and selected sociodemographic factors were investigated using a survey questionnaire designed for that particular purpse. Mann-Whitney U test and Kruskal-Wallis test were applied to identify statistically significant differences between the examined variables. Additionally, Spearman’s rho correlation coefficient was applied. The study adopted a significance level of p<0.05. Calculations were performed using IBM SPSS Statistics 20.
Results. The findings revealed some significant differences (p<0.05) related to gender, age and employment status, as well as selected constituents of fat mass and fat free mass in the subjects.
Conclusions. Selected sociodemographic factors significantly affect the components of body composition in adults. Further longitudinal studies are needed to confirm the reported differences.