The use of mathematical model of hardness spread in the research on the property of cast-iron molds

The paper determines the range and form of a surface layer of a spheroid cast iron founding. It presents proofs of the possibility to form an operative surface of a product in the range of an intermediate surface layer of the cast. Based on research and experience, one has stated that the hardness spread and structures in cross sections of the wall of a cast are the most representative parameters determining the range of the surface layer of the iron cast

Performance comparison of conventional and composite leaf spring

The automobile industry has shown increased interest in the use of composite leaf spring due to its high strength to weight ratio. The introduction of composite materials has made it possible to reduce the weight of the leaf spring without any reduction in load carrying capacity and stiffness. In this paper, results of research on vibration suppression in steel and composite (Glass Fibre Reinforced plastic – GFRP) leaf springs are presented. Polymeric composite leaf springs and steel springs are studied. Composite springs were designed in such a way that they could replace steel springs in a van. The amplitude of vibrations and the reaction of props were measured and recorded. These parameters rendered it possible to calculate the coefficient of vibration suppression for steel and composite leaf springs. It is concluded that composite leaf springs in comparison to steel springs about three times better suppress vibrations, they are about five times lighter and generate smaller dynamic burdens to vehicle bodies

Performance comparison of conventional and composite leaf spring

The automobile industry has shown increased interest in the use of composite leaf spring due to its high strength to weight ratio. The introduction of composite materials has made it possible to reduce the weight of the leaf spring without any reduction in load carrying capacity and stiffness. In this paper, results of research on vibration suppression in steel and composite (Glass Fibre Reinforced plastic – GFRP) leaf springs are presented. Polymeric composite leaf springs and steel springs are studied. Composite springs were designed in such a way that they could replace steel springs in a van. The amplitude of vibrations and the reaction of props were measured and recorded. These parameters rendered it possible to calculate the coefficient of vibration suppression for steel and composite leaf springs. It is concluded that composite leaf springs in comparison to steel springs about three times better suppress vibrations, they are about five times lighter and generate smaller dynamic burdens to vehicle bodies

Modelling of the Flow of Streams of Cohesionless and Cohesive Bulk Materials in a Conveyor Discharge Point with a Flat Conveyor Belt

The paper presents the analysis of flow conditions of cohesive and cohesionless bulk materials in a conveyor discharge point of a flat conveyor belt. The analysis was carried out for stationary flows at high velocities. It presents mathematical methods for the description of the velocity of a material leaving a throwing point of a flat conveyor belt as well as final equations which enable the determination of velocity of the material after it has left the throwing point (with the accuracy sufficient for practical use). Next, the velocity calculated for the proposed mathematical description (for selected material groups) has been compared with the velocity obtained from mathematical relations commonly used by engineers. The proposed equations for determining the velocity of the material beyond the point have proved useful, since they enable excluding the indirect equations. Finally, the difference between the values of the velocity obtained with the proposed and indirect equations have been determined and the relative error for the proposed method has been calculated

Modelling of the flow of streams of cohesionless and cohesive bulk materials in a conveyor discharge point with a flat conveyor belt

The paper presents the analysis of flow conditions of cohesive and cohesionless bulk materials in a conveyor discharge point of a flat conveyor belt. The analysis was carried out for stationary flows at high velocities. It presents mathematical methods for the description of the velocity of a material leaving a throwing point of a flat conveyor belt as well as final equations which enable the determination of velocity of the material after it has left the throwing point (with the accuracy sufficient for practical use). Next, the velocity calculated for the proposed mathematical description (for selected material groups) has been compared with the velocity obtained from mathematical relations commonly used by engineers. The proposed equations for determining the velocity of the material beyond the point have proved useful, since they enable excluding the indirect equations. Finally, the difference between the values of the velocity obtained with the proposed and indirect equations have been determined and the relative error for the proposed method has been calculated

Some Problems of Automation and Robotization of Welding Process in the Large Size Constructions

W opracowaniu przedstawione zostały wybrane problemy w technologii wykonania kontenerowej konstrukcji stalowej. Omówiona została problematyka możliwości zastosowania robotów przemysłowych w zautomatyzowaniu procesów spawania blachy trapezowej w poszyciu kontenerów.In the study the selected, technological problems of container steel structure manufacturing are presented. Possibility of application of the industrial robots in automation of welding the trapezoidal sheet metal in container plating is discussed

Metabolic syndrome is associated with similar long-term prognosis in non-obese and obese patients. An analysis of 45 615 patients from the nationwide LIPIDOGRAM 2004-2015 cohort studies

Aims We aimed to evaluate the association between metabolic syndrome (MetS) and long-term all-cause mortality. Methods The LIPIDOGRAM studies were carried out in the primary care in Poland in 2004, 2006 and 2015. MetS was diagnosed based on the National Cholesterol Education Program, Adult Treatment Panel III (NCEP/ATP III) and Joint Interim Statement (JIS) criteria. The cohort was divided into four groups: non-obese patients without MetS, obese patients without MetS, non-obese patients with MetS and obese patients with MetS. Differences in all-cause mortality was analyzed using Kaplan-Meier and Cox regression analyses. Results 45,615 participants were enrolled (mean age 56.3, standard deviation: 11.8 years; 61.7% female). MetS was diagnosed in 14,202 (31%) by NCEP/ATP III criteria, and 17,216 (37.7%) by JIS criteria. Follow-up was available for 44,620 (97.8%, median duration 15.3 years) patients. MetS was associated with increased mortality risk among the obese (hazard ratio, HR: 1.88 [95% CI, 1.79-1.99] and HR: 1.93 [95% CI 1.82-2.04], according to NCEP/ATP III and JIS criteria, respectively) and non-obese individuals (HR: 2.11 [95% CI 1.85-2.40] and 1.7 [95% CI, 1.56-1.85] according to NCEP/ATP III and JIS criteria respectively). Obese patients without MetS had a higher mortality risk than non-obese patients without MetS (HR: 1.16 [95% CI 1.10-1.23] and HR: 1.22 [95%CI 1.15-1.30], respectively in subgroups with NCEP/ATP III and JIS criteria applied). Conclusions MetS is associated with increased all-cause mortality risk in non-obese and obese patients. In patients without MetS obesity remains significantly associated with mortality. The concept of metabolically healthy obesity should be revised