Kazimierz Wielki University in Bydgoszcz

About: Kazimierz Wielki University in Bydgoszcz is a education organization based out in Bydgoszcz, Poland. It is known for research contribution in the topics: Luminescence & Population. The organization has 1109 authors who have published 2923 publications receiving 19548 citations. The organization is also known as: Casimir the Great University & Uniwersytet Kazimierza Wielkiego w Bydgoszczy.

Properties of wood–plastic composites made of milled particleboard and polypropylene

Abstract: Particles derived from milling three-layer particleboards, with sizes from 0.5 to 3 mm, were used for making composites with polypropylene by an injection moulding method. Maleated polypropylene was used as a coupling agent. The objective of this study was to evaluate the mechanical and physical properties of the composites made from particleboard and polypropylene with respect to the content of particles derived from particleboard and coupling agent addition. Properties of the composites did not differ significantly from those of composites with virgin industrial wood particles used for manufacturing particleboards. Moreover, these properties were comparable with the properties of typical wood–plastic composites with wood flour. Particles derived from milling particleboards have proved to be an effective alternative wood component of wood–plastic composites.

Analysis of the influence of the cutting edge geometry on parameters of the perforation process for conveyor and transmission belts

Abstract: Perforated belts, which are used in vacuum conveyor belts, can have significantly different mechanical properties like strength, elasticity due the variety of used materials and can have different thickness from very thin (0,7 mm) to thick belts (6 mm). In order to design a complex machine for mechanical perforation, which can perforate whole range of belts, it is necessary to research the influence of the cutting edge geometry on the parameters of the perforation process. Three most important parameters, which describe the perforation process are the cutting force, the velocity and the temperature of the piercing punch. Results presented in this paper consider two different types of punching (a piercing punch with the punching die or with the reducer plate) and different cutting edge directions, angles, diameters and material properties. Test were made for different groups of composites belts – with polyurethane and polyester fabric, polyamide core or aramid-fiber reinforced polymers. The main goal of this research is to specify effective tools and parameters of a perforation process for each group of composites belts.

Relationship between ACTN3 R577X polymorphism and maximal power output in elite Polish athletes

Abstract: Background and objective: The main purpose of this study was to examine the association between ACTN3 R577X polymorphism and the ability to produce peak power in young male athletes from various sports. Our hypothesis was that the ACTN3 R577X polymorphism is associated with jumping performance and athletes with RR genotype have better scores in tests than athletes with XX or RX genotype independently of the sport discipline. Materials and methods: Two hundred young Polish male participants representing different disciplines were recruited for this study. Genotyping for ACTN3 gene was performed using polymerase chain reaction. The power output of lower extremities and the height of rise of the body mass center during vertical jumps were measured on a force plate. Results: The genotype distribution of the ACTN3 gene did not differ significantly between groups of athletes. The significant difference in height of counter-movement jump was found between athletes with RR and XX genotype (0.446 ± 0.049 m vs. 0.421 ± 0.036 m, respectively, P = 0.026). The ACTN3 RR genotype was associated with greater muscle power and height of jump in young male athletes. Conclusions: These results suggest that the ACTN3 gene may play a significant role in determining muscle phenotypes. However, this gene is only one of many factors which could contribute to athletes' performance and muscle phenotypes.

The Probable Explanation for the Low Friction of Natural Joints.

Abstract: The surface of an articular cartilage, coated with phospholipid (PL) bilayers, plays an important role in its lubrication and movement. Intact (normal) and depleted surfaces of the joint were modelled and the pH influence on the surface interfacial energy, wettability and friction were investigated. In the experiments, the deterioration of the PL bilayer was controlled by its wettability and the applied friction. The surrounding fluid of an undamaged articular cartilage, the synovial fluid, has a pH value of approximately 7.4. Buffer solutions were formulated to represent the synovial fluid with various pH values. It was found that the surface interfacial energy was stabilised at its lowest values when the pH varied between 6.5 and 9.5. These results suggested that as the PL bilayers deteriorated, the hydration repulsion mechanism became less effective as friction increased. The decreased number of bilayers changed the wettability and lowered PL lubricant properties.

Effects of virtual reality-based cognitive training in older adults living without and with mild dementia: a pretest–posttest design pilot study

Abstract: Modern technologies are increasingly used in the development of cognitive interventions for older adults. Research into possible applications of virtual reality in such interventions has begun only recently. The aim of present study was to evaluate the effects of 8 sessions of VR-based cognitive training using the GRADYS game in healthy older adults (n = 72; aged 60–88) and older adults living with mild dementia (n = 27; aged 60–89). Older adults with mild dementia demonstrated worse baseline cognitive performance than participants without dementia. Both groups showed progress in training, which was greater in healthy older adults. There were also significant differences in cognitive functioning before and after the training. However, positive changes were revealed almost exclusively in the group of older adults without dementia. Based on the findings, we can recommend the GRADYS game for cognitive enhancement and as a possible counter-measure for cognitive decline experienced in normal cognitive ageing. Our results provide also support for the usefulness of VR technology in cognitive interventions in older adults. The use of the GRADYS game in persons living with dementia, however, would require several of the hardware and software modifications. Trial registration ISRCTN17613444, date of registration: 10.09.2019. Retrospectively registered