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.

The depopulation of the Bulgarian villages.

Abstract: The depopulation process in Bulgaria, especially in rural areas, is intensifying due to deepening unfavourable trends in the dynamics of demographic processes. Depopulation is a typical process in the fourth phase of demographic transition in rural areas of Bulgaria. The death rates exceed birth rates in the rural areas in the mid-1970s. The size of rural population and the number of villages in the country has been decreasing in the last decades. A large part of the villages were affected by depopulation processes during the period 1985-2007. A high depopulation level is observed in border and mountainous regions. The depopulation generates an array of different negative trends in the spatial aspect - in socio-economic development, technical and social infrastructure, as well as the erasure of many small villages. The regional development plans need to embed measures for infrastructural development in order to attract and retain residents, utilise natural and cultural-historical heritage, and to stimulate economic activities and the development of various types of tourism, etc.

Effects of Heavy Metals in Lake Water and Sediments on Bottom Invertebrates Inhabiting the Brackish Coastal Lake Łebsko on the Southern Baltic Coast.

Abstract: Lake Łebsko is the largest and most productive coastal lake of the southern Baltic Sea to which it is permanently connected. The shoreline is well-developed, and the lake is divided into three parts: eastern, central, and western. Seawater intrusion affects most strongly the eastern part, where the Łeba River connects it with the sea. Samples of water and sediments were collected in 2014–2015. In the same places and time interval, bottom fauna was collected to determine the influence of environmental predictors on its qualitative-quantitative structure. Metals Cr (chromium), Pb (lead), Ni (nickel), Cu (copper), and Al (aluminium) in the samples were analyzed using inductively coupled plasma optical emission spectrometry. Most of the analyzed physicochemical variables of water were significantly higher in the eastern part: conductivity, salinity, sulfates (p < 0.0001) and chlorides (p = 0.01). Metal concentrations in water did not differ significantly between the lake parts, but in sediments they were generally higher in the western part. During the study, we detected significant changes in descriptors and abundance of the major groups of benthic fauna (Oligochaeta and Diptera), mostly between the eastern and western parts. BIO-ENV analysis showed that the benthic community of Lake Łebsko is shaped primarily by physicochemical variables of water (42% of the variance), linked with intrusion of seawater. Secondarily, the structure of the benthic community is affected by the amounts of heavy metals in sediments (31%) and water (12%). The findings can help us improve the principles of management of coastal lakes, including modification of hydrological conditions.

The use of CAD applications in the design of shredders for polymers

Abstract: Computer-aided design is now the primary design tool, providing opportunities for enhancing project quality, allowing for detailed analysis of the features of the solution. In the methodology, computer simulation elements were used. Computer simulation aims to reconstruct the course of the studied process from its mathematical model using a computer and to examine the influence of the environment (input signals) and the internal properties of the object (process parameters) on the characteristics of the object. In designing the shredder, in addition to the selection of structural features, it is also possible to perform strength and kinematic simulations, resulting in a higher quality of the target solution. The results of the simulation work presented in the paper indicate a wide range of possible applications - also in the field of food engineering and processing of polymers - eg shredder mechanisms. Particular attention has been paid to limiting the energy consumed on the deformation of samples, eg by pre-compaction of the sample before introduction To the working area of ​​the shredder. It has been estimated that the gap between the rotating discs should be minimized. Establishing design guidelines has resulted in a number of concept designs.

Partial reproductive isolation between European subspecies of honey bees

Abstract: Northern Poland is inhabited by native Apis mellifera mellifera (AMM) and the non-native A. m. carnica (AMC) which was introduced by beekeepers. However, hybrids between the two subspecies of honey bee are relatively rare. The lower than expected proportion of hybrids is hypothesised to be related to reproductive isolation between AMM and AMC. To verify this hypothesis, we allowed the AMM and AMC queens to be naturally inseminated in an area inhabited by both AMM and AMC drones. Genotype of the queens and their sexual partners were derived based on random samples of their worker offspring. Assignment of parental genotypes to the two subspecies was performed with a Bayesian clustering method. In colonies headed by AMM queens, workers were fathered mainly by AMM drones. On the other hand, in colonies headed by AMC queens workers were fathered by drones of both subspecies. The partial reproductive isolation reported here between AMM and AMC may facilitate conservation of the declining population of AMM. Apis mellifera mellifera / Apis mellifera carnica / reproductive isolation / assortative mating / parentage analysis