Research papers of the week – February 22, 2021 / Uniwersytet Przyrodniczy we Wrocławiu

Toxic Metals Content in Impacted Third Molars and Adjacent Bone Tissue in Different Groups of Patients

Ewelina Bryła, Maciej Dobrzyński, Damian Konkol, Piotr Kuropka, Marzena Styczyńska, Mariusz Korczyński

Materials

The aim of the study was to determine the content of: Pb, Cd, Cr, Ni, Fe, Mn, Cu, Zn in the impacted third molars and a fragment of covering bone. Patients were divided according to following criteria: place of residence, age, gender, anatomical location of the removed tooth. Content of Cd, Pb, and Mn in the samples increases with age of the patient. The content of Cd and Pb in the tooth and bone was higher in patients living in Wroclaw. Residents of the Wroclaw had higher Cu content in the teeth, while they had a lower content in the jawbone. In contrast to Cd and Pb, an average of 68% higher concentration of Zn in the jawbone than in the tooth was noted. The content of Cr in tooth was lower by 33% than in the mandible bone and, similarly to the content of Ni, it decreased with age. In women, the Fe content in bone of the jaw was higher than in the removed tooth. The presence of Pb and Cd aggregates is confirmed in all hard tissues of the tooth and bone, in contrast to bioelements which show a stronger tendency to aggregate, essentially within the dentine.

10.3390/ma14040793

READ THE PAPER UPWr Base

Innovative aerodynamic grain separation system for plant harvesting in sloped areas: problems, research and optimization of parameters

Jerzy Bienek, Piotr Komarnicki, Jerzy Detyna

Archives of Civil and Mechanical Engineering

This article presents the main problems associated with cereal harvesting in sloping areas. The presented innovative aerodynamic system supporting the separating unit of combine harvester can be one of the ways to counteract the negative effects of harvesting machines work on slopes. The Monte Carlo numerical method, presented in this article, was applied in the optimization of an aerodynamic sieve separation process on an inclined terrain. The given variables are the transverse slope of separator α (of the sieve), longitudinal slope β and the output of the main and side fans. The Monte Carlo method makes it possible to determine an optimized set of parameters (α = 10°, β = 2.8°, δ = 9°), the output of the main fan (0.67 m3 s−1) and the output of the side fan (1.86 m3 s−1), allowing to obtain the best indicator values of 2.1% grain loss and 97.5% grain purity.

10.1007/s43452-021-00174-x

READ THE PAPER UPWr Base