Effect of high-temperature exposure on the microstructure and mechanical properties of the Al5Ti5Co35Ni35Fe20 high-entropy alloy

Effect of high-temperature exposure on the microstructure and mechanical properties of the Al5Ti5Co35Ni35Fe20 High-Entropy Alloy was studied. High-entropy alloys belong to the group of multi-principal element alloys composed of at least five elements with a concentration between 5 and 35 atomic pct. Despite the multicomponent composition, the goal is to achieve a simple solid solution. The alloy was exposed to a temperature range of 650-900 degrees C for 168 h (7 days), after hot rolling and air-quenching. After hot rolling the investigated alloy was not fully supersaturated. The application of air cooling caused gamma' precipitation, which was uniformly distributed within the microstructure. High-temperature exposure caused the growth of gamma' particles. At 700 degrees C and higher, additional continuous and discontinuous precipitation of gamma' was observed. Finally, the microstructure of the investigated alloy consisted of gamma matrix and three types of gamma' precipitates, i.e. spherical gamma' phases with bimodal distribution within the grains and elongated DP gamma' phases present at the grain boundaries. The highest mechanical properties were obtained after exposure to 650 degrees C, which was caused by gamma' precipitation. Further increase in temperature decreased the mechanical properties.Web of Science9155955

Bending and Compression Properties of ABS and PET Structural Materials Printed Using FDM Technology

The bend and compression mechanical properties of 3D-printed polyethylene terephthalate (PET) and acrylonitrile butadiene styrene (ABS) rectangular and cylindrical specimens (fully-dense and with circular, hexagonal, and rectangular perforations) are presented. In three-point bending, fully-dense PET flexural strength was 69 MPa, yield stress was 48.9 MPa, and yield stress from compression was 31.4 MPa. For ABS, these values were 59, 41.7, and 51.2 MPa, respectively – not significantly different from those of polymers manufactured by common techniques. Whereas perforation reduced density, the strength values were significantly lower, decreased for the circular perforation to a value of 20% strength for the fully-dense specimen. Specific strengths dropped quite significantly for the specimens tested in bending, whereas they did not differ significantly when tested by compression

Ocena wartości przyrodniczych polskiej sieci obszarów Natura 2000

The Natura 2000 network includes two types of areas: Special Protection Areas (SPAs) for birds (SPAs) and Special Areas of Conservation (SACs) for species other than birds, and for habitats. The main objective of the functioning of the Natura 2000 is to preserve certain types of natural habitats and species of plants and animals that are considered as a valuable and endangered species across Europe. In Poland, the Natura 2000 network, which is still developing, covers nearly one fifth of the land area. It consists of 845 areas very important to the European Union (areas of “habitat” – future special areas of conservation of habitats) and 145 special protection areas for birds. For each Natura 2000 area a panel of independent experts develop Standard Data Form (SDF), which contains the most important information about the location and size of the area, occurring types of natural habitats and species, their abundance or representative in the country and the natural values and threats. An integral part of the form is a digital map of the area (as a vector and raster). SDF and the borders of areas are often updated. The authors conducted a detailed assessment of the value Polish Protected areas Natura 2000 from the base, dated April 2012 (data for 961 areas). Two criteria were takeninto consideration : 1) the population of the species in a given area, and 2) the representativeness of habitats. The first evaluate typicality of habitat for describing patterns of natural or semi-natural conditions in which habitat and their characteristic flora and fauna is developing, the second – the size of the population in a given area compared to the national population (the larger the share, the greater the need to designate the area protected). From 325 species 19 left as a priority species within14 areas and from 80 habitats there were 16 priority habitats within 282 areas – the results meet the objectives of the adopted procedure.Artykuł nie zawiera abstraktu w języku polski

An Interactive Viewer for Mathematical Content Based On Type Theory

Contains fulltext : 175979.pdf (publisher's version ) (Open Access)24 p

Application of machine-learning methods to recognize mitoBK channels from different cell types based on the experimental patch-clamp results

(1) Background: In this work, we focus on the activity of large-conductance voltage- and Ca2+-activated potassium channels (BK) from the inner mitochondrial membrane (mitoBK). The characteristic electrophysiological features of the mitoBK channels are relatively high single-channel conductance (ca. 300 pS) and types of activating and deactivating stimuli. Nevertheless, depending on the isoformal composition of mitoBK channels in a given membrane patch and the type of auxiliary regulatory subunits (which can be co-assembled to the mitoBK channel protein) the characteristics of conformational dynamics of the channel protein can be altered. Consequently, the individual features of experimental series describing single-channel activity obtained by patch-clamp method can also vary. (2) Methods: Artificial intelligence approaches (deep learning) were used to classify the patch-clamp outputs of mitoBK activity from different cell types. (3) Results: Application of the K-nearest neighbors algorithm (KNN) and the autoencoder neural network allowed to perform the classification of the electrophysiological signals with a very good accuracy, which indicates that the conformational dynamics of the analyzed mitoBK channels from different cell types significantly differs. (4) Conclusion: We displayed the utility of machine-learning methodology in the research of ion channel gating, even in cases when the behavior of very similar microbiosystems is analyzed. A short excerpt from the patch-clamp recording can serve as a “fingerprint” used to recognize the mitoBK gating dynamics in the patches of membrane from different cell types

Metastatic tumors of pancreas — whether and when surgical intervention is gainful for diseased people. Retrospective analysis of data from three surgery centers

Introduction. Metastatic tumors in the pancreas constitute a small (2–5%), but steadily growing percentage of all neoplasms of this organ. The aim of the study was to analyze the surgical treatment of metastases in the pancreas, in particular its effectiveness and the risk of surgical complications. Material and methods. The retrospective analysis was performed on 21 patients treated surgically in three surgical centers. This group included 16 women (76%) and 5 men (24%). The median age at the time of diagnosis of the underlying disease was 55.5 years (41–71). We analyzed the location of secondary lesions, their size, number, type and radicality of surgical intervention, histopathological diagnosis of the disease, as well as the occurrence of postoperative complications. Results. The starting point for metastatic lesions in 16 patients (76%) was renal cell carcinoma (RCC), in other cases — skin melanoma, eyeball melanoma, adenocarcinoma of the rectum, non-small-cell bronchi carcinoma. R0 radical surgery was performed in 15 patients (74%) and perioperative mortality was 5% (1 patient died). The median total survival time was 151 months (10–342), with 168 months for RCC (25–344) and 62 months for the remaining cancers (10–241). Conclusions. The main factor that determines the patient’s future fate is the type of primary neoplasm and surgical treatment of metastatic tumors in the pancreas is the best solution for selected RCC cases