Influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper

In this study, the influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper after casting and cold deformation was investigated. It was shown that the increase in the casting speed from 0,09 m / min to 0,22 m / min resulted in refinement of the macrostructure and reduction of the crystal cross-sectional area from 3,221 mm2 to 1,2 mm2, which resulted in an increase in microhardness after casting by 8 %, while in the state after cold working, an increase in microhardness by 3 % and ultimate tensile strength by 2,5 %

Influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper

In this study, the influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper after casting and cold deformation was investigated. It was shown that the increase in the casting speed from 0,09 m / min to 0,22 m / min resulted in refinement of the macrostructure and reduction of the crystal cross-sectional area from 3,221 mm2 to 1,2 mm2, which resulted in an increase in microhardness after casting by 8 %, while in the state after cold working, an increase in microhardness by 3 % and ultimate tensile strength by 2,5 %

Ferromagnetism and Electronic Structure of (Ga,Mn)As:Bi and (Ga,Mn)As Epitaxial Layers

The photoreflectance (PR) spectroscopy was applied to study the band-structure in GaAs:Bi, (Ga,Mn)As and (Ga,Mn)As:Bi layers with the 4% of Mn and 1 % of Bi content and, as a reference, undoped GaAs layer. All films were grown by low temperature (LT) MBE on semi-insulating (001) GaAs substrates. Photoreflec-tance studies were supported by Raman spectroscopy and high resolution X-ray diffractometry (XRD) measurements. Magnetic properties of the films were characterized with a superconducting quantum in-terference device (SQUID) magnetometer. Our findings were interpreted in terms of the model, which as-sumes that the mobile holes residing in the valence band of GaAs and the Fermi level position determined by the concentration of valence-band holes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3533

Branching patterns of the foetal popliteal artery

Background: The objective of the study is to evaluate the popliteal artery topography and the origin variability of its branches in human foetuses at the gestational age of from 4 to 9 months. The basis for the analysis are direct observations of classic anatomic dissections of the popliteal fossa. Possible dimorphic and bilateral differen- ces, as well as the gestational age variability at the foetal period, were considered. A typology of popliteal artery branches will be made on the basis of the studies.  Materials and methods: The research material of this study comprises 231 foetuses (including 116 males and 115 females). The foetuses were divided into five 28-day age classes. The vessels of the lower extremity were injected with LBSK 5545 latex through the femoral artery. The bilateral dissection of the po- pliteal artery along with its branches was performed. No visible malformations were found in the research material, and the foetuses came from spontaneous abortions and premature births.  Results and Conclusions: Ten per cent of the cases featured the variations of popliteal artery terminal branches. Three most commonly seen variations are the trifurcation, anterior tibial-peroneal trunk, and high terminal division of the po- pliteal artery. The most common course of the superior muscular branches is that there are two large branches which are distributed from the popliteal artery at the height of the knee joint cavity and they do not distribute cutaneous branches. Sural branches are also present as two large vessels without cutaneous branches. The genicular anastomosis branches that run on their own are a typical topographic system of these branches.

Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress

Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress. Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing. Results: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P =.038) and 11% lower concentration of UA (P =.005). TOS was 20% lower (P =.014). The activity of SOD was up to 5% higher (P =.037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity. Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes

The effect of the size of sea trout (Salmo trutta L.) females from Pomeranian Rivers on the size of eggs

The aim of the work was to assess statistically the effect of length and weight of sea trout females from the rivers Rega, Parsęta, Wieprza and Grabowa on diameter and weight of swollen eggs

Feeding of sea trout (Salmo trutta L.) migrating upstream for spawning in lower Oder River system

The paper presents an analysis of the food tracts of sea trout (Salmo trutta L.) migrating from the Baltic Sea for spawning to the Gulf of Szczecin and lower Oder River, i.e. to waters of the lower Oder system

The effect of the size of sea trout (Salmo trutta L.) females from Rega River upon the size of eggs

The aim of work was to assess statistically the effect of body length, weight and age of sea trout (Salmo trutta L.) females from Rega River upon average diameter and weight of swollen eggs, and weight of mature eggs