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  • Author: Katarzyna Lisiecka x
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Abstract

In the aerospace industry, passenger safety depends on proper quality control at each production stage. The main responsibility for the correct operation of the aircraft lies within a gas turbine. A proper and rigorous selection of the gas turbine construction material is required, and in a further step, the method of joining the construction parts. Nickel superalloys due to the high heat resistance, strength and creep resistance at high temperatures, toughness and corrosion resistance, are very often used for the construction of a gas turbine engine. In the next step, the selection of joining method is necessary. This method must be able to achieve high-quality connections, resistant to work at high temperatures and corrosive environments. The most effective bonding method that meets the above conditions is brazing. In this study non-destructive (visual) test and destructive (metallographic) test of brazed joint of Inconel 718 and Inconel 625 were conducted.

Abstract

Increasingly, many conventional and advanced automotive coatings applications demand materials with well-defined surface properties, fulfilling specific requirements and affecting automotive industrial development. The main assumption for the study was to analyze the microstructure and adhesion of epoxy powder coating on a steel substrate. The results of optical microscope metallographic, SEM/EDX, XRD analysis and adhesion test are presented.

Abstract

The aim of the work was to determine the influence of screw speed and variable amounts of fresh vegetable additives on selected aspects of extrusion-cooking of corn-vegetable blends. Corn grit as a basic component was supplemented with a fresh pulp of beetroot, carrot, leek and onion in amounts of 2.5-10% in the recipe. The extrusion-cooking was carried out using a single-screw extruder in the temperature range 120-145°C and extrudates were formed into directly expanded snacks. Two indicators were measured: the production efficiency (Q) and the specific mechanical energy (SME) consumption. As a result of the findings it was noted that the rotational speed of the extruder’s screw showed a greater impact on both production efficiency and SME as compared to the variable amounts of applied additives. A tendency to increased efficiency and specific mechanical energy consumption was observed along with the increase of screw speed during processing. The highest production efficiency was observed if fresh leek and onion were used as additives and the highest extrusion speed screw was applied. The largest specific energy consumption was noted during the extrusion-cooking of blends containing fresh carrot and onion addition at high screw speed.

Abstract

Introduction

Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits with experimental trichophytosis were assessed by flow cytometry.

Material and Methods

Virulent species of T. mentagrophytes var. granulosum (Tm-K) isolated from rabbits with natural trichophytosis was used for experimental infection. The phagocytic activity of granulocytes was measured in whole blood by flow cytometry using the commercial Phagotest kit. Oxidative burst was measured in whole blood by flow cytometry using the commercial Bursttest kit.

Results

It was found that rabbits were susceptible to infection with Trichophyton mentagrophytes under experimental conditions. The analysis of the phagocytic activity indices and oxygen metabolism of granulocytes in peripheral blood of infected rabbits showed that changes of the indices were connected with the progression and regression of the disease. A significant decrease in phagocytic activity and oxygen metabolism was observed during development of fungal lesions and it remained similar throughout the progress of the disease. The highest means of the percentage of activated and ingesting phagocytes and a significant increase in the mean fluorescence intensity (representing the number of ingested bacteria) were observed during spontaneous recovery. Therefore, the decrease or increase in the indices of phagocytic activity and oxygen metabolism of granulocytes from rabbits experimentally infected with T. mentagrophytes is somehow related to the progress of infection and suppressive activity of the fungus, whose elimination during recovery caused significant increases in investigated indices of non-specific cellular immunity.

Conclusion

The results of the present investigation confirm that the mechanism of oxygen-dependent killing is crucial in infections caused by T. mentagrophytes.

Abstract

The clinical form of natural zearalenone intoxication was observed in sheep that were kept indoors and fed a constant diet of feed concentrates containing high concentrations of zearalenone and its metabolite α-zearalenol. The clinical form of the disease was not noted in the control group, consisting of sheep that were kept on a pasture from spring to late autumn; only in the winter they were fed wheat pellets, in which the zearalenone concentration was determined to be the lowest among all used feed concentrates. During the course of natural zearalenone intoxication, metabolism of arachidonic acid increased, mainly due to enzymes of the cyclooxygenase group, which are responsible for the generation of prostaglandin F2α and thromboxane B2, and an increase in their concentration. Increased production of F2α and B2 was closely correlated with the serum level of SAA, an indicator of the intensity of the inflammatory reaction. This indicates that both compounds participated in the development of inflammatory reactions in the terminal end of the digestive tract that accompanied zearalenone intoxication in sheep. The imbalances noted between the eicosanoid classes investigated in this study were fundamentally responsible for the development of clinical symptoms in sick sheep that showed symptoms of partial or total prolapse of the anus and rectum and prolapse of the large intestine, which were the direct cause of the animals death.