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Number of results: 10
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Abstract

The number of human cases of salmonellosis in the EU was 94,625 in 2015. Considering the source of these infections, Salmonella spp. was most frequently detected in broiler chicken meat and Salmonella Enteritidis (SE) was the most commonly reported serovar. The efficacy of probiotics in limiting Salmonella spp. infection in poultry has been demonstrated in numerous papers. The administration of probiotics at the level of primary production reduces the risk of contamination of poultry food products with Salmonella spp. A study was carried out in order to determine the potential for reducing the Salmonella spp. population in broiler chickens with the use of the Lavipan (JHJ, Poland) probiotic that comprised selected stains of lactic acid bacteria and Saccharomyces cervisae. Salmonella spp.-free broiler chickens were divided into two groups and received the same feed with (group L) or without (group C) the probiotic throughout the experiment. All day-old chickens were infected per os with SE. Samples of cecum content were collected 2, 4, and 6 weeks after SE infection and pectoral muscles were collected 6 weeks following SE infection for the evaluation of the SE population number. Serum samples for serological examinations were collected 6 weeks after infection. Six weeks after infection, the number of SE-positive cecal samples was lower in the L group (12.5% positive) in comparison to the C group (87.5%). Similar results were demonstrated for the muscle samples (25% in contrast to 87.5%). At the same time, in both cases, the SE CFU/g was significantly lower in the L group. The results of our study indicate that Lavipan was capable of reducing the population of SE in the gastrointestinal tract, which eventually improved the hygienic parameters of the pectoral muscles. Four weeks after infection, SE was not detected in any of the experimental groups. In both groups, no specific anti-SE antibodies were detected.
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Abstract

The results of testing the strength properties of experimental ceramic materials containing spending moulding sand after initial mechanical reclamation as a material for subsequent layers of the stucco composition were presented. Tests were carried out on spent moulding sands from various foundry technologies, i.e. sand with furfuryl resin and sand with hydrated sodium silicate. The spent, agglomerated moulding sand has undergone a crushing process. Next, the required granular fractions used for individual layers of the stucco material were separated. Ceramic samples, in which the spent moulding sand was a substitute for fresh silica sand in successive layers of the stucco composition, were prepared. As a reference material, identical ceramic samples were used but with all layers made from the fresh silica sand. Samples prepared in this way were used to determine the bending strength of ceramic materials in the temperature range from 20 to 900ºC. The obtained values of the bending strength have demonstrated that spent moulding sand can be used in investment casting with no adverse effect on the strength of ceramic materials.
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Abstract

The article presents the results of research on the finishing of M63 Z4 brass by vibratory machining. Brass alloy was used for the research due to the common use of ammunition elements, cartridge case and good cold forming properties on the construction. Until now, the authors have not met with the results of research to determine the impact of abrasive pastes in container processing. It was found that the additive for container abrasive treatment of abrasive paste causes larger mass losses and faster surface smoothing effects. The treatment was carried out in two stages: in the first stage, the workpieces were deburred and then polished. Considerations were given to the impact of mass of workpieces, machining time and its type on mass loss and changes in the geometric structure of the surface. The surface roughness of machining samples was measured with the Talysurf CCI Lite optical profiler. The suggestions for future research may be to carry out tests using abrasive pastes with a larger granulation of abrasive grains, and to carry out tests for longer processing times and to determine the time after which the parameters of SGP change is unnoticeable.
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Abstract

Nonlinearities in optical fibers deteriorate system performances and become a major performancelimiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.
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Abstract

The paper presents selected granular ceramic materials available on the Polish market. Their characteristics have been determined in the aspect on application in the production of iron alloy-ceramic composite. The possibility of obtaining a composite layer by means of bulk grains in molds of plates were considered, which was the foundation for experimental molds to be used in service tests. On the basis of obtaining results was stated that the knowledge of the characteristics of bulk grains enables the calculation of their quantity necessary for the composite production. When using the bulk grains the thickness of the composite layer is restricted by the thermal relations (cooler) and the physical phenomena (buoyancy, metal static pressure). Increasing amount of grains above definite condition causes surface defects in the castings. Each casting, due to its weight, shape and place of composite layer production requires an individual approach, both at the stage of formation and that of calculation of the required quantity of ceramic grains.
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Abstract

A personal data referring to the scaphoid skull housed in the Department of Anatomy of the Jagiellonian University, Medical College was established thanks to reviewing 19th century literature performed by Dr. Sofi caru. We received information that the skull had belonged to an adult man who was a carpenter, born at Cracow. Th e original anthropometrical study of this skull was performed by prof. Kopernicki 19th century.
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