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Number of results: 26
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Abstract

In the paper, an effective way to design asymmetrical optics for a uniform vertical surface illumination was presented. Assessment of the obtained distribution of luminance (illuminance) on the illuminated surface is done almost at the same time as designing the optical system elements. Advantage of the final application of the presented method in 3D will be independence from the implementation of time-consuming simulations in order to verify the already designed optics. Understanding the method and its application is simple and intuitive. Observing the luminance distribution, created on the illuminated surface almost at the same time as its design, allows to see the effect of adding the next elements of the optical system on this distribution.

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Authors and Affiliations

K. Kubiak
ORCID: ORCID
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Abstract

The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman

method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the

longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of

withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based

on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould

(3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was

proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5

and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

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Authors and Affiliations

J. Sieniawski
D. Szeliga
K. Kubiak
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Abstract

This paper presents modern methods for designing optical systems for luminaires in the context of long years of light sources development. It shows that the development of technology for producing increasingly precise optical systems has led to an evolution in the construction of luminaires with increased efficacy and utilizing more efficiently the features of a specific family of light sources. Methods for designing and modelling optical systems with the use of mathematical curves as well as advanced the free-forming method are described. The paper also shows methods for modelling light sources features, especially luminance ones, designed to make precise simulation calculations required in any luminaire design process. Knowledge of luminance distributions of light sources and precise luminance distributions of optical systems for luminaires raises the design process to a very high level, enabling positive modern light source features, such as high luminance and their small dimensions, to be used consciously while minimizing negative ones, such as discomfort glare, caused by luminaires. The paper presents the results of simulation calculations and laboratory measurements for a selected case of luminaire equipped with a discharge lamp of maximum luminance exceeding 30 million cd/m2.

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Authors and Affiliations

W. Żagan
S. Zalewski
S. Słomiński
K. Kubiak
ORCID: ORCID
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Abstract

Despite the consensus on the role of lung and pleura ultrasound in human medicine, veteri- nary medicine questions credibility of the pulmonary evaluation in ultrasound examination, based on the analysis of artifacts in animals with clinical signs of respiratory failure and possibility of pulmonary edema diagnosis with recognition of the degree of its severity. The study was conduct- ed on 47 animals (29 dogs and 18 cats) of different breeds, age and sex. In all of animals prior to the transthoracic lung and pleura ultrasound examination (TLPUS), all animals were subjected to a clinical examination and hematological blood test as well as chest radiography examination in three projections. Ultrasound imaging of the chest in each animal was performed at designated four defined segments. TLPUS in dogs and cats based on an analysis of artifacts allows recogni- tion of pulmonary edema, to the degree comparable to chest X-ray examination. The number of depicted B-lines artifacts is proportional to the degree of pulmonary edema. These results allow to reduce the number of radiographs and allow the shortening of the diagnostic process for pa- tients in life-threatening condition.

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Authors and Affiliations

J. Szymczak
Z. Kiełbowicz
W. Kinda
U. Zaleska-Dorobisz
K. Kubiak
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Abstract

The effect of Ca element on the microstructure evolution of the AZ91 magnesium alloy was investigated in this research. The magne-sium-aluminium alloy AZ91 was inoculated with the Emgesal® Flux 5 to refine its microstructure and also improve its microstructure. Six different concentrations of the Emgesal® Flux 5 content were tested, ranging from 0.1 to 0.6% wt., and compared to the baseline of the AZ91 alloy without inoculation. Melted metal was poured into a preheated metallic mould. Samples to test were achieved after turning treatment. Formed microstructure was assessed using an optical microscope. The microstructure was refined for every tested samples. Me-chanical properties such as tensile strength, elongation, Brinell hardness, Vickers microhardness, abrasion resistance and adhesive resistance were tested on the inoculated samples and compared to the non-inoculated AZ91. Introducing an Emgesal®Flux 5 inoculant caused a change in the tensile strength, elongation, Brinell hard-ness, Vickers microhardness, abrasive wear resistance as well as adhesive wear resistance in each examined concentration.
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Authors and Affiliations

C. Rapiejko
1
ORCID: ORCID
D. Mikusek
1
K. Kubiak
2
ORCID: ORCID
T. Pacyniak
1
ORCID: ORCID

  1. Department of Materials Engineering and Production Systems, Lodz University of Technology, Stefanowskiego 1-15, 90-924 Łódź, Poland
  2. Faculty of Engineering and Physical Sciences, School of Mechanical Engineering, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, United Kingdom
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Abstract

The aim of the study was to assess the physiological stiffness of the normal canine jejunal mucosa based on shear wave elastography. The study was carried out on 60 dogs. In all the animals studied, the abdominal ultrasound was carried out using the SuperSonic Imagine Aixplorer system. The site of the jejunal elastography was determined using standard ultrasonography and all the measurements were carried out thrice. The stiffness of the area examined was determined during each measurement. Mean values were calculated based on the results obtained. The normal stiffness of the jejunal mucosa ranged from 1.305 kPa to 9.319 kPa (mean 5.31 ± 2.04 kPa). Based on our findings, we determined the range of normal values of the jejunal mucosal stiffness in healthy dogs. In addition, shear wave elastography was found to be safe and easy to perform. Moreover, it did not require anaesthesia or patient immobilisation for long periods.

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Authors and Affiliations

J. Spużak
K. Kubiak
ORCID: ORCID
K. Glińska-Suchocka
M. Jankowski
P. Borusewicz
D. Kubiak-Nowak

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