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Number of results: 43
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Abstract

This work aims to create an ANN-based system for a musical improviser. An artificial improviser of "hearing" music will create a melody. The data supplied to the improviser is MIDItype musical data. This is the harmonic-rhythmic course, the background for improvisation, and the previously made melody notes. The harmonic run is fed into the system as the currently ongoing chord and the time to the next chord, while the supplied few dozen notes performed earlier will indirectly carry information about the entire run and the musical context and style. Improvisation training is carried out to check ANN as a correctlooking musical improvisation device. The improviser generates several hundred notes to be substituted for a looped rhythmicharmonic waveform and examined for quality.
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Authors and Affiliations

Jarosław Mazurkiewicz
1

  1. Wrocław University of Science and Technology, Faculty of Information and Communication Technology, Department of Computer Engineering
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Abstract

Termites, wasps, bees, certain aphids, thrips, beetles ... and of course ants. Some species of the rich and diverse world of insects, rather than living alone, have instead developed communities of various kinds. But should a group of such eusocial insects, ranging in size from a few hundreds to many millions of individuals, still be considered a set of distinct individuals, or rather a kind of superorganism.
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Authors and Affiliations

Paweł J. Mazurkiewicz
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Abstract

What is patriotism as opposed to nationalism? And which of these is what sometimes surfaces in contemporary rock music?

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Authors and Affiliations

Michał Maurycy Mazurkiewicz
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Abstract

Historia nauki pełna jest przypadkowych, a równocześnie przełomowych w dziejach ludzkości odkryć. Wynalezienie metody Czochralskiego jest jednym z nich.
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Authors and Affiliations

Adam Mazurkiewicz
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Abstract

In this work, numerical modeling of steady state heat and mass transfer is presented. Both laminar and hydrodynamically fully developed turbulent flow in a pipe are shown. Numerical results are compared with values obtained from analytical solution of such problems. The problems under consideration are often denoted as extended Graetz problems. They occur in heat exchangers using liquid metals as working fluid, in cooling systems for electric components or in chemical process lines. Calculations were carried out gradually decreasing the mesh size in order to examine the convergence of numerical method to analytical solution.

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Authors and Affiliations

Piotr Duda
Grzegorz Mazurkiewicz
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Abstract

This paper deals with wastewater treatment systems placed in motorway service areas (MSAs). In the years 2008-2009 eight of such facilities installed on the stretch of the A2 motorway between Poznań and Nowy Tomyśl were examined and analyzed. The system consists of a septic tank, a submerged aerated biofilter and an outflow filter. The volume of traffic on the highway was analyzed, the amount of water use was measured and peak factors were calculated. On this basis it was concluded that the inflows to the wastewater treatment systems in many cases exceeded the nominal design values.

Based on the analysis of effluent quality it was found that the effects of plant operation in large part did not meet the requirements. It was found that the bioreactor aeration system and the design of the suspension separator (outflow filter) should be modified. One of the solutions was to use the soil-reed bed for wastewater treatment. The treatment of wastewater from the MSAs is a task that must take into account the unusual character of these facilities and the atypical quality of the effluent.

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Authors and Affiliations

Małgorzata Makowska
Jakub Mazurkiewicz
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Abstract

Termity, osy, pszczoły, niektóre mszyce, wciornastki i chrząszcze. I oczywiście mrówki. W bogatym i różnorodnym świecie owadów są gatunki, które zamiast żyć samotnie, wykształciły różnego rodzaju społeczności. Czy owady eusocjalne to liczące od kilkuset do wielu milionów osobników zbiory odrębnych jednostek, czy też swoiste superorganizmy?
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Authors and Affiliations

Paweł J. Mazurkiewicz
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Abstract

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

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Authors and Affiliations

Michał Maurycy Mazurkiewicz
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Abstract

Physicochemical parameters of water and phytoplankton composition were studied in the dirnictic, submountain Dobczyce Reservoir (southern Poland) affected by summer storrnflow, which took place in September 2007. During summer (except September) temperature, pH, dissolved oxygen, and carbonates showed vertical differentiation. Stormwater flow through the system had a destabilizing effect on summer stratification. It diluted the concentrations of salts (sulphate and chloride) and slightly increased the concentration of nutrients in the reservoir. In phytoplankton some changes in the dominant species among the Cyanobacteria group were noted.
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Authors and Affiliations

Ewa Szarek-Gwiazda
Grażyna Mazurkiewicz-Boroń
Elżbieta Wilk-Woźniak
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Abstract

This study focused on the effect of heavy metal cobalt ions (at concentrations of 1–1000 ppm) on the development and enzymatic activity of four entomopathogenic fungi: Beauveria bassiana, Beauveria brongniartii, Isaria fumosorosea and Metarhizium robertsii, commonly used in biological plant protection. It was found that each of the tested species of fungi reacted individually to contact with the Co2+ ions at their various concentrations. Depending on the variants of the experiment carried out, there were changes in the development of the mycelia (mainly growth inhibition) and their morphological features (color and structure) in comparison to the control samples. Co2+ ions had a fungistatic effect on all fungal strains, whereas a fungicidal effect was noted at concentrations of 750 ppm and 1000 ppm against M. robertsii and I. fumosorosea, respectively. In addition, there was a discrepancy in enzymatic activity between the tested fungal species developing in the medium with varying concentrations of metal salt. The inhibitory effect of Co2+ ions on lipase production was observed in I. fumosorosea. Protease production was stimulated in B. bassiana at all Co2+ concentrations, whereas in M. robertsii this effect was noted at 1 ppm. The changing dynamics of extracellular fungal hydrolases, due to the action of Co2+ ions, may translate into the role of these microorganisms in the processes of insect pathogenesis. This work suggests that severe pollution of the environment by cobalt could be a restrictive factor for the development and pathogenicity of entomopathogenic fungi and must be taken into account for their successful application in biological plant protection.

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Authors and Affiliations

Łukasz Łopusiewicz
Kinga Mazurkiewicz-Zapałowicz
Cezary Tkaczuk
Artur Bartkowiak
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Abstract

The aim of the presented research was to test different carbon supports, such as graphene oxide (GO), graphene oxide modified with ammonia (N-GO), and reduced graphene oxide (rGO) for catalysts used in a low-temperature fuel cell, specifically a proton exchange membrane fuel cell (PEMFC). Modification of the carbon supports should lead to different catalytic activity in the fuel cell. Reduction of GO leads to partial removal of oxygen groups from GO, forming rGO. Modification of GO with ammonia results in an enrichment of GO structure with nitrogen. A thorough analysis of the used supports was carried out, using various analytical techniques, such as FTIR spectroscopy and thermogravimetric (TGA) analysis. Palladium and platinum catalysts deposited on these supports were produced and used for the oxygen reduction reaction (ORR). Catalytic activity tests of the prepared catalysts were carried out in a home-made direct formic acid fuel cell (DFAFC). The tests showed that the enrichment of the GO structure with nitrogen caused an increase in the catalytic activity, especially for the palladium catalyst. However, reduction of GO resulted in catalysts with higher activity and the highest catalytic activity was demonstrated by Pt/rGO, because platinum is the most catalytically active metal for ORR. The obtained results may be significant for low-temperature fuel cell technology, because they show that a simple modification of a carbon support may lead to a significant increase of the catalyst activity. This could be useful especially in lowering the cost of fuel cells, which is an important factor, because thousands of fuel cells running on hydrogen are already in use in commercial vehicles, forklifts, and backup power units worldwide. Another method used for lowering the price of current fuel cells can involve developing new clean and cheap production methods of the fuel, i.e. hydrogen. One of them employs catalytic processes, where carbon materials can be also used as a support and it is necessary to know how they can influence catalytic activity.

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Authors and Affiliations

Zuzanna Bojarska
Marta Mazurkiewicz-Pawlicka
Łukasz Makowski
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Abstract

The paper presents the results of the effect of isothermal heating time on the disappearance of strain hardening (the softening degree) of the studied high-manganese TRIPLEX type steels at a temperature of 900 and 1000°C. In order to determine the kinetics of recrystallization of austenite plastically deformed for selected steels, hot compression tests with draft ε = 0.2 were made. The presented results reveal that the complete recrystallization of austenite needs long isothermal heating times. In industrial conditions, such long times are not used, therefore in the initial rolling passages, the time required for half recrystallization of austenite t0.5 is often used. The total disappearance of the strain hardening, completion of the recrystallization of austenite tested high-manganese X98 and X105 TRIPLEX type steels isothermal heating time requires far more than 200 s. The increase of the deformation temperature is a factor influencing the acceleration of the disappearance of strain hardening.

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Authors and Affiliations

L. Sozańska-Jędrasik
J. Mazurkiewicz
W. Borek

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