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Number of results: 7
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Abstract

Due to the fixed rotor magnetic field, the main magnetic flux of conventional permanent magnet synchronous motors (PMSMs) cannot be flexibly adjusted. Recently, the axial-radial flux type permanent magnet synchronous machine (ARFTPMSM) based on the hybrid excitation concept is proposed, which provides a new method for the speed and magnetic field regulations for PMSMs. To analyze the mechanism of magnetic field variation inside the ARFTPMSM, in this paper, three – dimensional finite element models for electromagnetic field calculation of the ARFTPMSM are established. On this basis, the influence of the axial device on the motor is discussed, and the mechanism of flux regulation is explained. By the quantitative calculation of air-gap flux density and the noload back-electromotive force (EMF), the flux regulation capability of the ARFTPMSM is verified. In addition, the effect of the excitation magnetomotive force on the magnetic field harmonics is analyzed combined with the winding theory, and the influence of the axial magneto-motive force (MMF) on the torque fluctuation is obtained. The flux regulation performance of the motor and the validity of the numerical calculation analysis are verified by the experiments.
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Authors and Affiliations

Cunxiang Yang
1
Kun Wang
1
ORCID: ORCID
Ziyang Liu
1
Bin Xiong
2
Qiang Zhao
3

  1. Zhengzhou University of Light Industry, Zhengzhou, Henan, China
  2. Institute of Electrical Engineering of Chinese Academy of Sciences, Beijing, China
  3. Wolong Electric Nanyang Explosion Protection Group Co., LTD.China
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Abstract

Eating disorders are a heterogeneous group of diseases affecting mainly young people in devel-oped countries. Among them, anorexia nervosa (AN) is the one with the highest mortality, up to five times higher compared to healthy individuals. The etiology of this medical condition is complex and still un-certain. However, disturbances of the autonomic nervous system (ANS) and increased lipolysis resulting in a decrease of the adipose tissue volume are common findings among AN patients. Since ANS is directly connected to adipocyte tissue, thus significantly affecting the body’s metabolic homeostasis, we suspect that this relationship may be a potential pathophysiological underpinning for the development of AN. In this narrative review, we have analyzed scientific reports on ANS activity in AN considering different phases of the disease in humans as well as animal models. Due to the different effects of the disease itself on the ANS as well as specific variations within animal models, the common feature seems to be dysre-gulation of its function without the identification of one universal pattern. Nonetheless, higher norepi-nephrine concentrations have been reported in adipocyte tissue, suggesting local dominance of the sym-pathetic nervous system. Further studies should explore in depth the modulation of sympathetic in adipose tissue factor and help answer key questions that arise during this brief narrative review.
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Authors and Affiliations

Andrzej Boryczko
1 2
Kamil Skowron
1
Magdalena Kurnik-Łucka
1
Krzysztof Gil
1

  1. Department of Pathophysiology, Jagiellonian University Medical College, Kraków, Poland
  2. Doctoral School of Medical and Health Sciences, Jagiellonian University Medical College, Kraków, Poland
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Abstract

From all the detonation parameters of explosives, “strength” – the capability to perform work is the most important for the user. The detonation of explosives in the blast hole is a quick and complicated process: first there is a detonation pressure causing the crushing of the rock in the vicinity of the explosive, then the pressure of the detonation products causes the cracking of the rock. The article presents the methods of determining the capability to perform work by explosives for civil use (dynamite and ANFO) used in the accredited Laboratory of Explosives and Electric Detonators Testing of the Experimental Mine “Barbara” of the Central Mining Institute – the lead block (Trauzl) method and the ballistic pendulum method. The aim of the research was to determine the relationship between the values of the capability to perform the work received in a ballistic pendulum method and a lead block method. As a result of the performed tests and the analysis of the results, the α-Pb coefficient was determined, which can be used to convert the value of the capability to perform work on the ballistic pendulum to the corresponding value of the capability to perform work in the lead block. At present, the Central Mining Institute is the only Notified Body of the European Union in the scope of Directive 2014/28 /EU, which has a station for smelting lead blocks and equipment and for determining the capability to perform work by explosives in lead blocks – this method was abandoned in other research units for testing with a ballistic pendulum and/or underwater test.

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Authors and Affiliations

Michał Szastok
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Abstract

Calculations were performed of the thermal system of a power plant with installed water pressure tanks. The maximum rise in the block electric power resulting from the shut-off of low-pressure regenerative heaters is determined. At that time, the boiler is fed with hot water from water pressure tanks acting as heat accumulators. Accumulation of hot water in water tanks is also proposed in the periods of the power unit small load. In order to lower the plant electric power in the off-peak night hours, water heated in low-pressure regenerative heaters and feed water tank to the nominal temperature is directed to water pressure tanks. The water accumulated during the night is used to feed the boiler during the period of peak demand for electricity. Drops in the power block electric power were determined for different capacities of the tanks and periods when they are charged. A financial and economic profitability analysis (of costs and benefits) is made of the use of tanks for a 200 MW power unit. Operating in the automatic system of frequency and power control, the tanks may also be used to ensure a sudden increase in the electric power of the unit. The results of the performed calculations and analyses indicate that installation of water pressure tanks is well justified. The investment is profitable. Water pressure tanks may not only be used to reduce the power unit power during the off-peak night hours and raise it in the periods of peak demand, but also to increase the power capacity fast at any time. They may also be used to fill the boiler evaporator with hot water during the power unit start-up from the cold state.

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Authors and Affiliations

Jan Taler
Marcin Trojan
Dawid Taler
Piotr Dzierwa
Karol Kaczmarski
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Abstract

The following work presents the idea of constructing a digitally controlled active piezoceramic transducer matrix for ultrasonic projection imaging of biological media in a similar way as in case of roentgenography (RTG). Multielement ultrasonic probes in the form of flat matrices of elementary piezoceramic transducers require attaching a large number of electrodes in order to activate the individual transducers. This paper presents the idea of minimising the number of transducer connections in an active row-column matrix system. This idea was verified by designing a model of a matrix consisting of 16 ultrasonic transducers with electrode attachments optimised by means of electronic switches in rows and columns and miniature transistor switches in the nodes of the matrix allowing to activate selected transducers. The results of measurements and simulations of parameters of the designed matrix show that it is suitable to be used in projection imaging of biological media as a sending probe. In to use the matrix as a universal sending or receiving probe, it was suggested to add further switches that would eliminate the undesired effect of crosstalks in case of switches used for toggling the transducers in the nodes of the matrix.

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Authors and Affiliations

Krzysztof Opieliński
Tadeusz Gudra
Piotr Pruchnicki
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Abstract

The author examines ontological premises adopted in the Controversy over the Existence of the World by Roman Ingarden. He points out that these premises have been informed by mereological insights. This reading of Ingarden is substantiated by the postulate that ‘pure qualities’ are components of ‘ideas’ and constitute their proper parts. This is the reason why they cannot be attributed to individuals as their properties. The role of properties is consequently filled in by ‘concretizations’, proposed as a new category of existence. This author claims however that ‘concretizations’ can be easily dispensed with by reinterpreting ideas in the distributive mode. Assuming this new rendition, one makes it possible to interpret ‘pure qualities’ as properties of possible individuals, which results in a comfortable simplification of Ingarden’s ontology.
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Authors and Affiliations

Adam Nowaczyk
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Abstract

The article deals with a phenomenon unique for Belarusian literature of the Soviet period: the dissident, non‐conformist work of Znich (Oleg Bembel). In the context of the history of Belarusian literature, the poet is known as the author of religious‐patriotic and spiritual‐meditative poems, many of which were created outside the walls of the monastery, where the poet has lived since 1996. The author of the article explores a little‐known page in the writer’s work: the early, dissident poetry of Oleg Bembel of the first half of the 1980s, which was distributed in manuscripts, samizdat, was published in the émigré press (newspaper and the “Belarus” publishing house). In terms of genre, these were mostly short epigrams and poems dedicated to the classics of Belarusian literature (Francis Bahushevich, Janka Kupala, Maxim Bahdanovich). Thematically the article is concerned with poems about the tragic situation of the Belarusian language, culture, science in the USSR, Russification and the decline of spirituality in an atheistic country. Attention is drawn to the artistic form of the poems, emphasized is their attachment to the intellectual and philosophical trends within modern Belarusian poetry.
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Authors and Affiliations

Siergiej Kowalow
1

  1. Lublin, Uniwersytet Marii Curie‑Skłodowskiej

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