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Number of results: 11
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Abstract

This paper presents the design method and the construction details of a subsonic low-speed wind tunnel, which has been designed to achieve the flow velocity of 35 m/s in the measurement section with expected uniform velocity field at its inlet. To achieve such objectives a very detailed design was performed using a theoretical 1D analysis and computational fluid dynamics simulations. This approach was applied to improve the flow quality along the wind tunnel sections. When the wind tunnel has been launched a direct comparison of the experimentally measured flow field in the test section and numerical simulation results was conducted. Such comparison of the simulation results with the experimental one is presented in this paper. The obtained results confirm that assumed wind tunnel design method was correct, i.e. the pressure drop in the wind tunnel has been predicted very well and drive system is effective and sufficient to accelerate the airflow to required values.
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Bibliography

[1] Barlow J.B., Rae Jr W.H., Pope A.: Low-Speed Wind Tunnel Testing. John Wiley and Sons; New York 1999.
[2] Bradshaw P., Pankhurst R.C.: The design of low-speed wind tunnels. Prog. Aerosp. Sci. 5(1964), 1–69.
[3] Anderson J.D. Jr.: Fundamentals of Aerodynamics (5th Edn.). McGraw-Hill; 2011.
[4] Kneba Z.: Modeling of the internal combustion engine cooling system. Arch. Thermodyn. 40(2019), 3, 109–121.
[5] Muszynski T., Andrzejczyk R., Park W.I., Dorao C.A.: Heat transfer and pressure drop characteristics of the silicone-based plate heat exchanger. Arch. Thermodyn. 40(2019), 1, 127–143.
[6] Mehta J., Bradshaw P.: Design rules for small low speed wind tunnels. Aeronaut. J. 83(1979), 827, 443–453.
[7] Stathopoulos T.: Design and fabrication of a wind tunnel for building aerodynamics. J. Wind Eng. Ind Aerod. 16(1984), 2–3, 361–376.
[8] Cattafesta L., Bahr C., Mathew J.: Fundamentals of wind-tunnel design. In: Encyclopedia of Aerospace Engineering. John Wiley and Sons, Hoboken 2010.
[9] Bell J.H., Mehta R.D.: Boundary-layer predictions for small low-speed contractions. AIAA J. 27(1989), 3, 372–374.
[10] Noor A., Ed.: Wind Tunnel Designs and their Diverse Engineering Applications. IntechOpen, 2013.
[11] Discetti S., Ianiro A., Aref H.: Experimental Aerodynamics. CRC Press – Taylor & Francis Group; Boca Raton 2017.
[12] Idelchik I.E.: Handbook of Hydraulic Resistance. Coefficients of Local Resistance and of Friction. US Atomic Energy Commission and the National Science Foundation. Washington DC 1966.
[13] Ansys Fluent Fluid Simulation Software https://www.ansys.com/products/fluids/ ansys-fluent (access: 5 Jan. 2020).
[14] Ansys Meshing https://www.ansys.com/products/platform/ansys-meshing (access: 5 Jan. 2020).
[15] Ochrymiuk T.: Numerical analysis of microholes film/effusion cooling effectiveness. J. Therm. Sci. 26(2017), 5, 459–464.
[16] Szwaba R., Ochrymiuk T., Lewandowski T., Czerwinska J.: Experimental investigation of microscale effects in perforated plate aerodynamics. J. Fluids Eng. 135(2013), 12, 121104-1-10
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Authors and Affiliations

Ryszard Szwaba
1
Krzysztof Hinc
1
Tomasz Ochrymiuk
1
Zbigniew Krzemianowski
1
Piotr Doerffer
1
Marcin Kurowski
1

  1. Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland
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Abstract

As the virtual reality (VR) market is growing at a fast pace, numerous users and producers are emerging with the hope to navigate VR towards mainstream adoption. Although most solutions focus on providing highresolution and high-quality videos, the acoustics in VR is as important as visual cues for maintaining consistency with the natural world. We therefore investigate one of the most important audio solutions for VR applications: ambisonics. Several VR producers such as Google, HTC, and Facebook support the ambisonic audio format. Binaural ambisonics builds a virtual loudspeaker array over a VR headset, providing immersive sound. The configuration of the virtual loudspeaker influences the listening perception, as has been widely discussed in the literature. However, few studies have investigated the influence of the orientation of the virtual loudspeaker array. That is, the same loudspeaker arrays with different orientations can produce different spatial effects. This paper introduces a VR audio technique with optimal design and proposes a dual-mode audio solution. Both an objective measurement and a subjective listening test show that the proposed solution effectively enhances spatial audio quality.
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Authors and Affiliations

Shu-Nung Yao
1

  1. Department of Electrical Engineering, National Taipei University, No. 151, University Rd., Sanxia Dist., New Taipei City 237303, Taiwan
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Abstract

The paper presents an analysis of hard coal prices offered at the coal depots in Poland. Coal depots are one of the most popular forms of purchasing coal by Polish households. Prices refer to price offers for cobble coal (grain size: 60–120 mm) and their analysis is performed based on the regions rather than on all Polish provinces. From January 2010 to May 2019, there were two regions that were distinguished in terms of price spread: the S-W region and the N-E region. In the case of the S-W region, the difference between the province with the minimum price (Śląskie Province) and with the maximum price (Dolnośląskie Province since September 2017) ranged from PLN 53–83/ton, and in the N-E region the difference ranged PLN 64–130/ton. In the case of the remaining two regions, prices varied from a few to approximately PLN 80/ton for the N-W region, and from a few to about PLN 40 /ton for the S-E region. In order to determine how the origin of the coal affects its prices (domestic coal, imported coal), the analysis also included cobble coal price offers that are part of the Author’s own database created for several years. In the case of cobble coal from domestic producers, price offers varied betwwen PLN 14–33/GJ, and price offers for imported cobble coal stood varied between PLN 12–32/GJ. The N-E region attracted particular attention as the price offers for imported cobble coal reached a level similar to the offers from the S-W region, i.e. the region closest to Silesian coal mines. Price differentials within provinces belonging to a given region were influenced by the geographical rent. The paper also analyses average selling prices offered by domestic producers for various size grades of steam coal as well as selling prices for imported coal (free-at-frontier price).

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Authors and Affiliations

Katarzyna Stala-Szlugaj
ORCID: ORCID
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Abstract

The paper presents a summary of research on the possibility of influencing the state of residual stresses in railway rails by changing the pass design of vertical and horizontal straightener rollers and optimising their distribution on the rail perimeter. The presented results are devoted to the influence of profiled rollers on the level of residual stresses. A wide range of theoretical considerations were carried out based on the use of the finite element method using the commercial Forge software package. In order to verify the results of the theoretical considerations most reliably, a series of “in situ” experiments were conducted in industrial conditions on an existing production line. The tests were carried out on 120 meters long 60E1 railway rails. A significant reduction in the level of residual stresses compared to the standard requirements was achieved.
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Authors and Affiliations

S. Żak
1
ORCID: ORCID
D. Woźniak
2
ORCID: ORCID

  1. ArcelorMittal Poland S.A., Al. Józefa Piłsudskiego 92, 41-300 Dąbrowa Górnicza, Poland
  2. Institute for Ferrous Metallurgy, ul. Karola Miarki 12, 44-100 Gliwice, Poland
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Abstract

In this paper, I intend to explore the influence of sentimentalism in the works of Gábor Dayka (1769– 1796), a Hungarian poet, an author of sentimental poems imbued with the ideals of the Enlightenment. The sentimental tones of his verses derive first of all from being misunderstood and oppressed and from the impossibility of unveiling the opaque sadness of the mysterious melancholy. Dayka, forced to choose the ecclesiastical career and then abandon it because of his liberal ideas, gradually becomes a sentimental and pessimistic poet who thinks love is painful and projects his pain into nature. I will focus on the sentimental means of expression of Dayka from the poem titled Rettenetes éjszaka (Terrible Night) to Titkos bú (Mysterious Melancholy).
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Bibliography

1. ABAFI, L. (1880): “Dayka Gábor élete”, in: ID.: Dayka Gábor költeményei, Aigner Lajos, Budapest, V–XLIII.
2. BARÓTI, D. (1971): “Dayka Gábor”, in: ID.: Írók, érzelmek, stílusok, Magvető, Budapest, 192–203.
3. BÍRÓ, F. (1994): “A titkos bú poétája”, in: ID.: A felvilágosodás korának magyar irodalma, Balassi, Budapest, 363–371.
4. GÁLOS, R. (1913): “Dayka Gábor költészete”, Egyetemes Philologiai Közlöny, 145–154.
5. KABDEBÓ, L. (1968): Dayka Gábor költői pályája, Városi Könyvtár, Miskolc.
6. KABDEBÓ, L. (1969): “Dayka Gábor: A rettenetes éjszaka”, Irodalomtörténeti Közlemények, 2–3, 269–274.
7. KAZINCZY, F. (1813): “Dayka’ élete”, in: Ujhelyi Dayka Gábor’ versei. Öszveszedte ’s kiadta barátja, Kazinczy Ferencz, Trattner, Pest, III–XLVIII.
8. KOVÁCS FERENCNÉ ÓNODI, I. (szerk.) (1993): Dayka Gábor versei, Gazdász, Miskolc.
9. KOVÁCS, Gy. (1962): “Szentjóbi Szabó László és Dayka Gábor szentimentális költészete”, Irodalomtörténet, 1, 78–95.
10. LŐKÖS, I. (1962): “Dayka Gábor egri éveiről”, Irodalomtörténet, 3–4, 398–409.
11. MAKAY, G. (1993): “Dayka Gábor: Titkos bú”, in: ID.: “Édes hazám, fogadj szívedbe...”, Aqua Kiadó, Budapest, 42–45.
12. MARTINÁK, J. (2015): “Dayka Gábor költészete”, Kazinczy és kora, Széphalom, 25, 147–155.
13. MEZEI, M. (szerk.) (2000): Magyar költők. 18. század, Neumann Kht., Budapest.
14. SZABÓ, Z. (1986): “A szentimentalizmus”, in: ID.: Kis magyar stílustörténet, Tankönyvkiadó, Budapest, 136–148.
15. SZAUDER, J. (1963): “A magyar szentimentalizmus problémái”, Irodalomtörténeti Közlemények, 4, 405–421.
16. SZILÁGYI, M. (2000): “A ‘titkos bú’ poétája? Dayka Gábor kánonizálódásának kérdőjelei”, Irodalomtörténeti Közlemények, 5–6, 603–616.
17. TOLDY F. (1833): “Dayka’ élete”, in: Dayka’ versei. Öszveszedte Kazinczy Ferencz, Egyetem betűivel, Buda, III–XIV.

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Authors and Affiliations

Judit Papp
1

  1. Università Degli Studi Di Napoli “L’Orientale”, Napoli
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Abstract

Cities seeking their individual development path use various development models. Urban development management through large urban projects is an expression of departure from the so-called global change regulated urbanism to urbanism through projects. This approach is also used by the city of Lodz, recovering, e.g. through large revitalization projects, its industrial heritage, but processed and adapted to the needs of current residents. The Horticultural EXPO 2024 exhibition (so-called Green EXPO) planned in Lodz belongs to the highest world-class exhibitions, i.e. class A1. The topics of this type of exhibition focus on various aspects related to, among others with greenery in cities, ecology, agriculture and gardening. It is another development opportunity for Lodz in accordance with a relatively new and innovative model – urban agriculture – in urban planning. The article presents the historical context of the organization of the exhibition, the results of research on the needs and expectations of the inhabitants of Lodz related to the planned exhibition, including the spatial aspect, the importance of the exhibition for the needs of shaping a healthy living environment.
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Authors and Affiliations

Elżbieta Strzelecka
1
Magdalena Woźna
1

  1. Politechnika Łódzka, Wydział Budownictwa, Architektury i Inżynierii Środowiska, Kolegium Gospodarki Przestrzennej, al. Politechniki 6, 90-924 Łódź
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Abstract

Waterproof lime dust used in coal mines is an important element in the system of protection against explosions. This is one of the oldest methods used to prevent coal dust explosions and, according to an expert’s opinion, it will remain so for a long time. T he work is a summary of research on the development of a new method of producing waterproof limestone dust to use it as an anti-explosive powder in coal mines. The typical method of hydrophobic dust production (milling limestone with stearic acid) is no longer profitable due to the restructuring of the mining industry. The main research was conducted on raw materials traditionally used during the production of anti-explosion powder, namely limestone meal with a grain size diameter equal to 80 μm (Czatkowice Limestone Quarry) and stearic acid as a modifier. Silicone preparation and bituminous preparation (Bitumenovoranstrich) were used as additional modifiers. The hydrophobization process was conducted with the use of different techniques: from stearic acid ether solution, from stearic acid vapor, from methyl silicone resin or bituminous preparation solutions. A series of research on modified powders to determine hydrophobization and flow properties was conducted. Depending on method of hydrophobization, the test of “floating on water”, the extraction of stearic acid was carried out, water contact angles on compacted material were determined, the thermal decomposition of powder was made. The increase in moisture after wet storage was indicated. The flow properties of powders were measured with the use of the Powder Characteristics Tester. The evaluation of the suitability of each hydrophobization methods in achieving the intended purpose was valued.

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Authors and Affiliations

Elżbieta Vogt
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Abstract

A mine cannot function without monitoring systems: environmental, basic mining machinery and equipment. The exploitation of ore in the mine depends heavily on properly functioning machines and mining equipment, and acceptable for the miner technical environmental conditions occurring in underground excavations. The monitoring systems of the technical environment in underground mines are primarily telemetry and gasometry systems. The first part of the article shows the typical structure of gasometry systems operating in the Polish underground mines. The existing provisions include the so-called security systems of the mining plant. The article presents a quantitative summary of the telephone exchange types and count of main telecommunication lines operating in these systems. Monitoring systems of machines and mining equipment are an essential element of the effec-tive management of the mine, because they affect the safe operation and increase time of effi-ciency equipment. The second part of the article shows selected monitoring systems of mining machinery and equipment currently used in the dispatcher rooms of mines. Attention was paid to the monitoring systems, which are only software tools as well as those in which additionally use dedicated IT solutions for these systems, hardware and measuring tools. The table shows the types of monitoring systems and technological configurations used in underground mines, preferred for them.

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Authors and Affiliations

Antoni Wojaczek
Adam Wojaczek
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Abstract

In the paper presented is a novel concept to utilize the heat from the turbine bleed to improve the quality of working fluid vapour in the bottoming organic Rankine cycle (ORC). That is a completely novel solution in the literature, which contributes to the increase of ORC efficiency and the overall efficiency of the combined system of the power plant and ORC plant. Calculations have been accomplished for the case when available is a flow rate of low enthalpy hot water at a temperature of 90 °C, which is used for preliminary heating of the working fluid. That hot water is obtained as a result of conversion of exhaust gases in the power plant to the energy of hot water. Then the working fluid is further heated by the bleed steam to reach 120 °C. Such vapour is subsequently directed to the turbine. In the paper 5 possible working fluids were examined, namely R134a, MM, MDM, toluene and ethanol. Only under conditions of 120 °C/40 °C the silicone oil MM showed the best performance, in all other cases the ethanol proved to be best performing fluid of all. Results are compared with the "stand alone" ORC module showing its superiority.
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Authors and Affiliations

Dariusz Mikielewicz
Jarosław Mikielewicz
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Abstract

The multi-dimensional cooperation between Count Władysław Zamoyski and St. Albert Chmielowski is an important fragment of Zakopane’s tradition. Their activity marked the period of the development of the town, which was on its way to becoming not only a famous spa, but also a centre of the Polish spiritual and political life. Owing to Zamoyski’s assistance, St. Albert erected a hermitage at the foot of the Tatra Mountains, which hosted some eminent artists from the Young Poland period. In line with the vision of Zakopane consistently implemented by Zamoyski, the sanctuary of prayer and contemplation was an indispensable element. There are testimonies according to which Count Zamoyski felt a monastic vocation and discussed the issue with the founder of the Albertine Brothers. St. Albert’s refusal to allow him to go resulted from his belief that Zamoyski’s economic activity was particularly beneficial from the social point of view, promoting not only civilizational but also spiritual progress. The cooperation of the two outstanding figures is without any doubt one of the most significant threads of Polish culture at the turn of the 20th century.

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Authors and Affiliations

Wiesław Ratajczak
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Abstract

Public education is educating influence of wide range media on political beliefs, worldviews and patterns of the everyday life of the audience, and of the potential electorate. The public intellectuals (the Henry A. Giroux concept), significant and respected experts (academics, journalists, politicians) play a special role. The article contains the presentation and analysis of the reaction of American public intellectuals to the election of Donald Trump as President of the United States – from the perspective of critical-emancipatory pedagogy. These are extremely critical to the consequences of D. Trump's choice: Ken Wilber's, Henry A. Giroux’s, Noam Chomsky’s, and several authors in the Berkeley Review of Education 2017/1 publications and speeches are recalled. The author concludes that Poland no longer has to imitate America, because in authoritarian drift (turn) it is ahead of it.

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Authors and Affiliations

Zbigniew Kwieciński
ORCID: ORCID

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