Wyniki wyszukiwania

Filtruj wyniki

  • Czasopisma
  • Autorzy
  • Słowa kluczowe
  • Data
  • Typ

Wyniki wyszukiwania

Wyników: 5
Wyników na stronie: 25 50 75
Sortuj wg:

Abstrakt

In this study, the thermal conductivity ratio model for metallic oxide based nano-fluids is proposed. The model was developed by considering the thermal conductivity as a function of particle concentration (percentage volume), temperature, particle size and thermal conductivity of the base fluid and nano-particles. The experimental results for Al2O3, CuO, ZnO, and TiO2 particles dispersed in ethylene glycol, water and a combination of both were adopted from the literature. Artificial neural network (ANN) and power law models were developed and compared with the experimental data based on statistical methods. ANOVA was used to determine the relative importance of contributing factors, which revealed that the concentration of nano-particles in a fluid is the single most important contributing factor of the conductivity ratio.
Przejdź do artykułu

Autorzy i Afiliacje

Mohammad Hanief
1
Qureshi Irfan
1
Malik Parvez
2

  1. Mechanical Engineering Department, National Institute of Technology Srinagar, India
  2. Chemical Engineering Department, National Institute of Technology Srinagar, India
Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This study addresses the issues related to the quality of the connection between cast iron liners and inserts in a pressure die-cast automotive engine block, along with the macro and micro wear of the cylinder bearing surface. it was found that the commonly used HPDC high-pressure casting technology of Al-Si alloy engine blocks with cast iron liners, in which the cylinder liner is then recreated, does not ensure their metallic connection. The micro-gap created there becomes thicker as the engine is used, which worsens the conditions for heat dissipation from the sleeve to the block. Locally, on the surface of the cylinder bearing surface, reductions in honing effects and longitudinal cracks were observed. The presented literature mechanism of micro wear of the cylinder bearing surface, dependent on the morphology of graphite segregations, was confirmed. The mechanism of creating micro-breaks in the area of phosphoric eutectic and graphite precipitation occurrence was presented, initiated by the formation of microcracks in the eutectic and delaminations at the eutectic-matrix boundary.
Przejdź do artykułu

Bibliografia


[1] Kim, J.-K., Xavier, F.-A. & Kim, D.-E. (2015). Tribological properties of twin wire arc spray coated aluminum cylinder liner. Materials & Design. 84, 231-237. DOI: 10.1016/j.matdes.2015.06.122.

[2] Longa, W. (1978). Theory of foundry processes. AGH, Wydział Odlewnictwa, Instytut Odlewnictwa. (in Polish).

[3] Pietrowski, S. & Szymczak, T. (2004). Construction of the connection between alfined coating and silumin. Archives of Foundry. 4(14), 393-404. (in Polish).

[4] Pietrowski, S. (2004). Construction of the alfined layer on gray cast iron. Archives of Foundry. 4(11), 95-104. (in Polish).

[5] Pietrowski, S. & Szymczak, T. (2006). The influence of selected technological factors on the structure of the alfined layer on iron alloys. Archives of Foundry. 6(19), 251-266. (in Polish).

[6] Pawlus, P., Michalski, J. & Ochwat, S. (2012). Surface characteristics of cylinder liners intended for pouring using the Alfin method. Pomiary Automatyka Robotyka. 4, 61-65. (in Polish).

[7] Mahle Diesel Symposium, Stuttgart 2005.

[8] Volvo, DAF, MAN, PSA-BMW technical information from Mahle project meetings. Unpublished materials. Krotoszyn 2005-2010. (in Polish).

[9] Gruszka, J. (2011). Global trends in cylinder liners technology. Polskie Towarzystwo Naukowe Silników Spalinowych. 50(3), 1-7.

[10] Kozaczewski, W. (2004). Construction of the piston-cylinder group of combustion engines. Wydawnictwa Komunikacji i Łączności WKŁ. (in Polish).

[11] Podrzucki, Cz. (1991). Cast iron: structure, properties, application. Kraków: Wydaw. ZG STOP.

[12] Çakır, M. & Akcay, İ.H. (2014). Frictional behavior between piston ring and cylinder liner in engine condition with application of reciprocating test. International Journal of Materials Engineering and Technology. 11(1), 57-71.

[13] Shirokov, V.V., Arendar, L.A., Slyn’ko, H.I. & Volchok, I.P. (2003). Influence of phosphide eutectics on the wear resistance of high-strength cast irons. Materials Science. 39(2), 295-298. DOI: 10.1023/B:MASC.0000010284.56057.72.

[14] Uetz, H. (1969). Einfluß der honbearbeitung von zylinderlaufbuchsen auf die innere grenz-schicht und den einlaufverschleiß. Forschungsvereinigung Verbrennungskraftmaschinen. MTZ, 3.

[15] Ronen, A., Etsion, I. & Kligerman, Y. (2001). Friction-reducing surface-texturing in reciprocating automotive components. Tribology Transaction. 44(3), 359-366. DOI: 10.1080/10402000108982468.

[16] Picas, J.A., Forn, A. & Matthäus, G. (2006). HVOF coatings as an alternative to hard chrome for pistons and valves. Wear. 261(5-6), 477-484. DOI: 10.1016/j.wear.2005.12.005.

[17] Skopp, A., Kelling, N., Woydt, M. & Bergrer, L.-M. (2007). Thermally sprayed titanium suboxide coatings for piston ring/cylinder liners under mixed lubrication and dry-running conditions. Wear. 262(9-10), 1061-1070. DOI: 10.1016/j.wear.2006.11.012.

[18] Grabon, W., Pawlus, P., Woś, S., Koszela, W. & Wieczorowski, M. (2016). Effects of honed cylinder liner surface texture on tribological properties of piston ring-liner assembly in short time tests. Tribology International. 113, 137-148. DOI: 10.1016/j.triboint.2016.11.025.

[19] Johansson, S., Nilsson, P.H., Ohlsson, R. & Rosén, B.-G. (2011). Experimental friction evaluation of cylinder liner/piston ring contact. Wear. 271(3-4), 625-633. DOI: 10.1016/j.wear.2010.08.028.

[20] Igartua, A., Nevshupa, R., Fernandez, X., Conte, M., Zabala, R., Bernaola, J., Zabala, P., Luther, R. & Rausch, J. (2011). Alternative eco-friendly lubes for clean two-stroke engines. Tribology International. 44(6), 727-736. DOI: 10.1016/j.triboint.2010.01.019.

[21] BN-78/1372-01. Piston combustion engines. Cylinder liners made of alloy cast iron. General requirements and tests. (in Polish).

[22] Orłowicz, A.W., Mróz, M., Tupaj, M., Trytek, A. (2015). Shaping the microstructure of cast iron automobile cylinder liners aimed at providing high service properties. Archives of Foundry Engineering. 15(2), 79-84. DOI : 10.1515/afe-2015-0043.

[23] Orłowicz, A.W. & Trytek, A. (2003). Effect of rapid solidification on sliding wear of iron castings. Wear. 254(1-2), 154-163. DOI: 10.1016/S0043-1648(02)00301-0.

Przejdź do artykułu

Autorzy i Afiliacje

A. Orłowicz
1
ORCID: ORCID
M. Radoń
1
ORCID: ORCID
M. Lenik
1
ORCID: ORCID
G. Wnuk
1
ORCID: ORCID

  1. Rzeszow University of Technology, Poland

Abstrakt

In this study, music teachers' exposure to sound was tested by measuring the A-weighted equivalent sound pressure level (SPL), the A-weighted maximum SPL and the C-weighted peak SPL. Measurements were taken prior to and after acoustic treatment in four rooms during classes of trumpet, saxophone, French horn, trombone and percussion instruments. Results showed that acoustic treatment affects the exposure of music teachers to sound. Daily noise exposure levels (LEX, 8 h) for all teachers exceeded a limit of 85 dB while teaching music lessons prior to room treatment. It was found that the LEX, 8 h values ranged from 85.8 to 91.6 dB. The highest A-weighted maximum SPL and C-weighted peak SPL that music teachers were exposed to were observed with percussion instruments (LAmax = 110.4 dB and LCpeak = 138.0 dB). After the treatments, daily noise exposure level decreased by an average of 5.8, 3.2, 3.0, 4.2 and 4.5 dB, respectively, for the classes of trumpet, saxophone, French horn, trombone and drums, and did not exceed 85 dB in any case.

Przejdź do artykułu

Autorzy i Afiliacje

Emil Kozłowski
Rafał Młyński

Abstrakt

The paper On the Psychohistory as a Historiographical Paradigm reviews a book by Tomasz Pawelec: History and the Unconsciousness. Theoretical Premises and Research Practice of Psychohistory, Katowice 2004. The book includes both the reconstruction of the theoretical and methodological assumptions shared by psychohistorians based on the psychoanalysis or the neofreudian conceptions and the characteristics of their actual studies of the history. The psychohistory is presented by T. Pawelec as a vivid and constantly changing paradigm in historiography of 20th century. His book is recommended to psychologists interested in the psychoanalysis and, even more strongly, to historian.
Przejdź do artykułu

Autorzy i Afiliacje

Maciej Dymkowski
ORCID: ORCID

Ta strona wykorzystuje pliki 'cookies'. Więcej informacji