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Leszek Ułanowicz

1966. Ułanowicz L.: Identification of technical condition of the fluid power transmission on the basis of variation-related description of structural parameters. "Scientific Problems of Machines Operation and Maintenance" ("Zagadnienia Eksploatacji Maszyn"), z. 1 (145), vol. 41, 2006. Ułanowicz L.: Outline of the method for prediction of lifetime achieved by avionic hydraulic drives operated under real field conditions. "Journal of Kones Powertrain and Transport" 2009, vol. 16, no. 2

Open access

Jonas Wagner, Eva Binkowski and Robert Bronsart

-SHALLO user guide, HSVA - report 1646/4. Hamburg: Hamburgische Schiffbau Versuchsanstalt GmbH. Temple, D. and Collette, M., 2012. Multi-objective hull form optimization to compare build cost and lifetime fuel consumption. International Marine Design Conference, IMDC, Glasgow, Scotland, 11-14 06 2012, II, pp.391-403. Røe, M.A., 2010. Quantum - A container ship concept for the future. DNV Container Ship Update, No. 1 2010. Oslo: DNV. Wagner, J. and Bronsart, R., 2011. A contribution to scenario based ship design. International

Open access

Jürgen Schiffer, István Gódor, Florian Grün and Wilfried Eichlseder

A Model Scale Test Method for the Piston Ring - Cylinder Liner Tribosystem of Internal Combustion Engines

Rising technical standards of customers, legal requirements and the trend to minimize maintenance effort raise the thermal, mechanical and tribological loads on components of combustion engines. In this regard, emphasis is laid on improving the piston ring - cylinder liner tribosystem, one with the highest energy losses. An efficient performance has to be guaranteed during its lifetime. Tribological investigations could be carried out on engine test benches, but they are highly cost-intensive and time-consuming. Therefore, a damage-equivalent test methodology was developed with the analogous tribological model, "ring-on-liner". The research was carried out under two characteristic operating conditions. One with a "standard" operating system, modelled in line with ideal lubrication conditions, and the other "extreme abrasive" operating system, typical to a system running on a lubricant contaminated by abrasive particles. To optimize the tribological loading capacity of the cylinder liner, with focus on these two operating conditions, numerous nitride coatings have been investigated. The key aspects being seizure resistance, running-in characteristics and long term wear behaviour.

Open access

Paweł Lindstedt and Rafał Grądzki

A Synthetic Method to Investigate Reliability and Safety Potential of a Technical Facility During its Operation

The paper presents presumptions to an innovative way intended to bring down each diagnostic information, even if it has been provided with participation of an expert, to the form that can be expressed in a conventional manner by the corresponding score of points. Each change of the signal (depending on its value and the moment when it appears) is associated with the score that has been already established by experts. The proposed innovative method consists in utilization of the obtained signals to find out parameters of the current settings and the technical status (equations 3, 4) and the safety and reliability of the object (equations 5, 6) with application of the combined status equations [3,5]. It will enable to perform continuous monitoring and prediction of the reliability and safety of the facility during its lifetime. The described method may prove to be extremely useful as it exhibits the overall deterioration of the facility in an unambiguous and synthetic manner and makes it possible to predict future operation status of the facility and, in consequence, to schedule appropriate maintenance operations (adjustments, repairs, overhauls).

Open access

Josifs Survilo and Antons Kutjuns

Operation Modes of HV/MV Substations

A distribution network consists of high voltage grid, medium voltage grid, and low voltage grid. Medium voltage grid is connected to high voltage grid via substations with HV/MV transformers. The substation may contain one, mostly two but sometimes even more transformers. Out of reliability and expenditure considerations the two transformer option prevail over others mentioned. For two transformer substation, there may be made choice out of several operation modes: 1) two (small) transformers, with rated power each over 0.7 of maximum substation load, permanently in operation; 2) one (big) transformer, with rated power over maximum substation load, permanently in operation and small transformer in constant cold reserve; 3) big transformer in operation in cold season, small transformer-in warm one. Considering transformer load losses and no load losses and observing transformer loading factor β it can be said that the mode 1) is less advantageous. The least power losses has the mode 3). There may be singled out yet three extra modes of two transformer substations: 4) two big transformers in permanent operation; 5) one big transformer permanently in operation and one such transformer in cold reserve; 6) two small transformers in operation in cold season of the year, in warm season-one small transformer on duty. At present mostly two transformers of equal power each are installed on substations and in operation is one of them, hence extra mode 5). When one transformer becomes faulty, it can be changed for smaller one and the third operation mode can be practiced. Extra mode 4) is unpractical in all aspects. The mode 6) has greater losses than the mode 3) and is not considered in detail. To prove the advantage of the third mode in sense of power losses, the notion of effective utilization time of power losses was introduced and it was proven that relative value of this quantity diminishes with loading factor β. The use of advantageous substation option would make it possible to save notable amount of electrical energy but smaller transformer lifetime of this option must be taken into account as well.

Open access

Ana Marija Grancarić, Anita Tarbuk and Lea Botteri

Abstract

The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R) crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA), UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm), the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm) of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration range without/with the addition of natural zeolite or silicone- polydimethylsiloxane. UV protection was determined in vitro through ultraviolet protection factor. Additionally, the influence to fabric whiteness and hand was researched

Open access

Francisco A. Sagasta, Juan L. Torné, Antonio Sánchez-Parejo and Antolino Gallego

energy index for damage evaluation of reinforced concrete slabs under seismic loads , Structural Health Monitoring, 11 , 1, 69-81. 4. Carpinteri A., Lacidogna G., Pugno N. (2007), Structural damage diagnosis and life-time assessment by acoustic emission monitoring , Engineering Frac- ture Mechanics, 74 , 1-2, 273-289. 5. Gallego A., Benavent-Climent A., Cristobal I. (2011), Health monitoring of reinforced concrete slabs subjected to earthquake-type dynamic loading via mea- surement and analysis of acoustic emission signals , Smart

Open access

Piotr Barszcz, Mariusz Wesołowski and Krzysztof Blacha

References 1. Augustyn S.: Żywotność lotniczego systemu antropotechnicznego . AON. Warszawa 2013. ( Lifetime of an antropotechnical avionic system . National Defence University (AON), Warsaw, 2013). 2. Bondaruk A.: Badanie wpływu uszkodzeń i niesprawności samolotów wielozadaniowych na bezpieczeństwo lotów . Praca doktorska. Dęblin 2010. ( Investigation of impacts effected by faults and deficiencies of multi-task aircrafts onto flight safety . PhD Thesis, Dęblin, 2010). 3. Gołębiowski W.: Badanie percepcji szkolonych pilotów w procesie

Open access

Zdeněk Chobola, Miroslav Luňák, Jiří Vaněk, Eduard Hulicius and Ivo Kusák

Fluctuations ICNF 2003, Prague, pp. 735–748. [8] KOKTAVY, P.—VANEK, J.—CHOBOLA, Z. : Solar Cells Noise Diagnostic and LBIC Comparison, 19th International Conference on Noise and Fluctuations, AIP conference proceedings, vol. 922, Tokyo, Japan, 2007, pp. 306–309. [9] BYCHIKHIN, S.—POGANY, D.—VANDAMME, L. K. J.—MENEGHESSO, G.—ZANONI, E. : Low-Frequency Noise Sources in As-Prepared and Aged GaN-based Light-Emitting Diodes, J. Appl. Phys 97 No. 12, Article Nr. 123714, 2005. [10] KONCZAKOWSKA, A. : Lifetime Dependence on 1/f Noise of Bipolar Transistors, Proc

Open access

Andrzej Gębura and Mirosław Zieja

Aviations’, 1983, No. 4 (95)] 12. Witoś M.: Zwiększenie żywotności silników turbinowych poprzez aktywne diagnozowanie i sterowanie . „Prace Naukowe Instytutu Technicznego Wojsk Lotniczych” 2011, nr 29. [ Lifetime extension of turbine motors by active maintenance and monitoring of deterioration , ‘Research Works of Air Force Institute of Technology’, 2011, No. 29].