Autor: Rokicki, R. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Measurements of nanohardness and elasticity modulus of titanium after magnetoelectropolishing
Pomiary nanotwardości i modułu sprężystości tytanu po magnetoelektropolerowaniu
Autorzy:: Hryniewicz, T.
Rokosz, K.
Valicek, J.
Rokicki, R.
Harnicarova, M.
Vylezik, M.
Powiązania:: https://bibliotekanauki.pl/articles/153005.pdf
Data publikacji:: 2013
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: nanoindentation
titanium biomaterials
nanohardness
Young's modulus
magnetoelectropolishing (MEP)
nanoindentacja
tytan
magnetoelektropolerowanie (MEP)
nanotwardość
moduł Younga
Opis:: Nanohardness is one of the main mechanical properties of the studied metal surface after electropolishing operations. The nanoindentation measurements were performed on CP-titanium biomaterial after its treatment under a standard electropolishing (EP) and magnetoelectro-polishing (MEP) conditions, with abrasive polishing (MP) performed on the samples for reference. In the studies, both the Young’s modulus of elasticity and nanohardness were investigated. It was found that the mechanical properties of titanium biomaterial indicated an evident dependence on the type and conditions of surface treatment. After magnetoelectropolishing (MEP) operation a considerable change in mechanical properties of the same Ti biomaterial was observed. One may state that the mechanical properties obtained on the titanium samples both after abrasive polishing (MP) and after a standard electropolishing (EP) are very different from those gained on the magnetoelectropolished titanium sample.
Nanotwardość jest jedną z ważniejszych cech mechanicznych powierzchni metali po obróbce elektropolerowaniem. W tradycyjnych badaniach twardości materiału, diamentowa końcówka wgłębnika służy badaniu twardości i modułu sprężystości. Pod obciążeniem wgłębnika następują odkształcenia sprężyste i plastyczne. Dobór wielkości obciążenia uzależniony jest od celu badania – samego materiału, czy też warstewek pasywnych powstałych na powierzchni metalu po określonej obróbce wykończającej. W artykule przedstawiono wyniki pomiarów metodą nanoindentacji próbek tytanu o czystości komercyjnej po polerowaniu elektrolitycznym w warunkach standardowych (EP), i magnetoelektro-polerowaniu (MEP), oraz po polerowaniu ściernym (MP) próbek, które posłużyły jako odniesienie. Badano moduł sprężystości Younga oraz nanotwardość materiału. Wyniki badań pokazują, że własności mechaniczne tytanu zależą od rodzaju i warunków obróbki wykończającej. Po magnetoelektropolerowaniu (MEP) wyniki nanoindentacji różnią się zasadniczo od analogicznych wyników uzyskanych po standardowym elektropolerowaniu (EP) i po polerowaniu ściernym (MP). Taka zmiana zasadniczo wpływa na poprawę odporności na przeginanie, zginanie i skręcanie biomateriału.
Źródło:: Pomiary Automatyka Kontrola; 2013, R. 59, nr 7, 7; 676-679
0032-4140
Pojawia się w:: Pomiary Automatyka Kontrola
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Towards optimal operation control in rural low voltage microgrids
Autorzy:: Parol, M.
Rokicki, Ł.
Parol, R.
Powiązania:: https://bibliotekanauki.pl/articles/200413.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: microgrids
centralized control
distributed control
rural areas
Opis:: The paper raises the issue of controlling rural low voltage microgrids in an optimal manner. The impact of different criterion functions, related to the amount of energy exchanged with the distribution system operator network, the level of active power losses, the amount of energy generated by different energy sources and the value of financial performance measures regarding the microgrid operation, on the choice of operating points for devices suggested by the optimization algorithm has been analyzed. Both island and synchronous microgrid operation modes are being considered. We propose two variants of the optimization procedure: the first one is based on the particle swarm optimization algorithm and centralized control logic, and the second one takes advantage of the decentralized approach and Monte Carlo methods. A comparison of the simulation results for two sample rural microgrids, obtained for different objective functions, microgrid operation modes and optimization procedure variants, with the use of prepared algorithm implementations, has been provided. The results show that the proper choice of an objective function can have a crucial impact on the optimization algorithm’s behavior, the choice of operating points and, as a consequence, on microgrid behavior as well. The choice of the proper form of the objective function is the responsibility of the person in charge of both the microgrid itself and its operation. This paper can contribute towards making correct decisions in this area. Generally, slightly better results have been achieved for the centralized control mode of operation. Nevertheless, the results also suggest that in many cases the approach based on distributed logic can return results that are better or sufficiently close to the ones provided by the centralized and more sophisticated approach.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 4; 799-812
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: The control of solidification kinetics of the vacuum-cast thin-wall nickel-based superalloys by changing the geometrical characteristics of the ceramic mold
Autorzy:: Cygan, R.
Szeliga, D.
Rokicki, P.
Sieniawski, J.
Suchy, J. S.
Powiązania:: https://bibliotekanauki.pl/articles/381982.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: nickel based superalloy
ceramic mold
thin walled casting
investment casting
nadstop niklu
forma ceramiczna
odlewanie cienkościenne
odlewanie precyzyjne
Opis:: This paper provides an analysis of experimental research and results of investment casting process. Temperature field in a ceramic mold is one of the problems during numerical simulation. Reducing the costs of production in precision casting involves the reduction of scraps, which is one of the fundamental problems of the foundry industry. Reducing these costs is associated with optimization of precision casting technology of aircraft engines critical parts, including control of the solidification front in thin-walled castings of nickel super alloys cast in a vacuum. It is achieved by changing the geometrical characteristics of the ceramic mold. The results of the tests were used to optimize the industrial production of aircraft components in Precision Foundry of WSK Rzeszów. Temperature distribution gained in the conducted tests allowed verification and optimization of computer simulations.
Źródło:: Archives of Foundry Engineering; 2013, 13, 4; 21-28
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Effective approach to distributed optimal operation control in rural low voltage microgrids
Autorzy:: Parol, M.
Kapler, P.
Marzecki, J.
Parol, R.
Połecki, M.
Rokicki, Ł.
Powiązania:: https://bibliotekanauki.pl/articles/201003.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: microgrids
optimal operation
distributed control
rural areas
Opis:: The paper raises the issue of optimizing the control of the rural low voltage microgrids. Microgrids can operate in a synchronous mode with grids of distribution system operators and in an island mode. We can distinguish two control strategies in microgrids: one approach based on centralized control logic, which is usually used, and another on decentralized control logic. In this paper we decided to present the approach based on the distributed control, combining the efforts of the distributed cooperative control and modified Monte Carlo optimization method. Special attention has been paid to the impact of the order of processing particular devices’ groups on results of optimization calculations. Moreover, different scenarios of behavior of the microgrid control system with respect to the communication loss have been also presented. The influence of the issue of continuity of communication between particular devices’ groups on the possibility of carrying out the optimization process has been investigated. Additionally, characteristics of power loads and generation of electricity from small renewable energy appearing in rural areas have been described and the sensitivity of the optimization algorithm to the changes of demanded power values and changes of values of power generated by renewable energy sources has been studied. We analyzed different objective functions which can be can be used as an optimization goal both in synchronous and island operation modes of microgrid. We decided to intensively test our approach on a sample rural LV microgrid, which is typical in the countryside. The observed results of the tests have been presented and analyzed in detail. Generally, results achieved with the use of proposed distributed control are the same as with the use of centralized control. We think that the approach based on distributed control is promising for practical applications, because of its advantages.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 661-678
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Optical measurement of aircraft engine turbine blades
Autorzy:: Budzik, G.
Kubiak, K.
Rokicki, P.
Dziubek, T.
Nowotnik, A.
Matysiak, H.
Cygan, R.
Tutak, M.
Boś, P.
Powiązania:: https://bibliotekanauki.pl/articles/247470.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aircraft engines turbine blades
optical measurements
coordinate measuring technique
Opis:: Manufacturing of aircraft engine turbine blades requires control of blade geometric parameters at different stages of technological process. Acceleration and automation of measurement process can affect the duration of the finished item production. Modern technologies for measurement of aircraft engine turbine blades are based on numerical machines - measurement process is based on processing of numerical data obtained by measurement using coordinate measuring machines. The paper presents the opportunity of automation of aircraft engine turbine blades measurements using scanner ATOS II Triple Scan with blue light source technology. Coordinate measuring technique allows to specify full methodology for designation of complex dimensions of physical objects and transform them into a computer program space of coordinate measuring devices. Presented paper includes capabilities of device used in the study to improve the measurement process in the technological and economical aspects. Another issue described in the paper is impact of measurement performance in automatic mode on the quality of performance – the numerical model of surface, from the standpoint of accuracy and number of collected data points in time. The paper includes an analysis of conditions related to the measurement works, such as the process of preparing the model, measurement equipment and data processing capacity. As the result methodology for automated scanning measurements of aircraft engine turbine blades will be presented.
Źródło:: Journal of KONES; 2013, 20, 2; 21-26
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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