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Number of results: 17
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Abstract

The subject of discussion is a tank gun horizontal stabiliser. In order to simplify identification, the system was divided into appropriate functional parts. Then, via laboratory tests, dynamic and static characteristics of those parts were obtained, and numerical values of coefficients of suitable mathematical model of the system were determined. The structural scheme of the overall system was derived on the basis of the obtained static characteristics and transfer functions of individual parts of the system, and based on the knowledge about the system feedbacks. For the investigation of the considered control system, one applied a method of computer simulations. The mathematical model and its numerical implementation was experimentally verified. To this aim: • the results of model testing (for open-loop system) were compared with the existing results of experimental tests carried-out on a real tank; • tests of the complete closed-loop system were carried -out and their results were compared with the results of numerical computations. The results of experimental and model simulation investigations showed that the mathematical model and its numerical implementation was worked-out correctly.
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Authors and Affiliations

Krzysztof M. Papliński
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Abstract

The presented research shows that commercially available graphene on quartz modified with rhenium oxide meets the requirements for its use as a conductive and transparent anode in optoelectronic devices. The cluster growth of rhenium oxide enables an increase in the work function of graphene by 1.3 eV up to 5.2 eV, which guarantees an appropriate adjustment to the energy levels of organic semiconductors used in organic light-emitting diode devices.
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Bibliography

  1. Zou, S. J. et al. Recent advances in organic light-emitting diodes: Toward smart lighting and displays. Chem. Front. 4, 788–820 (2020). https://doi.org/10.1039/c9qm00716d
  2. Hou, S. et al. Recent advances in silver nanowires electrodes for flexible organic/perovskite light-emitting diodes. Chem. 10, 864186 (2022). https://doi.org/10.3389/fchem.2022.864186
  3. Naghdi, S., Sanchez-Arriaga, G. & Rhee, K. Y. . Tuning the work function of graphene toward application as anode and cathode. Alloys Compd. 805, 1117–1134 (2019). https://doi.org/10.1016/j.jallcom.2019.07.187
  4. Adetayo, A. E., Ahmed, T. N., Zakhidov, A. & Beall, G. W. Improvements of organic light-emitting diodes using graphene as an emerging and efficient transparent conducting electrode material. Opt. Mat. 9, 2002102 (2021). https://doi.org/10.1002/adom.202002102
  5. Krukowski, P. et al. Work function tunability of graphene with thermally evaporated rhenium heptoxide for transparent electrode applications. Eng. Mat. 22, 1900955 (2020). https://doi.org/10.1002/adem.201900955
  6. Meyer, J. et al. Metal oxide induced charge transfer doping and band alignment of graphene electrodes for efficient organic light emitting diodes. Rep. 4, 5380 (2014). https://doi.org/10.1038/srep05380
  7. Meyer, J. et al. Transition metal oxides for organic electronics: Energetics, device physics and applications. Mat. 24, 5408–5427 (2012). https://doi.org/10.1002/adma.201201630
  8. Kowalczyk, D. A. et al. Local electronic structure of stable mono-layers of α-MoO3−x grown on graphite substrate. 2D Mat. 8, 025005 (2021). https://doi.org/10.1088/2053-1583/abcf10
  9. Kowalczyk, P. J. et al. Flexible photovoltaic cells based on two-dimensional materials and their hybrids. Przeglad Elektrotechniczny 98, 117–120 (2022). (in Polish) https://doi.org/10.15199/48.2022.02.26
  10. Kowalczyk, D. A. et al. Two-dimensional crystals as a buffer layer for high work function applications: the case of monolayer MoO3. ACS Appl. Mater. Interfaces. 14, 44506–44515 (2022). https://doi.org/10.1021/acsami.2c09946
  11. Lei, Y. et al. Graphene and beyond: recent advances in two-dimensional materials synthesis, properties, and devices. ACS Nanosci. Au (2022). https://doi.org/10.1021/acsnanoscienceau.2c00017
  12. Pabianek, K. et al. Interactions of Ti and its oxides with selected surfaces: Si(100), HOPG(0001) and graphene/4H-SiC(0001). Coat. Technol. 397, 126033 (2020). https://doi.org/10.1016/j.surfcoat.2020.126033
  13. Momeni Pakdehi, D. et al. Minimum resistance anisotropy of epitaxial graphene on SiC. ACS Appl. Mater. Interfaces. 10, 6039–6045 (2018). https://doi.org/10.1021/acsami.7b18641
  14. Miao, Y. et al. Small-size graphene oxide (GO) as a hole injection layer for high-performance green phosphorescent organic light-emitting diodes. Mater. Chem. C 9, 12408–12419 (2021). https://doi.org/10.1039/d1tc02898g
  15. Chen, Y., Gong, X. L. & Gai, J. G. Progress and challenges in transfer of large-area graphene films. Sci. 3, 1500343 (2016). https://doi.org/10.1002/advs.201500343
  16. Fisichella, G. et al. Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates. Beilstein Nanotechnol. 4, 234–242 (2013). https://doi.org/10.3762/bjnano.4.24
  17. Huet, B. & Raskin, J. P. Role of the Cu substrate in the growth of ultra-flat crack-free highly-crystalline single-layer graphene. Nanoscale 10, 21898–21909 (2018). https://doi.org/10.1039/c8nr06817h
  18. Zheng, F. et al. Critical stable length in wrinkles of two-dimensional materials. ACS Nano 14, 2137–2144 (2020). https://doi.org/10.1021/acsnano.9b08928
  19. Venables, J. A. Atomic processes in crystal growth. Sci. 299300, 798–817 (1994). https://doi.org/10.1016/0039-6028(94)90698-X
  20. Greiner, M. T. et al. The oxidation of rhenium and identification of rhenium oxides during catalytic partial oxidation of ethylene: An in-situ XPS study. Phys. Chem. 228, 521–541 (2014). https://doi.org/10.1515/zpch-2014-0002
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Authors and Affiliations

Paweł Krukowski
1
ORCID: ORCID
Michał Piskorski
1
ORCID: ORCID
Ruslana Udovytska
2
ORCID: ORCID
Dorota A. Kowalczyk
1
ORCID: ORCID
Iaroslav Lutsyk
1
ORCID: ORCID
Maciej Rogala
1
ORCID: ORCID
Paweł Dąbrowski
1
ORCID: ORCID
Witold Kozłowski
1
ORCID: ORCID
Beata Łuszczyńska
2
ORCID: ORCID
Jarosław Jung
2
ORCID: ORCID
Jacek Ulański
2
ORCID: ORCID
Krzysztof Matuszek
2
ORCID: ORCID
Aleksandra Nadolska
1
ORCID: ORCID
Przemysław Przybysz
1
ORCID: ORCID
Wojciech Ryś
1
ORCID: ORCID
Klaudia Toczek
1
ORCID: ORCID
Rafał Dunal
1
ORCID: ORCID
Patryk Krempiński
1
ORCID: ORCID
Justyna Czerwińska
1
ORCID: ORCID
Maxime Le Ster
1
ORCID: ORCID
Marcin Skulimowski
3
ORCID: ORCID
Paweł J. Kowalczyk
1
ORCID: ORCID

  1. Department of Solid State Physics (member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, 149/153 Pomorska St., 90–236 Łódź, Poland
  2. Department of Molecular Physics (member of National Photovoltaic Laboratory, Poland), Lodz University of Technology, 116 Żeromskiego St., 90– 924 Łódź, Poland
  3. Department of Intelligent Systems, Faculty of Physics and Applied Informatics, University of Lodz, 149/152 Pomorska St., 90–236 Łódź, Poland
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Abstract

The effect of air humidity on oscillatory flow around the NACA 0012 airfoil was investigated experimentally at Mach number M=0.71 and airfoil angle of attack a=8.5''. The background tlow oscillations were produced by a rotating rectangular plate placed downstream of the airfoil. The generated oscillation frequencies were in the range from 0.5 up to 1.5 of the buffet frequency. The presented results shown that the normal aerodynamic force variations strongly depend on the excitation frequency and reach a maximum value at frequencies typical to the buffet. The increase of the air humidity leads to considerable diminishing of the aerodynamic force variation.
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Authors and Affiliations

Witold C. Selerowicz
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Abstract

The authors present a proposal for modelling the process of scraping of load units (packages) from sorting belt conveyors with the use of deflection scrapers. The continuous scraping process was subjected to discretisation. Characteristic stages of the process were distinguished, such that determine different kinematics-dynamic properties of the load. The created model makes it possible to test the scraping process, and to optimise it.
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Authors and Affiliations

Tomasz Piątkowski
Janusz Sempruch
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Abstract

The paper presents theoretical analysis of excited vibrations of the vehicle in a wide range of excitation frequencies (from I to 80 Hz). The mathematical model and calculations were prepared for the accepted physical model of the vehicle. The model was used to simulate the excited vertical vibrations. The bifurcation figures with an excitation frequency as a bifurcation parameter were determined on the basis of the simulation results - the changes of kinematics values in time. Bifurcation diagrams give a picture of vehicle vibrations. This picture gives the possibility of identification of characteristic parameters of sprigs and dumping elements and can be used for control, diagnostic aims, and for making technical investigations of vehicle suspension.
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Authors and Affiliations

Ryszard Andrzejewski
Jerzy Werner
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Abstract

An application of nonlinear optimisation methods to the solution of optimal brake torques for the ESP system is presented. The plane model of a vehicle is worked out and then used in the optimisation process. Two tasks are considered; the first when the vehicle motion is disturbed by bumps and ruts, the second when the vehicle changes the lane. The results of numerical calculation are included.
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Authors and Affiliations

Witold Grzegożek
Stanisław Wojciech
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Abstract

The paper presents a methodology for creating dynamic characteristics of fuel consumption and intensity of emission of toxic components of exhaust gas. The source of data is the result of modal analysis of fuel consumption and emission intensity obtained from experimental drive tests. Two certified tests have been used: European NEDC and American Ff P- 75. A general algorithm for obtaining dynamic characteristics in the form of approximated functions is formulated on the basis of measured data. Examples of characteristics obtained for a real car with spark ignition engine are presented. The results obtained from experimental measurements and numerical simulations are compared and discussed.
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Authors and Affiliations

Krzysztof Brzozowski
Kazimierz Romaniszyn
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Abstract

Results and low-cycle fatigue tests analysis of 45 steel in conditions of block programmed loading with a different sequence of levels were presented in the paper. During tests four types of programs were applied: gradually increasing, gradually decreasing, gradually increasing and decreasing, and irregular. The sequence of levels in the block loading program was the parameter, which diversified the applied programs. The results of tests were analysed in the aspect of influence of loading program character on the course of the stabilization process. The analysis of the stabilization process was performed by comparing the stress loading amplitude for the chosen levels of the program in the following blocks. The hardening index was proposed as a description of the stabilization process. The comparative analysis showed similarity of the stabilization processes both under the programmed and the constant - amplitude loading.
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Authors and Affiliations

Stanisław Mroziński
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Abstract

In the paper, the author presents a certain approach to interpretation of surface vorticity distribution on the airfoil surface, which leads to reduction of computational cost of surface vorticity distribution method (SYM). Some examples of the calculations are shown, and the results compared with solutions based on conformal mapping method as well as with experimental data. The calculations were done employing linear vortex distributions on each panel. The Neuman boundary condition was established at the collocation points. An unloaded trailing edge Kutta-Joukowski condition was applied in the present work. The interpretation of continuous vorticity distribution at the airfoil surface made it possible to reduce the number of panels on airfoil surface, and a satisfactory accuracy was maintained. In these circumstances one can do the calculations even by means of a programmable calculator.
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Authors and Affiliations

Piotr Strzelczyk
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Abstract

The article presents methods of evaluating energy consumption of water pumps. Pump characteristics during work at variable rotational speed and constant head are discussed. Characteristics of the upper slope of pump efficiency curve were determined for the cases of constant and variable growth of rotational speed The left-sided coefficient of pump efficiency correction was defined.
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Authors and Affiliations

Leszek Szychta
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Abstract

The paper introduces a new design of a platform mechanism with 6 DOF. The platform is supported on three active legs, each equipped with two rotating drives. The mechanism can be used in active vibration control systems. The values of drive angular velocities are precisely controlled, so that the transmission of the base vibrations onto the platform could be minimal. The values of drive torques to be generated are determined. The mechanism was modelled using the Working Model® 30. The effects of active vibration control are also presented.
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Authors and Affiliations

Grzegorz Tora
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Abstract

The authors present an optirrusanon method, based on the thermodynamic consideration and applied to the inlet and exhaust systems of turbocharged engine. The goal function in this method is defined as a sum of exergy irreversible losses - occurring in the whole flow path. The decision variables, optimisation parameters and, also, the constraint conditions in the discussed method are defined and determined. The validation results of specially written and unique programmes, used for flow simulations in the analysed systems, are also presented. The optimisation results, based on the discussed method and related to a specific turbocharged engine are discussed in part II.
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Authors and Affiliations

Krzysztof Nakonieczny
Tadeusz R. Fodemski
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Abstract

The objective of this study was an analysis of the thickness of a plasticized zone that appears after surface burnishing of machine parts with a non-deformable roller of a torus contour. A function defining the plasticized zone thickness depending on burnishing parameters was determined. M. T. Huber's hypothesis of plastic deformation was used in the solution. It was found that the thickness of the plasticized zone depends principally on the pressure force and yield point, and it is insignificantly dependent on the geometrical dimensions of the workpiece and burnishing roller.
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Authors and Affiliations

Józef Jezierski
Tomasz Mazur
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Abstract

The subject of this paper is a real stabilising and tracking control system-namely, the tank gun horizontal stabiliser. The simulation investigations of the influence of regulation potentiometers settlings on stabilisation exactness and transient processes quality were carried-out using a verified mathematical model of the system. The author analysed the possibilities of improving performance characteristics of the stabiliser via altering of feedback's gain coefficients as well as the influence of disturbing inputs amplitude and frequency (propagated from the hull on the gunturret) on stabilisation exactness of a given position. In the result of model investigations, it was found that it would be impossible to improve significantly the stabiliser performance quality with its present structure. For this reason, one investigated the possibilities of adding new feedbacks and their influence on the stabilisation quality. The introduced feedbacks improved performance parameters of the stabiliser by about thirty to fifty percent.
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Authors and Affiliations

Krzysztof M. Papliński
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Abstract

The paper presents a model of a car with special attention given to the drive system. Two possible drive systems were considered: with standard differential and independent drive of each wheel by means of an electric motor. In both cases, flexibilities of live axle shafts have been taken into consideration. A 3D model of the car was assumed. The model consists of a system of rigid bodies connected one with another by means of elastic-damping elements. The phases of static and kinetic friction were considered in the steering and drive systems. The method of homogenous transformations was used in the mathematical description. The results of computer simulations are presented.
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Authors and Affiliations

Marek Szczotka
Stanisław Wojciech
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Abstract

The problem of transmitting vibrations with audible frequencies by steel springs, constituting the vibration isolation system was considered in this paper. The analytical relationships allowing determining the value of the transmissibility for the springs resonance frequencies responsible for the transmissibility of high frequency vibrations have been derived and checked by means of FEM method. Also the occurrence of the increasing stresses in the springs in the areas between the resonances has been shown. The typical system, i.e. the serial system with rubber cushion, has been analyzed, reducing the transmission of high frequency vibrations by the spring. It has been shown that the transmission is reduced not as a result of differences in the wave impedance of the boundary of both media but due to the increased dispersion of energy in the rubber, and the analytical relationships allowing the evaluation of the effectiveness of this method have been derived.
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Authors and Affiliations

Jerzy Michalczyk
Leszek Majkut

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