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Number of results: 4
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Abstract

The article has presented the method of 3D Digital Light Processing printing as one of the technologies used for rapid prototyping of dental models and making elements of dentures. In this work the research was presented, which the aim was to determine the effect of additional exposure time on the properties of the obtained printouts. Dynamic Mechanical Analysis test showed significant differences in stiffness between uncured specimens as well as specimens cured for 10, 20 and 30 minutes. In turn the obtained TG and DTG curves allowed to determine the most optimal curing time for DLP printouts. These studies provide the basis for determining the most appropriate method for handling printouts after the process of printing from liquid resin, so that they are the best possible quality for dentists and prosthodontists.
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Authors and Affiliations

J. Redutko
1
ORCID: ORCID
A. Kalwik
1
ORCID: ORCID
A. Szarek
1
ORCID: ORCID

  1. Czestochowa University of Technology, Faculty of Mechanical Engineering and Computer Science, Department of Technology and Automation,21 Armii Krajowej Av., 42-201 Czestochowa, Poland
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Abstract

Carbon steel is one of the most widely used alloys in many industries, however, its use is limited by its low corrosion resistance. Depositing a layer of phosphate on its surface improves the corrosion resistance as well as other properties, such as wear resistance, adhesion etc. Accordingly, preliminary studies demonstrated that carbon steel coated with phosphate layers can be used in the manufacture of carabiners for various fields: civil engineering, oil industry etc. Whereas, to demonstrate their capacity to operate in severe conditions related to fire rescue and extinguishing operations, it is necessary to evaluate the thermal behaviour of these materials. Thus, the main goal of this paper is to study the behaviour at high temperatures of three different types of phosphate layers deposited on carbon steel surface, by STA analysis. Also, the paper aims to study the formation of different phosphate layers by determining the types of compounds formed after the completion of the phosphating process, by XRD analysis.
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Authors and Affiliations

D.-P. Burduhos-Nergis
1
ORCID: ORCID
C. Bejinariu
1
ORCID: ORCID
A.M. Cazac
1
ORCID: ORCID
A.V. Sandu
1
ORCID: ORCID
P. Vizureanu
1
ORCID: ORCID

  1. "Gheorghe Asachi” Technical University of Iasi, Faculty of Materials Science and Engineering, 41 “D. Mangeron” Street, 700050, Iasi, Romania
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Abstract

The paper presents the results of experimental validation of a set of innovative software services supporting processes of achieving, assessing and maintaining conformance with standards and regulations. The study involved several hospitals implementing the Accreditation Standard promoted by the Polish Ministry of Health. First we introduce NOR-STA services that implement the TRUST-IT methodology of argument management. Then we describe and justify a set of metrics aiming at assessment of the effectiveness and efficiency of the services. Next we present values of the metrics that were built from the data collected. The paper concludes with giving the interpretation and discussing the results of the measurements with respect to the objectives of the validation experiment.

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Authors and Affiliations

Janusz Górski
Aleksander Jarzębowicz
Jakub Miler
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Abstract

The wind energy conversion systems (WECS) suffer from an intermittent nature of source (wind) and the resulting disparity between power generation and electricity demand. Thus, WECS are required to be operated at maximum power point (MPP). This research paper addresses a sophisticated MPP tracking (MPPT) strategy to ensure optimum (maximum) power out of the WECS despite environmental (wind) variations. This study considers a WECS (fixed pitch, 3KW, variable speed) coupled with a permanent magnet synchronous generator (PMSG) and proposes three sliding mode control (SMC) based MPPT schemes, a conventional first order SMC (FOSMC), an integral back-stepping-based SMC (IBSMC) and a super-twisting reachability-based SMC, for maximizing the power output. However, the efficacy of MPPT/control schemes rely on availability of system parameters especially, uncertain/nonlinear dynamics and aerodynamic terms, which are not commonly accessible in practice. As a remedy, an off-line artificial function-fitting neural network (ANN) based on Levenberg-Marquardt algorithm is employed to enhance the performance and robustness of MPPT/control scheme by effectively imitating the uncertain/nonlinear drift terms in the control input pathways. Furthermore, the speed and missing derivative of a generator shaft are determined using a high-gain observer (HGO). Finally, a comparison is made among the stated strategies subjected to stochastic and deterministic wind speed profiles. Extensive MATLAB/Simulink simulations assess the effectiveness of the suggested approaches.
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Authors and Affiliations

Awais Nazir
1
Safdar Abbas Khan
1
Malak Adnan Khan
2
Zaheer Alam
3
Imran Khan
4
Muhammad Irfan
5
ORCID: ORCID
Saifur Rehman
5
Grzegorz Nowakowski
6
ORCID: ORCID

  1. Department of Electrical Engineering, National University of Science and Technology, Pakistan
  2. Department of Electronics Engineering, University of Engineering and Technology Peshawar, Abbottabad campus, Pakistan
  3. Department of Electrical and Computer Engineering, COMSATS University Islamabad, Abbottabad Campus, Pakistan
  4. Department of Electrical, Electronics and Computer Systems, College of Engineering and Technology, University of Sargodha, Pakistan
  5. Electrical Engineering Department, College of Engineering, Najran University, Saudi Arabia
  6. Faculty of Electrical and Computer Engineering, Cracow University of Technology, Warszawska 24, 31-155 Cracow, Poland

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