Publication in University of Dunaújváros
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Hatékony tanulási környezet kialakításának innovatív megoldása a Dunaújvárosi Egyetemen
Get PDFA 21. század második dekádjában az azonnali kommunikáció
korában, túl számos ipari, információs és kommunikációs forradalmon, olyan oktatási rendszer és -környezet kialakítása szükséges, amely képes a technológiai változásokkal lépést tartani és a tanulási-tanítási folyamat korszerűsítésével kiszolgálni az oktatás iránti növekvő keresletet. A digitális oktatási stratégia megvalósításában jelentős szerepet kapnak a 3D-s megjelenítést biztosító
platformok. A Dunaújvárosi Egyetemen az addigi online kurzusok a MaxWhere platform alkalmazásával kerültek 3D-s térbe. A Pilot Projekt keretében több tantárgy, így például a Szakmódszertan I. és Multimédia I. tananyagok továbbfejlesztése, továbbá a munkakörnyezet kialakítása és a tanulásszervezés korszerűsítése történt meg a VR által kínált lehetőségek megragadásáva
Peridynamic Modelling of Deformation Thermo-Mechanically Loaded Body
Get PDFSurface mounted electronic devices (SMD) are subjected to complex thermo-mechanical loads during manufacturing as well as during their service life. Even during manufacturing, voids and cracks can nucleate in soldered joints and also in components such as capacitors, made of brittle materials. An initial damage can have a detrimental effect on the lifetime of the product.
Modelling of crack initiation and propagation is difficult in classical finite element analysis (FEM), due to the singularity of the mathematical functions in the differential analysis. Extended FEM (X-FEM) and meshless methods
were developed to overcome these problems, nevertheless thermo-mechanical coupling of cracks and crack branching is still open for further research. Peridynamic Continuum Modelling (PCM) is dedicated to solve the crack initiation, propagation and fracture by integral equations.
In original bond-based peridynamics, tearable springs are defined between all the couples of material points of the continuum, while in a more advanced formulation as a state-based modelling, a force vector is defined as well.
In this work, the state based peridynamic model of the coupled thermomechanical problem was developed, and applied to detect deformations due to thermal loads of board models, and initiation and propagation of cracks during cooling, in relation with modelling wave soldering technologies of
components to a printed circuit board
Efficiency of different kinds of aluminium during deoxidation at the Steelworks of ISD Dunaferr Co. Ltd.
Get PDFIn all areas of life, cost-effectiveness is increasingly emphasized. It is true for materials used in metallurgical processes too. In many cases, however, not only the composition of the materials used affects the efficiency, but also their consistency. The use of various Al carrier
alloys used for deoxidation during converter steel production differs due to different degrees of
burns. In this article we will compare the utilization of cast (solid) “mokka” aluminium and the loose waste “shredder” aluminium used in ISD DunaferrZrt. Steel Works during the deoxidation process and the economics of the use of two deoxidation aluminiums.
The experiment involved a total of 67 heats. Taking into account the results of the statistical analysis, 3 heats were excluded from the heats deoxidized with “mokka” aluminium. The calculations related to the experiment were performed on the basis of 35 heats deoxidized with
“mokka” aluminium and 29 heats pre-deoxidized with “shredder” aluminium. In the calculation of aluminium utilization it can be observed that the “mokka” aluminium is ~ 2.3% better utilized in comparison to the „shredder” aluminium and it can be observed also based on the total amount of aluminium delivered during the whole production process, that the total aluminium utilization
is ~ 3.7% better for heats where pre-deoxidation was made with “mokka” aluminium.
On the basis of economical calculations it can be stated that the use of “shredder” aluminium is
only economical, if its price per tonne does not exceed ~ 80% of the price of “mokka” aluminium
Improved learning environment for calculus courses
Get PDFThe Department of Mathematics of the University of Dunaújváros is devoted to the success of their students. It results in the deep understanding of the students’ needs. Appropriate course material including video lectures, notes, handbook, practice tests, detailed study guide, consultations personally and via email, chat using social networks make this approach fruitful. Modern learning methods are also introduced. Several studies show that changing the learning environment (LE) of higher education courses increase student success. In this work the improvement of the LE applied for the Mathematics course of University of Dunaújváros is introduced. Using this LE the education is much more effective than in the traditional ways
Hopf bifurcation in a circadian rhythm model
Get PDFIn this work the Hopf bifurcation in a biological model discribing the circadian rhythm of Drosophila Melanogaster is studied. The value of the bifurcation paraméter is found numerically using AUTO and XPPAUT
Az éghajlatváltozás minden képzeletet felülmúló dinamikája
Get PDFAz emberek nagy többsége – beleértve ebbe a tudományos világot is – kényelmes és nem hajlandó mélyen belegondolni abba, hogy az indokolatlan túlfogyasztás és az átgondolatlan energiafelhasználás révén egyre növekvő sebességgel, kézenfogva rohan a vesztébe a Föld Bioszférája
és őrületes tempóban növekvő lakossága. Első komoly jel és figyelmeztetés a klímaváltozás, amelynek változásáról nap-mint-nap ízelítőt kapunk, ha figyeljük a furcsa időjárási jelenségeket és rekordokat. Ezek a jelek előrevetítik
a nagyobb változásokat, különösen annak tükrében, hogy a trendek sajnos minden fronton gyorsulva romlanak. A cikk ennek a folyamatnak a gyorsuló trendjeit kívánja bemutatni és ezzel felhívni a világmentő cselekvésre a
figyelmet
Comprehensive analysis of local corrosion degradation on austenitic pipeline
Get PDFCorrosion degradation was observed in a nuclear power plant spent fuel cooling system. A systematic and comprehensive investigation program was developed to reveal the root
cause of the degradation. Series of corrosion tests, mechanical, microstructural and microbiological investigations were carried out. Also, simulations of the operating conditions and welding parameters were performed. Based on the results, the major contributors to the degradation process were identified and a possible degradation mechanism was propose
An improvement for a mathematical model for distributed vulnerability assessment
Get PDFHadarics et. al. gave a Mathematical Model for Distributed Vulnerability Assessment. In this model the extent of vulnerability of a specific company IT infrastructure is measured by the probability of at least one successful malware attack when the users behaviour is also incorporated into the model. The different attacks are taken as independent random experiments and the probability is calculated accordingly. The model uses some input probabilities related to the characteristics of the different threats, protections and user behaviours which are estimated by the corresponding relative frequencies. In this paper this model is further detailed, improved and a numerical example is also presented
Hogyan legyünk jó kutatók?
Get PDFKi a jó kutató? Ki a sikeres kutató? Azonos-e a kettő, vagy különbözik? A jó kutató a valóságot vizsgálja, és elkerüli a torzításokat. Ez a cikk azt mutatja be, hogy milyen kutatói hibákat követhetünk el a megfigyelés és az interjú során
Difficulties in 3D metal printing : The inner stress evolution due to nonequilibrium phase transformation.
Get PDFAlthough thin metal strips or amorphous ribbons offer a higher magnetic performance compared to the presently used thicker crystalline electrical steels in electric motors, they have been considered unsuitable to build the rotor and/or the stator of classical electric motors because of fabricating limitations. Nowadays the development of high efficiency electrical motors has an outstanding significance, so an attempt is made to apply the soft magnetic glassy tapes to build stator and rotor elements for this application.
However Fe based amorphous ribbons are promissing base materials, but in order to use them, several additional requirements have to be satisfied, like cutting the soft magnetic elements into the appropriate shapes, avoiding
the degradation (local crystallization) of the individual glassy elements. In this paper the heat affected zone of soft magnetic materials like FINEMET and METGLAS were examined after laser cutting. The investigations were
focused on structural changes (XRD and DSC) and microhardness distribution of the heat affected zone which have a strong relation to mechanical properties for example embrittlement. These materials will be used in electric motors to increase its efficiency therefore it is important to us for later
machinability and handling of laser cutted part