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  • Author: Enikő Bitay x
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Organization of Curriculum and Education in Technical Training

Abstract

Proper management of the realization of the general and special training objectives of technical higher education makes it necessary to organize the curriculum and the educational process according to didactic, methodological aspects. Selection of curriculum elements with deductive and inductive approach and their horizontal and vertical arrangement are required. In addition, the curriculum concentration of a given subject, i.e. its connection to other subjects, must be taken into account. This article intends to add to this by raising some points.

Open access
Issues of The Usability of Copper Ore (Chalcopyrite) From Bălan for Ustensiles Production in The Bronze Age

Abstract

Archaeological publications connect the raw material used for the production of copper and bronze artifacts discovered during the excavations carried on in Szeklerland to the use of the chalcopyrite from the Bălan copper ore deposit. So far, this assumption has not been confirmed by concrete evidence. Men of the Bronze Age can’t possibly have had knowledge of the metallurgy of sulphide-type copper ores such as chalcopyrite. Applying investigations based on spectroscopy, the Bronze Age use of chalcopyrite from Bălan could be either confirmed or refuted, the new data throwing more light on the provenance of the bronze artifacts discovered in the Szeklerland.

Open access
Application Features of Ultrasonic Welding

Abstract

The technological advantages of ultrasonic welding: (no requirement for filler metal; use of small electrical transient resistance contacts; ability to weld thin materials to thick materials) results in a helium-solid weld seam; the computer configuration of the welding parameters can easily be solved; clean and safe workflow (no sparks, flame or smoke); can be integrated into the production line. This article deals with some of the additional application features of this welding process.

Open access
The Role of Focus Position in Single Pulse Laser Drilling of Highly Reflecting Materials

Abstract

The laser processing of materials which are highly reflective at laser wavelengths is problematic. We have to take into account that only a small part of the energy is absorbed, the main part being reflected. In this article we examine the laser processing of highly reflective copper and silver at 1070 nm wavelength. In laser drilling of printed circuit boards it is necessary to drill copper layer as well. In highly reflecting materials we can drill smaller holes because of the low energy efficiency. Naturally in single pulse laser drilling the focus position plays a key role: at the focal spot of the laser beam smaller diameter holes are produced, further from the focal spot, higher diameter holes are produced.

Open access
A New Method for Determining the Pullability of Composite Reinforcing Ceramic Fibres

Abstract

A unique method for producing aluminium matrix composite wires is the Blücher’s process, i.e. continuous gas-pressure infiltration. An essential condition of the process is that the fibre roving of the reinforcing fibres can be pulled across the orifices of the gas-pressure system with the least damage. The article describes a new test procedure that is capable of characterizing this essential functional property of the ceramic reinforcing fibres in a manner comparable and quantitative.

Open access
Electrospinning of Polymer Fibres Using Recycled PET

Abstract

The effective recycling of polymer materials remains unresolved to this day, and this has had a devastating effect on the environment. This study examines an alternative method to PET recycling that is the generation of polymer fibers and fiber mats for filtration applications. The electrospinning instrumentation used in this study had to be designed and built in order to carry out the research. We have managed to produce PET fibers with 200-600 nm diameter, and free-standing fiber mats that could potentially be used in filtration applications.

Open access
Chemical Durability of Uranium Oxide Containing Glasses

Abstract

ZrO2 doped Na-Ba-borosilicate glasses suitable as matrix materials for HLW immobilization were synthesized and corrosion behaviour was investigated in different aqueous media. Hydrolytic stability is increased with the doping level until 5 mol %; above this value the glass vitrification tendency is strongly intensified. Unexpectedly, ZrO2 doping diminished the corrosion stability in 1M HCl solution, and low ZrO2 content showed a low corrosion resistance in 1M Na2CO3 solution also. Doping effect was negligible in case of synthetic seawater. The glass structure is significantly stabilized by the integration of the 30% UO3 added.

Open access
Comparative Study of Roman Iron Slags Discovered in the Roman Auxiliary Fort and Settlement of Călugăreni

Abstract

Iron slag samples unearthed at the eastern border of Roman Dacia, in the auxiliary fort and the military settlement of Călugăreni (Mikháza) are investigated by macroscopic inspection, optical microscopy (OM) and FTIR spectroscopy in order to comparatively characterize their macro- and microstructure as well as their mineralogical composition. During the recent archaeological excavations, a large number of iron artefacts were discovered together with a great quantity of iron slag fragments. The present paper focuses on the data obtained from 17 slag samples.

Open access