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Workplace Noise Examination in a Laboratory (Case Study)

Abstract

In this case study, the course and assessment of a work noise problem in a laboratory environment are described. Noise measurements are performed for the evaluation of workplace noise levels caused by the dominant sources at the site of the investigation. The results are evaluated according to the current Hungarian legislation, which is harmonized with the directives of the European Union. Based on the results noise protection interventions are shown to be required and proposals are described to solve the current situation.

Open access
The Deformaton of The Gear Hob’s Generating Surfaces Due to Re-Sharpening

Abstract

The side relief faces of the monolithic involute gear hob are machined through relieving. The resulting surfaces are bevel helical surfaces in which the side cutting edges result from the intersection of these with the helical rake face. Theoretically, the gear hob is derived from an involute worm. Resharpening decreases the diameter of the hob, thus the edges became closer to the axis, and as a consequence they will be situated on a smaller worm than the original. The present paper analyses the deviation of the re-sharpened gear hob’s carrying worm from the theoretically perfect involute worm whose characteristic dimensions were adjusted considering the re-sharpened gear hob characteristic diameters. It was proven that the evolution of the errors is significantly different from that described in the literature. Thus, increasing the new gear hob diameters in comparison with the calculated dimensions is unnecessary, because it cannot reduce the error to half with this procedure. The mathematical model was built up accepting that the edges result from the intersection of an involute worm with a helical rake face and the side relief faces result from the rototranslation of the edges on a bevel helix leading curve dressed by the relieving parameter.

Open access
The Development of Laboratory Equipment for Testing The Characteristics of Unsaturated Soils

Abstract

The laboratory assessment of the hydraulic characteristics of unsaturated soils usually requires expensive equipment and an extended time period. With lack of financial support, yet taking advantage of local knowledge and resources, the development of cheaper alternative equipment is presented in the present paper. The automated setup allows the assessment of the saturation degree of soil samples subjected to different suctions.

Open access
Examination of Acacia-Tree Gasification Process Under Varying Operating Parameters

Abstract

This paper presents the thermokinetic modeling of the gasification process performed on the acacia-tree under varying operating circumstances and different humidity levels. Gasification does not produce flue gas, but due to imperfect burning, synthesis gas appears which is rich in flammable components (CO2 and H2). The chemical structure of this gas depends on the components of the fuel and the humidity level, but is also greatly affected by the technological parameters, such as pressure and temperature, as well as the air-ratio. The study shows the change of chemical composition, fuel value and the reaction efficiency as a function of varying gasification temperature and pressure. Rising temperature results in improved efficiency, while higher pressure worsens reaction efficiency. However, at higher temperature intervals, the effect of the pressure is neglectable.

Open access
Hungarian Language Technical Terminology from 1920 Until Today

Abstract

This study is the last one of a three-part series reviewing the history of Hungarian language technical terminology. In this article, we strive to present all the factors that have influenced the state of Hungarian technical language and terminology at a particular period of time during the past hundred years. Over a long period of time, the most important part in establishing and disseminating adequate Hungarian terms was played by standards, dictionaries and the publishing of technical literature. Since this situation has dramatically changed by now, after presenting the current state of affairs, we make suggestions on handling terminological problems emerging in the course of technical communication, the instruction of technical language or the translation of technical literature.

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
Mathematical and Assembly Modeling of The Mechanism for Implementing Intermittent Rotational Motion and Speed Setting of The Metering Shaft for Seed Drills

Abstract

The metering shaft of the drilling machine is driven from the impeller. The standard traditional gearbox, the Norton gearbox, provides a constant rotating motion between the impeller and the metering shaft. Manufacturers have started to replace this gearbox with an intermittent rotating movement. Using the stepless variable speed gearbox, the speed of the metering shaft and thus the seed rate is set steplessly. The aim of the thesis is the mathematical modeling of the intermittent rotating motion of the seed drill of a particular drilling machine, and the creation of a striping model.

Open access
Moderization of Cortically Supported Individual Implants

Abstract

Digital product processing, 3D and finite element analysis techniques, modern, tissue-friendly implants with adequate surface treatment and proper screw-fixing make it possible for a good idea to successfully treat patients who do not have a sufficient amount of bone tissue for the implantation of conventional cylindrical-shaped dental implants. The duration of the surgical procedure of a complete, toothless jawbone becomes much shorter. Complicated measurements and risky techniques that require substantial expertise become unnecessary. The implant can be placed precisely into position with a simple surgical procedure. Then, it can be fixed to the bone tissue with the help of pre-designed fixation points. After this, only the professional closing of the wound has to be carried out. We have designed and manufactured a titanium cortical implant that is novel both in the view of chemical composition and surgical procedure. The final connection shaping of the sleeve and abutment system of the personalized cortical-backup implants was designed with the help of finite element analysis methods after the healing process.

Open access
Monitoring System of Rail Surface Crack Propagation

Abstract

Industrially produced rails can contain some inherent failures without evident damage. If a fracture propagates beyond a critical size, it can lead to breakage. The study of fracture mechanics suggests many different theories for detecting the fracture. Continuous monitoring of the rail surface state is necessary in order to assure uninterrupted and safe transportation.

Open access
The Operation of Bucket Wheel Excavators When Encountering Inclusions with Excessive Mining Resistance

Abstract

The Bucket Wheel Excavator (BWE) is the main piece of harvesting equipment used in open-pit lignite or brown coal open-pit mines worldwide. Despite the continuous increase in size, productivity and technical sophistication in recent decades, they have not adapted to the changes of operating environment. In this respect, the increasingly frequent occurrence of hard inclusions – in terms of layers, boulders and other forms – has revealed a consistent failure of BWE-s to meet this challenge. This paper, inspired by the research project RFCR-CT-2015-00003-BEWEXMIN „Bucket wheel excavators operating under difficult mining conditions including un-mineable inclusions and geological structures with excessive mining resistance” deals with preliminary considerations and results that aim to contribute to solving this problem.

Open access