rss_2.0Műszaki Tudományos Közlemények FeedSciendo RSS Feed for Műszaki Tudományos Közleményekűszaki Tudományos Közlemények 's Cover Trends in Mining Equipment Design<abstract> <title style='display:none'>Abstract</title> <p>Mining machinery and equipment have changed little in recent decades, from the point of view of the principle of operation, construction and structure. But in terms of dimensions, performance and stresses they have made a lot of progress, experiencing unprecedented sophistication and complexity. In order to fulfil the new requirements imposed by the increasing productivity and efficiency demands, as well as the economic, environmental and safety constraints, their design and development must comply with the general advance of overall technology. Therefore, recently, modern analytical methods have also been included in the design and development of mining machines. Among other issues, the present paper examines the theoretical and conceptual aspects related to the mining machinery’ design requirements involving mechatronics.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Chromatic Discrimination Towards the Confusion Points<abstract> <title style='display:none'>Abstract</title> <p>In this paper chromatic discrimination thresholds of normal colour-observers are analysed. Measurements were obtained with the Cambridge Colour Test, in different reference points. The results show differences in terms of the reference chromaticities. Reference points within the gamut of a CRT display were found where thresholds of normal colour observers measured towards the confusion points exceeded the normative upper threshold limit of normal colour observers. The discrimination thresholds estimated towards the confusion lines based on Trivector measurements exceeded the thresholds estimated by the Ellipse tests. Our results indicate that in case of determination of discrimination ellipses, measurements towards the confusion points are recommended.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Reduction of Retained Austenite in Tool Steels<abstract> <title style='display:none'>Abstract</title> <p>Tools are devices for machining materials which must have different properties depending on their intended application. These properties are determined by the chemical composition and microstructure of the tool steel. The desired steel microstructure can be achieved with suitable heat treatment technology. During this heat treatment, the microstructure of the tool steel may develop various lattice structural transformations which in turn can cause internal stresses, cracks and distortions. One possible reason for these undesirable results may be the retained austenite. These effects are most pronounced in tool steels. In this study, the possibilities for reducing the amount of residual austenite during the heat treatment of tool steel is investigated.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Relontouml: Development of a Model Based on Relational Model, Ontology and UML<abstract> <title style='display:none'>Abstract</title> <p>This paper presents a model that combines ontology, UML modeling, and a relational model. The ontology model (and the Ontology Web Language - OWL), UML, and relational model are first introduced in the article. After a review of the literature, the comparison and conversion of the systems are presented. The created model is then presented and a real ontology is modeled using the presented model.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Interpretation of Road Traffic Noise Changes with Noise Mapping<abstract> <title style='display:none'>Abstract</title> <p>With the advancement of technology and the drastic increase in the number of noise sources, environmental noise emission is increasing year by year. In the case of urban dwellers, noise from road traffic accounts for the largest share of noise pollution, with a number of negative health effects. The aim of our research is to monitor the road noise emission of the city of Debrecen in detail, using hourly traffic data. After data processing, various situations were modeled according to the MSZ 15036:2002 standard with the help of the IMMI noise mapping program. Overall, it can be said that the studies we have carried out support the high level and increasing trend of noise exposure.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Study of the Effect of Soil Volumetric Weight on the Energy Requirement for a Spading Machine by Simulation<abstract> <title style='display:none'>Abstract</title> <p>In this paper, we simulate the operation of a spading machine on three soil types; easy to work, medium to work and heavy, using a previously validated SimuLink model of an MSS-1.40M spading machine. We determine the forces during spading. We explore the physical and mechanical properties of the soil that play a role in the spading process. By simulation of the spading process with the MSS-1.40M spading machine, we determine the torque on the drive shaft and the required mechanical work on the three soil types.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00About the Grinding of Gear Hob’s Rake Face<abstract> <title style='display:none'>Abstract</title> <p>The most simple and robust construction of the monolithic gear hobs present a common helical rake face for a given line of teeth, whose generatrix is a straight-line segment perpendicular to the hob’s axis while its directory is a helix, perpendicular to the pitch helix. As a consequence, constructive rake angles are zero on all edges. Total curvatures of such a surface are negative. Thus, it can be grinded only using the conical surface of a platter type grinding wheel, or a grinding bit. Despite this, some industry practices, possibly for reasons of simplicity and cost lowering, involve the plain grinding surface, supposed to a helical motion. This paper deals with the CAD-simulation of the grinding process using the plain wheel surface, and it shows the differences between the theoretical and rake face and the real obtained helical surface.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Modelling and Simulation of the Structural Elements and the Operating Processes of Mining Machines<abstract> <title style='display:none'>Abstract</title> <p>The paper deals with theoretical bases of the implementation in mining equipment design of up-to-date methods using modelling and simulation, supported by examples of personal research. This has become necessary due to the structural complexity of this equipment, and the variety and aggressiveness of their operating environment. The presented examples refer to different kinds of the equipment used in the mechanical extraction of mineral raw materials, from overall system to working part or tool.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Strategic Planning and Performance Management for Citizens of Harghita County with the Introduction of the CAF Based Quality Management Tool (CAFHR) Project<abstract> <title style='display:none'>Abstract</title> <p>The Harghita County Council has decided to carry out a self-assessment to evaluate the adequacy of its processes in the framework of a complex organizational development project using the CAF (Common Assessment Framework). The outcome of the performed self-assessment showed the capabilities and results of the operation, as well as the tasks of ensuring short- and medium-term development. This article aims to point out the needs and possibilities for improving administrative processes by presenting the experiences of the project. An important experience of the project is to prove the necessity of taking into account the specific features in addition to prove the general applicability of the model.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Impact Energy Absorbtion by Active Braking<abstract> <title style='display:none'>Abstract</title> <p>Due to urbanization and the significantly increasing number of vehicles, urban roads are becoming more congested day by day, with the result that the rear-end collision has become the third most common type of collision. By developing and integrating active and passive safety systems, car manufacturers are working to prevent accidents and reduce the consequences of an accident. The present study examines a braking procedure and its applicability based on the integration of a passive and active safety system and provides development guidelines for the reduction of personal injuries and property damage in the event of a rear-end accident.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Partial Examination of the Design of the Bombed Olt Bridge in Sâncrăieni<abstract> <title style='display:none'>Abstract</title> <p>Throughout Transylvania, the ruins or remains of many engineering structures and buildings can be observed, and this allows us to draw a lot of interesting conclusions. This research seeks to shed some light on the design process of older bridges in Transylvania through a case study. Hydraulic calculations based on field measurements show the hydraulic requirements used in the original design of the bridge. The obtained data was compared to the current requirements of the Romanian design standards.</p> </abstract>ARTICLE2022-07-18T00:00:00.000+00:00Curvature Measurement of Thin Plates with the Help of Digital Image Processing<abstract> <title style='display:none'>Abstract</title> <p>The verification of different plate bending problems require a punctual measurement method of the bent shape. However, with a proper curvature measurement procedure the calculations can be made more accurate. This is due to the workaround this method provides by neglecting the inaccuracies of the beam theory and the tensile tests, measuring directly the function between the curvature and bending moment for a given sheet metal. The measurements in this paper are made with the help of a digital camera and telephotographic lens. The evaluations of these images are compared to the results obtained from the Euler-Bernoulli beam theory. While the results regarding the curvature measurements have a significant deviation, the shape of the plate is in good agreement with the numerical calculations.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Development of a Complex Treatment Process for Recycling Household Laundry Water<abstract> <title style='display:none'>Abstract</title> <p>The goal of our research is to study the treatment possibilities of the laundry water fraction of domestic greywater as an alternative water source, as well as to apply a complex treatment method with which we obtain purified greywater. This treated water can be used during household tasks that do not require drinking water. By optimizing each treatment step, we determined a complex process with the following steps: coagulation- quartz sand filtration-oxidation. We also investigated the usability of purified greywater for irrigation by performing a standardized seedling test and determining the SAR factor. In conclusion, based on the measured and analysed water analytical parameters, we have successfully applied an appropriate complex treatment method, using optimal amounts of chemicals, which according to international recommendations can be potentially reused at household level, and can also be used for irrigation purposes.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Safety Issues Concerning Installation of Welding Robots<abstract> <title style='display:none'>Abstract</title> <p>The aim of this research is to summarize the safety measures related to the application of welding robots, as well as to apply them in the ÓE-Cloos Robot Welding Laboratory of Bánki Faculty at Óbuda University. This article describes the safety requirements for welding robot systems, the requirements for commissioning and safe operation. The concluding part of the dissertation presents the preparation and implementation of the installation of a new robot cell in the laboratory.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Control of a Permanent Magnet Synchronous Motor in Simulink<abstract> <title style='display:none'>Abstract</title> <p>Nowadays, before the era of modern Steer-by-wire steering systems, the most widely used steering technology is Electric Power Steering (EPS). This paper contains the developing of a Permanent Magnet Synchronous Motor (PMSM) control circuit for EPS systems, in Matlab Simulink environment. The mathematical model of the Permanent Magnet Synchronous Motor was created via the four equations that represent the relation between the fluxes, voltages and currents in d-q reference frame and the motor torque equation. Mathematical transformations are required to generate the equivalent input values of the model from analog input waves. In this way, the embedded software is able to communicate with the motor through the analog input and output signals. The control model was also tested in a physically implemented system. The control software is executed on a dSpace AutoBox hardware. The output interface block creates the output phase voltages specified by the control module, and the input interface block allows the phase currents generated by the output voltage to be measured back.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Development of a Mechatronic System for Demonstration Purposes<abstract> <title style='display:none'>Abstract</title> <p>The aim of the paper is to present a modular system, with the help of which it is possible to reveal the structure and analysis of a mechatronic system, taking into account several disciplines that contribute to the structure of the system. The planned system will include devices from different disciplines, the operation and coordination of which will be observable. The designed system is a two-degree-of-freedom mechanism with a translational and a rotary joint. The movement of the joints are obtained by different types of energy converters (pneumatic, electric). The replacement of the different types of drives can be performed quickly and easily without drastically changing the system setup. The simulations are implemented using the MATLAB Simscape software package.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Comparative Analysis of Native and Cross-Platform iOS Application Development<abstract> <title style='display:none'>Abstract</title> <p>Nowadays, mobile applications are developed for more and more areas, providing great help for our everyday lives. When designing a mobile application, the first important decision to make is to choose the targeted platform. Is it only phone or tablet as well? Should the app run on Android or iOS, or should it be available on both mobile operating systems? In the latter case, besides the native development environments, it is worth considering a cross-platform development environment to write the software. This study investigates both the development and performance aspects of some possibilities for iOS application development, namely, native iOS development in Xcode, Xamarin.iOS, and Xamarin.Forms frameworks.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Implementation of the Full-Newton Step Algorithm for Weighted Linear Complementarity Problems<abstract> <title style='display:none'>Abstract</title> <p>We present a path-following interior-point algorithm for solving the weighted linear complementarity problem from the implementation point of view. We studied two variants, which differ only in the method of updating the parameter which characterizes the central path. The implementation was done in the C++ programming language and the obtained numerical results prove the efficiency of the proposed method.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00The Developement of a New Shoulder Joint Prothesis System<abstract> <title style='display:none'>Abstract</title> <p>In our work, we designed a new metal-polymer shoulder implant system that fully meets today’s requirements - minimal invasive technology, a high degree of modularity - and can be personalized as needed. At the same time, its production does not exceed the currently available production technologies. Also, the data and parameters which are needed to design the tailor-made construction are easily accessible, as we have chosen a device that is widespread and commonplace in medical diagnostics and available in any hospital. Furthermore, we have tried to make our system as easy and fast to authorize as possible because it is challenging to place medical devices on the market, especially implants. We have tried to create the cheapest, most economical system and in addition, we wanted to gain the trust of implant specialists, as we incorporated their insights and experiences into our construction through continuous consultation.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00Educational Materials and Didactic Tools in Engineering Training Practices<abstract> <title style='display:none'>Abstract</title> <p>Educational materials are closely related to educational (didactic) tools, as they allow their preparation and presentation. The production of technical higher education (engineering training) materials or preparation can be approached from many perspectives. This article deals with some aspects of this.</p> </abstract>ARTICLE2021-12-09T00:00:00.000+00:00en-us-1