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  • Fémhabstruktúrák elemzése és geometriai modellezése
    145-152
    Views:
    145

    The development of an efficient procedure for 3D modelling and finite element simulation of metal foams is one of the greatest challenges to engineer researchers nowadays. Creating 3D CAD model is alone a demanding engineering task due to its extremely complex geometry, and the proper finite element analysis process is still in the center of the research. The aim of this project is to analyze the related literature and to adapt the results may be considered

  • Vibration Measurement of a Screening Machine
    116-123
    Views:
    171

    In this paper we use linear vibration approach to make a model of a horizontal vibration screen, which can be applied at gravel pit in order to perform separation operation of the wet gravel particles. The model can produce the natural frequencies of the system, which are useful in the adjustment of the angular velocity of the vibration exciter. A laser triangulation unit is well applicable to measure peak-to-peak amplitude of the working vibration screen. Comparison has been performed between the results of the simulation and the measurements.

  • The CAD Modelling Possibilities of Gear Pairs by Two Ways in the Mechanical Engineering Practice
    205-219
    Views:
    151

    The GearTeq 2021 software is a complex gear designer software which is capable to design different types of gears based on the initial geometric parameters by the user. Naturally, the users’ appropriate knowledge for the gear theorem and the manufacturing technology is indispensable for the design. The possibilities of the software are shown in this publication. The designed gear pairs are usable for different engineering fields (robots, working machines, vehicles, etc.).

  • Visual Analysis and Geometric Modeling of Metal Foams
    89-92
    Views:
    114

    The development of an efficient procedure for 3D modelling and finite element simulation of metal foams
    is one of the greatest challenges to engineer researchers nowadays. Creating 3D CAD model is alone a demanding
    engineering task due to its extremely complex geometry, and the proper finite element analysis process is still in the
    center of the research. The aim of this project is to analyze the related literature and to adapt the results may be
    considered.

  • Simulation of a Quadcopter with LabVIEW
    46-49
    Views:
    104

    The aim of the paper was to create a LabVIEW-based Real-Time embedded system supported development environment, which was used for the Real-Time kinematics and dynamics simulation of a quad copter as well as the adherent state-feedback controller. The state-feedback controller was designed with Linear Quadratic Regulator (LQR) based method.

  • Maintenance from the Work Safety Point of View
    190-196
    Views:
    137

    Deterioration of the technical condition of plant equipment is a common phenomenon nowadays. According to the experience of authorities, all this contributes to the occurrence of malfunctions and accidents. Plants that operate with an inadequate conservation strategy are now nearing the end of their design life, thus posing an increased accident risk. Aging processes are often accelerated by the operator's underestimation of the effects of equipment stress and the extent of deterioration mechanisms, and the consequent inadequate design and operation of condition monitoring and maintenance procedures. The aim of our work is to examine trends in the light of modern maintenance optimization methods and, in connection with this, to make proposals for the optimization of maintenance scheduling for employers.

  • Conemporary Danish Architecture- Humanity and Rationality
    6-10
    Views:
    149

    In my study I have examined the characteristics of contemporary Danish architecture and the way how they formed. In Denmark, there is strongly rooted social atmosphere. The architectural efforts strongly reflects the social problems every time, considering the environmental aspects. The regionalist methods appear in the architecture, because of this the different architectural styles appear specific way. Self-reflective and analytical way the Danish architects try to answer the contemporary issues, even more emphasize the human factor.

  • Maintenance of Electric and Hybrid Vehicles
    37-46
    Views:
    505

    An electric car is a vehicle powered by one or more electric engines, utilizing energy stored within batteries that are rechargeable. The first register of a usable electrical vehicle dates from 1880s. A hybrid vehicle incorporates two or more different power types, including, e.g., gasoline engines and electric motor. The goal in this work is to present the overall overview of the structure of the electric, hybrid and electric-hybrid vehicles, advantages and disadvantages of these types, the main points to focus when maintaining these and the challenges involved in its production and maintenance.

  • Price Analysis Practices in the Pig Sector
    1-12
    Views:
    111

    The analysis of sales prices has become a particularly important topic in pig production research, including statistical analysis. With globalisation, we can say that today we are talking about a sector constantly exposed to the effects of the world market. It is also worth pointing out that, compared with other sectors, the impact of external regulation and influence is less pronounced. Thus, the aim of the present research was to identify the journal articles published on the subject of price analysis and, on the basis of these, to establish the correlation with the methodologies often used. It examines the spatial location of price analysis. The results obtained show that the practice of price analysis is mainly carried out in the context of market leading countries, usually on the basis of a cross product chain issue. The research shows the emergence in recent years of increasingly sophisticated methodologies that allow more accurate conclusions to be drawn, while also facilitating planning from a practical point of view.

  • Development and Characterization of Sisal Fiber Reinforced Polypropylene Composite Materials
    348-358
    Views:
    428

    In most of the developing countries, plastic polypropylene is not fully recycled and converted in-to use after it is once used. Sisal fiber is also widely available in different developing countries like Ethiopia. Adding this two materials and developing automotive interior part was taken as a primary motive for it reduces cost and is environmentally friendly. Thus, the main purpose of this research is to develop composite material from natural fibre (sisal fiber) reinforced with recycled plastic waste (polypropylene) for interior automobile accessories specifically for internal door trim panel application. This research examines effect of fiber length, fiber loading and chemical treatment of fiber on the physical and chemical properties of the sisal fiber reinforced polypropylene (SFRPP) composite material. The waste polypropylene and the treated and untreated sisal fiber with variable length and weight ratio (fiber/matrix ratio) were mixed. Flammability of sisal fiber reinforced Polypropylene (SFRPP) composites material was examined by a horizontal burning test according to ASTM D635 and chemical resistance of the sisal fibre reinforced PP composites was studied using ASTM D543 testing method. The result on the flammability test shows that treated fiber has lower burning rate than untreated fiber and decreases with increase in fiber length and fiber loading. The resistance of the composites to water has increased as the fiber length increases and decreased as the fiber loading increase. Generally, SFRPP composite is found to have better resistance to water than NaOH and H2SO4 and treating the fiber has brought considerable improvement on chemical resistance of the composite. Fiber loading and fiber length has positive and negative effect on the flammability of the SFRPP composite respectively.

  • The Top 5 e-commerce Competitive Advantages in Hungary
    128-139
    Views:
    245

    Abstract. In my article, I map out the key competitive advantages that are essential to online commerce, online store sales, success, and popularity. There is a wealth of literature on the subject. Year after year, more and more research and surveys are conducted on customer value, shopping habits, consumer behavior, digital transformation, which I would like to summarize and articulate, and highlight the main elements without which online sales would not be effective.

  • Efficient removal of salts from the residual dross of aluminium melting
    259-269
    Views:
    147

    A residual dross of high quantity and high salt content arises from the hot (thermo-mechanical) treatment of the primary dross generated by the production of aluminium alloys from scrap. It contains a relatively low concentration of metal (5 – 10 %) but a high amount (30 - %) of chloride salts and some other components beside the oxide matrix. Due to the components dissolved in or reacted with water, this industrial residue - arising in thousands of tons also in Hungary – qualifies as hazardous and causes a real burden to the environment. According to the laboratory experiments aimed at an economical technology, the chlorides are dissolved within a few minutes when a liquid/solid ratio of 1:1 cm3/g (water volume:sample mass) is assured with an intensity of the horizontal shaking to prevent sedimentation. However, the filling ratio of the vessel also appears to have an effect. An implementation of relatively low cost would allow the recycling of the salt and the application of the final residue for alternative purposes.

  • The Mechanical Properties of 3D Printed CuZn28 Brass Specimens with Different Orientations
    253-259
    Views:
    237

    In this paper, the properties of CuZn28 brass raw material were presented. The 3D printed metal specimens are made from this material with different orientations. Their mechanical properties (tensile strength, yield strength) and elongation were investigated according to MSZ EN 6892-1: 2012 standard. The strength of the different printing directions is analyzed and it is determined which printing direction is the most favourable. Finally, the effect of the different printing directions upon the structure of the material is studied.

  • Consumer Perception of Electric Cars in Hungary – Theoretical Considerations and Empirical Results
    1-23
    Views:
    461

    Electric cars are becoming increasingly popular in the automotive industry and among consumers; partly as a result of their environmentally friendly characteristics. The aim of the study is to compare the main characteristics of electric and conventional cars in the context of environmental protection. In the first half of the study, we present the life cycle of electric and conventional cars and we compare the overall environmental impact traditional an electric vehicles. We point out that although the operation of an electric car does not pollute the environment locally, the manufacture, charging and disposal of batteries required for operation raises several issues related to environmental pollution. In the second part, we examine the respondents' attitudes towards electric cars based on our own questionnaire research. On the basis of the answers, it can be said that consumers still consider electric cars expensive and are aware that electric cars address some pollution issues to a small extent.

  • Security Evaluation of MODBUS RTU Protocol, Testing New Cryptographic Methods
    35-42
    Views:
    169

    In the late decade, the number of attacks against SCADA, CIS, or ICS systems had grown considerably. The purpose of this paper is to summarize the results of the implementation of a new cryptographic method on th e MODBUS RTU line.

  • Investigation of application and development of precision irrigation technology
    239-248
    Views:
    250

    Due to the extreme weather conditions irrigation is nowadays considered an increasingly necessary factor. After evaluating the water requirements of the plant and the available water resources is necessary to decide what irrigation method to use. One of the most commonly used methods in field conditions is rain-type irrigation, of which there are several types (eg linear, winding drum). The uniformity of the field nozzles can be characterized by the Christiansen uniformity factor (CU%) and the distribution uniformity factor (DU%). The coefficients can be derived from the volume of water captured by the rain gauges. Our investigations were carried out in July and August 2019 at the University of Debrecen's Vision Plant Experimental Plant and at a linear irrigation equipment of a Nyírbátor company. The aim of the study was to compare the uniformity of water dispersion applied by conventional linear technology and precision linear irrigation technology. In addition we examined the intercept values of maize.

  • Laboratory Testing of Rediffusion of Contaminants Using DKS-Permeameter
    41-48
    Views:
    145

    Decades long hydrocarbon contaminations effecting heterogenous groundwater systems is a common problem both in Hungary and worldwide. Only the treatment of aquifer layers is possible with remediation technologies, so the contaminations remained in the aquitards are released back to the treated porous layer  after the treatment due to the changes in concentration-gradient. This process is the so-called back-diffusion: as a result, the previously removed contaminations appear in the remediated layer again. In order to get better understanding of the rediffusion process and the influencing parameters series of measurements were carried out at the University of Miskolc Faculty of Earth Science and Engineering using a special laboratory device called DKS-permeameter. With the help of some small modifications it can be used for the modeling of backdiffusion. Artificially contaminated soil samples were built in the DKS-permeameter from which contaminanant release occured due to back-diffusion. The concentration values were determined with spectrophotometric measurements.

  • Synthesis of Polylactic Acid (PLA) by Polycondensation Method
    286-293
    Views:
    359

    The Polylactic acid (PLA) is compostable and natural renewable sourced plastic type. Its mechanical properties quite similar to the PET, therefore the PLA is a good alternative for strongly ruled food industrial application. The PLA only has one critical attribute – the relatively low glass transition temperature. According to the relevant literature the glass transition of PLA is in the range of 40-70°C. In light of this fact, this material can be used only in that segments of food industrial field where the packaging process temperature are under of the lower limit of Tg range. The actual Tg of a material is highly depends on the molar mass and material structure, therefore the molar mass and the structure of material should be designed according to the future requirements of application and procedures.

  • Application of Rexroth Controlling for Inverted Pendulum
    174-179
    Views:
    154

    This paper deals with the control of an inverted pendulum. Balancing techniques are used in great many controlling problems. The inverted pendulum problem is often used as a benchmark. The theoretical background is well-known and easy to treat. A commercially available Rexroth axis controller and a CKK compact module are used to control the input of the system, which is usually applied in industrial fields. A test bench has been designed and built. A PLC based program has been developed to swing up the pendulum from the rest location to inverted position and LQR controller is designed to balance the system.

  • The Implementation of the Japanese and the German Culture into the Operation Hungarian Firm
    1-9
    Views:
    256

    How can the Japanese culture be implemented into the operation of a firm - partly a German property  working in Hungary. In my presented arcticle I have studied various organisational culture models, and compared them to the culture of our enterprise, seeking for similarities and contraries. I have studied the environmental factors and resources which have an effect on our production. During the investigation I have also considered how can we harmonize cultures of different nations and how it affects the production on the whole. I have also investigated the installation of robots, and searched for the solution how we can make our production much more economical. Due to the persistent decrease of population, and leck of professionals, the use of robots is neccessary to fulfill the customer requirements in time, with the sufficient quantity and required quality of goods. According to the Japanese Toyota-method,theautomatization of a technology can only be successful, if it is tested at least ten times, but –beacuse of the leck of time- we do not have the possibility of it. As the manufacturing parameters and observations have not developed the proper way, the scrap rate is higher than it is at firms, where is more available time for the building up of the technology.

  • Laboratory investigation of the rediffusion of contaminants originated from the aquiclude
    232-238
    Views:
    115

    Many organic pollutants are released into the soil and thus into the groundwater due to anthropogenic effects (a chain of harmful human activities). Layers with low permeability (e.g. clay) play an important role in blocking the path of these contamintants. However, due to their sorption and diffusion properties, such aquiclude layers can also serve as long-term sources of contamination. Once the layer is contaminated, it is already very difficult to recultivate, and there is a potential for the pollutant to spread to higher permeability layers by slow diffusion processes. This phenomenon is defined as a so-called rediffusion process, in which contaminants are retransferred from the aquiclude to the layer with higher permeability. The purpose of this study is to demonstrate the possibility of modeling this rediffusion process in a laboratory scale and to quantify the effect of influencing parameters on pollutant transport.

  • Investigation on Double Oxide Film Initiated Pore Formation in Aluminum Casting Alloys
    141-153
    Views:
    363

    The most common, and in fact, the most deleterious defects of aluminum casting alloys are the so-called double oxide films or bifilms, which have a central role in porosity formation, as they can easily unfurl and inflate into pores during the solidification of the alloys. Sr addition is generally used in the foundry industry for the modification of the eutectic Si phase of hypoeutectic Al-Si alloys. However, Sr microalloying usually leads to an increased pore formation tendency. As bifilms are preferred sites for pore formation, it should be expected that Sr additions have a significant effect on the number and/or the structure of double oxide films present in the melt. In this work, the relationship between Sr-concentration and the susceptibility to pore formation has been investigated through the evaluation of melt quality of melts which had different levels of Sr. The bifilm content of the melts was investigated by the analysis of K-mold specimens and X-ray computed tomography (CT) of reduced pressure test (RPT) samples. It was found that liquid alloys with a higher Sr concentration had a significantly greater tendency to pore formation, which can be explained by the presence of a larger number of bifilm defects in the liquid alloy.

  • Local Annealing of Cold Rolled Aluminum Sheets by LASER Treatment
    21-26
    Views:
    134

    LASER treatment widely used in material processing technologies. The annealing is not the typical application of the LASER treatment, but this is possible to apply in case of cold deformed metals. In the article a cold rolled EN AW 8006 aluminum sheet is annealed by LASER treatment. The microstructure of the annealed sheets is observed by optical microscopy. An existing cellular automata simulation of recrystallization process is modified to study the LASER annealing. The observed microstructure and the simulated results are compared to determine the further development of the developed automaton.

  • Examining the Social Involvement of Sports Civic Organizations
    23-34
    Views:
    176

    Analyzing the information available in the Hungarian database of the CSO, we can see that a significant part of the income of classical non-governmental organizations, especially non-governmental organizations with a sports profile, comes mainly from state or private support. In addition, it can be said that these organizations are essentially non-profit-oriented and play a significant role in social integration and the performance of essential social tasks. Therefore, the relevant question is to what extent and in what way their social embeddedness is realized, in what way do NGOs influence people in the course of their operation? Within this, the study of the social usefulness of sports non-governmental organizations and the sphere of support conditions in the sphere emerges as a priority area. In our study, we undertake to examine the activity of the organizations included in the survey, their social impact and to compare the results with their role in local society. Nearly 50% of the NGOs surveyed in the study have a local scope, and more than 50% typically engage in grassroots and leisure-related activities.

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