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  • Simulation of an Operating Machine in Dust Chamber
    266-275
    Views:
    113

    Auxiliary equipment used in the automotive industry, such as generator, air conditioner, or starter, is often exposed to harsh conditions, for example splash water, frost, or serious dust load. Therefore, these auxiliary devices are intended to be prepared by the manufacturers to these conditions. The topic of this paper is a part of the analysis of the dust control of generators, which in principle is no different from the examination of other equipment. The flow around the generator and in the dust chamber was simulated by Ansys FLUENT.

  • Application of Additive Technology in Precision Casting
    43-56
    Views:
    203

    In this paper the surface of the prepared test specimens had been examined with light microscopy and surface roughness measurements. In order to improve the surface smoothness of PLA specimens, application of ethyl acetate was required. After this surface treatment, microscopic images were taken again. The melting and decomposition temperatures of the materials had been determined using derivatography. The chosen method was precision casting with gypsum molding. Also, the plaster molds had been burnt out according to the predefined melting and firing diagram. The measurement series shows that the samples produced by 3D printing can also be used in the field of precision casting. They provide greater freedom of design, more sophisticated pieces, and prototypes can be finished in a shorter amount of time.

  • CSR Reporting Practices of Hungarian Banks
    70-81
    Views:
    164

    The disclosure of information on the exercise of corporate social responsibility (CSR) is the tool most frequently used by companies to promote understanding of the social and environmental performance of an organisation and to improve relationships with stakeholders. For most of the world’s largest companies, reporting on non-financial information appears to be a continuing trend, so it is essential to present the new corporate reporting trends of the 21st century. The disclosure of socially responsible information will be analysed, with a focus on the application of the Global Reporting Initiative guidelines related to CSR. Global Reporting Initiative (GRI) is the best-known framework for voluntary reporting of environmental and social performance by business worldwide. The main objective of the paper is to explore the corporate voluntary disclosure practices of the listed and non-listed banks in Hungary. The extent of voluntary disclosure has significantly improved for decades worldwide, but the situation is not that obvious regarding the Hungarian financial sector. This paper aims to describe the status of disclosure practices of corporate sustainability in the annual reports, sustainability reports or CSR reports of the banking industry in Hungary. Also, increased corporate visibility and financial risk increase stakeholder demand for transparency on the social impact of financial institutions and their CSR practices. Finally, the analysis and subsequent comparison of available CSR reports of banks will be presented.

  • Temporal Changes of Pyrite Oxidation Rate in Bolivian Sulphidic Mining Wastes
    194-202
    Views:
    100

    Since the 70's, when huge sulphidic open pits were developed, the acidic rock drainage (ARD) become the leader problem of the sulphidic mining industry. Although the recycling is an essential technology, it cannot cover the demand alone, thus mining activity needs to continue. Acidity in mine drainage commonly requires most of the attention, but the main problem is the caused elevated level of metal mobility and leaching, which are generated by the increased rates of sulphide weathering under acidic conditions. The Itos mine is a polymetallic vein deposit in Bolivia, had been mined for silver and tin until 1990, leaving behind much and huge tailings and mine waste heaps, where quite often the pyrite content exceeds 10 %. Serious ARD effects take place in the mine waste heaps. These processes can be well characterized with the pH 1 or 2 of the seepage water, which forms serious alteration in the waste itself and the neighbouring rocks. In three consecutive years, the pyrite oxidation rate was investigated on the same 7 samples by humidity cell test. 5-6 months pauses were left between the humidity cell test periods, which mimics the alternation of wet and dry periods, typical for the place. The results give much more information, than the oxidation rate in the individual test periods, showing the changes by time. This applied method gave good result to characterize the behaviour of the waste in long-term. The column test was complemented with mineralogical analyses, such as electron probe micro analysis. The mineralogical and column test analyses show, that the changes of the pyrite oxidation rate split the samples into three different groups, one where the oxidation rate decreases, second where it increases with time and the third where oxidation rate is maximal and stays stable for several years.

  • Investigation of the Granulometric and Mechanical Properties of Inorganic Used Sand
    302-308
    Views:
    185

    This paper examines the use of a modified inorganic binder in metal-alloy casting. The results of investigations regarding the effect of reusing the used sand multiple times without reclamation. The technological properties of silica sand with inorganic binders were presented, two different temperatures were applied to make the used sands. After lump crushing the inorganic used sand was recycled in order to make a new sand mixture. Our work was focused on the effect of multiple usage of inorganic used sands on the mechanical and granulometric properties prepared with modified inorganic binder.

  • Testing of Micro Switches for Garden Tools
    206-213
    Views:
    110

    The aim of this paper is to introduce the design of testing method for the prediction of the life and acceleration methods of the micro switches applied in different type of garden tools. These products will be tested for complex stressing, for example higher temperature, humidity, current load and so on. Therefore, the most important information and multi-factor acceleration models are summarized, the Weibull, the lognormal and the exponential distributions which are suitable for performing and evaluating tests.

  • Component Development Using Topological Methods
    54-62
    Views:
    105

    The article aims to briefly summarize the design aids which can be used nowadays, such as topology optimization and generative design, which are common in integrated CAD systems. A case study is used to present the results and comparisons provided by the previously mentioned methods.

  • Application of Nanomaterials in Food Industry and Agriculture
    116-126
    Views:
    170

    Nanomaterials have unique application features which can mainly be associated with their size properties. These materials have much higher surface than the normal particle size variant of the same materials. Due to these properties, nanomaterials are widely used in the industry. Food industry and the agrarian sector are using these materials increasingly. The main goal of nano size components and additives are the improvement of some parameters of the food manufacturing process, the elongation of the best before date of the food and the improvement of the texture, stability and the consistence of the food. Probably, nanomaterials will play an important role in the development of the food industry, moreover, it can be anticipated that nanotechnology will also appear there and will influence the whole food chain. It should be noted that food industry is using several nano size class materials which are not referred to as nanomaterials. Some examples are the micelles of some proteins, like milk protein, and fatty acids. Considering all these, the aim of our work was to present a thorough review and summary of the current applications.

  • Application of Rexroth Controlling for Inverted Pendulum
    174-179
    Views:
    161

    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.

  • Effect of the Changes in Bulk Density and Granulometric Properties on the Strength Properties of the Moulding Sand Mixtures
    116-122
    Views:
    194

    Foundry technology uses a lot of several natural materials. Sands use for preparing mixtures whereby making moulds or cores. Sand is defined as a granular, refractory major portion of mixture (90 – 98% in dependence on used binder). Sand properties depend on it has chemical and mineralogical composition; mainly particle size distribution and shape of grains and its size and sand surface texture. A comparative measurement of two quartz sand with different surface quality was carried out. Greensand mixtures were prepared to measure their permeability, compressive strength and wet tensile strength. The strength of sand mixtures has two main components. One of them is the cohesion of the binder; the other one is the adhesion between the binder and the foundry sand. The aim of this research is to determine the ratio of cohesion and adhesion within the strength values.

  • Investigation of Zeta Potential of Water Based Nanomagnetite-Bentonite Dispersions
    54-66
    Views:
    156

    The stability of different type nanomaterials play an important role among recent scientific and industrial
    challenges, including the examination of the effect of polymers, surfactants and their mixture on surface and electric surface properties and aggregation extent of dispersed particles, which are of utmost importance. Bentonite and its composite with different nanomaterials are frequently used for instance in environmental protection for wastewater treatment, since due to their great specific surface area they have excellent sorption properties. There are several publications in the literature for the application of bentonite in drilling muds. By using them the fluid loss can be decreased during the drilling process, the filtration of the fluid can be increased, it also improves the rheological properties and the formation damage can also be mitigated. During research the investigation and the analysis of the zeta-potential of nanoparticles and their composites at different pH and salt content can be an interesting topic. During our experiments the electric surface properties of nanomagnetite synthetized in laboratory (NM), cation
    exchanged bentonite from Mád (Be) and the composite particles of these particles were investigated. Hybrid particles of different compositions (9:1, 7:3, 1:1, 3:7, 1:9) were analyzed at different potassium chloride concentrations (0.1 – 0.0001 M). The surface adsorption on the surface, i.e. the change in the surface charge can be traced well by analyzing the obtained zeta-potential values. The behavior of such systems was observed in the full pH interval, thus, valuable data were obtained regarding the colloidal stability. As for the stability, different requirements may emerge in practice, there are application fields where the colloidally stable system is advantageous, on the other hand, in some cases, ceasing the stabile system is the goal. Our investigations are of high importance in terms of stability and its characterization.

  • Analysis of a Special, 3D Metal-Printed HPDC Tool Material
    251-265
    Views:
    202

    High Pressure Die Casting (HPDC) is still the most productive metal-casting method of our time, however the more demanding are the industrial expectations, the more challenging it becomes to ensure the creation of the difficult cavity geometries and the thermal balance of the die-cast tool. New perspective is required, thus we can utilize high heat-conductivity tool steels and additive manufacturing technology.

  • PVC/LDPE Blends: Relationship Between Thermal/Mechanical Properties, Structure and Blend Behaviour
    162-165
    Views:
    208

    In this paper the effect of LDPE content in PVC foams are examined on the structure of both the foam and the LDPE. We attempt to understand how LDPE content affects the structure of PVC in blends and how it changes the glass-transition (Tg). These parameters often provide important information related to the overall macromolecular structure of the polymer blend. Thermal analytical techniques such as differential scanning calorimetry (DSC) often used to determine the structural transformation of samples. The effect of the miscibility and composition of the PVC/LDPE foam blends on the thermal stability were also investigated.

  • The Challenges of the Labour Law and Economic in the Future Labour Market
    116-130
    Views:
    811

    The aim of the study is to examine how the effects of globalization affect the global labor market, and how high-level automation and digitalization affect the expectations of labor market actors and the world of labor law. We analyze the legal framework and the economic and social utility of acquiring competences for new challenges in the industry. We will look in more detail at the future of the low-skilled labor force in a changing labor market as a function of acquiring new competencies. We believe that changes in the labor market and novel processes will also pose new challenges for employers and employees. Changes in the labor market raise the question of what kind of benefits an outgoing worker will receive until he or she acquires new competencies. Is the social welfare system in the current sense capable of supporting lifelong learning, or is it necessary to explore alternatives such as basic income? All this needs to be done in the light of the legal and economic scrutiny of the concepts of efficiency and economy. This is because acquiring competences for the new employee also brings new added value.

  • Maintenance from the Work Safety Point of View
    190-196
    Views:
    145

    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.

  • Design of Chip Conveyor
    81-85
    Views:
    123

    The following article examines the design methodology of screw conveyors. The most significant steps are discussed concerning the design of the apparatus and its use in machine tools as a service component is explained.

  • The Impact of Optical Character Recognition Artificial Intelligence on the Labour Market
    9-16
    Views:
    394

    Because of present day information technology, there is neither need to plant complicated computers for more millions price if we would like to process and store big amounts of data, nor modelling them. The microprocessors and CPUs produced nowadays by that kind of technology and calculating capacity could not have been imagined 10 years before. We can store, process and display more and more data. In addition to this level of data processing capacity, programs and applications using machine learning are also gaining ground. During machine learning, biologically inspired simulations are performed by using artificial neural networks to able to solve any kind of problems that can be solved by computers. The development of information technology is causing rapid and radical changes in technology, which require not only the digital adaptation of users, but also the adaptation of certain employment policy and labour market solutions. Artificial intelligence can fundamentally question individual labour law relations: in addition to reducing the living workforce, it forces new employee competencies. This is also indicated by the Supiot report published in 1998, the basic assumption of which was that the social and economic regulatory model on which labour law is based is in crisis.

  • Numerical analysis of effects of an open-pit coal mine to groundwater
    70-74
    Views:
    137

    In this study we investigated the hydrogeological problems of an open-pit brown coal mine in the Borsod coal basin with Processing Modflow software. The coal mine is located in the valley of the Sajó-river with high transmissivity overburden layer where the traditional dewatering solutions were not encouraging due to inrush risks and low cost-efficiency. A new way of barrier forming was found out and numerically simulated to prove the efficiency of the solution. Since there are several contaminated sites in the surroundings it was a key factor to assure that the new mine dewatering technique has only a negligible effect on the groundwater regime that undisturbs the known contaminant plumes nearby.

  • Innovative Utilization Possibilities of Industrial Wastes from Hungary as Construction Industrial Material
    203-212
    Views:
    131

    The research results carried out at the University of Miskolc Faculty of Earth Science and Engineering in the Center of Excellence of Sustainable Natural Resource Management show that the physical and mechanical properties of the construction industrial products (strength, compactness) made of waste sources can be controlled reasonably by the appropriate processing technologies and under optimized circumstances and characteristics (particle size distribution, specific surface area). It was established that beside the chemical activation, the mechanical activation of solids is an effective tool for improving the product characteristics. However, this modifies the physical as well as structural, mineralogical properties of the raw materials, therefore its determination is of great importance.

  • Determination of the Differential Equations of a Dynamical System using Dual Description
    41-48
    Views:
    69

    The paper deals with the description of a mathematical model of a mechanical system using the so-called energy-based approach. The model is created using both generalized displacements and generalized momenta. The latter prescription method is less common in practice, due to its complexity. The two ways are presented through the same example mechanical problem, and a control task is also solved with the help of a PID block.

  • Boundary Value Problem for a Heated Nanofluid Flow in the Presence of Magnetic Field
    58-66
    Views:
    111

    The aim of this paper is to introduce some new numerical results on the magneto-thermomechanical interaction between heated viscous incompressible magnetic nanofluid and a cold wall in the presence of a spatially varying magnetic field. The governing nonlinear boundary layer equations are converted into coupled nonlinear ordinary differential equations by similarity transformation. The ODE system is solvable numerically for example using higher derivative method. The investigation is focused on the influence of governing parameters corresponding to various physical conditions. Numerical results are exhibited for the dimensionless wall skin friction and for heat transfer coefficients at the wall, along to distributions of the velocity and the temperature.

  • Environmental Index and Environmental City Resilience Index calculation for Four Settlements in Szabolcs-Szatmár-Bereg County and Four in Győr-Moson-Sopron County
    17-29
    Views:
    141

    Globalization and urbanization pose a number of challenges for different settlements. Stakeholders seek to cure global problems through sustainable projects. Since the Brundtland Commission's definition of sustainable development in 1987, the approach to sustainability has permeated all dimensions of the economy, including the environmental dimension. In Hungary, IBM conducted a study (Lados - Horváthné Barsi, 2011), in which the search for green, sustainable solutions defined in the definition of a livable city plays a key role. The characteristics of sustainable cities, that they are resilient to disasters, return to equilibrium after a shock has occurred (Seeliger, Turok, 2013). Resilience can also be mentioned as one of the pillars of sustainability. In a UN-Habitat statement, resilience refers to the ability of any urban system to withstand and recover from multiple shocks and to maintain the continuity of its services (OECD, 2018). In my study, I would like to present the results of the environmental index and the Environmental Urban Resilience Index (EURI) of the four largest cities selected on the basis of the population in the easternmost and westernmost counties of the country.

  • Social Innovation for the Welfare of the Community
    480-494
    Views:
    176

    The aim of the study is to highlight the focal points that are potentially activating factors in social innovation efforts in the most disadvantaged areas. The study examines certain social initiatives in the Nyírbátor district, with particular emphasis on the efforts promoting community welfare. The study primarily presents the results of qualitative interviews as part of a doctoral research. The examined cases play an important role in the management of the unfavourable processes in the region, and their adaptation as good practice can support the catching-up process. The study identifies the main groups of aspects that, in addition to structuring the case descriptions, also facilitate comparability of good practice. Documentation based on defined criteria supports the adaptation process, which is critical to the successful implementation of social innovation efforts.

  • Submerged aquatic plant (Vallisneria spiralis and Egeria densa) utilisation as a biogas cleaner and feedstock of co-digestion
    172-180
    Views:
    204

    Biogas was produced from sheep manure and two types of submerged aquatic plant (Vallisneria spiralis and Egeria densa). The gas cleaning was carried out by a water scrubber, where a significant part of CO2 and H2S can be separated from the gas. A part of water from the scrubber was circulated through an aquatic plant growth tank and the growth of used plants was examined. Addition of E. densa to sheep manure increased gas yield by 8% and the mixing of sheep manure and V. spiralis resulted in 21% increase in gas yield. With the used scrubber, 70-80 vol% methane content can be reached in the cleaned biogas, and the water from the scrubber (which contained dissolved CO2 and H2S) resulted in 56-87% increase in size as opposed to 12-44% increase in the control group.

  • Safe, Health Working in Health Care in the Shadow of a Pandemic
    85-97
    Views:
    251

    Safe work that does not endanger health is a complex category, the provision of which creates an obligation on the part of the state, the employer and the employee. The task of the state is to determine the basic requirements for work that does not endanger health and safe, as well as the related rights and obligations, and to develop a national policy on occupational safety and health. As a result of the coronavirus epidemic in early 2020, we have faced a whole new form of accidents at work and occupational diseases. In my study, I want to examine the course of the investigation of the infection that takes place during the pandemic in healthcare work, and the possibilities of remuneration for the duration of the illness.

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