Hungarian Journal of Industry and Chemistry
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Published By University Of Pannonia

2450-5102, 0133-0276

2021 ◽  
Vol 49 (1) ◽  
pp. 17-21
Author(s):  
Péter Decsi ◽  
Ádám Bors ◽  
Péter Kocsor ◽  
Bálint Vörös ◽  
Barnabás Horváth ◽  
...  

Distance-learning has become widespread around the world. Many training areas such as engineering require the acquisition of practical rather than theoretical knowledge. In this paper, a framework is presented in the form of four pilot projects which is used for practical laboratory measurements in a distance-learning environment. Four demonstration devices consisting of an induction motor drivetrain, a magnetorheological clutch as well as a rolling resistance and an ultrasonicsensor were built and several examples of measurements presented.The system, based on accessible and user-friendly hardware, is cost-effective, simple to program and can be adapted to suit any application.


2021 ◽  
Vol 49 (1) ◽  
pp. 31-35
Author(s):  
Tamás Rózsenberszki ◽  
László Koók ◽  
Péter Bakonyi ◽  
Nándor Nemestóthy ◽  
Katalin Bélafi-Bakó

Anaerobic degradation processes: anaerobic digestion (biogasification), biohydrogen fermentation (dark) and microbial fuel cells were applied to treat the organic fraction of a municipal solid waste. The processes were compared based on their ability of energy recovery and Chemical Oxygen Demand reduction.


2021 ◽  
Vol 49 (1) ◽  
pp. 77-82
Author(s):  
Katalin Eszter Hubai

The increasing need for environmental protection has led to the development of alternative biofuels. While the use of alternative fuels has significantly increased recently, only a few studies have addressed the problem of their ecotoxicity. The main aim of this work was to provide a short review of the \textit{Daphnia magna} acute immobilization test, which has been the most commonly discussed in the literature.


2021 ◽  
Vol 49 (1) ◽  
pp. 71-76
Author(s):  
Márta Kákonyi ◽  
Ágnes Bárkányi ◽  
Tibor Chován ◽  
Sándor Németh

The increasing amount of municipal solid waste (MSW) is a growing challenge that current waste-treatment practices are having to face. Therefore, technologies that can prevent waste from ending up in landfill sites have come to the fore. One of the technologies that produces a valuable product from waste, namely synthesis gas, is gasification. The raw material of this technology is the so-called Refuse-Derived Fuel, which is made from MSW. Three separate zones are located in downdraft gasification reactors: the pyrolysis, oxidation and reduction zones. This work is concerned with the determination of kinetic parameters in the pyrolysis zone. It also discusses the estimation of the product composition of this zone, which defines the raw material of the following zone.


2021 ◽  
Vol 49 (1) ◽  
pp. 1-8
Author(s):  
Zoltán Lukács ◽  
Dávid Baccilieri ◽  
Tamás Kristóf

The determination of typical parameters of electrochemical systems, e.g. the polarization or charge transfer resistances, can be critical with regard to the application of Electrochemical Impedance Spectroscopy (EIS) if the lower frequency range is biased as a result of transport and/or adsorption/desorption processes. In such cases, the charge transfer resistance should be assessed from the higher frequency range which is typically inadequate in itself as an input for nonlinear parameter fitting. In earlier publications, an alternative mathematical treatment of both the Equivalent Circuit (EC) and of the parameter dispersion was provided using a generalized model of ECs and also a dispersion-invariant model of the electrochemical interface. In the present work, the previously presented experimental EIS results were crosschecked to verify the performance of the generalized model against a series of redox and corrosion systems. The results proved that the applied method is consistent and provides a fairly good correlation between the principal resistance data assessed by different methods.


2021 ◽  
Vol 49 (1) ◽  
pp. 47-58
Author(s):  
Bálint Levente Tarcsay ◽  
Ágnes Bárkányi ◽  
Tibor Chován ◽  
Sándor Németh

The importance of recognizing the presence of process faults and resolving these faults is continuously increasing parallel to the development of industrial processes. Fault detection methods which are both robust and sensitive help to recognize the presence of faults in time to avoid malfunctions, financial loss, environmental damage or loss of human life. In the literature, the use of various model-based fault detection methods has gained a considerable degree of popularity. Methods usually based on black-box models, data-based techniques or models using symbolic logic, e.g.\ expert systems, have become widespread. White-box models, on the other hand, have been applied less despite their considerable robustness because of multiple reasons. Firstly, their complexity and the relatively vast amount of technological and modelling knowledge needed to construct them for industrial systems. Secondly, their large computational demand which makes them less suitable for online fault detection. In this study, the aim was to resolve these problems by developing a method to simplify the complex Computational Fluid Dynamics models employed to describe the equipment used in the chemical industry into less complex model structures. These simpler structures are Compartment Models, a type of white-box model which breaks down a complex system into smaller units with idealized behaviour. In the case of a small number of compartments, the computational load of such models is not significant, therefore, they can be employed for the purposes of online fault detection while providing an accurate representation of the system. For the purpose of identifying the compartmental structure, fuzzy logic was employed to create a model which approximates the real behaviour of the system as accurately as possible. Our future objective is to explore the possibility of combining this model with various diagnostic methods (expert systems, Bayesian networks, parity relations, etc.) and derive robust tools for the purpose of fault detection.


2021 ◽  
Vol 49 (1) ◽  
pp. 9-16
Author(s):  
Asfandyar Khan ◽  
Zsolt Valicsek ◽  
Ottó Horváth

This study focuses on the photocatalytic degradation of Rhodamine B (RhB) in heterogeneous and homogeneous photo-Fenton reactions. In the heterogeneous system, iron(II) doped copper ferrite CuII(x)FeII(1-x)FeIII2O4 nanoparticles (NPs) prepared in our previous work were employed as potential catalysts. The photodegradation of RhB was carried out in a quartz cuvette located in a diode array spectrometer. The experimental conditions such as pH, NPs dosage and H2O2 dosage with regard to the photocatalytic degradation of RhB were optimized to be 7.5, 500 mg/L and 8.9x10-2 mol/L, respectively. In addition, visible light-induced photodegradation of RhB was also carried out by using \ch{H2O2} over a wide pH range in the absence of heterogeneous photocatalysts. It was observed that the reaction rate significantly increased above pH 10, resulting in a faster rate of degradation of RhB, which may be attributed to the deprotonation of hydrogen peroxide. Furthermore, the potential antibacterial property of such catalysts against the Gram-negative bacterium Vibrio fischeri in a bioluminescence assay yielded inhibition activities of more than 60% in all cases.


2021 ◽  
Vol 49 (1) ◽  
pp. 83-88
Author(s):  
Eszter Kelemen-Cserta ◽  
István Gábor Gyurika

Granites are becoming increasingly popular and, as a result, their areas of use are expanding. In addition to their colour and particle size, the surface roughness of the machined material is becoming an important aspect of their application. In order to create a suitable surface roughness, the type of rocks located on the surface, elemental composition and microhardness of the minerals are important, because knowledge of these characteristics can be used to determine the machining parameters. Microhardness is affected by the atomic percentage values of Si, Al and Na. In addition, for some minerals, a correlation can also be established between the Si, Al and Na components.


2021 ◽  
Vol 49 (1) ◽  
pp. 59-69
Author(s):  
Abbes Benchadli ◽  
Tarik Attar ◽  
Boulanouar Messaoudi ◽  
Esma Choukchou-Braham

Polymers are materials composed of macromolecules characterized by duplicates of smaller molecules that are covalently bonded together to provide a set of properties. Corrosion inhibition by such compounds is usually attributed to their adsorption on the metal-solution interface. The inhibition effect of different sizes of polyvinylpyrrolidone (PVP) on the corrosion of carbon steel (C-steel) in solutions of perchloric acid was investigated. The inhibition efficiency increases as the size of the inhibitor and its concentration increases, but decreases as the temperature increases and can reach a value of 81.53% and 5.0x10^-3 mol L^-1(PVP: 58,000 g mol^-1) at 30°C. The most remarkable inhibition efficiency was confirmed by the presence of the film formed on the metal surface by scanning electron microscopy. The kinetic and thermodynamic parameters for the corrosion of C-steel and adsorption of the inhibitor were determined and discussed. The combination of PVP with potassium iodide produced a strong synergistic effect on the inhibition of C-steel corrosion leading to a significant improvement in the inhibition efficiency. Quantum chemical parameters were studied using density functional theory to determine the possible relationship between the inhibitor and its electronic properties.


2021 ◽  
Vol 49 (1) ◽  
pp. 37-46
Author(s):  
Aminu Babangida ◽  
Péter Tamás Szemes

Even though the Internal Combustion Engine (ICE) used in conventional vehicles is one of the major causes of global warming and air pollution, the emission of toxic gases is also harmful to living organisms. Electric propulsion has been developed in modern electric vehicles to replace the ICE.The aim of this research is to use both the Simulink and Simscape toolboxes in MATLAB to model the dynamics of a light commercial vehicle powered by electric propulsion. This research focuses on a Volkswagen Crafter with a diesel propulsion engine manufactured in 2020. A rear-wheel driven electric powertrain based on a Permanent Magnet Synchronous Motor was designed to replace its front-wheel driven diesel engine in an urban environment at low average speeds.In this research, a Nissan Leaf battery with a nominal voltage of 360 V and a capacity of 24 kWh was modelled to serve as the energy source of the electric drivetrain. The New European Driving Cycle was used in this research to evaluate the electric propulsion. Another test input such as a speed ramp was also used to test the vehicle under different road conditions. A Proportional Integral controller was applied to control the speed of both the vehicle and synchronous motor. Different driving cycles were used to test the vehicle. The vehicle demonstrated a good tracking capability in each type of test. In addition, this research determined that the fuel economy of electric vehicles is approximately 19% better than that of conventional vehicles.


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