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Analecta technica SzegedinensiaVol. 15. No. 1. (2021.)

Tartalom

  • Sándor Csikós ,
    György Czifra ,
    József Sárosi :

    Industry 4.0 requires the cooperation of several technologies. The intersections of these technologies present us with new challenges. One of these challenges is identification, since we have to identify all the items that are on the network that do work and those that are worked upon. If we fail to identify one of these items the network is presented with an unidentified potentially malicious device or a misidentified product which can cause production to halt. Blockchains or otherwise known as Distributed Ledger Technology, DLT for short is a technology that builds upon the current bookkeeping paradigm and expands it in a decentralized direction. This however can be used in more than just banking since it is essentially a distributed database that has memory of past events not just the current state. By using a blockchain based distributed database to hold processing details and using RFID-s as keys to certain entries in the database it is possible to build a tamper proof production system that can handle the challenges of industry 4.0. It may also be possible to use blockchain technology as a form of digital paper trail that can be used to validate messages sent to the nodes of the system.

  • Oluwole Timothy Ojo ,
    Temitope Olumide Olugbade ,
    Babatunde Olamide Omiyale :

    Indiscriminate disposal of beverage cans as waste poses a great threat to the environment, causing flooding, landfill, and blockage of drainages, leading to land pollution and sometimes accident. Hence, there is a need to design a system capable of converting these wastes into usable products. In this study, a simulation-based analytical design for aluminium recycling processing plant was carried out to ascertain the efficiency and reliability of the design before fabrication using finite element analysis (FEA) approach. The simulation results revealed a lesser maximum stress of 6.323 MPa for the furnace outer casing under the action of load with a displacement of 0.0795 mm. The stress of the machine components is less than the yield strength of the selected materials, making the machine fit and workable. The analytical results agree with the numerical analysis; hence the conceptual design is fit for fabrication based on the design analysis and evaluation. After the design analysis and simulation, the designed recycling process plant parts are found to be under negligible deflection and stress which is far below the yield strength of chosen materials.

  • Tamás Antal :

    Blueberries (Vaccinium corymbosum L.) were dried combining vacuum, infrared, hot-air and freeze drying technologies. In this paper, examined the drying time and energy consumption of dewatering methods. The rehydration as a physical property were evaluated in dried blueberries. Combination of vacuum dried and freeze dried blueberries had higher rehydration ratio, followed by the single freeze drying, combination of hot-air drying and freeze drying, and infrared-freeze drying methods. The performance evaluation indicated that combination drying of blueberries at two-stage infrared-freeze drying with 60°C and 15 min pre-drying reduced the drying time by 53.4%, besides consuming less energy (52.9%) compared to single freeze drying. Based on the results, primarily vacuum pre-drying, infrared pre-drying and freeze finish-drying may be the economical and optimal solution for dehydrating blueberries.

  • Gergő Kecsmár ,
    Tamás Koós ,
    Zsolt Dobó :

    The utilization of liquid products as transportation fuel derived from the thermal decomposition of different plastic waste mixtures was investigated. The production of pyrolysis oils was performed in a laboratory-scale batch reactor utilizing polystyrene (PS), polypropylene (PP), and high-density polyethylene (HDPE) waste blends. Two different mixtures (10% PS – 60% PP – 30% HDPE; 10% PS – 30% PP – 60% HDPE) were prepared, and the influence of reflux was also studied. The pyrolysis oils were blended to commercial gasoline in the 0-100% range. It was found that each blend could be successfully used as an alternative fuel in a traditional spark-ignition engine without any prior modifications or fuel additive. However, based on the engine tests, the presence of the reflux is vital as the composition of the pyrolysis oil is closer to the commercial gasoline. The emission measurements showed increasing NOx emissions compared to neat gasoline, but, on the other side, a decrease in CO was noticed. These changes were much smaller in cases when reflux was used during oil production. Based on the obtained results, the utilization of reflux-cooling is an effective method to enhance the gasoline range hydrocarbons in the plastic waste pyrolysis oils, and therefore blending these oils to commercial gasoline might be viable.

  • Effect of vibration on the efficiency of ultrafiltration37-44en [646.22 kB - PDF]EPA-02592-00016-0050

    Nowadays, several environmental challenges are present to cope with. One with outstanding importance is the protection of our water supplies, therefore examination of wastewater treatment technology is a priority, especially in the European Union. In this work, the effect of membrane module vibration amplitude on the efficiency of ultrafiltration (UF) was investigated in a vibratory shear enhanced membrane filtration system. Based on the results of model dairy effluent UF and statistical analysis, the maximum vibration level available resulted in the most efficient filtration process, due to the most significant reduction of membrane fouling. From our results it was observed that the permeate fluxes more than doubled, specific energy demand was roughly halved, with almost identical retentions for organic matter, and total filtration resistance was reduced to less than half. Results also showed that setting the optimal operating parameters, an advantageous, efficiency focused, and sustainable wastewater treatment technology can be established.

  • Lendvai Edina ,
    Huszár Csilla :
    The erasmus program and its effect to the labour market45-52en [530.76 kB - PDF]EPA-02592-00016-0060

    In our work, we deal with the question of what impact the Erasmus programme has on linguistic and personal competences and how it helps the economy forward. We look around this topic in the literature review. We managed to get almost 100 surveys filled out among the participants however, the representatives of the companies proved to be quite passive, with only nearly 30 of them replying. In the form of a survey, we found that it has a positive effect on improving language skills and helping with independence or problem-solving ability. In the quantitative survey we found that companies often prefer other factors than the people in a mobility programme, and they do not show favour toward a mobility student in a job interview, although the skills acquired during the programme help the person. Therefore though indirectly, but the programme has a positive impact on the economy as well.

  • Ivana Nikolić ,
    Ljubica Dokić ,
    Zita ©ereą ,
    Dragana ©oronja-Simović ,
    Nikola Maravić ,
    Jana Zahorec :

    Cellulose based fat mimetics play important role in substitution of fat in reduced fat food products. Production of food often includes application of additives. This work examines the influence of additives on the obtaining stable fat mimetic based on fibers of microcrystalline cellulose. Applied additives affect to the durability of food products and increase their shelf life. The influence of added additives was observed trough the rheological and textural properties of MCG fat mimetic, thus its further functional characteristics. Increasing concentration of fibers positively influenced to crosslinking during hydration and increased strength and consistency of obtained gel. But, application of small hydrophilic molecules of additives disturbed rheological and textural properties of fat mimetics. Obtained gels were still with the thixotropic behavior, but with significantly reduced viscoelastic properties, consistency, firmness and cohesiveness. Based on results, in the aim to ensure obtaining of stable, cross–linked gel of fat mimetic with adequate rheological, textural and functional properties, the mixture of additives is added after the hydration of fat mimetic gels, because of competition for polar water molecules between small additives molecules and available hydroxyl groups of cellulose chains.

  • This article presents the potentiometric method of determination of chlorides using the original BO-05 electrochemical microanalyzer. The quantification of chlorides is one of the frequently performed methods, both in the indirect determination of active pharmaceutical ingredients (API) and impurities in pharmaceutical raw materials, pharmacopoeial substances or pharmaceutical formulations as well. Successfully validated method was used to the analysis of chlorides in the preparations containing verapamil hydrochloride in form of tablets Staveran® and Verapamil®. The mean content of the studied API calculated to one tablet was close to the declared and equal to 123.6±1.5 mg and 122.6±1.1 mg, respectively. The presence of excipients have no significant impact on the final results. Thus shown that the electrochemical microanalyzer BO-05 is suitable for scientific, didactic and analytical applications.

  • József Csanádi ,
    Ottilia Bara-Herczegh ,
    Attila Szabolcsi ,
    József Mihalkó ,
    Ádám Lőrincz :

    More researches published data about the milk curd properties, evaluated the importance in the cheese making, but an analysis of importance of these properties in practical applications is usually lacking. We investigate the milk curd behaviour using different enzyme preparations at the cutting of curd. We focused on the well measurable properties as clotting time, viscosity of curd, texture properties and whey separation rate of cur at cutting time. Approximately five minutes difference was determined between the clotting times. Investigated the curd properties we found significant differences between the hardness on samples clotted with CHY MAX® M 1000 and NATUREN® Premium 145 enzymes. Other properties did not show significant differences, but in some case differences were remarkable. Discovered differences e.g. approx. 5% whey separation rate difference and the different trends of adhesive force and adhesiveness confirm that such studies should be carried out. Summarized effect of different enzymes can alter the cheese making technology significantly in practice. Considering every aspect, in our investigation the CHY MAX® M 1000 enzyme seemed the best.

  • Zsolt Dobó ,
    Tamara Mahner ,
    Balázs Hegedüs ,
    Gábor Nagy :

    The pyrolysis of plastic waste is a promising method to reduce waste accumulation while it could provide value-added transportation fuels. The main goal of this study is to investigate the influence of PET and PBT contamination during plastic pyrolysis oil production utilizing HDPE, LDPE, PP, and PS mixtures as these plastics are good candidates for transportation fuel production via pyrolysis and distillation. Seven different waste blends were prepared and pyrolyzed in a laboratory-scale batch reactor equipped with reflux. Mass balance, gas analysis, thermogravimetric analysis, and deposit formation were evaluated. It was concluded that by increasing the PET or PBT concentration in the initial solid waste mixtures, the oil production decreases while the amount of gases increases. Additionally, either PET or PBT generates operational difficulties due to they form deposits in piping system in form of benzoic acid. The maximum concentration of these plastic waste materials was 20% (PET) and 25% (PBT) in this study as further increase blocked the cross-section of piping, causing operational difficulties. Based on the obtained results the concentration of PET and PBT should be limited in waste mixtures when transportation fuel production is desired.

  • Dóra Major ,
    Brigitta Zsótér :
    The mysteries of financial culture and financial habits88-95en [356.56 kB - PDF]EPA-02592-00016-0110

    In this research we will investigate the financial culture among the students of the Technical Faculty of University of Szeged. We will analyse the results of questionnaires about the students’ financial culture and financial habits. We aim to learn more about the student’s financial knowledge, debit card usage, savings and loan habits. Also, our research how the students’ demographic and social background impact their financial decisions and habits. The results highlight that the respondents mainly seek financial advice from their family regarding financial decisions. Their financial behaviour is based on their communication with their parents and family background. Furthermore, the results show that the majority of the respondents have savings and are concerned about their future. We did not find any significant differences between gender, both genders equally have long-term savings. Generally, the respondents keep their savings in bank accounts or in cash, stocks or investing is not typical. We drew the conclusion that the students tend to refuse to take out personal loans and are risk-adverse in this matter. Finally, the students use their debit card widely and in their day-to-day life without the intention of influencing others.

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