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Analecta technica SzegedinensiaVol. 15. No. 2. (2021.)


  • The significance of the impact of water-related diseases on human health has been recognized as a major threat to sustainable human development in some international forums. This study is an investigation into the correlation between unclean water and the outbreak of water-related diseases in Nigeria. It was established from the review of previous researches that the concept of clean water and sanitation is critical to the good health and well-being of all individuals. Nigeria still has a long way to go towards achieving the Sustainable Development Goal number 6 (SDG 6) of the United Nations, hence it is high time government at all levels and individuals embraced Water, Sanitation and Hygiene (WASH) agenda 2030.

  • Temitope Olumide Olugbade ,
    Babatunde Olamide Omiyale :

    The corrosion rate of surface-conditioned 301 and 304 stainless steels (SS) was determined by salt spray test in a controlled accelerated corrosive medium (9.5 L of pure distilled water + 500 g NaCl). Surface conditioning via mechanical attrition treatment was firstly carried out before the salt spray test. The corrosion rate was determined by weight loss method before and after the salt spray test. Compared to the untreated 301 SS sample with a weight loss of 0.15 g, the surface-conditioned 301 SS samples treated for 300 s and 1200 s experienced a lower weight loss of 0.04 and 0.02 g, respectively. A similar reduction in weight loss was achieved for 304 SS sample when treated for 300, 600, and 1200 s.

  • Qudama Al-Yasiri ,
    Márta Szabó :

    Cooling and air-conditioning systems are responsible for the highest energy consumption in buildings located in hot areas. This high share does not only increase the building energy demand cost but also increases the environmental impact, the topmost awareness of the modern era. The development of traditional systems and reliance on renewable technologies have increased drastically in the last century but still lacks economic concerns. Passive cooling strategies have been introduced as a successful option to mitigate the energy demand and improve energy conservation in buildings. This paper shed light on some passive strategies that could be applied to minimise building cooling loads to encourage the movement towards healthier and more energy-efficient buildings. For this purpose, seven popular passive technologies have been discussed shortly: multi-panned windows, shading devices, insulations, green roofing, phase change materials, reflective coatings, and natural ventilation using the windcatcher technique. The analysis of each strategy has shown that the building energy could be improved remarkably. Furthermore, adopting more passive strategies can significantly enhance the building thermal comfort even under severe weather conditions.

  • Róbert Lipták ,
    István Bodnár :
    Simulation of fault detection in photovoltaic arrays31-40en [1.24 MB - PDF]EPA-02592-00017-0040

    In solar systems, faults in the module and inverter occur in proportion to increased operating time. The identification of fault types and their effects is important information not only for manufacturers but also for investors, solar operators and researchers. Monitoring and diagnosing the condition of photovoltaic (PV) systems is becoming essential to maximize electric power generation, increase the reliability and lifetime of PV power plants. Any faults in the PV modules cause negative economic and safety impacts, reducing the performance of the system and making unwanted electric connections that can be dangerous for the user. In this paper have been classified all possible faults that happen in the PV system, and is presented to detect common PV array faults, such as open-circuit fault, line-to-line fault, ground fault, shading condition, degradation fault and bypass diode fault. In this studies examines the equivalent circuits of PV arrays with different topological configurations and fault conditions to evaluate the effects of these faults on the performance of a solar system, taking into account the influence of temperature and solar radiation. This work presents the validation of a simulated solar network by measuring the output curves of a low-power photovoltaic array system under real outdoor conditions. This method can be useful in future solar systems.

  • Gábor Hornyák ,
    Péter Bencs :
    Changes in the energy production to reduce the environmental impact41-52en [552.95 kB - PDF]EPA-02592-00017-0050

    One of the most debated topics of our time is climate change. For this reason, the European Union and the countries of the world are taking several steps to reduce and reverse the effect. When we talk about climate change or sustainable development, it is very important to also talk about the energy sector. The European Union aims to achieve climate neutrality by 2050, which will require significant changes in our lives, it will be a major challenge for mankind. In 2019, fossil fuels accounted for 80% of the world’s energy production. The production of energy from fossil fuels has several negative effects aside from climate change. When fossil fuels are burned, gases and particles harmful to human health are released into the air and some of the fossil fuels are raw materials to produce plastics, for example. If we use it for energy production, we waste our raw materials. What are the options for reducing the environmental impact? How can coal-based energy production be replaced? What are other ways to reduce the environmental impact? These topics are discussed in the article.

  • Laura Haranghy ,
    Zoltán Jákói ,
    Cecília Hodúr ,
    Sándor Beszédes :

    Microwave irradiation is a promising pre-treatment method for sludge stabilisation, but there are few studies focusing its effect on organic matter solubility and biodegradability of wastewater and sludge originated from the food industry. In our research, microwave irradiation was applied standalone and in combination with alkaline treatment to enhance the solubilisation and biodegradation of organic matter content of meat industry wastewater and municipal sludge, respectively. The energy efficiency was investigated, as well. Dielectric measurement is a suitable method to detect physicochemical changes; therefore our research work covered the determination of dielectric properties of the investigated materials. Our experimental results have revealed that the lower power and energy intensity microwavealkaline treatments were the most efficient pre-treatment process from energetically aspects to increase the organic matter solubility and biodegradability of wastewater and sludge. Furthermore, a strong linear correlation was found between the dielectric constant and the indicators of the solubility of organic matter (SCOD/TCOD) and aerobic biodegradability (BOD/COD) in both treated materials, respectively. Our results show that the dielectric measurements can be applied for detection of physicochemical changes, predict the improvement of biodegradability, and considered as a promising method to estimate the efficiency of sludge pre-treatment methods.

  • Balázs Hegedüs ,
    Zsolt Dobó :
    Gasoline like fuel from plastic waste pysrolysis and hydrotreatment58-63en [472.68 kB - PDF]EPA-02592-00017-0070

    Recycling of plastic waste is desirable to lower environmental pollution and fulfil the requirements of circular economy. Energetic utilization is another possibility, however, municipal solid waste containing plastics is usually combusted to generate heat and electricity. An attractive way of dealing with plastic waste is pyrolysis, which has the potential of producing liquid hydrocarbons suitable as a transportation fuel. The pyrolysis results of three plastics produced in the largest amount globally, namely polyethylene, polypropylene and polystyrene as well as their mixtures are presented. The experiments were performed in a laboratory scale batch reactor. The pyrolysis oils were further processed by distillation to provide gasoline and diesel like (distillation cuts at 210 and 350 °C) hydrocarbons. The gasoline fractions were analysed by GC-MS and the composition was compared with the EU gasoline standard. It was found that the oils from PE, PP and PS contain compounds present in standard gasoline. Mixing PS with PE and PP before the pyrolysis, or the oils afterward produces much closer results to standard requirements as PS pyrolysis generates mostly aromatic content. As standard maximizes the olefin content of gasoline to 18 Vol%, hydrogenation was also performed using Pd based catalyst. The hydrogenation process significantly reduced the number of double bonds resulting in low olefin content. Results show that the pyrolysis of plastic waste mixtures containing PE, PP and PS is a viable method to produce pyrolysis oil suitable for gasoline-like fuel extraction and further hydrogenation of the product can provide gasoline fuels with low olefin content.

  • John Femi Akinfolarin ,
    Buliaminu Kareem ,
    Oladunni Oyetola Alabi :
    Development of iron oressintering machine for blast furnace process64-75en [510.14 kB - PDF]EPA-02592-00017-0080

    There must be proper means to sinter and, agglomerated iron ore concentrate before it can be further processed in the blast furnace. A Sintering machine of 5kg capacity of agglomerated ore was designed and fabricated using mild steel material, which was locally sourced. The machine was fabricated with a combustion chamber of 30 by 30 cm and with 15cm depth. It was also lined with refractory material to reduce the chamber to the volume of 3375 cm3. However, the sintering chamber was designed to have a truncated square pyramid shape to the volume of 2150 cm3 after lining with refractory material. The design was made to utilize coke and palm kernel shell char as fuel which will be ignited to produce heat into the sintered material by suction of the heat into the agglomerated sintered ore. Tests such as tumbler index, abrasion, and porosity test were carried out on the sintered products in agreement with ASTM E276 and E389 standards. The results from the test gave a tumbler index of 70.2% and 65.7% for coke and palm kernel shells respectively. Also, abrasion index of 5.1% and 4.6% for coke and palm kernel char, and porosity of 6.8% and 6.5% for coke and palm kernel char respectively. The results from the experimental test were in agreement with other research work. Therefore, the developed iron ore sintering machine has a better efficiency of producing sinter for blast furnace operation.

  • József Richárd Lennert ,
    József Sárosi :

    The aim of this study is to investigate the effect of layer height used during 3D printing on the impact strength, their standard deviations, and the printing time by using UNI EN ISO 180 unnotched specimens manufactured by FDM 3D printing technology. Every specimen is made of PLA, which is the most basic material of the FDM printing technology by using the same 3D printer. In this study it plays a key role to find out whether the layer height can be used to optimize the researched mechanical property within an economical framework or not. What is more, the possibly observable tendencies and crucial influential parameters will be analysed as well.

  • Veronika T. Szabó ,
    Balázs Szabó ,
    Tamás Tarjányi ,
    Eszter Szőke-Trenyik ,
    Balázs Szabó P ,
    Márk Fráter :

    Periodontitis is one of the most common conditions affecting oral health among adults, posing a great challenge for both patients and also for dentists aiming to treat this disease. In severe stages such deterioration of the supporting tissues, namely the periodontal ligaments and the bone, can occur, which will affect the biomechanical behavior and therefore the longevity and survival of the affected teeth. In order to be able to plan both periodontal and subsequent restorative treatment properly, valid modelling of the current clinical situation is advised. The aim of the present article is to comprehensively discuss possible analog and digital modeling methods of periodontally affected teeth and the periodontal structures surrounding them. Modelling possibilities can serve later as the basis of mechanical load, digital finite element studies, and also aid clinical treatment planning.

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