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Precision farming may play an important role in agricultural innovation. The study focuses on the attitude of Hungarian farmers toward precision farming. Based on the relevant technical literature, we performed a nationally representative questionnaire survey of 594 farmers and deep interviews with experts and farmers (30 persons). As regards the questionnaire, the authors found that the management of the average farm size in Hungary has the highest willingness to innovate and the second highest level of education among the developed clusters. The survey shows undertrained farmers with large farms to be the second most open group, which may result in the partial application of precision farming techniques. One of the most unexpected results of the Precision Farmers’ cluster is that the positive socio-economic utility of precision farming is rated as extremely low. In-depth interviews prove that the use of precision technologies does not increase local social cohesion. Strong organisational isolation of precision farmers prevents the spread of innovation knowledge and precision farming amongst the farming community, and the challenges of competitiveness alone do not force farmers to apply precision farming. Our results may be useful for the establishment of agricultural strategy.
Péter Balogh; Attila Bai; Ibolya Czibere; Imre Kovách; László Fodor; Ágnes Bujdos; Dénes Sulyok; Zoltán Gabnai; Zoltán Birkner. Economic and Social Barriers of Precision Farming in Hungary. Agronomy 2021, 11, 1112 .
AMA StylePéter Balogh, Attila Bai, Ibolya Czibere, Imre Kovách, László Fodor, Ágnes Bujdos, Dénes Sulyok, Zoltán Gabnai, Zoltán Birkner. Economic and Social Barriers of Precision Farming in Hungary. Agronomy. 2021; 11 (6):1112.
Chicago/Turabian StylePéter Balogh; Attila Bai; Ibolya Czibere; Imre Kovách; László Fodor; Ágnes Bujdos; Dénes Sulyok; Zoltán Gabnai; Zoltán Birkner. 2021. "Economic and Social Barriers of Precision Farming in Hungary." Agronomy 11, no. 6: 1112.
In this chapter, we present the opportunities and general importance of woody biomass production (forests and short-rotation coppices) and waste management in a common system. Wastewater and different forms of sewage sludge, as energy- and nutrient-rich materials, can contribute to reaching resource efficiency, savings in energy, and reduction of CO2 emissions. Within certain limits, these woody plantations are suitable options for the environmentally sound disposal of wastewater and/or sewage sludge; in addition, they can facilitate the realization of full or partial energy self-sufficiency of the wastewater plant through bioenergy production. Focusing on circular economy, we introduce the aspects of the treatment process and the sizing issues regarding the municipal wastewater treatment and the woody biomass in a complex system. Based on a specific case study, approximately 826 ha of short-rotation coppices (with a 2-year rotation) are required for the disposal of sewage sludge generated by a 250,000 population equivalent wastewater treatment plant. If we look at the self-sufficiency of its energy output, 120–150 ha of short-rotation coppices may be adequate. This complex system can replace the emissions of around 5650 t of CO2 through electricity generation alone and another 1490 t of CO2 by utilizing the waste heat.
Attila Bai; Zoltán Gabnai. Opportunities of Circular Economy in a Complex System of Woody Biomass and Municipal Sewage Plants. Forest Biomass - From Trees to Energy 2021, 1 .
AMA StyleAttila Bai, Zoltán Gabnai. Opportunities of Circular Economy in a Complex System of Woody Biomass and Municipal Sewage Plants. Forest Biomass - From Trees to Energy. 2021; ():1.
Chicago/Turabian StyleAttila Bai; Zoltán Gabnai. 2021. "Opportunities of Circular Economy in a Complex System of Woody Biomass and Municipal Sewage Plants." Forest Biomass - From Trees to Energy , no. : 1.
The current paper analyzes the awareness of renewable energy sources (RES), the relationship between self-reported and actual knowledge, and the correlation among the knowledge of renewable energy sources, the characteristic stereotypes, and the typical attitude of different social groups to energy, comparing them with international experience. A nationwide representative questionnaire-based survey was carried out involving 1002 people in Hungary in 2019. Better education, a higher income, an active white-collar profession, and a health- and environment-conscious approach to life (LOHAS (lifestyle of health and sustainability) segment) are definitely an advantage when it comes to knowledge of renewable energy sources. No significant relationship was detected in terms of age; however, in cluster formation, young people were typically found to be better informed. Overall, the actual knowledge of the Hungarian respondents is more favorable than the self-reported one, and the basic level of knowledge of energy sources in the case of wind and hydropower exceeds international experience. The social factors of better knowledge essentially correspond to the international trends; however, regarding firewood, solar, and wind energy, the average Hungarian has certain false stereotypes that can be considered typical. The assessment of convenience and that of environmental aspects are almost the same.
Zoltán Szakály; Péter Balogh; Enikő Kontor; Zoltán Gabnai; Attila Bai. Attitude toward and Awareness of Renewable Energy Sources: Hungarian Experience and Special Features. Energies 2020, 14, 22 .
AMA StyleZoltán Szakály, Péter Balogh, Enikő Kontor, Zoltán Gabnai, Attila Bai. Attitude toward and Awareness of Renewable Energy Sources: Hungarian Experience and Special Features. Energies. 2020; 14 (1):22.
Chicago/Turabian StyleZoltán Szakály; Péter Balogh; Enikő Kontor; Zoltán Gabnai; Attila Bai. 2020. "Attitude toward and Awareness of Renewable Energy Sources: Hungarian Experience and Special Features." Energies 14, no. 1: 22.
Ethanol is a widely produced fuel, as well as a fuel additive. Its price is closely related to the price of gasoline, its major substitute. This paper focuses on the impacts of the related variables on regional ethanol prices. Additionally, the length of the price dataset made it possible to isolate the impacts of COVID-19 on the ethanol prices. Using multiple regression and Confirmatory Factor Analyses, we found no significant correlation between the European and US ethanol prices because the major influencing factors were regionally different. In the case of the European ethanol markets, the positive factors were wheat, maize, and potassium chloride prices, while the European sugar and diammonium phosphate prices were negative. In the US markets, gasoline, sugar, and most of the artificial fertilizer prices were positive, while wheat prices were negative. Based on factor analysis, artificial fertilizers and maize factors proved to be important to the European markets, while US ethanol prices were driven by the crude oil-gasoline and raw materials factors. The COVID variable showed no significant connection with the EU prices, but negatively affected the US ethanol prices. This is explained by the different market characteristics, as the US is not only the major consumer, but also the major producer of the different oil products. Therefore, COVID-19 had a double effect on their oil and ethanol markets.
Tamás Mizik; Lajos Nagy; Zoltán Gabnai; Attila Bai. The Major Driving Forces of the EU and US Ethanol Markets with Special Attention Paid to the COVID-19 Pandemic. Energies 2020, 13, 5614 .
AMA StyleTamás Mizik, Lajos Nagy, Zoltán Gabnai, Attila Bai. The Major Driving Forces of the EU and US Ethanol Markets with Special Attention Paid to the COVID-19 Pandemic. Energies. 2020; 13 (21):5614.
Chicago/Turabian StyleTamás Mizik; Lajos Nagy; Zoltán Gabnai; Attila Bai. 2020. "The Major Driving Forces of the EU and US Ethanol Markets with Special Attention Paid to the COVID-19 Pandemic." Energies 13, no. 21: 5614.
The basic question of our research is what crop-producing farmers know about PF (precision farming), and how economic value and social factors motivate the acceptance and implementation of PF. We conducted a cross-sectional survey, using standardized questionnaires, in 2018, that was nationally representative of Hungarian crop producers. Besides this, we conducted 30 semi-structured interviews about the meaning of PF, with the farmers who use PF in practice. They defined it as a tool of strategic planning, to serve input savings, using state-of-the-art technologies. Based on the questionnaire, we found that the farmers currently applying PF do not seem to have such a significant impact on the agricultural society that would make others want to move to precision technology, following their example. As a result of the factor analysis, we could differentiate direct and indirect factors. Potential human resources are undereducated, their willingness to improve their knowledge is low, and the level of cooperation ability is low, making it excessively difficult, or even impossible, to acquire the equipment necessary for a technology switch and to purchase the necessary services. It can be concluded that age, production, and technical usefulness carries greater weight over things like monetary factors, productivity of cultivated land, knowledge capital, and willingness of Hungarian farmers to cooperate.
Péter Balogh; Ágnes Bujdos; Ibolya Czibere; László Fodor; Zoltán Gabnai; Imre Kovách; János Nagy; Attila Bai. Main Motivational Factors of Farmers Adopting Precision Farming in Hungary. Agronomy 2020, 10, 610 .
AMA StylePéter Balogh, Ágnes Bujdos, Ibolya Czibere, László Fodor, Zoltán Gabnai, Imre Kovách, János Nagy, Attila Bai. Main Motivational Factors of Farmers Adopting Precision Farming in Hungary. Agronomy. 2020; 10 (4):610.
Chicago/Turabian StylePéter Balogh; Ágnes Bujdos; Ibolya Czibere; László Fodor; Zoltán Gabnai; Imre Kovách; János Nagy; Attila Bai. 2020. "Main Motivational Factors of Farmers Adopting Precision Farming in Hungary." Agronomy 10, no. 4: 610.
The energy sector is undergoing radical changes, and this transition is expected to accelerate all over the world over the coming years. In our recent research, we conducted a questionnaire survey at different levels and asked the experts in the area, the businesses involved in the issue, the operators and maintainers of existing systems, as well as the potential consumers and end users, about their knowledge and intentions related to renewable energy sources. Our empirical research can be divided into three parts. Our exploratory research was based on expert interviews, which show that the growing importance of localization is unquestionable, but the economic, social, and existing infrastructures impose significant barriers to the widespread adoption of certain technologies. Regarding the population survey, we see that the skepticism experienced in previous years has been replaced by a kind of expectation reflecting openness. In addition, it can be stated that in many cases technological development is faster than the possibility of its adaptation. Our gender tests significantly support men’s better knowledge of the subject and the fact that biomass (despite its major importance) is not one of the most known renewable energy sources.
Kornél Németh; Zoltán Birkner; Andrea Katona; Nikoletta Göllény-Kovács; Attila Bai; Péter Balogh; Zoltán Gabnai; Erzsébet Péter. Can Energy Be a “Local Product” Again? Hungarian Case Study. Sustainability 2020, 12, 1118 .
AMA StyleKornél Németh, Zoltán Birkner, Andrea Katona, Nikoletta Göllény-Kovács, Attila Bai, Péter Balogh, Zoltán Gabnai, Erzsébet Péter. Can Energy Be a “Local Product” Again? Hungarian Case Study. Sustainability. 2020; 12 (3):1118.
Chicago/Turabian StyleKornél Németh; Zoltán Birkner; Andrea Katona; Nikoletta Göllény-Kovács; Attila Bai; Péter Balogh; Zoltán Gabnai; Erzsébet Péter. 2020. "Can Energy Be a “Local Product” Again? Hungarian Case Study." Sustainability 12, no. 3: 1118.
Large-scale sewage plants in large cities are suitable for the production of large quantities of biogas, using economically viable biogas upgrading technologies and generally available public transport fleets of a sufficient number of local buses, as well as municipal vehicles. The conditions for the sale of locally produced CNGs do not depend on gas suppliers, they can be very well integrated with local waste management, and the local emission reductions occur in the inner city, where air pollution is the most serious problem. At the same time, the cogeneration solution currently of decisive importance for wastewater plants is more economically and environmentally advantageous in the production of biomethane. The consumption of heat and electricity by these plants is significant and must be supplied through the purchase of biomethane. However, for the local authority, when converting diesel buses, compressed biomethane (CBM) offers much greater savings, so at the municipal level, the process is economically profitable. The short-term spread of CBM (due to the small number of filling stations) is bound to local systems. If more and more cities operated a similar system (allowing refuelling within a few dozen kilometres), it would be expected that passenger cars would also be more widespread.
Attila Bai; Zoltán Gabnai. The Possible Role of Large-Scale Sewage Plants in Local Transport. Transportation Systems Analysis and Assessment 2020, 1 .
AMA StyleAttila Bai, Zoltán Gabnai. The Possible Role of Large-Scale Sewage Plants in Local Transport. Transportation Systems Analysis and Assessment. 2020; ():1.
Chicago/Turabian StyleAttila Bai; Zoltán Gabnai. 2020. "The Possible Role of Large-Scale Sewage Plants in Local Transport." Transportation Systems Analysis and Assessment , no. : 1.
This paper focuses on the economic and statistical evaluation of the production technology findings of the polyfactorial maize production experiments carried out between 2015-2017 at the Látókép Experiment Site of the University of Debrecen, Faculty of Agricultural and Food Sciences and Environmental Management. The examined agrotechnical factors included irrigation, previous crop, tillage, crop density, hybrid and N nutrient supply, while the effect of different crop years was taken into consideration. In addition to descriptive statistical methods, we used multivariate regression analysis during the statistical evaluation. In the course of the evaluation, we examined three models that differed in terms of tillage methods and the consideration of crop year. In our best fit model, the factors were 71% responsible for the change in yield value. We carried out efficiency and comparative analyses in the course of the economic evaluation.Averaged over the three examined years, it can be stated that nutrient supply and crop year had an outstanding effect on yield, while irrigation had a minimal effect. However, global warming may justify irrigation in the future, not only from a biological point of view, but also from an economic aspect.Ideal tillage is also greatly affected by crop year, too. Altogether, of the examined tillage systems, subsoiling proved to be the best from an economic point of view.Our investigations confirm that it is better to perform intensive farming under more favourable market conditions. The optimum of N fertilisation is probably outside of the range we examined, if the extreme changes in maize and fertiliser prices are ignored. JEL Classification: Q16, Q12, Q13, O32
Attila Bai; Zoltán Gabnai; Imre Kovách; Ibolya Czibere; János Nagy; Dénes Sulyok; Donika Maloku; Péter Balogh. Economic analysis of some agrotechnical factors in maize production - a Hungarian case study. Applied Studies in Agribusiness and Commerce 2019, 13, 5 -16.
AMA StyleAttila Bai, Zoltán Gabnai, Imre Kovách, Ibolya Czibere, János Nagy, Dénes Sulyok, Donika Maloku, Péter Balogh. Economic analysis of some agrotechnical factors in maize production - a Hungarian case study. Applied Studies in Agribusiness and Commerce. 2019; 13 (3-4):5-16.
Chicago/Turabian StyleAttila Bai; Zoltán Gabnai; Imre Kovách; Ibolya Czibere; János Nagy; Dénes Sulyok; Donika Maloku; Péter Balogh. 2019. "Economic analysis of some agrotechnical factors in maize production - a Hungarian case study." Applied Studies in Agribusiness and Commerce 13, no. 3-4: 5-16.
József Popp; Attila Bai. Megújuló energiaforrások, különös tekintettel a bioüzemanyag-gyártásra: Nemzetközi kitekintés. Magyar Tudomány 2018, 1 .
AMA StyleJózsef Popp, Attila Bai. Megújuló energiaforrások, különös tekintettel a bioüzemanyag-gyártásra: Nemzetközi kitekintés. Magyar Tudomány. 2018; ():1.
Chicago/Turabian StyleJózsef Popp; Attila Bai. 2018. "Megújuló energiaforrások, különös tekintettel a bioüzemanyag-gyártásra: Nemzetközi kitekintés." Magyar Tudomány , no. : 1.
The main goal of this paper is to analyse the efficiency of the plantlet production of Virginia fanpetals, to make economic calculations for their energetic use and to determine the most favourable plant density. According to the experiments, the cost of a healthy Sida plantlet is in the range of 38.4 − 60.6 Euro cents, using the nurse-in-tray technology (NIT). This cost range is much lower than the market prices of the plantlets and the production method is more reliable compared to sowing. In the second year, the dry matter yield originating from Sida plantlets was 10.2 – 11.9 t hectare−1 (ha) without fertilisation in the different planting densities. However, in the longer term, it is recommended to apply organic manure regardless of spacing. The theoretical market value of Sida is generally higher than total unit costs (36 − 60 EUR t−1) in the case of all methods used, except for biogas. The production of Sida can be economical for farmers farming in marginal conditions, using locally available organic manure, producing crops with high heat demand, or involved in beekeeping.
Erika Kurucz; Miklós G. Fári; Gabriella Antal; Zoltán Gabnai; József Popp; Attila Bai. Opportunities for the production and economics of Virginia fanpetals (Sida hermaphrodita). Renewable and Sustainable Energy Reviews 2018, 90, 824 -834.
AMA StyleErika Kurucz, Miklós G. Fári, Gabriella Antal, Zoltán Gabnai, József Popp, Attila Bai. Opportunities for the production and economics of Virginia fanpetals (Sida hermaphrodita). Renewable and Sustainable Energy Reviews. 2018; 90 ():824-834.
Chicago/Turabian StyleErika Kurucz; Miklós G. Fári; Gabriella Antal; Zoltán Gabnai; József Popp; Attila Bai. 2018. "Opportunities for the production and economics of Virginia fanpetals (Sida hermaphrodita)." Renewable and Sustainable Energy Reviews 90, no. : 824-834.
In our paper we examine the economics of a technological process which utilizes the separated biogas plant digestate as the primary material and, as auxiliary material, the waste heat produced by the cogeneration process, to produce a marketable pellet which can be used in two ways (to supply soil nutrients and heat energy). Using multivariate linear regression model we developed an equation for the biogas yield from the modelled production recipe and expected nutrient pellet prices, and sensitivity analysis were also performed for the substrate dry matter content. We found that pellets can be produced at a cost of 88–90 EUR/ton with a 6 to 10% dry matter substrate content and that, primarily, sales of pellets for heating justify pelleting; producer’s own use and use for nutrient purposes can only be justified in exceptional cases. In the case of dry solid content above 5%, the process does not require the total amount of waste heat; some of this can be used to cover other heat requirements.
Dávid Nagy; Péter Balogh; Zoltán Gabnai; József Popp; Judit Oláh; Attila Bai. Economic Analysis of Pellet Production in Co-Digestion Biogas Plants. Energies 2018, 11, 1135 .
AMA StyleDávid Nagy, Péter Balogh, Zoltán Gabnai, József Popp, Judit Oláh, Attila Bai. Economic Analysis of Pellet Production in Co-Digestion Biogas Plants. Energies. 2018; 11 (5):1135.
Chicago/Turabian StyleDávid Nagy; Péter Balogh; Zoltán Gabnai; József Popp; Judit Oláh; Attila Bai. 2018. "Economic Analysis of Pellet Production in Co-Digestion Biogas Plants." Energies 11, no. 5: 1135.
This paper examines the thermal properties of free-standing, ground-installed, south-facing crystalline and amorphous silicon photovoltaic modules, the remaining energy and the energy generation of the modules, in ideal and actual summer weather conditions. This work studies the algorithms in other studies used to describe the thermal processes occurring on the surface of photovoltaic modules. Using accurate devices and real, measured data, the deviations and the inaccuracies of theoretical approaches are investigated. The emphasis of the present study is to improve the simulation accuracy of the total emitted long-wave radiation at the module surface and to show the appropriate overall convection coefficient values for ground-mounted south-facing photovoltaic technologies. The innovative aspect of the present paper is an improved model resulting from an improved convective heat transfer and net long-wave radiation calculation. As a result of this research, algorithms describing the energy fluxes were developed. These algorithms have a 1–3% better accuracy of the net long-wave radiation calculations at the module surface. The rate of net energy exchange by convection at the module surface could be improved by 10–12% compared to the previous literature.
Henrik Zsiborács; Gábor Pintér; Attila Bai; József Popp; Zoltán Gabnai; Béla Pályi; Istvan Farkas; Nóra Hegedűsné Baranyai; Christian Gützer; Heidelinde Trimmel; Sandro Oswald; Philipp Weihs. Comparison of Thermal Models for Ground-Mounted South-Facing Photovoltaic Technologies: A Practical Case Study. Energies 2018, 11, 1114 .
AMA StyleHenrik Zsiborács, Gábor Pintér, Attila Bai, József Popp, Zoltán Gabnai, Béla Pályi, Istvan Farkas, Nóra Hegedűsné Baranyai, Christian Gützer, Heidelinde Trimmel, Sandro Oswald, Philipp Weihs. Comparison of Thermal Models for Ground-Mounted South-Facing Photovoltaic Technologies: A Practical Case Study. Energies. 2018; 11 (5):1114.
Chicago/Turabian StyleHenrik Zsiborács; Gábor Pintér; Attila Bai; József Popp; Zoltán Gabnai; Béla Pályi; Istvan Farkas; Nóra Hegedűsné Baranyai; Christian Gützer; Heidelinde Trimmel; Sandro Oswald; Philipp Weihs. 2018. "Comparison of Thermal Models for Ground-Mounted South-Facing Photovoltaic Technologies: A Practical Case Study." Energies 11, no. 5: 1114.
The aim of the study is to compare the tilt angle-orientation and dual-axis tracking characteristics of mono- (m-Si), polycrystalline (p-Si), and amorphous silicon (a-Si) modules in the summer of 2017, under real meteorological conditions with simulated data. The most important new element of our study is that, besides a comparison of the three most significant photovoltaic types, the technologies are differentiated by examining specific energy generation using dual-axis tracking and four different orientations at 5-degree intervals compared to simulated values, near to the summer solstice. For these types of measurements, as far as we are aware, there is no previous reliable, well-supported, comparative data. The simulated data show less accurate results, proving the importance of real data. Based on simulated data, the tilt angle and orientation showed about 10% favorable values compared to reality. Knowing our results can make it easier to plan investment, and estimate the investment and operational costs and their return on crystalline and amorphous silicon solar modules, for both sun-tracking and fixed systems with various orientations and tilt angles.
Henrik Zsiborács; Attila Bai; József Popp; Zoltán Gabnai; Béla Pályi; István Farkas; Nóra Hegedűsné Baranyai; Mihály Veszelka; László Zentkó; Gábor Pintér. Change of Real and Simulated Energy Production of Certain Photovoltaic Technologies in Relation to Orientation, Tilt Angle and Dual-Axis Sun-Tracking. A Case Study in Hungary. Sustainability 2018, 10, 1394 .
AMA StyleHenrik Zsiborács, Attila Bai, József Popp, Zoltán Gabnai, Béla Pályi, István Farkas, Nóra Hegedűsné Baranyai, Mihály Veszelka, László Zentkó, Gábor Pintér. Change of Real and Simulated Energy Production of Certain Photovoltaic Technologies in Relation to Orientation, Tilt Angle and Dual-Axis Sun-Tracking. A Case Study in Hungary. Sustainability. 2018; 10 (5):1394.
Chicago/Turabian StyleHenrik Zsiborács; Attila Bai; József Popp; Zoltán Gabnai; Béla Pályi; István Farkas; Nóra Hegedűsné Baranyai; Mihály Veszelka; László Zentkó; Gábor Pintér. 2018. "Change of Real and Simulated Energy Production of Certain Photovoltaic Technologies in Relation to Orientation, Tilt Angle and Dual-Axis Sun-Tracking. A Case Study in Hungary." Sustainability 10, no. 5: 1394.
Jijzsef Popp; Anna Kiss; Judit Olġh; Domicián Máté; Attila Bai; Zoltġn Lakner. Network Analysis for the Improvement of Food Safety in the International Honey Trade. www.amfiteatrueconomic.ro 2018, 20, 1 .
AMA StyleJijzsef Popp, Anna Kiss, Judit Olġh, Domicián Máté, Attila Bai, Zoltġn Lakner. Network Analysis for the Improvement of Food Safety in the International Honey Trade. www.amfiteatrueconomic.ro. 2018; 20 (47):1.
Chicago/Turabian StyleJijzsef Popp; Anna Kiss; Judit Olġh; Domicián Máté; Attila Bai; Zoltġn Lakner. 2018. "Network Analysis for the Improvement of Food Safety in the International Honey Trade." www.amfiteatrueconomic.ro 20, no. 47: 1.
This research focuses on the role of trust and the impact of its level on the revenue, earnings before tax and the degree of flexibility of logistics service providers (LSPs). More specifically, the role of the executive manager is examined in relation to the impact of business relationships (trust levels) within and between organizations. In addition, the analysis covers the development of revenue, earnings before tax and degree of flexibility of logistics service providers in the context of the role of the head manager. The data were collected from 51 logistics service providers in Hungary. The results show that the level of trust established in the organization (with the employees, co-workers etc.) has a positive impact on the earnings before tax. Furthermore, this paper confirms that the trust executive managers establish around them is an important performance factor which even consumers perceive and that it has major significance in terms of degree of flexibility. This research further increases our understanding of the role and importance of trust as a strategic success factor for LSPs.
Judit Oláh; Attila Bai; György Karmazin; Péter Balogh; József Popp. The Role Played by Trust and Its Effect on the Competiveness of Logistics Service Providers in Hungary. Sustainability 2017, 9, 2303 .
AMA StyleJudit Oláh, Attila Bai, György Karmazin, Péter Balogh, József Popp. The Role Played by Trust and Its Effect on the Competiveness of Logistics Service Providers in Hungary. Sustainability. 2017; 9 (12):2303.
Chicago/Turabian StyleJudit Oláh; Attila Bai; György Karmazin; Péter Balogh; József Popp. 2017. "The Role Played by Trust and Its Effect on the Competiveness of Logistics Service Providers in Hungary." Sustainability 9, no. 12: 2303.
This study presents the sequestration and emissions of forests and algae related to CO2 while providing a comparison to other biomass sources (arable crops, short rotation coppices). The goal of the paper is to analyze the impact of the current CO2 balance of forests and the future prospects for algae. Our calculations are based on data, not only from the literature but, in the case of algae, from our own previous experimental work. It was concluded that the CO2 sequestration and natural gas saving of forests is typically 3.78 times higher than the emissions resulting from the production technology and from the burning process. The economic and environmental protection-related efficiency operate in opposite directions. The CO2 sequestration ability of algae can primarily be utilized when connected to power plants. The optimal solution could be algae production integrated with biogas power plants, since plant sizes are smaller and algae may play a role, not only in the elimination of CO2 emissions and the utilization of heat but also in wastewater purification.
Attila Bai; József Popp; Károly Pető; Irén Szőke; Mónika Harangi-Rákos; Zoltán Gabnai. The Significance of Forests and Algae in CO2 Balance: A Hungarian Case Study. Sustainability 2017, 9, 857 .
AMA StyleAttila Bai, József Popp, Károly Pető, Irén Szőke, Mónika Harangi-Rákos, Zoltán Gabnai. The Significance of Forests and Algae in CO2 Balance: A Hungarian Case Study. Sustainability. 2017; 9 (5):857.
Chicago/Turabian StyleAttila Bai; József Popp; Károly Pető; Irén Szőke; Mónika Harangi-Rákos; Zoltán Gabnai. 2017. "The Significance of Forests and Algae in CO2 Balance: A Hungarian Case Study." Sustainability 9, no. 5: 857.
We analyzed the operation of a typical agricultural biogas plant in Hungary. Our aim was to optimize the composition of substrates for the biogas production and make a correct recommendation for completing feedstock recipes by considering the raw materials and technologies analyzed. The calculations were based on a very detailed database (including the daily operating data of 1673 days). Distribution of the biogas yields in summer and winter periods was normal based on the One-Sample Kolmogorov-Smirnov test, while the variance of data was homogeneous based on the Levene-test. Factor analysis of the biogas yield was performed with the Kaiser-Meyer-Olkin Measure of Sampling Adequacy probe (0.616) and the Bartlett's Test. According to the objectivity of our LP (linear program) model, we believe that a significant excess biogas yield (18-66%) could be achieved by the use of our model compared to the actual measured data. Although the amount of corn silage, grass silage, and the extract – as variables – was minimal in the recipe, they played a crucial role in the total biogas yield of the recipe because of their significantly higher organic matter contents and specific biogas yields. Our results could provide a reliable foundation for optimizing of the recipe in biogas plants with raw material base similar to the analyzed plants.Citation: Mézes, L., Bai, A., Nagy, D., Cinka, I., and Gabnai, Z. (2017). Optimization of Raw Material Composition in an Agricultural Biogas Plant. Trends in Renewable Energy, 3(1), 61-75. DOI: 10.17737/tre.2017.3.1.0031
Lili Mézes; Attila Bai; Dávid Nagy; István Cinka; Zoltán Gabnai. Optimization of Raw Material Composition in an Agricultural Biogas Plant. Trends in Renewable Energy 2017, 3, 61 -75.
AMA StyleLili Mézes, Attila Bai, Dávid Nagy, István Cinka, Zoltán Gabnai. Optimization of Raw Material Composition in an Agricultural Biogas Plant. Trends in Renewable Energy. 2017; 3 (1):61-75.
Chicago/Turabian StyleLili Mézes; Attila Bai; Dávid Nagy; István Cinka; Zoltán Gabnai. 2017. "Optimization of Raw Material Composition in an Agricultural Biogas Plant." Trends in Renewable Energy 3, no. 1: 61-75.
Methods of cooling monocrystalline and polycrystalline solar modules with water vaporizing are analysed in the paper regarding the effects of temperature on performance and its economic relations. Since water usage may present a significant cost the aim of the research was to create a cooling system that operates without loss of flowing water. Results are evaluated from technical and economic points of view in relation to several countries based on systems with 5 kW capacity. Ideal setting of spray heads at 2 bar pressure was achieved with a distance of 0.26 m between the spray heads. In our experiment, a temperature following procedure was tested manually. Due to this procedure, the surface of the module can be cooled with an average temperature value that is calculated after cooling, depending on the temperature of the control solar module. Analysing the daily data of monthly production the number of “ideal days” in a given month were estimated. Comparing the temperature decrease as a result of vaporization measured in summer and in autumn showed no significant difference. The results achieved confirm the connection between temperature change and efficiency change of monocrystalline and polycrystalline solar modules (0.5%/1 °C), discussed in previous scientific literature. Effective application of solar module cooling systems is around 10–15% more expensive than the cost of systems without cooling. In general, under current economic conditions the operation of cooled solar modules is viable mainly in South European countries.
Henrik Zsiborács; Béla Pályi; Gábor Pintér; József Popp; Péter Balogh; Zoltán Gabnai; Károly Pető; István Farkas; Nóra Hegedűsné Baranyai; Attila Bai. Technical-economic study of cooled crystalline solar modules. Solar Energy 2016, 140, 227 -235.
AMA StyleHenrik Zsiborács, Béla Pályi, Gábor Pintér, József Popp, Péter Balogh, Zoltán Gabnai, Károly Pető, István Farkas, Nóra Hegedűsné Baranyai, Attila Bai. Technical-economic study of cooled crystalline solar modules. Solar Energy. 2016; 140 ():227-235.
Chicago/Turabian StyleHenrik Zsiborács; Béla Pályi; Gábor Pintér; József Popp; Péter Balogh; Zoltán Gabnai; Károly Pető; István Farkas; Nóra Hegedűsné Baranyai; Attila Bai. 2016. "Technical-economic study of cooled crystalline solar modules." Solar Energy 140, no. : 227-235.
Attila Bai; Péter Jobbágy; József Popp; Ferenc Farkas; Gábor Grasselli; János Szendrei; Péter Balogh. Technical and environmental effects of biodiesel use in local public transport. Transportation Research Part D: Transport and Environment 2016, 47, 323 -335.
AMA StyleAttila Bai, Péter Jobbágy, József Popp, Ferenc Farkas, Gábor Grasselli, János Szendrei, Péter Balogh. Technical and environmental effects of biodiesel use in local public transport. Transportation Research Part D: Transport and Environment. 2016; 47 ():323-335.
Chicago/Turabian StyleAttila Bai; Péter Jobbágy; József Popp; Ferenc Farkas; Gábor Grasselli; János Szendrei; Péter Balogh. 2016. "Technical and environmental effects of biodiesel use in local public transport." Transportation Research Part D: Transport and Environment 47, no. : 323-335.
This paper focuses on the impact of sprinkling and refrigerant based cooling methods of photovoltaic modules on actual performance, the duration of cooling and the quickness of the impact of cooling in comparison with monocrystalline photovoltaic modules without cooling. The obtained findings were analysed both from technical and economic aspects.Based on the parameters of the regression model used in this study (r=0.61), it can be concluded that a 1 °C increase of air temperature in the examined range (18–29 °C) improves actual performance by 1.58 W and cooling is probably necessary at higher temperatures. On more cloudy days, the expected performance is 9.8 W lower on average (P=0.001).In both experiments, there was an obvious negative correlation between module temperature and actual performance under constant radiation conditions. On more sunny days, one unit change in temperature resulted in a performance change of 1.2–1.3% (R2=0.87–0.95), while more cloudy days resulted in less close correlation and a much lower change of temperature (0.8–0.9%) (R2=0.70–0.81).The following conclusions can be drawn in relation to the two examined cooling methods:•The actual performance of the sprinkling method is higher than that of the other two alternatives (by 19% and 25% in the case of the control method and by 13% and 18% in the case of refrigerant based cooling, depending on the day of measurement).•After deducting the electricity needed for sprinkling cooling, the electric performance was still 12% better on average, using 22.5 L water per day on average. In the case of the refrigerant based cooling method, the produced extra energy was less than the electricity need of the heat exchanger itself; therefore, this method obviously seems to be unviable both from energetic and economic aspects.
Attila Bai; József Popp; Péter Balogh; Zoltán Gabnai; Béla Pályi; István Farkas; Gábor Pintér; Henrik Zsiborács. Technical and economic effects of cooling of monocrystalline photovoltaic modules under Hungarian conditions. Renewable and Sustainable Energy Reviews 2016, 60, 1086 -1099.
AMA StyleAttila Bai, József Popp, Péter Balogh, Zoltán Gabnai, Béla Pályi, István Farkas, Gábor Pintér, Henrik Zsiborács. Technical and economic effects of cooling of monocrystalline photovoltaic modules under Hungarian conditions. Renewable and Sustainable Energy Reviews. 2016; 60 ():1086-1099.
Chicago/Turabian StyleAttila Bai; József Popp; Péter Balogh; Zoltán Gabnai; Béla Pályi; István Farkas; Gábor Pintér; Henrik Zsiborács. 2016. "Technical and economic effects of cooling of monocrystalline photovoltaic modules under Hungarian conditions." Renewable and Sustainable Energy Reviews 60, no. : 1086-1099.