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Found 6327 publications
Assessing physical activity and subjective health status among Hungarian secondary school students during the distance learning period caused by the COVID-19 pandemic
Publication Name: Orvosi Hetilap
Publication Date: 2022-04-24
Volume: 163
Issue: 17
Page Range: 655-662
Description:
Introduction: High school education took place in the form of distance learning during SARS-CoV-2 pandemic worldwide, including Hungary. Decreased physical activity and an increase in inactive behaviours may lead to an increased risk of obesity, diabetes, and cardiovascular disease. Objective: Our study focused on changes in physical activity (aerobic exercise, muscle strengthening, team sports) and subjective perceptions of health status in adolescents and young adults during the pandemic. Method: High school students in 66 public schools in 37 cities in Hungary (n = 2508) were surveyed. Questionnaire items on physical activity and subjective perceptions of health were adapted from the WHO Health Behaviour of School-aged Children Survey and the Centers for Disease Control and Prevention Youth Risk Behavior Survey. 2 × 2 × 4 factorial ANCOVA was used to test the effect of gender and/or age and region on changes in subjective perceptions of physical activity and health before and during distance education. Results: The majority of the high school students reported a decrease in physical activity frequency during the dis¬tance learning period, with an average of 2-3 fewer days of physical activity per week regardless of region. Nearly a quarter of them rated their health as worse during distance learning than before. A higher proportion of those who reported a subjective decline in health also reported a decline in physical activity. Conclusion: A decline in physical activity during the period of distance learning is associated with a decline in subjec¬tive perceptions of health, especially among rural adolescent girls.
Open Access: Yes
Parameter Determination and Drive Control Analysis of Axial Flux Permanent Magnet Synchronous Motors
Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science
Publication Date: 2022-04-01
Volume: 66
Issue: 2
Page Range: 205-214
Description:
Axial flux electric motors have received a lot of attention in recent years due to successful implementations in industrial or traction applications. Particularly, axial flux permanent magnet synchronous motors (AFPMSM) can be an attractive choice in case of high torque-density requirements or when the drive environment (packaging) is geometrically limited to a disc-shaped motor. However, compared to radial flux motors, axial flux machine modeling possibilities are much less documented. In the present study, different electromagnetic modeling approaches have been compared through an example AFPMSM design. The motor parameters were determined by analytical and finite element methods. A 2D equivalent model (2D Linear Motor Modeling Approach - 2D-LMMA) and a 3D model results have been compared. The calculated values were used to carry out a drive control analysis of the axial flux motor.
Open Access: Yes
DOI: 10.3311/PPee.19714
Ecotoxicological investigations of milking cow slurry and changes of oestrogenic compounds in the solid and liquid phase
Publication Name: Energy Ecology and Environment
Publication Date: 2022-04-01
Volume: 7
Issue: 2
Page Range: 97-110
Description:
Due to the appearance of intensive livestock-rearing systems since the 1970s, a vast amount of liquid manure (slurry) has been produced. The application and utilization are partly regulated for this special substance, which contains urine, excrement, process water, and other chemicals, such as insecticides and disinfectants. Our research was conducted on a slurry management system of a dairy cattle farm, focusing on the investigation of the presence of oestrogenic substances and toxicity of slurry before and after using a separator technology. Yeast oestrogen screen shows in this study that the separation of the liquid and solid phases of slurry contributes to the reduction in oestrogenic substances. Based on the toxicological studies, the growth inhibition of algae was 93%, and the inhibition of the germination of higher plant seeds was 25%, without separation. After separation of the phases, growth and germination were comparable with the negative control; moreover, some stimulation was detected. Consequently, harmful substances were removed with the suspended solid phase. From the present study, we can conclude that stakeholders should support separation technology in intensive livestock-rearing systems, and ecotoxicological investigations obviously help the risk management of slurry utilization. To our best knowledge, this is the first paper presenting detailed and complex toxicological study on slurry samples.
Open Access: Yes
Overview of the COMPASS results
M. Berta
M. Farník
M. Gobbin
R. Dejarnac
W. Bin
M. Komm
R. Roccella
J. K. Park
J. Havlicek
O. Hronova
D. Naydenkova
D. Šesták
N. Lemoine
J. Horacek
J. Seidl
D. Tskhakaya
I. Ďuran
N. C. Logan
M. Peterka
M. Poradzinski
I. Mysiura
P. Hacek
J. Gerardin
J. Cavalier
D. Réfy
O. Grover
T. Markovic
M. Imrišek
K. Kovarik
J. P. Gunn
V. Yanovskiy
P. Junek
J. Preinhaelter
L. Kripner
A. Casolari
F. Jaulmes
O. Bogár
A. Podolnik
S. Entler
J. Krbec
G. Grenfell
I. Borodkina
P. Kulhánek
A. Devitre
M. Iafrati
D. Fridrich
A. Havranek
J. Čeřovský
F. J. Artola
O. Ficker
E. Matveeva
P. Barton
None Fuková
M. Dimitrova
N. Isernia
P. Mácha
M. Grof
F. Napoli
J. Adamek
P. Lourenco
A. Marin Roldan
S. Atikukke
G. Mazzitelli
S. Lukes
A. Prishvitsin
K. Hromasová
D. Cipciar
J. Čaloud
K. Bogár
J. Čečrdle
O. Kovanda
N. Patel
M. Jeřáb
E. Macúšová
P. Bilková
L. Krlín
M. Rabinski
S. Brezinsek
Y. Gribov
J. Mlynar
M. Hron
C. Castaldo
J. Matějíček
P. Pavlo
P. Buratti
X. Litaudon
T. Loarer
F. Brochard
P. Böhm
H. Fernandes
A. Loarte
R. Pitts
R. Pánek
E. Gauthier
M. Jirsa
C. Hidalgo
Y. Q. Liu
A. Kallenbach
A. Bencze
M. Lehnen
Publication Name: Nuclear Fusion
Publication Date: 2022-04-01
Volume: 62
Issue: 4
Page Range: Unknown
Description:
COMPASS addressed several physical processes that may explain the behaviour of important phenomena. This paper presents results related to the main fields of COMPASS research obtained in the recent two years, including studies of turbulence, L-H transition, plasma material interaction, runaway electron, and disruption physics: Tomographic reconstruction of the edge/SOL turbulence observed by a fast visible camera allowed to visualize turbulent structures without perturbing the plasma. Dependence of the power threshold on the X-point height was studied and related role of radial electric field in the edge/SOL plasma was identified. The effect of high-field-side error fields on the L-H transition was investigated in order to assess the influence of the central solenoid misalignment and the possibility to compensate these error fields by low-field-side coils. Results of fast measurements of electron temperature during ELMs show the ELM peak values at the divertor are around 80% of the initial temperature at the pedestal. Liquid metals were used for the first time as plasma facing material in ELMy H-mode in the tokamak divertor. Good power handling capability was observed for heat fluxes up to 12 MW m-2 and no direct droplet ejection was observed. Partial detachment regime was achieved by impurity seeding in the divertor. The evolution of the heat flux footprint at the outer target was studied. Runaway electrons were studied using new unique systems - impact calorimetry, carbon pellet injection technique, wide variety of magnetic perturbations. Radial feedback control was imposed on the beam. Forces during plasma disruptions were monitored by a number of new diagnostics for vacuum vessel (VV) motion in order to contribute to the scaling laws of sideways disruption forces for ITER. Current flows towards the divertor tiles, incl. possible short-circuiting through PFCs, were investigated during the VDE experiments. The results support ATEC model and improve understanding of disruption loads.
Open Access: Yes
How human catabolism processes relate to the combustion of liquid fuels regarding oxygen consumption and carbon dioxide emissions in Hungary
Publication Name: Idojaras
Publication Date: 2022-04-01
Volume: 126
Issue: 2
Page Range: 233-246
Description:
— In connection with road vehicles and their internal combustion engines, their effects on our environment are being dealt with more and more. Plenty of parameters could be listed, but human catabolism and combustion of liquid fuels probably have not been examined together. Carbon dioxide has the most priority as a greenhouse gas in environmental change and metrology, thus it is a constant topic. Oxygen consumption has been examined rarely or never in such a context. In this article, calculations have been carried out from different points of view regarding these two parameters. The results of total-quantity calculations show, that the oxygen demand for the combustion of fuels used for road transport in 2019 in Hungary is the same as the 6-year oxygen demand of the Hungarian population, and the amount of the carbon dioxide emitted by the combustion of fuel used in road transport in Hungary is the same as the amount emitted by the Hungarian population during 5.2 years. The results might be worth examining on a larger scale.
Open Access: Yes
Using the CERES-Maize Model to Simulate Crop Yield in a Long-Term Field Experiment in Hungary
Publication Name: Agronomy
Publication Date: 2022-04-01
Volume: 12
Issue: 4
Page Range: Unknown
Description:
Precision crop production requires accurate yield prediction and nitrogen management. Crop simulation models may assist in exploring alternative management systems for optimizing water, nutrient and microelements use efficiencies, increasing maize yields. Our objectives were: (i) to access the ability of the CERES-Maize model for predicting yields in long-term experiments in Hungary; (ii) to use the model to assess the effects of different nutrient management (different nitrogen rates—0, 30, 60, 90, 120, and 150 kg ha−1). A long-term experiment conducted in Látókép (Hungary) with various N-fertilizer applications allowed us to predict maize yields under different conditions. The aim of the research is to explore and quantify the effects of ecological, biological, and agronomic factors affecting plant production, as well as to conduct basic science studies on stress factors on plant populations, which are made possible by the 30-year database of long-term experiments and the high level of instrumentation. The model was calibrated with data from a long-term experiment field trial. The purpose of this evaluation was to investigate how the CERES-Maize model simulated the effects of different N treatments in long-term field experiments. Sushi hybrid’s yields increased with elevated N concentrations. The observed yield ranged from 5016 to 14,920 kg ha−1 during the 2016–2020 growing season. The range of simulated data of maize yield was between 6671 and 13,136 kg ha−1. The highest yield was obtained at the 150 kg ha−1 dose in each year studied. In several cases, the DSSAT-CERES Maize model accurately predicted yields, but it was sensitive to seasonal effects and estimated yields inaccurately. Based on the obtained results, the variance analysis significantly affected the year (2016–2020) and nitrogen doses. N fertilizer made a significant difference on yield, but the combination of both predicted and actual yield data did not show any significance.
Open Access: Yes
The Features of the Shadow Economy Impact’ on Biomass Energy Sector
Publication Name: Energies
Publication Date: 2022-04-01
Volume: 15
Issue: 8
Page Range: Unknown
Description:
The shadow economy is a significant factor in impoverishing the economies of countries and unequal operating and competitive conditions distort the market economy system, as opaque parallel activities impoverish socially responsible business units. The biomass energy sector faces this risk because the biomass supply chain is not yet fully secure and balanced. The study conducted by the authors showed that the manifestations of the shadow economy in the biomass energy sector are possible in the biomass production and transportation sub‐sectors. Lack of digitization and poor resource management can lead to the problem of misuse of resources, which has non‐transparent economic activities. The evaluation methodology developed by the authors allows to investigate the directions of shadow economy in the biomass energy sector and to measure the possible extent of such activities. The measurements were made in order to compare the official activities of enterprises with the factors attributable to the shadow economy. This is also due to the lack of innovation and digital solutions. The application of innovative solutions would help to reduce the size of the shadow economy, which would increase the income of regions and the state, and reduce the level of poverty.
Open Access: Yes
DOI: 10.3390/en15082932
Performance Comparison of Quantized Control Synthesis Methods of Antenna Arrays
Publication Name: Electronics Switzerland
Publication Date: 2022-04-01
Volume: 11
Issue: 7
Page Range: Unknown
Description:
There is a great potential in small satellite technology for testing new sensors, processes, and technologies for space applications. Antennas need careful design when developing a small satellite to establish stable communication between the ground station and the satellite. This work is motivated by the design of an antenna array for a future rotatorless base station for the VZLUSAT group of Czech nano-satellites. The realized antenna array must cover a relatively broad range of elevation and azimuth angles, and the control must be fast enough to track the satellite in low Earth orbits. The paper deals with possibilities of synthesis of quantized control of the antenna array. It compares quantization influence for well-known deterministic synthesis methods. It shows the method for decreasing computational cost of synthesis using optimization approach and presents the multi-criteria optimization as a tool for reaching required radiation pattern shape and low sensitivity to quantization at the same time.
Open Access: Yes
Synthesis of biogenic silver nanoparticles using butter fruit pulp extract and evaluation of their antibacterial activity against Providencia vermicola in Rohu
Publication Name: Journal of King Saud University Science
Publication Date: 2022-04-01
Volume: 34
Issue: 3
Page Range: Unknown
Description:
Objective: Development of antimicrobial materials using nano approach and several industries like aquaculture greatly depend on novel biogenic materials. Biogenic techniques to develop nanomaterials with potent antimicrobial activity have been explored recently. The present study demonstrates the green synthesis of AgNPs using butter fruit (Persea americana) pulp extract and its antibacterial efficacy against the fish pathogen Providencia vermicola using Rohu fish. Results: The AgNPs were prepared and characterized using various spectroscopic and microscopic techniques. The infrared spectroscopic analysis identified that the fruit biological molecules were involved in the stabilization of AgNPs. Transmission electron microscopic analysis revealed that particles size ranged from 20 to 50 nm. Further, the nanoparticles (5 µg) encapsulated fish feed were given to P. vermicola infected Rohu fish. The survival rate observed was 72 % in experimental group as compared to the control group. Total plate count and histopathological results indicated that the AgNPs treated groups showed significant reduction of bacterial population and restore the tissues in the normal range. Conclusion: The results suggest that the green synthesized (AgNPs) using butter fruit pulp have good efficiency in reducing the infection caused by P. vermicola in Rohu fish.
Open Access: Yes
