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Abstract

Due to the technological progress, new approaches such as model-based design are spreading in the development process in the automotive industry to meet the increased requirements related to lower fuel consumption and reduced emission. This work is part of a research project which focuses on dynamic modeling of vehicles aimed at analyzing and optimizing the emission and fuel consumption. To model the driver behavior, the simulation control algorithm requires a predetermined speed-time curve as an input. The completeness of this driving cycle is a crucial factor in the simulation, and as far as the legislative driving cycles are not accurate enough, it is indispensable to develop our own one representing our narrower area and driving conditions. This article considers two common drive cycle design methods, comparing the micro-trip-based approach and the Markov-chain approach. The new driving cycle has been developed applying the Markov-chain approach and compared to a driving cycle introduced in our recent paper using the micro-trip method. The comparison basis is the Speed-Acceleration Probability Distribution, which sufficiently reflects the dynamic behavior of the vehicle, and the root mean square error, including parameters such as the average speed, average cruising speed, average acceleration, average deceleration, root mean square acceleration, and idle time percentage. The representative Bus Driving Cycle for Debrecen is prepared to be applied in the vehicle dynamics simulation for evaluating and improving the fuel economy of vehicles, selecting the proper power source for various applications and the optimization of the powertrain and the energy consumption in researches to be continued.

Open access

Abstract

Increasing food demand poses a challenge for the economy and places a burden on the environment. In agricultural food production, each product chain stage shows scarce resources and negative environmental impacts are becoming increasingly significant. Food consumption has a significant impact on the environment and on human health. Sustainable food consumption is characterised by health and environmental consciousness. This study focuses on the relationship between perceived and real consciousness – more specifically on environmental and health consciousness – concerning food consumption. Following a concise overview of the conceptual background, the definitions of conscious consumption, conscious food consumption, health conscious consumer and environmentally conscious consumer behaviour are explained based on the available literature. The primary research draws conclusions from the results of a 500-person questionnaire survey among the students attending the University of Debrecen on the relationship between perceived and real health and environmental consciousness regarding food consumption. It was concluded that environmental consciousness (10.0%) was less characteristic of students than health consciousness (18.2%); the relationship between perceived and real consciousness is significant; the role of price in determining food purchases is less pronounced for those claiming to be self-conscious food consumers than those who are neither health conscious, nor environmentally conscious.

Open access

Abstract

The helical gear pair is widely used in different mechanical constructions such as vehicle industry and working machine industry. The main property of them is the skew tooth direction with which better tooth connections could be available than in case of straight tooth direction. The analysis of the effect of the addendum modification coefficient for the normal stress and the normal deformation is the aim of the research which could be determined by finite element analysis. Five helical gear types are designed and modelled. The difference among them is only the different addendum modification coefficients. All of the other initial parameters are constant. After the result we determine the conclusions based on the diagram's results which are received by the mechanical parameters and the addendum modification coefficients.

Open access

Abstract

In this project an ECG measurement and wave identification system was made. The measuring system hardware is based on a Texas Instruments ADS1298ECG amplifier and analog-to-digital converter board. The measurement and processing software was created in LabVIEW environment using the built-in functions of the Biomedical toolkit. Initially, the theory behind heartbeat and its effect on the skin surface potential are presented. Then the measurement techniques of these are described. The research group provide information on the mathematical background of how the ECG curve is processed and the waves are identified. The HRV analysis, the statistical analysis of identified R waves are described. Subsequently, publications dealing with electrocardiographic examinations in various fields will be presented. Then an overview of the specifications of the amplifiers used in this work and the capabilities of their original software are given. The final device structure is presented. The system validation process and the properties of the reference devices are illustrated.

Open access

Abstract

Nowadays, vehicles with alternative drives are playing an increasingly important role in road transport. Among the various types of alternative-drives, the most widespread ones are hybrid and electric ones, thanks for the rapid development of modern batteries, and hybrid and electrical systems. The above fact establishes the importance of research on various types of electric motors. The Faculty of Engineering of the University of Debrecen has more than a decade of experience in developing prototype race cars with pneumatic and electric drive. For the more effective and conscious development and racing a simulation program has been developed in MATLAB/Simulink environment for the computation of the dynamic functions of a vehicle moving in a linear path. The program is characterized by a modular structure, so the different structural units (vehicle body, front and rear wheels, power train, motor) are modelled and simulated separately. In this study we present models and simulation programs for different electric motor types (series-wound DC and brushless DC motors) in MATLAB/Simulink and apply them in our vehicle dynamics simulation program. From the simulation results the performance of a vehicle – driven by an electric motor – can be predicted in a race situation, consequently the most suitable motor with the optimal characteristics can be selected to it.

Open access

Abstract

This study intends to examine the soil behaviour in the case of finite thickness, represented by the hard layer under a soft layer of soil. A further aim is to define load-bearing capacity parameters (n and k). The experimental work is carried out under laboratory conditions by using hydraulic bevameter to apply the load. A circular plate with a diameter of 100 mm is used to push down the load over the targeted area with a penetration rate of about 9 cm/min for sinkage plates. The study was conducted in a soil bin (length of 200 cm, width of 100 cm and variable thickness) using a sandy loam soil. First, the study has been done with loose soil with a thickness of 11 cm, which maintained with 10% moisture content and initial density of 1.190 g/cm3. After that, a two thickness of 6 and 18 cm with 8% moisture content and initial soil density of 1.375 g/cm3 were tested to explain the effect of thickness. In each test, the bevameter plate was loaded at multiple locations, the result showed the soil was near uniform. The result suggests that it is not easy to obtain one equation for the load bearing capacity because the layer near to the surface behaves like soil with infinite thickness and the deeper layer like soil with finite thickness.

Open access

Shewanella putrefaciens supernatant was found to increase the virulence factors of Vibrio parahaemolyticus by efficiently degrading its acylhomoserine lactone (AHL). To further reveal the regulation mechanism and its key degrading enzyme, a potential AHL-degrading enzyme acylase (Aac) from S. putrefaciens was cloned, and the influences of temperature, pH, protein modifiers, and metals on Aac were tested. Aac was significantly influenced by temperature and pH, and exhibited the highest AHL-degrading activity at temperatures of 37 °C and pH of 8. Mg2+ and Fe2+ can further increase the AHL-degrading activity. 10 mM EDTA inhibited its activity possibly by chelating the co-factors (metals) required for Aac activity. Tryptophan and arginine were identified as key components for Aac activity that are critical to its AHL-degrading activity. This study provides useful information on Aac and for V. parahaemolyticus control.

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During the production of natural gas one of the major problems is the formation of hydrate crystals in the pipeline. The forming hydrate crystals can form hydrate plugs in the pipeline. The hydrate plugs lengthen production outages and result in financial losses for the producer, because the removal of the plugs is a time consuming procedure. One of the solutions used to prevent hydrate formation is the injection of modern compositions to the gas flow. The modern compositions help to dehydrate the gas, thus, the size of hydrate crystals does not increase. The substances, used in low concentrations, have to be locally injected, at the gas well sites. Inhibitor dosing depends on the amount of gas hydrate present. In the article a neural network based predictive detection solution is presented, which uses four factors.

Open access

The aim of this work was to evaluate the antioxidant and antibacterial activities of two marine algae, Cystoseira mediterranea and Padina pavonica, extracts. Total phenols (TPC), carotenoids, and phlorotannins contents of the extracts obtained by four extraction solvents were determined and compared. The highest TPC content was observed for aqueous extract of C. mediterranea with 37.09±0.46 mg GAE/g DE followed by ethanol extract of P. pavonica (24.28 ±0.99 mg GAE/g DE), which showed the highest phlorotannins content (1.18±0.18 mg PE/g DE), while its methanol extract held carotenoids content of 66.96 ±4.78 μg g–1 DE. Ethanol extract of C. mediterranea exhibited the best antioxidant activity with an EC50 of 58.3 ±1.16 μg ml . The antibacterial activity screening against MRSA and E. coli showed that ethanol extract of C. mediterranea towards a Methicillin resistant Staphyloccocus aureus (20.33±0.28 mm) and E. coli (15.66±0.57 mm) was more efficient with MICs about 80 mg ml–1 and 20 mg ml–1, respectively. Ethanol extract of C. mediterranea seems to have the highest potential for use in food industries.

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Pollack Periodica
Authors: Richard Honti, Ján Erdélyi, and Alojz Kopáčik

Nowadays huge datasets can be collected in a relatively short time. After capturing these data sets the next step is their processing. Automation of the processing steps can contribute to efficiency increase, to reduction of the time needed for processing, and to reduction of interactions of the user. The paper brings a short review of the most reliable methods for sphere segmentation. An innovative algorithm for automated detection of spheres and for estimating their parameters from 3D point clouds is introduced. The algorithm proposed was tested on complex point clouds. In the last part of the paper, the implementation of the algorithm proposed to a standalone application is described.

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