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Designing of Lab-scale Anaerobic Digester Equipped with Maxblend Impeller to Evaluate Effect of Mixing on Anaerobic Digestion
404-413Views:313Operational parameters can be easily controlled at lab scale experiments for an anaerobic digestion process. Our aim is to design a lab-scale digester equipped with an impeller to investigate how the geometry of impeller and different mixing modes effect the biogas yield of digester. Further, the methods of measuring the gas volume, gas composition, mixing intensity, torque, temperature are discussed in this article. The assembling of 4 liters digester is described which can be operated at various operating parameters which control the anaerobic digestion process. Mixing is very important to enhance efficiency of an anaerobic digester. To attain mixing Maxblend impeller is used in this lab-scale digester due to its better performance for mixing and power consumption. Various design consideration has been described.
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Longitudinal Dynamic Simulation Possibilities of Vehicles Using AVL Cruise M
743-748Views:468For creating vehicle dynamic simulations, in most cases, an appropriate software is required to help the dynamic model design. For this purpose several kinds of software are available in the market with different properties and user interfaces. In this article a leading simulation software of the market, AVL Cruise M, is shortly presented.
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Overview of the Appearance of Management Information Systems In Hungarian Higher Education through the Example of the University of Debrecen
60-68Views:274In recent years, the ever-decreasing number of students in Hungarian higher education has created a serious competition between institutions, in which not only national but also foreign universities prove to be competitive. In order for national institutions to be able to compete adequately in this competition, managers need to be provided with well-structured, up-to-date information that can support decision-making. The management information system, which successfully adapted at the University of Debrecen, has been in operation for years and provides significant support in data reporting and ad hoc reporting, but there are still many opportunities for advancement. The study draws attention to the importance of management information systems through the example of the University of Debrecen.
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Survey of the Application Fields and Modeling Methods of Automotive Vehicle Dynamics Models
196-209Views:473In this paper, a review is presented on automotive vehicle dynamics modeling. Applied vehicle dynamics models from various application fields are analyzed and classified in the first section. Vehicle dynamics models may be simplified because of different reasons: several control/estimation/analysis methods are suitable only for simplified models (e.g. using control-oriented models), or because of the computational cost. Detailed/truth models of vehicle dynamics represent another field of vehicle dynamics modeling, these models play an important role in the virtual prototyping of vehicles. In the second section, the main modeling considerations of vehicle dynamics are presented in longitudinal, lateral and vertical directions. Various physical effects must be considered in the case of vehicle dynamics modeling, a lot of these effects are significant only in a specific direction of the vehicle body, which is the main potential of model simplification. The section presents vehicle modeling considerations in all of the three translational directions of the vehicle body.
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The Effect of MMS Lubrication on Surface Roughness During Machining
452-457Views:205I display this paper the chipping front metal of cutting allocated geometric, considering particular the friction. I catch the attention energy's balance sheet someday metal of cutting, open one new direction the manufacture technology. I display this new direction's metal of cutting condition. but built I delineate his paper final division this new policy searching programme, consumed trial instruments as well as the evaluation's mode.
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Synthesis of Polylactic Acid (PLA) by Polycondensation Method
286-293Views:547The Polylactic acid (PLA) is compostable and natural renewable sourced plastic type. Its mechanical properties quite similar to the PET, therefore the PLA is a good alternative for strongly ruled food industrial application. The PLA only has one critical attribute – the relatively low glass transition temperature. According to the relevant literature the glass transition of PLA is in the range of 40-70°C. In light of this fact, this material can be used only in that segments of food industrial field where the packaging process temperature are under of the lower limit of Tg range. The actual Tg of a material is highly depends on the molar mass and material structure, therefore the molar mass and the structure of material should be designed according to the future requirements of application and procedures.
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Optimization and Analysis of Structure about Lifting Device of Logistics Sorting
425-431Views:285The lifting device of a logistics sorting machine needs high frequency upward and downward reciprocating motion therefore the cutting fork arms and matching parts of the shaft are often worn out. In this paper the problem of the shear fork types applied for the lifting mechanism is studied at first. Then the advanced numerical simulation software ANSYS adopted for the lifting mechanism of the shear fork type, and the means of virtual simulation is introduced. Hence the possible location of faults and fault modes are analysed. Then improving measures about the lifting mechanism of the logistics sorting machine are suggested.
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Combustors with Low Emission Levels for Aero Gas Turbine Engines
503-514Views:708The aircrafts are responsible for emitting several types of pollutants, especially the pollutants in the form of NOX, CO2, CO, UHC, SOX and Particulate Matter PM (smoke/soot). The impact of aviation emissions on the global is well known, where these emissions modify the chemical and microphysical properties of the atmosphere resulting in changes of earth’s climate system, which can ultimate in critical changes in our planet fragile ecosystem, also the pollutants produced by aircraft engines cause many health problems. This is why the International Civil Aviation Organisation (ICAO) is seriously seeking to control the emission levels by issuing new standards during the successive meetings of the Committee on Aviation Environmental Protection CAEP (CAEP/01 in 1986, CAEP/2, CAEP/4, CAEP/6, CAEP/8, etc). The new regulations include more stringent standards aimed to reduce emission levels, this led to increased interest in low emission technologies. In this paper, a comprehensive review of low emissions combustion technologies for modern aero gas turbines is represented. The current low emission technologies include the high Technologies Readiness Level (TRL) including RQL, TAPS, DAC and LDI. Also, there are advanced technologies at lower TRL including LPP, ASC and VGC.
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Exhaust System Muffler Volume Optimization of Light Commercial passenger Car Using Transfer Matrix Method
132-138Views:328Nowadays, the automotive industry is focused on weight and size reduction. Main advantage of this weight and size reduction are improving the fuel economy. The specific fuel consumption of a vehicle can be improved through e.g. downsizing area of heat loss, if we focus on vehicle with weight reduction. Weight reduction can be done by replacing material or by changing the size (dimensions) of components. In the present work we have focused on Audi A6 muffler, troubleshooting and optimizing the muffler by changing pipe length of inlet and outlet, also by replacing the original mesh plate to porous pipe. Based on optimization, prototype has been built with the help of 3D design tool CATIA V5 and the calculations of transmission loss (TL) have been performed by MATLAB. Plane wave-based models such as the transfer matrix method (TMM) can offer fast initial prototype solutions for muffler designers. The principles of TMM for predicting the transmission loss of a muffler was used. Result of this present study of an existing muffler has been analysed and then compared with vehicle level test observation data. Noise level have been optimized for new muffler design. Other literatures were played significant rule for validate our results.
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Analysing the Possible Connection Between Dark Triad Personality Traits and Ethical Attitudes of University Students
57-67Views:493In our paper we examined the possible connection between the Dark Triad personality traits and ethical attitudes among university students. The analysis of both topics has become the focus of interest in the past decades. Researchers consider the impact of many factors in the background of ethical attitudes and behavior. Among other things, personality is also a potential factor. The Dark Triad personality means the coexistence of the socially undesirable narcissism, Machiavellianism and psychopathy. Such people are characterized by self-love, aggression, the lack of guilt or conscience, so they are less likely to have ethical attitudes. In our research, this connection was examined by a questionnaire survey conducted among first year students of University of Debrecen Faculty of Natural Sciences and Technology and Faculty of Economics and Business. Respondents completed the validated Dirty Dozen questionnaire which was developed to measure Dark Triad personality and a questionnaire adapted from Lozier's research in which respondents were asked to evaluate school situations whether they are ethical or unethical and to what extent they are unethical. In our research, we were looking for significant relationships between the strength of the Dark Triad characteristics and the ethical judgment of situations. We also analyzed the differences between men and women and students of the two faculties.
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Analysis of Differences Between Levelling Networks in the County of Hajdú-Bihar
84-92Views:269The height determination of control and detail points is essential during the process of planning and manufacturing in the practice of civil engineering. Planning maps are drawn for the former, while the intended plan is set out on the ground during manufacturing, and after the manufacturing the completed installation is mapped. Using the same reference system in all three steps, both horizontally and vertically, is recommended even though in some cases it is unavoidable to change from one reference level to another. Regardless of the fact that both refer to the mean sea level of the Baltic Sea, this can create difficulties, since the difference between the EOMA and Bendefy networks used in Hungary shows varying values depending on the geographical location. The aim of the analysis is to determine a constant difference regarding the analysed settlements based on the common points of the networks.
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Safety Index Based on Geometric Probability Is Proposed to Represent the Uncertainty of Soil Parameters for Spread Foundations
43-52Views:314The overall factor of safety in geotechnics can be defined as the product of four partial factors of safety. One of these partial factors represents the uncertainty of the soil parameters. Based on geometric probability, a safety index is proposed to calculate the uncertainty of the soil parameters for spread foundations. Numerical examples have also been presented.
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Simulation of Hot Rolling by Cellular Automata
190-195Views:344Our research is focusing to one of the most complex and important production step of flat rolled products that is the simulation of hot rolling. During hot rolling two phenomena as work hardening and the process of regeneration of crystals has strong influence for physical properties of microstructure of aluminium alloys. It needs to be taken into account in case of rolling technology steps and development. When we talk about aluminium the dynamic softening in fact it is dynamic recovery that is followed by dynamic recrystallization. It goes in the same order of magnitude rate. But in steels the recovery has only a minor effect. Hot rolled and newly modified grain structure is influenced by these dynamic phenomena. Hot rolled grain structure goes through significant changes under further production steps like cold rolling and heat treatments. But aside from these intermediate production steps the microstructure that we get after hot rolling has significant effect for mechanical and grains structure of the final flat rolled product. Proper technology planning is essential that for cellular automata simulation method can ensure useable and good solution for the simulation of recrystallization.
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Investigation of Aluminum Dross as a Potential Asphalt Filler
445-451Views:286There is a great concern about utilizing different waste materials all over the world. Stockpiling in landfills is not a final solution, therefore researchers try to find alternative methods to utilize these materials [1-5]. One potential area may be road construction. Fillers are one of the most important components of asphalt pavements. It has a dual role. First of all, these fine grained mineral materials (d<0.063 mm) enhance the cohesion with bitumen. Second is to fill the gaps between the particles to produce more compact mixture [6]. The aim of this research is to reveal the possibility of utilization of aluminum dross as a potential asphalt filler. This material, which is a by-product of aluminum casting process, is produced in large quantities year by year and its storage in landfills is not a proper solution. Therefore, there is an increasing demand to utilize this material. During the research material structural tests were made, which can characterize the samples (limestone powder, dross), and the cohesion between bitumen and filler can also reveal. Particle size distribution, BET specific surface area and porosity were investigated. Scanning electron micrographs were taken and oil adsorption test were also made.
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Numerical Model Analysis of Natural Gas Combustion Burners
67-71Views:332Traditional power plants still the dominating power source for all the major industries and powerdemanding facilities, the most crucial facility for the whole plant operations is the industrial boiler which generatessteam, heating energy or electrical power. Boilers generate energy by combustion. The improvement of combustion efficiency could greatly influence the energy consumption and will make the boiler more efficient and cleaner (less emissions), that’s why it is important to understand the combustion and thermal flow behaviours inside the boiler. Beside experimental testing, computational work nowadays becoming more and more important due to lower cost and acceptable accuracy with minimum error. With numerical calculations method, the computational model created by a Computational Fluid Dynamics (CFD) software could reduce a lot of trial and error on experimental work. In this paper utilizing the ANSYS FLUENT 19.1 software to make crate the combustion model. The ratio of air to fuel mixture, the equivalency factor, mass flow rate of the mixture, velocity, mass fractions of the mixture components (fuel and air) and their temperatures will serve as the input parameter while the exhaust gase component mass fraction, temperature, mass flow and velocity will be monitored.
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Transaction Costs: A Conceptual Framework
131-139Views:1221Transaction Costs (TC) is a very important topic, especially in a changing work environment which has a large number of operational firms, and increasing business growth. The aim of this paper is to shed light on the transaction costs concept, and provide a conceptual framework to understand the meaning of transaction costs. Publications including articles and research papers have explained the notion of transaction costs and the theoretical issues related to them. The literature review reveals that, transaction costs are costs which arise because of the of a company‘s activities in the market , including (fees, commission, taxes) which are paid by the firm to provide a service or produce a good either to external parties or as internal costs. Therefore, according to the literature review. It emerges that firms must make a comparison between internal and external transaction costs and choose the lowest cost which enables them to increase profits. This means companies have to reduce transaction costs to the minimum level to achieve more profits and competitive advantage.
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The Expectations and Motivation Regarding Future Income and graduation of the Students of the University of Debrecen, Faculty of Engineering
1-11Views:241My research conducted among undergraduate students of the Faculty of Engineering of the University of Debrecen examined the students’ incentive and income expectation broken down by their gender and by their ducation level. At the same time, it aimed to measure the impact factors influencing their motivation to get the degree and their ideas regarding the payment.
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Manufacturing Process Optimization and Tool Condition Monitoring in Mechanical Engineering
72-89Views:472The optimization of manufacturing and production processes with various computer software is essential these days. Solutions on the market allow us to optimize and improve our manufacturing and production processes; one of the most popular software is called Tecnomatrix, which is described in this paper. Tool condition monitoring is a vital part of the manufacturing process in the industry. It requires continuous measurement of the wear of the cutting tool edges to improve the surface quality of the work piece and maintain productivity. Multiple methods are available for the determination of the actual condition of the cutting tool. Vibration diagnostics and acoustic methods are included in this paper. These methods are simple, it requires only high sensitive sensors, microphones, and data acquisition unit to gather the vibration signal and make signal improvement. Extended Taylor equation is applied for tool edge wear ratio. Labview and Matlab software are applied for the measurement and the digital signal processing. Machine learning method with artificial neural network is for the detection and prediction of the edge wear to estimate the remaining useful lifetime (RUL) of the tool.
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Examining the Social Involvement of Sports Civic Organizations
23-34Views:330Analyzing the information available in the Hungarian database of the CSO, we can see that a significant part of the income of classical non-governmental organizations, especially non-governmental organizations with a sports profile, comes mainly from state or private support. In addition, it can be said that these organizations are essentially non-profit-oriented and play a significant role in social integration and the performance of essential social tasks. Therefore, the relevant question is to what extent and in what way their social embeddedness is realized, in what way do NGOs influence people in the course of their operation? Within this, the study of the social usefulness of sports non-governmental organizations and the sphere of support conditions in the sphere emerges as a priority area. In our study, we undertake to examine the activity of the organizations included in the survey, their social impact and to compare the results with their role in local society. Nearly 50% of the NGOs surveyed in the study have a local scope, and more than 50% typically engage in grassroots and leisure-related activities.
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Influence of MTP on Surface Roughness and Geometric Accuracy of Machined Surface at WEDM
91-97Views:280Electrical discharge machining technology is one of the most precise machining methods. Therefore, even the smallest deviation of micro and macro geometry generally has a significant impact on the overall quality of products produced by this progressive technology. The quality of the machined surface after Wire Electrical Discharge Machining (WEDM) is influenced by a large number of factors, most of which are influenced by the Main Technological Parameters (MTP). The aim of the paper was to describe the results of experimental research aimed at assessing the impact of MTP for WEDM on the quality of machined surface in terms of geometric accuracy and roughness parameters Ra and Rz. The samples were made of high alloyed ledeburitic chromium-molybdenum-vanadium steel designated EN X155CrVMo12-1 on a Sodick AQ535 electroerosion machine. The tool used was a standard compact brass wire 0.25 mm with the designation Elecut Brass CuZn37.
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Micromechanical Model of Dry Friction Hybrid Polymer Composite Clutch Facings
335-340Views:243Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a complex material are described in this paper along with simplification ideas and solutions.
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Learning Curve Based Sigma Level Determination in Interrupted Non-Production Processes
260-270Views:242The philosophy and methods of six sigma process development have been applied successfully since mid1980s, and the application of the six sigma concept in non-production processes has increased significantly in the last decade. In this paper processes that can be characterized by learning curves are modeled. The quality of such processes can be analyzed on the basis of the six sigma concept. In this paper two back office processes are analyzed. The processes are built up of simple repeated steps and incorporate some interruptions. The application of the model allows the calculation of the maximally permitted number of interruptions in the process if the preliminary determined norm is to be kept.
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Concept Images of Primary School Students and University Students About Function
114-122Views:427The concept of function is fundamental importance to the mathematics. Since the most mathematical concept is not acquired in one step [13], thus we have to take a long journey for developing of the function concept. One of the aim of this process to develop an effective concept image which have an important role in problem solution. The students decides on the basis of a concept image whether a given mathematical object is an example or nonexample of the concept. (Vinner & Dreyfus, 1989). In this paper we are looking for the answer of the following question: what are the concept image of the function concept formed of the students by the end of the primary school (8th grade) and the first year engineering university students?
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Component Development Using Topological Methods
54-62Views:249The article aims to briefly summarize the design aids which can be used nowadays, such as topology optimization and generative design, which are common in integrated CAD systems. A case study is used to present the results and comparisons provided by the previously mentioned methods.
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Presentation of Employment and Economic effects of the Covid-19 Epidemic between March and November 2020 among Companies Dealing with Car and Parts Trade in Szabolcs-Szatmár-Bereg County
80-92Views:660The outbreak of the COVID-19 pandemic during the spring of 2020 entailed major economic and social changes all over the world. In this study, we aim to investigate the impacts of the COVID-19 pandemic on the labor market and the economy with relation to the automotive industry in Szabolcs-Szatmár-Bereg County. Apart from secondary data collection, this research also relies on primary data collection methods, including self-administered questionnaires and in-depth interviews, all conducted with several employees and finance directors employed by the automotive companies present in the county. The focus of this research is to study how the pandemic affected the balance sheets and the gross revenue of these companies; how it altered the repayment obligation of their current loans and how it influenced their willingness to enter into new loan agreements or relief options offering financial assistance. Apart from these factors, this research also studies how the pandemic restrictions affected the work schedule and the benefits of the employees.
