Simulation of acacia gasification process

This electronic document presents the thermokinetical modelling of the gasification process done on acacia-tree with variable operating conditions and different humidity levels. Gasification does not produce flue gas, but due to imperfect burning, synthesis gas appears which is rich in flammable components (CO2 and H2). The chemical structure of this gas depends on the components of the fuel and the humidity level, but greatly affected by the technological parameters too, such as pressure and temperature, as well as the air-ratio. The study shows the change in the amount of the fuel and the reaction efficiency, caused by varying gasification temperature and pressure. Rising temperature results in improved efficiency, while higher pressure worsens reaction efficiency. However, at higher temperature intervals, the effect of the pressure is neglectable

The study of natural kinds in the Academy

"Most often in the literature we would find comparisons and contrasts between Plato and Aristotle, stressing how much Aristotle differs from, or how much owes to Plato. The contemporary cultural and philosophical matrix, however, was much-much richer.

Arisztotelészi és peripatetikus természetfilozófia: Az égi természet problémaköre = Aristotelian and Peripatetic natural philosophy: The problem of celestial nature

A projektum a peripatetikus és az arisztoteliánus természetmagyarázat kulcsfontosságú elemeinek kontinuitásával, és a tradíción belül megfogalmazott újabb égboltelméleti álláspontok vizsgálatával foglalkozott. Ennek keretében módunk nyílt Arisztotelész Égbolt c. művének sajtó alá rendezésére; a változás arisztotelészi elméletének részletesebb vizsgálatára; Arisztotelész azon szöveghelyeinek értékelésére, ahol saját bolygómegfigyeléseiről számol be; az égboltról szóló számadáson belül érvényesülő oksági megfontolások vizsgálatára; az égboltelmélet különböző peripatetikus változatainak összevetésére, külön kiemelve ezek közül Theophrasztosz és Alexandrosz égboltelméletét, valamint Szimplikiosz Fizikakommentárjából az égalatti elemek mozgásával foglalkozó szakasz fordítására és kommentálására. | Our project studied the continuity of some key elements in Aristotelian and Peripatetic theory of nature, and within this, the different theories of the heavens put forward in this tradition. In the course of this we prepared the Hungarian edition of Aristotle’s De caelo for publication; discussed in more detail Aristotle’s theory of alteration; we examined the import of those passages Aristotle where he reports about his own planetary observations; we discussed the causal explanatory factors in Aristotle’s account about the heavens; we compared the different versions of Peripatetic celestial theory, with special emphasis on Theophrastus and Alexander; and we translated and commented on the passage of Simplicius’ Commentary on Aristotle’s Physics which discusses the motion of sublunary elements

Effects of photovoltaic systems on the behavior of harmonic components in low voltage network

Renewable energy sources, especially solar systems, have become increasingly important energy sources in recent times. Connecting large PV systems to utility networks can cause a number of operational problems for distribution networks. The extent of these problems depends directly on the percentage of PV penetration and the geographical location of the installation. Possible problems caused by PV systems: over-voltage, output power fluctuation, harmonic distortion, frequency fluctuation Harmonic distortion is a serious energy quality problem which can occur in photovoltaic systems due to the use of power inverters that convert direct current to alternating current. The resulting harmonics can cause parallel and series resonances, transformer overheating, and protection device malfunctions, which can reduce the reliability of power supply systems

Simulation of fault detection in photovoltaic arrays

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

Simulation of acacia gasification process

This electronic document presents the thermokinetical modelling of the gasification process done on acacia-tree with variable operating conditions and different humidity levels. Gasification does not produce flue gas, but due to imperfect burning, synthesis gas appears which is rich in flammable components (CO2 and H2). The chemical structure of this gas depends on the components of the fuel and the humidity level, but greatly affected by the technological parameters too, such as pressure and temperature, as well as the air-ratio. The study shows the change in the amount of the fuel and the reaction efficiency, caused by varying gasification temperature and pressure. Rising temperature results in improved efficiency, while higher pressure worsens reaction efficiency. However, at higher temperature intervals, the effect of the pressure is neglectable

Városi tömegközlekedési járművek energiafogyasztása

This paper presents the energy consumption of urban public transport vehicles. During my research work, I investigated the relative energy consumption of diesel and CNG fueled buses equipped with internal combustion engines, as well as electric buses. In addition to energy consumption, I also calculated fuel costs.A tanulmány a városi tömegközlekedési járművek energiafogyasztását mutatja be. Kutatómunkám során azt vizsgáltam, hogy az egyes belső égésű motorral szerelt diesel és CNG üzemanyagú, valamint az elektromos meghajtású autóbuszok egymáshoz viszonyítva mekkora energiafelhasználással rendelkeznek. Az energiafogyasztás mellett számoltam az üzemanyag-költségekkel is