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Analecta technica SzegedinensiaVol. 9. No. 2. (2015.)

Tartalom

  • B. Zsótér ,
    N. Domonics :

    In this present study we are publishing a part of the results of a survey made in the spring of 2015 which we accomplished among the population living in the inner area of a small town called Mezőhegyes. It was a questionnaire survey connected to a field trip. We chose systematic sampling in making our questionnaire. The objects of the examinations were whether the people living there are conscious in choosing the energy rating of their electrical household appliances and how their energy consumption changed in the last 10 years. What is the most important point when purchasing a new electrical item: the price, the energy rating, the brand, the design or the others’ opinion? Which are the most common household appliances? Do they use alternative energy resources?

  • A. Oprea-Kiss ,
    I. Kiss :

    Today one of the goals of the automobile industry is to reduce weight. And physical foaming has already demonstrated its potential in this sector, improving the value and performance of applications under the bonnet: engine and gearbox cases, inlet air filters, cockpits, radiator baffles and so on. Around the world, the microcellular injection molding (MuCell) is used in thousands of applications in the automotive, packaging, technical molding, office machinery and electric and electronic component industries. The research opportunities purpose is to obtain even lighter pieces, with greater dimensional stability and with an excellent surface finish, in other words, perfect plastic parts. More component functionality with reduced weight, and cost control at the same time: MuCell is a process to physically foam thermoplastics, which combines technical and economic objectives. Besides weight reduction, it also provides improved dimensional stability of the moulded parts.

  • J. Sárosi ,
    L. György :

    Many researchers have investigated different properties and behaviour of pneumatic muscles actuators (PMAs). Most of them have dealt with the force-contraction (force-relative displacement) characteristics or control of PMAs. In this paper two different type PMAs are compared: Fluidic Muscle made by Festo Company and Shadow Air Muscle made by Shadow Robot Company. The most relevant difference between them can be noticed in their structure. The Fluidic Muscle is an embedded muscle which means the load carrying element is embedded in its membrane, while Shadow Air Muscle is a netted muscle, but in its non-loaded condition there is a gap between the membrane and the load carrying element. Among other things, force developed by pneumatic muscle actuators depends on applied pressure, contraction, geometry and the used materials. As it is described in this paper, they show significantly different force-contraction characteristics despite having similar dimensional properties. These characteristics are determined by experimental measurement.

  • J. Gál ,
    O. Demény :

    I am writing about procurement of the restaurants in relation to the defects of quality. A lot of quality problems are resulted by negligence, so firms, restaurants can easily become bankrupt. Some reasons for quality defects should be avertable if workers of the given restaurant utilized the old stocks when cooking or in other ways. In addition, I will mention how to solve problems of quality defects. Naturally, restaurants can have other procurement problems, too, for example they need cooking equipment, dishes, utensils etc., but the goods can get spoiled if they are unutilized. The firm will not get back the expenses. They should make an effort to reduce costs. In some cases because of the substandard, they should destroy as refuse by other firms (the restaurants need contract with them). The only targets are to be competitive at a variety of market and to meet the customer’s requirements.

  • D. Cornea ,
    C. Bulei ,
    M. Todor ,
    I. Kiss :

    These days, people have been talking a lot about renewable energy. The world is growing too dependent on non-renewable energy, such as fossil fuel, natural gas, oil and coal. There needs to be another idea to be green and environmentally friendly. And with the use of renewable energy source, the world can be a better place. These renewable energy sources can be used for hundreds of years without hurting the environment. There has been much research going on in science labs and farms across the country, so these sources are always evolving into better and better things. The sources are almost limitless, but there are some common ones. The most widely used heating installations in current technologies are based on burning fossil fuel but we should take in consideration that health policies nowadays are directed towards lowering the use of this kind of fuel. This paper presents the processes of designing and development of a heating system that uses entirely solar energy. The heating system consists of two parts. The first part consists of a photovoltaic solar panel made from 36 photovoltaic cells capable of developing 65 W and 3.6 A. The second part is made of recycled materials (aluminum cans), forming radiant tubes.

  • K. Keçeci ,
    B. Lemmer ,
    Sz. Kertész ,
    G. Keszthelyi-Szabó ,
    Zs. László ,
    C. Hodúr :
    The effect of the implementation of ultrasound in enzyme separation34-41en [929.40 kB - PDF]EPA-02592-00005-0060

    Enzymes are biological catalysts that generally are designed to do one job well, but to do one job only. Therefore, the enzymes that catalyze the hydrolysis of cellulose to sugar do not break down the sugars. Enzymatic hydrolysis processes have been under development for only 10 years. The important research issues include understanding the processes necessary to render the crystalline cellulose easily digestible, understanding and improving the basic mechanisms in the hydrolysis step, and developing better and less expensive enzymes. The other way to make a process less expensive may be the recycling of enzymes. The essential unit operation in the bioethanol production is the cellulose enzymatic degradation, so the question of recycling is very important. In our work the sonication assisted ultrafiltration was investigated as a potential method for enzyme recycling. The results showed the ultrasound effects the permeate flux since the resistance is reduced by the sonication. The sonicated enzyme keeps its activity so the recycling mechanism might be used for bioethanol production.

  • T. Molnár :

    The purpose of my research is to examine the quantity and methane content of landfill gas originating from the characteristic organic matter potential, weather parameters and exploitation technology used in the region and by that, determine useful relationships. Results are defined in working dimensions where the quality and quantity of landfill gas is defined by the efficiency of the extraction system, environmental conditions, the composition of waste and the technology of unloading. The theoretical and practical phenomenon confirms that processing the generated waste by modern European Union-compliant technology systems can be used as alternative energy instead of fossil energy sources to produce electricity and heat. The quality and quantity of biogas presumably depends on the weather parameters of the refuse dump, the technical parameters of the biogas recovery system and the organic matter content, typical of the Hodmezovasarhely region.