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Search Results: 1 - 10 of 229107 matches for " Samuel Rybár "
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Devínska Kobyla – a window into the Middle Miocene shallow-water marine environments of the Central Paratethys (Vienna Basin, Slovakia)
Matú? Hy?ny,Natália Hudá?ková,Radoslav Biskupi?,Samuel Rybár
Acta Geologica Slovaca , 2012,
Abstract: Middle Miocene strata exposed at Devínska Kobyla Hill (Malé Karpaty Mts) document the temporal and spatial changes in shallow-water environments of the northern Vienna Basin during the Late Badenian and Early Sarmatian. Middle Miocene deposits of the Studienka and Holí formations border this hill essentially along its full perimeter. The present overview of 16 localities based on published observations and new sampling shows that the Middle Miocene deposits contain species-rich micro- and macrofaunal assemblages as well as nannoflora. This contribution includes lists of all marine faunal (except tetrapods) and microfloral taxa known to date. The localities can be divided into three groups on the basis of their lithology and the abundance of molluscs and foraminifers in fossil assemblages: Devín area, Dúbravka area and Devínska Nová Ves area. On the basis of foraminifers the localities in the Dúbravka area (Dúbravská hlavica, Pektenová lavica, Stary lom, partly Fuchsov lom) can be assigned to the Early Sarmatian (based on benthic taxa), whereas the localities in the Devín ( ibeni ny vrch, títová, Terasy, Lomnická, Lingulová lavica, Glosusová lavica) and Devínska Nová Ves (Sandberg 1–2, Maly Sandberg, Waitov lom, Glavica, tokeravská vápenka-Bonanza) areas are predominantly of the Late Badenian age (based on benthic and planktonic taxa). However, molluscs imply that the deposits from the Dúbravka area are of Late Badenian age. The differences in the estimates of stratigraphic age between on molluscs and foraminifers can be explained with the persistence of typically Badenian mollusc taxa in the marginal parts of the Central Paratethys Sea during the Middle Miocene. For every studied locality palaeoenvironmental conditions based mostly on molluscs and foraminifers are inferred.
International science conference RESPECT report to support the renewable energy sources position in the context of specific
Pavol Rybár,Radim Rybár
Acta Montanistica Slovaca , 2008,
Abstract: Selected articles from the international scientific conference RESPECT 2008 are introduced. The main aspect in the selection processwas to cover the conference agenda, complexity of the global understanding of this area of research, and the achieved results. The choiceat the same time points on the technological, evaluative, environmental, economical and application aspects of the RES usage, withthe emphasis on conditions typical for the Central Europe.
Planning and management of surface mining in quarries by means of computer models
Rybár Pavol
Acta Montanistica Slovaca , 1996,
Abstract: Possibility of planr.ing and control o mining needs a suitable computer model of deposit to verify sirategic intants in surface mine as well as control of daily produciion. In the article are presented case studies and approaches of author how to model tne deposit and planning and scheduling Ihe productior.
The anticipated state of mining in the first half of 21th century
Rybár Pavol
Acta Montanistica Slovaca , 2002,
Abstract: The development and state of mining and availability of earth resources is also connected with the required state of the environment, human population, respecting the concept of the sustainable development, adopting new technologies and materials, globalization, the transfer of the capital in the form of investments, and with political and economic intentions of decision-taking countries and groups throughout the world.In the presented study I devote a minimum attention to the problem of energetic resources because such studies are numerous, easily available and well-known. Another reason is that the question of availability of fossil fuels is today especially a matter of politics. Therefore, the study is primarily directed toward the mining industry and availability of non-energetic resources.Basing on the development in the second half of the 20th century, we can expect that in the 21th the same mineral resources will be explored. Ceramic materials, glass, polymers, composite materials and laminates, which may decrease the demand for metals, will be certainly of a higher importance. The same metals however will be of use in new technologies and products. Commodities for which an increased demand can be expected with a high probability are: light, strong materials such as magnesium, titanium, carbon filaments and materials of petrochemical industry. The volume of production of plastics should overcome that of metals at the beginning of the 21th century. The development of plastics is oriented toward regulating their durability or biological tolerance because of the environmental protection. Zirconium, tantalum, rare-earth elements, pure quartz in high-tech applications elements of platinum group iron, aluminium, copper steel is expected to persist as a dominant metal in the 21th century concerning the produced amount. A high consumption of aluminium and its alloys could also be predicted. Copper will increasingly be consumed in technologies for utilization of alternative sources of energy. Concretes the development of second generation (nonporous and homogeneous) with mechanical propertie comparable to these of aluminium alloys is assumed.In the second half of the 20th century, important changes in the world mining occured. Most European mining companies producing coal and metals dramatically restricted their activities. The reason were political and social changes in the Europe leading to the increase of expenses for the man work and protection of nature. The new environmental legislation complicated opening of new mines. The next important fa
The earth`s resources, its utilisation and protection
Rybár Pavol
Acta Montanistica Slovaca , 1996,
Abstract: The article is published to present needs for accessible information on utilisation and protection of Earth resources, which are defined in this article as sources present in the lithosphere, hydrosphere and atmosphere, economicaly extracted by previous technologies, and associated with a consumer culture. The article is focused on production and consumption of some selected sources as well as on world s environmental degradation.
Geothermal energy sources and possibilities of their exploitation
Pavol Rybár
Acta Montanistica Slovaca , 2007,
Abstract: The geothermal energy is everywhere beneath the surface of the earth. The earth’s interior is enormous thermal reservoir of energy, which can be utilized if favorable geological conditions exist.The electricity generation in 1942 at Larderello was a commercial success. The installed geothermoelectric capacity had reached 127 650 kWe. Several countries were soon to follow the example set by Italy. In 1919, first geothermal wells were drilled at Beppu in Japan, followed in 1921 by wells drilled at The Geysers, California, USA. In 1958 a small geothermal power plant began operating in New Zealand; in 1959 another one in Mexico, in 1960 in the USA, followed by many other countries in the years to come.The heat source can be either a very high temperature (> 600 °C) magmatic intrusion reaching relatively shallow depths (5-10 km) or, as in certain low-temperature systems at the Earth's normal temperature, which increases with depth. The reservoir is a volume of hot permeable rocks from which circulating fluids extract the heat. The reservoir is generally overlain by a cover of impermeable rocks and connected to a superficial recharge area through which the meteoric waters can replace or partly replace the fluids that escape from the reservoir through springs or are extracted by boreholes. The geothermal fluid is water, in majority of cases the meteoric water, in the liquid or vapour phase, depending on its temperature and pressure. This water often carries chemicals and gases such as CO2, H2S, etc.Another source of underground heat is so called the hot dry rock. The mater is to extract heat by creating a subsurface fracture system to which water can be added through injection wells. A creation of enhanced, or engineered, geothermal system requires improving the natural permeability of rock. Rocks are permeable due to minute fractures and pore spaces between mineral grains. The injected water is heated by a contact with the rock and returns to the surface through production wells, as in naturally occurring hydrothermal systems. The system improves the economics of resources without adequate water and/or permeability.In article are presented the recent circumstances from the point of view of knowledge and used technologies of extraction of geothermal energy.
Utilization of photovoltaic panels in urban build-up areas grid on
Tau? Peter,Rybár Radim
Acta Montanistica Slovaca , 2001,
Abstract: Photovoltaic systems belong to the most perspective alternative sources of energy. We expect that during a relatively short period of time, the photovoltaic systems will slowly cover 5 to 10 % of the whole consumption of the electricity. One of the conditions of integration to European Community is the rising of the part of alternative sources in the production of energy. Besides another technologies, it s also possible to reach it with an installation of the photovoltaic systems in already-existed building-up area. The photovoltaic systems Grid on are used especially in places with the advanced net of electric lines in big cities. The invertors developed especially for the photovoltaic systems "Grid on" have the effeciency higher than 90 % and they are absolute safe against the bias voltage.From the entire number of days of an year in Slovakia the sun shines from 1300 to 2200 hours, in Ko ice it s 2100 hours. An average amount of energy falling down by one day is 3,3 kW.h.m-2. An average effective power of one m2 of the photovoltaic panels is 110 W.m-2 of the standard illuminance 1000 W.m-2 and the solar spectrum AM 1,5. Annually it s possible to make from the photovoltaic panel (1 m2) 120,45 kW.h. Average amount of the solar energy shape to the south-orient area in Ko ice is 101,5 kW.h.m-2. In Ko ice is an ideal inclination of the absorption area of the photovoltaic panels from horizontal plains from 58° to 65° for the year-around operation. At optimal conditions it s possible by integrating photovoltaic panels with the construction of the balcony barrier from one block of flats about 10 MW.h per year. If we utilise the all areas applicable for the installation of photovoltaic panels (building exteriors, roofs, shady component,..), we able to cast about a few multiple of these value just for one block of flat.Today, the cost of the photovoltaic systems is many times higher than the cost of the electric energy. But the cost consequently a new technology of production of the primary materials is allways falling.
Technical analysis of utilization suitability of various wind rotor s types for compressor s power driving
Du?an Kudelas,Radim Rybár
Acta Montanistica Slovaca , 2005,
Abstract: Conception is from the converting of wind energy, which flows across the wind turbine in mechanic work needed for compressor working. The wind motor one part of energy transform into mechanical work, part of energy is unused and part of energy of stead flow is transformed into eddy after wind rotor.The aim was rendering of technical analysis for equipment, which would use the wind with parameters for chosen area and whole unit would supply power in peak demand. Unit consists of wind turbine, which pushes compressor. Compressor pumps air into the compressed air storage. The air is used for power producing in time of peak demand.
Research and development as contribution of the Renewable Energy Sources Centre to the wind energy utilization in Slovakia
Du?an Kudelas,Radim Rybár
Acta Montanistica Slovaca , 2007,
Abstract: The expected development of renewable energy sources utilization was not reached in last years in Slovakia. This is caused by some barriers. These barriers decrease the easiness of investments into the Renewable energy sources utilization. We recognize specific barriers for each of renewable energy sources and general barriers for all renewable energy sources. Activities of the Renewable Energy Sources Centre help to eliminate both specific and general barriers in Slovakia. The main activities are: a realization of research projects, working out expertises and feasibility studies, information of public about principals and specifics of the wind energy utilization. How the Renewable Energy Sources Centre encourages of the utilization wind energy can be demonstrated on one of the research projects: The designing a stable standpoint with a sufficient storage tank of wind energy, possibly of compressed air. The wind energy serves as a primary resource when it powers the compressor, which fills the pneumatic accumulator (storage tank of compressed air). The compressed air is at a time of peak endurance consumed from pneumatic accumulators for the work of pneumatic engine, which powers the generator and the produced electric energy is being supplied to the public network.
Changes in the German law system, the role of banks and the effects on the contribution of renewable energy sources after the governmental changes in 1998 and 2005
Daniel Gerner,Pavol Rybár
Acta Montanistica Slovaca , 2008,
Abstract: Effected by the party Bündnis 90 die Grünen, ruling together with the SPD for the first time as the Red-Green-coalition Germany from 1998 to 2005 and by the global efforts fighting climate change, renewable energy sources got more and more important during the last years. For Minister Sigmund Gabriel, sustainable usage and supply of energy belongs to the most important challenges of the 21st century.[1] During the last eight years, government undertook many efforts to improve the use of renewable energy sources. There are many studies about amendments and the effect of state promotion. The aim of this evaluation is to show in which years remarkable changes in the allocation of renewable energy sources took place. In a further step reasons therefore will be given.
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