Wyniki wyszukiwania - BazTech

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Nowy rynek dla geodetów

Piechota A., Majer E., Ortyl Ł.

Geodeta : magazyn geoinformacyjny

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2018

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nr 12

16--19

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Lotniczy skaning laserowy (LiDAR-ALS) jako źródło danych do obliczeń stateczności skarp na terenach zadrzewionych i zakrzewionych

Piechota A.

Przegląd Geologiczny

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2017

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Vol. 65, nr 10/2

811--816

EN

The paper discusses the problem of quick acquire height data for calculation of escarpment stability. In past the slope of profile was obtainedfrom classical land survey methods (like Total Station, GNSS, etc.), carto- metric measurement on maps or measurements based on a Digital Terrain Modelfrom aerial photography. Now we have a new method that is Airborne Laser Scanning (LiDAR-ALS). In 2011-2014 almost all country was measured in this method. The declared accuracy of height measurement on the durable surfaces is about 0.10-0.15 m. Author compared this method with classical method Global Navigation Satellite System - Real Time Network (GNSS-RTN) on two wooded and bushy areas. The comparison was based on the measurement characteristic points on the profiles and acquisition of height data from LiDAR-ALS data. Data in this method were obtained in two ways: from point cloud and from DTM createdfrom this point cloud. In the next step, height differences were calculated and these data were subjected to basic statistical calculations. The result of the study was a mean error of height data from LiDAR-ALS and conclusions about its usefulness in acquire height data for calculation of escarpment stability.

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Analiza możliwości zastosowania metody tomografii elektrooporowej (ERT) do rozpoznania miąższości pokrywy laterytowej

Pacanowski G., Czarniak P., Piechota A., Mieszkowski R.

Przegląd Geologiczny

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2016

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Vol. 64, nr 4

245--253

EN

The paper discusses the problem of determining the thickness of a laterite cover using electrical resistivity tomography (ERT) in a selected area of the Seram Island in Indonesia. Seram Island lies in the tropical zone between the Seram and Banda seas. The laterite covers are rich in nickel, cobalt, iron and other metals. Concentrations of these metals in the laterites are high enough to form economic deposits. A significant part of the report concerns the measurement technique (ERT method) in difficult climatic (high humidity and temperature) and topographic conditions (equatorial jungle with significant variations in elevation) and the methods of processing and interpretation of the acquired data. The problem seems very interesting, because geophysical prospecting is currently more and more often conducted in poorly accessible regions of the world. Additionally, there are no sufficient and commonly available publications that would allow us to get acquainted with local measurement problems by potential contractors of similar geophysical investigations. The primary result of the geophysical survey was to determine the electrical resistivity of bedrock and laterite. This was the basis for the development of sections of electrical resistive distribution for the ERT profiles, which enabled to estimate the depth to the crystalline basement and the laterite thickness. It also facilitated to produce a map of laterite thickness, which may be an important material to develop the concept of searching and mining of nickel and cobalt ore.

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Praca paliła się w rękach

Piechota A.

Geodeta : magazyn geoinformacyjny

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2016

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nr 3

34--37

5

Po drugiej stronie globu

Piechota A.

Geodeta : magazyn geoinformacyjny

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2013

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nr 4

41--43

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CFD simulations of blood flow through abdominal part of aorta

Polanczyk A., Piechota A.

Challenges of Modern Technology

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2010

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Vol. 1, no. 1

34--39

EN

The aim of this research was to show superiority of using real geometries in simulations of blood fl ow through cardiovascular system. Our model compared blood fl ow through an abdominal part of aorta reconstructed with a use of data from an AngioTK research with the 3DDoctor software to geometries with the same diameters at inlet and outlet as mention before but created only with the Gambit 2.2.30 software without data from AngioTK. Blood fl ow simulations were prepared with the Fluent 6.2.16 software. Calculations of fl ow through a real geometry allows to obtain realistic results of values connected with process of blood fl ow. Results showed that calculations blood fl ow through a virtual geometry lasted two times longer than for a real geometry. Mesh for a real geometry consist about 600.000 elements and for a virtual geometry about 900.000 elements. Wall shear stress and blood velocity was higher for a real geometry and closer to that in human organism. It was shown that calculating a virtual geometry vessel was to big simplifi cation when investigating blood fl ow through a vessel. Application of mathematical models based on real geometries gives more realistic results than artifi cial geometries. Virtual models have lots of simplifi cations which results are far away from expectations. Simplifi cations depend on the model that is used.

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Late Triassic charophytes around the bone-bearing bed at Krasiejów (SW Poland) : palaeoecological and environmental remarks

Zatoń M., Piechota A., Sienkiewicz E.

Acta Geologica Polonica

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2005

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Vol. 55, no. 3

283-293

EN

Thousands of Late Carnian (Late Triassic) charophyte gyrogonites belonging to four species [Stellatochara germanica KOZUR & REINHARDT, Stomochara starozhilovae (KISIELEVSKY), Stenochara kisielevskyi BILAN and Porochara triassica (SAIDAKOVSKY)] occur in the beds around the vertebrate-bearing level at Krasiejów, SW Poland. The abundant and wellpreserved gyrogonites generally attest to fossilization in situ. Information about the habitat of recent charophytes is useful for reconstruction of their past environments. The factors limiting the habitat of modern charophytes suggests that these algae, and other micro- and macrofauna sedimented within the bone-bearing bed, lived in a shallow, freshwater environment (probably lacustrine). Above the bone bed, there is a rapid drop in gyrogonite abundance. This could have been caused by changes in environmental conditions: increase in salinity, or increase in water energy.The preliminary mineralogical data suggest arid to semi-arid climate.

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Geochemical and ecological aspects of lower Frasnian pyrite-ammonoid level at Kostomłoty (Holy Cross Mountains, Poland)

Racki G., Piechota A., Bond D., Wignall P. B.

Geological Quarterly

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2004

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Vol. 48, No 3

267--282

EN

The lower Frasnian (transitans Zone with Ancyrodella priamosica = MN 4 Zone) rhythmic basin succession of marly limestones and shales (upper Szydłówek Beds) at Kostomłoty, western Holy CrossMts., Central Poland, contains a record of the transgressive-hypoxic Timan Event in this drowned part of southern Laurussian shelf. The unique facies consists of organic-rich marly shales and a distinctive pyritic, goniatite level, 1.6mthick. The faunal assemblage is dominated by pyritized shells of diminutivemollusks with cephalopods (including goniatites Epitornoceras and Acanthoclymenia), buchioline bivalves (Glyptohallicardia) and styliolinids. This interval is marked by moderately low Th/U ratios and pyrite framboid size distributions suggestive of dysoxic rather than permanent euxinic conditions. The scarcity of infauna and bioturbation resulted in finely laminated sedimentary fabrics, as well as the low diversity of the presumed pioneer benthos (mostly brachiopods). In the topmost part of the Szydłówek Beds, distinguished by the Styliolina coquina interbedded between limestone-biodetrital layers, the above geochemical proxies and C-isotope positive shift indicate a tendency to somewhat increased bottom oxygen deficiency and higher carbon burial rate linked with a bloom of pelagic biota during high-productivity pulse. The geochemical and community changes are a complex regional record of the initial phase of a major perturbation in the earth-ocean system during a phase of intermittently rising sea level in the early to middle Frasnian, and associated with the highest positive C-isotope ratios of the Devonian.