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EN
The paper describes results of microgravity measurements made on the surface over an underground geo reactor where experimental coal gasification was performed in a shallow seam of coal. The aim of the research was to determine whether, and to what extent, the microgravity method can be used to detect and image a coal gasification zone, especially caverns where the coal was burnt out. In theory, the effects of coal gasification process create caverns and cracks, e.g., zones of altered bulk density. Before the measurements, theoretical density models of completely and partially gasified coal were analysed. Results of the calculations of gravity field response showed that in both cases on the surface over the gasification zone there should be local gravimetric anomalies. Over the geo reactor, two series of gravimetric measurements prior to and after gasification were conducted. Comparison of the results of two measurement series revealed the presence of gravimetric anomalies that could be related to the cavern formation process. Data from these measurements were used to verify theoretical models. After the experiment, a small cavern was detected at the depth of the coal seam by the test borehole drilled in one of the anomalous areas.
PL
W artykule przedstawiono wyniki badań georadarem otworowym, przeprowadzonych w ramach uzdatnienia podłoża pod budowę autostrady A-1 na odcinku od węzła Piekary Śl. do węzła Bytom. Przedstawiono charakterystykę warunków geologiczno-górniczych na terenach pogórniczych eksploatacji rud metali. Omówiono zastosowaną metodykę badawczą, z podkreśleniem analizy wyników wzajemnie uzupełniających się metod mikrograwimetrycznej i georadaru otworowego. Badania georadarem otworowym zostały przeprowadzone w otworach kontrolno-iniekcyjnych w strefie stwierdzonych anomalii mikrograwimetrycznych.
EN
The article presents the results of borehole GPR measurements, which were a complementary part of the project of basement treatment on A-1 motorway in the section from the Piekary Śl. junction to Bytom junction within the so-called area of “ogródki działkowe”. The borehole GPR measurements were carried out in the injection boreholes in the places of identified gravity anomalies within the motorway A-1 lane. In the article the geological and mining conditions together with the typical lithological profile of the study area were presented. In this area historical exploitation of metal ores was conducted. The article discusses the methodology of the research with emphasis on the complementary analysis of results from microgravity and borehole georadar methods. Two examples of research areas with identified gravity anomalies were discussed. These examples show, how the borehole GPR measurements improved the efficiency of basement treatment works on A-1. The advantages as well as the limitations of borehole GPR method were discussed. Research were led by the team of Mineral and Energy Economic Research Institute of the Polish Academy of Sciences.
EN
Western Anatolia has an extensional tectonic regime and the characteristics of the deformation in the continental crust observed in Aegean Region have a very complex structure. In our study area, the İzmir city, Turkey, which is located within this active region, the general geological setting is also rather complex. This first microgravity study in İzmir and its surroundings is related to the determination of active fault zones. It was conducted in the south of İzmir, with the aim to investigate this complex structure in detail through microgravity data collected from six profiles throughout the survey area. The variation in Bouguer values was profoundly investigated along Profile P1 in N-S direction that was delineated to intersect all the tectonic elements. For this reason, Profile P1 was modeled in this study as 2D. As a result, the created gravity model was investigated together with geology, earthquake focal depths, and isostasy.
PL
W artykule przedstawiono możliwości mikrograwimetrii w wykrywaniu stref rozluźnień nad wyrobiskami wydrążonymi w skałach metamorficznych. Na tle rozwoju metody mikrograwimetrycznej przedstawiono opis metodyki badań. Polegała ona na interpretacji pomierzonego rozkładu mikroanomalii siły ciężkości nad pustkami o znanych parametrach. Interpretacja przeprowadzona za pomocą modelowania grawimetrycznego. Uzyskane wyniki potwierdziły zróżnicowany obraz zmian gęstościowych nad badanymi pustkami.
EN
This paper presents the possibility of use of the microgravity method to recognize loosing zone over the hole hollowed in metamorphic rocks. Against a background of development of microgravity method there are presented an description of research method. This method consist in interpretation of microgravity observation over the well- known hole The interpretation is conducted by gravity modelling. Achieving results proved the diversity view of density changes over this hole.
PL
Podziemna, płytka eksploatacja minerałów i surowców skalnych pozostawiła po sobie liczne, płytko leżące wyrobiska, które coraz częściej udostępniane są turystycznie. Z tego powodu określenie ich stateczności jest więc sprawą priorytetową i wykorzystuje się w tym celu badania i modelowania geomechaniczne. W niniejszym artykule przedstawiono wykorzystanie metody mikrograwimetrycznej do rozpoznania gęstościowego górotworu ponad starymi wyrobiskami. Przedstawiono wyniki badań wykonane nad trzema sztolniami wydrążonymi w piaskowcach istebniańskich. Badania wykryły istnienie stref rozluźnień nad dwoma sztolniami. Przeprowadzone modelowanie grawimetryczne pozwoliło na określenie rozmiarów tych stref oraz wielkości obniżenia gęstości objętościowej w tych strefach. Otrzymane wyniki powinny pomóc w znalezieniu poprawnego modelu geomechanicznego, a także jakościowo określić stan wyrobiska.
EN
Shallow underground exploitation of mineral and rock resources has left behind shallow-seated workings that often are made accessible to tourists. Therefore the crucial matter is to determine the stability of the underground workings. Geomechanics research and modeling are applied to solving the problem. This paper presents the use of the microgravity method to recognize density distribution in the rockmass overlying old mining workings. Results of investigations made over three adits drifted in the Istebna sandstones. Rock slackness zones were discovered over two galleries. As a result of the gravity modeling, the size of the zones and bulk density decrease were obtained. The results should help in construction of right geomechanics model as well as qualitative evaluation of the condition of workings.
6
Content available Ocena likwidacji szybu metodą mikrograwimetryczną
EN
In the article, an example of using the microgravity method to location of old mine shafts and determination of extent of their liquidation is presented. The surveys were made near dwelling houses, over three old mine shafts. The results demonstrated the incomplete liquidation of two of them.
EN
Results of a microgravity survey performed in the abandoned Starunia ozokerite mine (Carpathian region, Ukraine), where in the early 20th century well preserved remains of large, extinct mammals were found, are discussed in the paper. A number of gravity anomalies indicating the geological heterogeneity at the sub-Quaternary strata have been observed. The assumed measurement observations also enabled the authors to interpret the results in view of density changes in the Quaternary strata. Most of the registered microanomalies coincide with the high-halite and ozokeritic Miocene salt-bearing Vorotyshcha beds. The distribution of the microanomalies reveals neither their correlation with the thickness of overburdens, nor any gravity impact of numerous abandoned wells. Gravity anomalies were mostly connected with the lithology of sediments and rocks obtained from geological boreholes drilled in the years 2007 and 2008, on the basis of which the anomalies' origin could be determined. A concentric, relatively negative gravity microanomaly of ca. 25 m in diameter was registered in the place, where very well preserved relics of the woolly rhinoceros had been found. They may be indicative of the existence of Pleistocene lakes (and/or palaeoswamps), into which the woolly rhinoceroses had sunk. Hence, an assumption can be made that the further search for successive zoological relics can be made in areas with similar anomalies under the low-density sub-Quaternary subcrop.
8
Content available remote Reduced gravity testing and research capabilities at new 2.0 second drop tower
EN
Purpose: The Queensland University of Technology's has recently (2006) decommissioned a 1.9 second drop tower adapted for operation within an unused lift well of a building and has fabricated a purpose built, stand alone 2.0 second drop tower specifically to accommodate reduced gravity experimentation and manufacturing. The specifications and operational procedures of this new research facility are presented along with information regarding the expected benefits of manufacturing in a reduced gravity environment with focus on the production of metallic materials and nanomaterials production (including silica sol-gels and carbon nanotubes). Opportunities will also be discussed regarding both collaborative research and the provision of reduced gravity test or manufacturing services. Design/methodology/approach: The operational characteristics of a reduced gravity testing facility located in the School of Engineering Systems at Queensland University of Technology (QUT) are described. The Phenomena in Microgravity Laboratory (PML) operates the tower, and runs several research programs investigating gravity dependent phenomena. Several of these programs are outlined in this paper in the areas of combustion, fluid dynamics and nanomaterials. Findings: Calibration of the QUT drop tower has been performed, and it is currently used to conduct research in diverse disciplines with novel and useful results being obtained. Practical implications: Reduced gravity experimentation is important to many research groups working in various fields investigating both fundamental and applied aspects of diverse physical phenomena. Very few terrestrial or extra-terrestrial experimental facilities are currently available that allow researchers or manufacturers access to reduced gravity environments for their work. Originality/value: The QUT drop tower provides an economical and accessible reduced-gravity facility for use by scientists and industry both nationally and internationally.
PL
Na obszarach pogómiczych istnieje niebezpieczeństwo związane z możliwością wystąpienia deformacji ciągłych i, o wiele groźniejszych, nieciągłych powierzchni terenu. Powstają one wskutek zapadania się podziemnych, zinwentaryzowanych i niezinwentaryzowanych, wyrobisk. Lokalizacja nieznanych wyrobisk jest możliwa przy użyciu metody mikrograwimetrycznej, która bardzo dobrze się sprawdza w warunkach zabudowy i infrastruktury miejskiej. Metodą tą można również określić położenie głębiej zalegającej pustki, mierząc nie tylko wpływ samej pustki, ale i rozluźnień występujących nad nią. W niniejszej pracy przedstawiono prace modelowe łączące modele geomechaniczne z modelami grawimetrycznymi. Dzięki pracom z zakresu geomechaniki możliwe jest określenie zasięgu i rozmiarów rozluźnień nad wyrobiskami. Modele grawimetryczne tych rozluźnień pozwolą na odpowiedź, jaki jest kształt anomalii zaburzonych ich występowaniem oraz w jakich warunkach są one możliwe do zarejestrowania. Z praktycznego punktu widzenia wykrycie stref o obniżonej gęstości umożliwi prawidłową lokalizację otworów podsadzających.
EN
Continuous as well as more dangerous discontinuous land surface deformations are one of hazards in post-mining areas. They result from collapsing underground workings, both recorded in mining maps and unrecorded. The position of unknown workings can be determined using the microgravity method, particularly applicable in built-up urban regions with dense infrastructure. The method is also useful in localization of deeper-laying hollows, measuring directly not only their gravity effects but also the effects of loosened zones within the rockmass above such hollows. The authors carried out modelling that combines geomechanical models and gravity models. The theory of geomechanics can determine the range and the dimensions of loosened zones overlaying underground workings. Due to gravity models it is possible to describe the shape of anomalies disturbed by the loosened zones and predict the conditions, in which they can be identified. Identifying zones with lowered density within the rockmass provides important practical guidelines as they help select proper position of boreholes used to inject backfill into old workings.
EN
Experiments on combustion of extremely lean mixtures in the vicinity of flammability limits have acquired importance from the viewpoint of development of new kinds of combustion systems having low fuel consumption and low emissions. Furthermore, the determination of combustion characteristics for vapor addition under normal gravity and microgravity is very important for control of safety engineering in the space. In this work, experiments have been carried out with extremely lean, quiescent hydrocarbon-air mixtures to examine the effects of water vapor and CO2 addition on combustion characteristics under normal gravity and microgravity conditions. The microgravity technique achieved in a freely falling chamber is employed because the realizations of symmetrical flame propagations in a tube are impossible. Experimental condition for the initial mixtures corresponds to room temperature and 0.1MPa and the fuels used are methane and propane of 99.9% purity, respectively. The experimental results in this study are as follows. : 1) The water vapor addition for low oxygen concentration of propane-air mixtures effectively increases the flame speed; 2) Effects of water vapor addition on flame speed depend on a fuel property; 3) It is possible to control the combustion behavior by water vapor addition in the mixtures under low oxygen concentration.
PL
Wyniki badań mikrograwimetrycznych przeprowadzonych na obszarze Złotego Stoku wskazują na możliwość zastosowania lam bezinwazyjnych badań geofizycznych w celu wykrycia podziemnych wyrobisk górniczych, które pozwoliłyby rozbudować i uatrakcyjnić istniejące podziemne trasy turystyczne. Badania te są kontynuacją prac prowadzonych na terenie dawnej kopalni złota w Głuchołazach. Podstawowe informacje dotyczące wyników pomiarów mi kro grawimetrycznych w Głuchołazach są również przedstawione w tym opracowaniu. Jak dotąd nie podjęte zostały badania geotechniczne mające na celu wyjaśnienie genezy wykrytych ujemnych mikroanomalii siły ciężkości. Jest to jednak jedyna droga postępowania w celu ekonomicznego rozpoznania sieci wyrobisk górniczych, występujących w pobliżu podziemnej trasy turystycznej.
EN
In the paper application of microgravity method for subsurface mine workings detection is presented. The mean aim of these measurements was to detect the mine galleries of old gold mines in Glucholazy and Zloty Stok areas in Lower Silesia region. Among the others geophysical method, the microgravity was chosen due to its effectivity and low cost. Microgravity research means the determination of microanomalies of high confidence level, taking into consideration all factors that creates it. The results of the microgravity method applications are presented on the figures.
PL
Przeprowadzono doświadczenie, którego celem było sprawdzenie charakterystyki spalania mieszanki powietrza i eteru dimetylowego przy wykorzystaniu technikę mikrociążenia, wymagające komory swobodnego opadania. Warunki początkowe badań były następujące: temperatura 293 K, ciśnienie 0,10 MPa a stosunek składników mieszaniny zmieniał się od stechiometrycznego do granic zapalności mieszanki. Uzyskano następujące wyniki: (1) technika mikrociążenia jest bardzo użyteczna w analizie zachowania płomienia, nawet dla bardzo ubogich mieszanek, oraz (2) szybkość spalania mieszanki eteru dimetylowego jest podobna do prędkości spalania metanu w całym zakresie analizowanych składów mieszaniny i wynosi 10,0 cm/s oraz 32,0 cm/s, odpowiednio dla mieszanki o stosunku 0,62 i 0,90 a także (3) na podstawie wyników badań można wnioskować, że użycie mieszanki z eterem dimetylowym nie jest wykluczone w przypadku silników.
EN
Experiment has been carried out to examine the fundamental combustion characteristics of DME fuel-air mixtures using micro-gravity technique, which is achieved in freely falling chamber. The initial conditions of temperature and pressure are 293 K and 0.10 MPa, respectively and the equivalence ratio is the range from stoichiometoric proportion to near the lower flammability limit. The results obtained in the study are as follows:(1) micro-gravity technique is very useful to analyze the flame behavior even at very lean mixtures, and (2) the burning velocity of DME fuel- air mixture is nearly the same with that of methane-air mixture at the range of all the equivalence ratios investigated and those values of DME fuel are 10.0 cm/s and 32.0 cm/s at 0.62 and 0.90 of equivalence ratio, respectively, and (3) from these experimental data it is suggested that the application to the engine combustion of DME fuel is not so impossible.
EN
This paper deals with the mathematical study of the problem of small oscillations of a liquid bridge with a free surface, held together by surface tension, between two rigid coaxial disks, under gravity zero, in the case of a spherical liquid bridge in the equilibrium position. The equation which gives the displacement of the free surface, is reduced to a variational equation. After a careful discussion, it can be shown that the bilinear form which appears in the equation, is always coercive. Then, the existence of the eigenfrequencies of the liquid mass can be proved by means of the method of the functional analysis.
PL
W pracy przedstawiono wyniki badań teoretycznych mających na celu określenie zakresu mikrograwimetrycznej metody wykrywania i oceny stopnia zagrożenia powierzchni terenu dla obszarów występowania prawdopodobnie zlikwidowanych szybów górniczych. Dokonano analizy metody tak pod kątem parametrów geometrycznych szybów, jak i stopnia ich podsadzenia - likwidacji. Przedstawiono praktyczne przykłady zastosowania metody mikrograwimetrycznej dla trzech szybów zlokalizowanych w odrębnych obszarach górniczych i o różnych stopniach likwidacji.
EN
In the paper the theoretical and experimental results of the microgravity research are presented. The mean goal of this works were to applied the microgravity measurements for detection of the old unfilled mine shafts. The next stage of the work was to find the relation between the shaft's parameters, density of material probable used to fill in the shaft, density of the microgravity points of the gravity pictures. The are presented three examples of application gravity method for estimation of the stage of filled in of the shafts. The shafts come from different areas of mine region. The first example is related to, shaft Rubin located in Piekary Śląskie. The negative extreme of the residual gravity microanomalies is presented on Fig. 5. It is near by the gravity point no 9 and derives from old compressed old shaft so is confirmed by georadar measurements (Fig. 7). The picture of the microgravity anomalies presented on Fig. 8 corresponds to unfilled old shaft Maria-Anna. On the base of gravity data it is possible to estimate of the hazardous area and state of the ground surface due to existence of the unfilled shaft. The distribution of the microgravity anomalies in profile (Fig. 10) presents the negative anomaly over the air-shaft I in coal mine Saturn-Czeladź. The negative gravity anomaly over the shaft corresponds to unfilled shaft with dilatation below the concrete plate over the shaft.
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