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42. O původu ssavců
- Creator:
- Bohumil Bauše
- Publisher:
- Knihtiskárna a nakladatelství J. Otty
- Format:
- print, svazek, and 36 stran.
- Type:
- model:monograph and TEXT
- Subject:
- Paleontologie, fosilní savci, fylogeneze živočichů, paleozoologie, 569, 575.86:59, 56:59, (042.3), 7, and 56
- Language:
- Czech
- Description:
- rozprava, kterou v klubu přírodovědeckém dne 26. února 1888 přednesl Boh. Bauše.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
43. Ohře
- Creator:
- Tomáš Miloslav Voldřich and Česká společnost zeměvědná
- Publisher:
- nákladem České společnosti zeměvědné
- Format:
- print, svazek, and 44 stran + 12 map.
- Type:
- model:monograph and TEXT
- Subject:
- Hydrologie, hydrologie povrchových vod, řeky, Ohře (Německo a Česko : řeka), 556.5, 502.51(282), (282.243.3), (437.31-15), (048.8), 7, and 556
- Language:
- Czech
- Description:
- po stránce hydrografické zpracoval Tomáš Miloslav Voldřich.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44. Palaeozoische Arachniden
- Creator:
- Frič, Antonín and Kaiserl. Akademie der Wissenschaften in Wien
- Publisher:
- Selbstverlag
- Format:
- print, svazek, and 80 stran, 15 dvojlistů obrazové přílohy s vysvětlivkami : ilustrace.
- Type:
- model:monograph and TEXT
- Subject:
- Paleontologie, paleontologie, pavoukovci, fosilní pavoukovci, prvohory, paleontology, arachnids, fossil arachnids, palaeozoic, 56, 595.4, 565.4, 551.73, (048.8), (084.11), and 7
- Language:
- German
- Description:
- von Anton Fritsch., KČSN (sg. S-H), S věnováním autora, and Obsahuje bibliografii, bibliografické odkazy a rejstřík
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
45. Period and Q-factor of Free Core Nutation, based on different geophysical excitations and VLBI solutions
- Creator:
- Jan Vondrák and Cyril Ron
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- geofyzika, geophysics, rotation of the Earth, geophysical excitations, geomagnetic jerks, VLBI, celestial pole offsets, free core nutation, 7, and 551
- Language:
- English
- Description:
- Three variants of geophysical excitations and seven different VLBI solutions of celestial pole offsets (CPO) are used to determine period and Q-factor of Free Core Nutation (FCN). Brzeziński’s broad-band Liouville equations (Brzeziński, 1994) are numerically integrated to derive geophysical effects in nutation in time domain. Possible effect of geomagnetic jerks (GMJ) is also considered. Best-fitting values of FCN parameters are estimated by least-squares fit to observed CPO, corrected for the differences between the FCN parameters used in IAU 2000 model of nutation and newly estimated ones; MHB transfer function is used to compute these corrections. It is demonstrated that different VLBI solutions lead to FCN parameters that agree on the level of their formal uncertainties, but different models of geophysical excitations change the results more significantly. Using GMJ excitations always brings improvement of the fit between integrated and observed CPO. The obtained results show that the best fit is achieved when only GMJ excitations are used. Our conclusion is that GMJ are very probably more important for exciting FCN than the atmosphere and oceans. Empirical Sun-synchronous correction, introduced in the present IAU 2000 nutation model, cannot be explained by diurnal atmospheric tidal effects., Jan Vondrák and Cyril Ron., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
46. Present-day stress orientation and tectonic pulses registered in the caves of the Slovensky kras mts. (South-eastern Slovakia)
- Creator:
- Briestenský, Miloš, Zdenko Hochmuth, Littva, Juraj, Hók, Jozef, Dobrovič, Roman, Stemberk, Josef, Ľubomír Petro, and Pavel Bella
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- geodynamika, geomechanika, geofyzika, geologie, geodynamics, geomechanics, geophysics, geology, Slovenský kras (Slovensko), Slovak Karst (Slovakia), recent geodynamics, neotectonics, microdisplacement monitoring, cavitonics, 7, and 551
- Language:
- English
- Description:
- The fault displacement monitoring network EU-TecNet was established to define microdisplacements across faults in the territory of Central Europe (www.tecnet.cz) using three-dimensional optical-mechanical extensometers. The results of long-term neotectonic activity obtained from two caves localized in the eastern part of the Slovenský kras Mts. (SE Slovakia) show generally NE-SW oriented dilatation. This orientation is in a good accordance with the orogen-parallel extension monitored in the Western Carpathians. Differing short-lasting trends were distinguished in 2011-2012 and 2013-2015, which supports the significance of the tectonic pulse at the end of 2012 and the beginning of 2013. Moreover, simultaneous short-lasting faulting occurred at both sites under the transtensional tectonic regime, where the principal maximum compressional axis operated in a NW-SE direction (σ1). The observed results were compared to data from monitoring points in distant areas of the European plate. and Briestenský Miloš, Hochmuth Zdenko, Littva Juraj, Hók Jozef, Dobrovič Roman, Stemberk Josef, Petro Ľubomír, Bella Pavel.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
47. Relationships among coking coals and related cokes characteristics: a statistical evaluation
- Creator:
- Serenčíšová, Jana, Zdeněk Klika, Ivan Kolomazník, Lucie Bartoňová, and Baran, Pavel
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- uhlí, koks, coal, coke, CRI, CSR, multivariate statistics, 7, and 551
- Language:
- English
- Description:
- From 61 coking coals, 36 coal blends were prepared. Using a pilot coke oven, cokes were prepared from both 61 coking coals (Type I cokes) and 36 coal blends (Type II cokes). Coals were characterized by 14 coal characteristics and cokes by Coke Reactivity Index CRI and Coke Strength after Reaction with CO2 CSR. For the study of mutual statistic relationships among experimentally determined characteristics of coals and cokes, the Factor (FA) and Regression Analyses (RA) were used. FA distributed characteristics of coals and Type I cokes into 4 factors while characteristics of coal blends and Type II cokes were distributed into 7 factors. In case of pure coals and Type I cokes, strong relationships with high correlation coefficients (R > 0.60 ) were more abundant than in case of coal blends and Type II cokes. FA was used for the selection of coal characteristics that influence the coke quality the most significantly. These characteristics were then recalculated by RA for the predictions of CRI/CSR of Type I cokes. Predictions of CRI/CSR of Type II cokes were calculated from coal blends by the same procedure. The comparison of the predicted and experimentally determined CRI and CSR indexes showed much more reliable prediction of CRI/CSR indexes calculated from coals than calculated from coal blends. This study also explains the dominant reasons of this observation., Jana Serenčíšová, Zdeněk Klika, Ivan Kolomazník, Lucie Bartoňová and Pavel Baran., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
48. Rock anisotropy and brittleness from laboratory ultrasonic measurements in the service of hydraulic fracturing
- Creator:
- Moska, Rafal, Kasza, Piotr, and Maslowski, Mateusz
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- geodynamika, geomechanika, geofyzika, geologie, ultrasonografie, měření, geodynamics, geomechanics, geophysics, geology, index lámavosti, ultrasonic laboratory measurements, elastic anisotropy, brittleness index, 7, and 551
- Language:
- English
- Description:
- Ultrasonic velocity anisotropy in the rock provides information of variability of the dynamic elastic moduli. Young’s modulus and Poisson’s ratio calculated from waves velocities can be used to determine brittleness index, which is usually used to predict rock susceptibility for hydraulic fracturing. This paper describes laboratory ultrasonic measurements carried out in order to improve hydraulic fracturing designing. The research was conducted over two types of rock: shale and limestone. The samples were cut out perpendicularly and parallel to the bedding planes. Next they were tested for effective porosity and mineral composition using XRD method. Directionally depended seismic velocities revealed noticeable anisotropy of laminated shale, caused by orientation of the bedding planes and weak anisotropy of limestone. Based on the velocities, dynamic elastic moduli and its anisotropy coefficients were determined. Calculations of brittleness index based on Young’s modulus to Poisson’s ratio relation and three types of mineral composition brittleness indexes, revealed strong variability in brittleness for both kind of tested formations. These results show, that different types of brittleness indexes should be used complementary, to better describe fracability of the rock. and Moska Rafal, Kasza Piotr, Maslowski Mateusz.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
49. Structural framework of the Zelten Platform, South Sirte Basin, Libya using potential fields modelling
- Creator:
- Eshanibli, Abdelhakim, Khalil, Amin, Younis, Abdellatif, and Ghanoush, Hussin
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- geodynamika, geodynamics, Libye, Libya, magnetic anomaly, gravity anomaly, geologic structure, Zelten platform, Sirt basin, 7, and 551
- Language:
- English
- Description:
- Integration between magnetic and gravity data at the Zelten platform, the southeast part of Sirt Basin Libya. Zelten Platform is first discovered oil field in Libya. It shows numerous geological structures of different tectonic events. The methods adopted can assist in locating the hidden subsurface structures. The platform is characterized by the NW-SE trending rift that belongs to the Early Cretaceous age (during the collapse of Sirt Arch). The study aimed to define the structural geology that assisted in the development of future exploration in this area. The analyses utilized several filtering and transformation algorithms to help in structural modeling. For instance, the total horizontal gradient and tilt angle derivative were applied for the edge detection of the tectonic boundaries. The results show NW-SE and NNW-SSE patterns that represents faults that controlled the positions of the troughs and platforms at the Sirt basin. On the other hand, Euler deconvolution and 2D forward modeling were utilized to determine the depth of the basement. The Integrated models deduced revealed that the main faults trends are NW-SE which refer to the rift phases and crustal extension period that occurred during the Mesozoic time (early cretaceous). Also, the basement depth ranges from 6.5 km to 8 km according to the structures that affected the study area., Abdelhakim Eshanibli, Amin Khalil, Abdellatif Younis and Hussin Ghanoush., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
50. Studies on the effect of the proppant embedment phenomenon on the effective packed fracture in shale rock
- Creator:
- Maslowski, Mateusz, Kasza, Piotr, and Wilk, Klaudia
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- geodynamika, geomechanika, geofyzika, geologie, geodynamics, geomechanics, geophysics, geology, břidlice, fracture width, embedment, hydraulic fracturing, shale, proppant, effective packed fracture, 7, and 551
- Language:
- English
- Description:
- This paper presents the subject related to the technology of creating fractures into a rock, as well as the subject related to the effect of the proppant embedment phenomenon on the effective packed fracture in a reservoir rock. This phenomenon occurs after the performed hydraulic fracturing treatment of hydrocarbon reservoirs, during closing of the rock mass. A key part of this experiment was to investigate the depth of proppant grains penetration into the fracture wall (shale rock) and size of damage to the fracture wall surface. The embedment phenomena effects on decrease in the width fracture packed with proppant. The tests were performed for shale rock initially soaked with fracturing fluid, lightweight ceramic proppant grains with a grain size of 0.600÷0.300 mm (medium diameter of proppant grains of 0.450 mm), low surface concentration of proppant of 2.44 kg/m2. Time of exposure of proppant grains to compressive stress of a value 48.3 MPa for 6 hours at 70 oC. Test results indicate that the developed testing methodology may be used for corrected evaluation of the fracturing fluid as well as proppant in hydraulic fracturing treatment of unconventional reservoirs, especially shale rocks. and Maslowski Mateusz, Kasza Piotr, Wilk Klaudia.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public