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Composition of bituminous coal in dependence on environment and temperature of alteration
Kurková M,Klika Z,Martinec P,Pěg？imo？ová J
Bulletin of Geosciences , 2003, DOI: 10.3140/bull.geosci.2003.01.023
Abstract: Bituminous coal from the proximity of red beds bodies of the Upper Silesian Coal Basin was altered by oxidation and thermally altered. This naturally altered coal was compared with laboratory-altered coal samples prepared at various temperatures and time, in oxidative and inert atmosphere, with weathered coal and with natural cokes. Comparison of samples was performed using coal petrographic and chemical analyses of individual coal samples.
Influence of selected rare earth metals on structural characteristics of 42CrMo4 steel
Bro？ová, S.,Drápala, J.,Jon？ta, P.,Kone？ná, K.,Kostiuková, G.,Sobotková, K.,Szurman, I.,Vontorová, J.
- , 2016,
Abstract: Sa？etak The influence of rare earth metals (REM) addition on solidification structure of the low-carbon 42CrMo4 steel was investigated. Alloys were prepared by means of a centrifugal casting. The addition of cerium, praseodymium or mischmetal in the steel produced greatly improved solidification structure with a suppressed columnar grain zone, finer grain size in the equiaxed grain zone. The additions occurred in the steel bath in the form of REM oxide and/or oxide-sulphide inclusions and as dissolved REM segregated along with other elements at prior grain boundaries and interdendritic spaces. Microstructure (light microscope), SEM/EDX chemical microanalysis, and TOF-SIMS analysis – mapping of elements in the structure of alloys were obtained
Renin and aldosterone are not associated with vulnerable plaque characteristics in patients with carotid artery disease - Journal of Vascular Surgery
Eef G. Lentjes,Gerard Pasterkamp,Gert J. de Borst,Hester M. den Ruijter,Imo E. Hoefer,Jean-Paul P.M. de Vries,Leo Timmers,Marieke A. Hillaert,Pieter A. Doevendans
- , 2018, DOI: https://doi.org/10.1016/j.jvs.2017.05.117
Abstract: The renin-angiotensin-aldosterone system is increasingly being recognized to play an important role in the development and clinical course of cardiovascular diseases. Renin-angiotensin-aldosterone system activation is associated with clinical outcome in various populations of cardiovascular patients, such as patients with coronary artery, peripheral artery, and cerebrovascular disease. In this study, we investigated the associations between plasma renin and aldosterone concentrations and atherosclerotic plaque characteristics and secondary vascular events in patients undergoing carotid endarterectomy. Baseline plasma renin and aldosterone concentrations from 506 subjects undergoing carotid endarterectomy (mean age, 67 ± 9 years; 65% male) were correlated with histopathologic characteristics and inflammatory protein concentrations of the excised atherosclerotic plaque. Ordinal logistic regression (for ordinal outcome parameters) or linear regression (for linear outcome) analysis did not show a statistically significant relationship between plasma renin or aldosterone concentrations and plaque fat, thrombus, calcifications, collagen, smooth muscle cells, or macrophage content. Neither could any association be found with intraplaque inflammatory mediators. During a median follow-up of 3 years, 102 (20%) patients experienced a major secondary vascular event (composite of stroke, myocardial infarction, leg amputation, vascular death, or coronary revascularization or peripheral intervention). In multivariable Cox regression analysis, including both renin and aldosterone, baseline renin concentrations were associated with the occurrence of secondary events. In patients with established atherosclerotic disease undergoing carotid endarterectomy, plasma renin and aldosterone concentrations were not associated with atherosclerotic plaque characteristics. Plasma renin concentration was positively associated with the occurrence of major secondary vascular events.
New photometric observations of the transiting extrasolar planet TrES-3b
M. Vaňko,M. Jakubík,T. Krej？ová,G. Maciejewski,J. Budaj,T. Pribulla,J. Ohlert,St. Raetz,V. Krushevska,P. Dubovsky
Physics , 2011, DOI: 10.1017/S1743921311027190
Abstract: We present new transit observations of the transiting exoplanet TrES-3b obtained in the range 2009 -- 2011 at several observatories. The orbital parameters of the system were redetermined and the new linear ephemeris was calculated. We performed numerical simulations for studying the long-term stability of orbits.
The influence of mechanical activation of chalcopyrite on the selective leaching of copper by sulphuric acid
Achimovi？ová, M.,Balá？, P.,Brian？in, J.
Metalurgija , 2006,
Abstract: In this paper chalcopyrite, CuFeS2, has been selective leached by H2SO4 as leaching agent (170 g/dm3) in procedure of hydrometallurgical production of copper. Mechanical activation of the chalcopyrite resulted in mechanochemical surface oxidation as well as in the mineral surface and bulk disordering. Furthermore, the formation of agglomerates during grinding was also occured. Surface changes of the samples using infrared spectroscopy and scanning electron microscopy methods were investigated before and after leaching. The leaching rate, specific surface area, structural disorder as well as copper extraction increased with the mechanical activation of mineral.
The influence of mechanical activation of chalcopyrite on the selective leaching of copper by sulphuric acid
Achimovi？ová, M.,Balá？, P.,Brian？in, J.
- , 2006,
Abstract: Sa？etak In this paper chalcopyrite, CuFeS2, has been selective leached by H2SO4 as leaching agent (170 g/dm3) in procedure of hydrometallurgical production of copper. Mechanical activation of the chalcopyrite resulted in mechanochemical surface oxidation as well as in the mineral surface and bulk disordering. Furthermore, the formation of agglomerates during grinding was also occured. Surface changes of the samples using infrared spectroscopy and scanning electron microscopy methods were investigated before and after leaching. The leaching rate, specific surface area, structural disorder as well as copper extraction increased with the mechanical activation of mineral
Map Resources – ECO Farms in the Czech Republic
J. Vanek,I. Bro？ová,J. Jarolímek,P. ？imek
AGRIS on-line Papers in Economics and Informatics , 2010,
Abstract: The present paper deals with the creation of maps for the sake of a special map portal using the database of ecofarms in the Czech Republic. The map output is being developed and implemented within the framework of theResearch Program in mutual cooperation of the Department of Information Technologies, Information andConsulting Centre, other departments of the Faculty of Economics and Management CULS Prague with externalpartners, especially with the Ministry of Agriculture (Environment and Ecological Agriculture Section,Department of Ecological Agriculture) and the Institute of Agricultural Economics and Information (UZEI) -Division of Agro-environmental Policy in Brno. The maps are visualized by means of MPPR 1.0 system andhave been processed – in the pilot stage - for the South Bohemian Region eco farms. The results represent initialdata from 2009 (as at 31st December 2009) that have been processed, verified and complemented in the courseof 2010.
The camp analogue, dbcAMP can stimulate rabbit reproductive functions: I. Effect on ovarian folliculogenesis, ovulation and embryo production
Chrenek P.,Pivko J.,Makarevich Av.,Kubovi？ová Helena
Acta Veterinaria , 2012, DOI: 10.2298/avb1203227c
Abstract: The aim of our study was to examine the influence of administration of N6,2’-dibutyryladenosine 3’5’-cyclic monophosphate (dbcAMP), a cAMP agonist, on ovarian folliculogenesis and atresia, as well as on reproductive efficiency in rabbits, whose ovarian cycle and ovulation was induced by gonadotropins. Ovarian cycle and ovulation of control rabbits were induced by 20 IU/kg PMSG followed by 35 IU/kg hCG administration. Experimental animals received PMSG and hCG together with dbcAMP (at 5, 25 or 50 μg/animal). After ovulation and insemination, the animals were sacrificed. Ovaries were weighted, histological sections of ovaries were prepared, and the presence of ovulated and not ovulated follicles and different stages of atresia was evaluated by light microscopy. The eggs were flushed from the oviducts after insemination and cultured up to blastocyst cell stage. Numbers of ovarian Corpora lutea, ovulated oocytes and oocyte-derived zygotes and embryos reaching hatched blastocyst stage were determined. Administration of dbcAMP (at doses 25 or 50 μg/animal, but not at 5 μg/animal) was able to increase the proportion of follicles with cystic and luteinization-related atresia. Furthermore, dbcAMP (50 μg/animal, but not lower doses) increased the ovarian mass, number of Corpora lutea, number of harvested oocytes, zygotes and embryos at blastocyst stage derived from these zygotes after culture. These data demonstrate that dbcAMP can stimulate rabbit ovarian follicle atresia, ovulation, oocyte, zygote and embryo yield and development. Furthermore, they confirm in the involvement of cyclic nucleotide-dependent intracellular mechanisms in the control of rabbit reproductive functions and potential practical usefulness of dbcAMP in improving animal reproduction and fertility.
Metamorphic history of skarns, origin of their protolith and implications for genetic interpretation; an example from three units of the Bohemian Massif
Pertoldová J,Tycová P,Verner K,Ko？uli？ová M
Journal of Geosciences , 2009, DOI: 10.3190/jgeosci.044
Abstract: Skarns in the Svratka Unit, in the neighbouring part of the Moldanubian Zone and in the Kutná Hora Complex were studied with respect to their metamorphic evolution, major- and trace-element geochemistry, oxygen isotopic composition and zircon ages. Skarns form competent lenses and layers in metamorphosed siliciclastic rocks and preserve some early deformation structures and several equilibrium assemblages representing the products of successive metamorphic reactions. The main rock-forming minerals, garnet and clinopyroxene, are accompanied by less abundant magnetite, amphibole, plagioclase, epidote ± quartz. In the Svratka Unit the early prograde M1, prograde/peak M2, and retrograde M3 metamorphic stages have been distinguished.
Metamorphic conditions in skarns of the Moldanubian Zone are limited to a relatively narrow interval of amphibolite facies. The prograde and retrograde events in the Kutná Hora Complex skarns probably took place under amphibolite-facies conditions.
The presence of magnetite and the increasing proportion of the andradite component in the garnet indicate locally increased oxygen fugacity.
Skarn geochemistry does not show systematic differences in the skarn composition among the three units. The regional variations are exceeded by differences among samples from individual localities. The Al2O3/TiO2, Al2O3/Zr, TiO2/Nb ratios point to the variable proportion of the detrital material, combined in skarn protoliths with CaO and FeO, the major non-detrital components. The skarns exhibit elevated abundances of Cu, Zn, Sn and As. The Eu/Eu* ratio varies in the range of 0.5-8.6, the total REE contents vary from 8 to 345 ppm. The lowest ΣREE values (< 100 ppm) occur in skarns with magnetite mineralization. The wide intervals of ΣREE and Eu/Eu* values are interpreted to indicate variations in the temperature and redox conditions among layers of the same locality and at various localities.
The oxygen isotope compositions of garnets, pyroxenes and amphiboles from skarns of the Svratka Unit exhibits a range of δ18O = 0.1 to 4.1 . In situ (laser-ablation ICP-MS) U-Pb dating of zircon from one of the Svratka Unit skarn bodies yielded a wide range of ages (0.5-2.6 Ga), supporting the detrital origin of this zircon population.
The skarn protoliths were probably rocks of mixed detrital-exhalative origin deposited on the sea floor.
The geological position of skarns, with their structural and metamorphic record, probably refl
Asymptotic properties of the differential equation $h^3(h''+h')=1$
J. Asch,R. D. Benguria,P. ？？ov\'？？ek
Physics , 2001,
Abstract: We derive the form of the asymptotic series, as $t\to +\infty$, for a general solution $h(t)$ of the non-linear differential equation $h(t)^{3}(h''(t)+h'(t))=1$.
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