oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 3 )

2019 ( 475 )

2018 ( 663 )

2017 ( 698 )

Custom range...

Search Results: 1 - 10 of 556258 matches for " Pěg?imo?ová J "
All listed articles are free for downloading (OA Articles)
Page 1 /556258
Display every page Item
Composition of bituminous coal in dependence on environment and temperature of alteration
Kurková M,Klika Z,Martinec P,Pěgimoová 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.
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.
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 $h(t)^{3}(h''(t)+h'(t))=1$.
Extreme Climatic Variability in North-western Nigeria: An Analysis of Rainfall Trends and Patterns
Imo J Ekpoh,Ekpenyong Nsa
Journal of Geography and Geology , 2011, DOI: 10.5539/jgg.v3n1p51
Abstract: Some aspects of the climate of north-western Nigeria were examined in this study, focusing more on rainfall, its inter- and intra-annual variability and patterns of distribution. Adopting the statistical distributions commonly used to describe climate states such as the mean, the standard deviation and the coefficient of variability, the climate of north-western Nigeria was analyzed for possible shifts in mean conditions and patterns. The study found that climatic conditions in north-western Nigeria have altered substantially as four drought episodes took place within the last three decades of the 20th Century and, the 1984 drought-year rainfall was 58.8 percent lower than the long-term mean rainfall. The study further showed that the 1968 to 2008 mean rainfall shifted downwards by 8.8 percent from the long-term mean, although it cannot be said if the shift is permanent or temporary since recent rainfall trends tend to suggest a recovery. Possible options for stabilizing the regional climate are suggested.
The Abuse of Presidential Power of Pardon and the Need for Restraints  [PDF]
Imo Udofa
Beijing Law Review (BLR) , 2018, DOI: 10.4236/blr.2018.92008
Abstract: This paper examined the nature and application of presidential power of pardon in Nigeria, the United States of America, India and South Africa, amongst others. The power of pardon is an important component of executive powers, which allows the President to intervene and grant pardon, as a way of “dispensing the mercy of government” in exceptional cases where the legal system fails to deliver a morally or politically acceptable result. It exists to protect citizens against possible miscarriage of justice, occasioned by wrongful conviction or excessive punishment. Nevertheless, in recent times, this power has, in practice, become a personal prerogative of the President, a remnant of tribal kingship generally reserved for the well-heeled or well connected. The power of pardon is virtually unfettered and unchecked by formal constraints in most jurisdictions, thereby rendering it susceptible to abuse. However, in some jurisdiction there are conventionally specified criteria which guide the grant of pardon. The paper also examined some of the incidents of abuse of presidential power of pardon in Nigeria and other jurisdictions and proffered suggestions aimed at ensuring a more purposeful and beneficial exercise of the pardon power, particularly in Nigeria.
Circulating Biomarkers for Predicting Cardiovascular Disease Risk; a Systematic Review and Comprehensive Overview of Meta-Analyses
Thijs C. van Holten, Leonie F. Waanders, Philip G. de Groot, Joost Vissers, Imo E. Hoefer, Gerard Pasterkamp, Menno W. J. Prins, Mark Roest
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0062080
Abstract: Background Cardiovascular disease is one of the major causes of death worldwide. Assessing the risk for cardiovascular disease is an important aspect in clinical decision making and setting a therapeutic strategy, and the use of serological biomarkers may improve this. Despite an overwhelming number of studies and meta-analyses on biomarkers and cardiovascular disease, there are no comprehensive studies comparing the relevance of each biomarker. We performed a systematic review of meta-analyses on levels of serological biomarkers for atherothrombosis to compare the relevance of the most commonly studied biomarkers. Methods and Findings Medline and Embase were screened on search terms that were related to “arterial ischemic events” and “meta-analyses”. The meta-analyses were sorted by patient groups without pre-existing cardiovascular disease, with cardiovascular disease and heterogeneous groups concerning general populations, groups with and without cardiovascular disease, or miscellaneous. These were subsequently sorted by end-point for cardiovascular disease or stroke and summarized in tables. We have identified 85 relevant full text articles, with 214 meta-analyses. Markers for primary cardiovascular events include, from high to low result: C-reactive protein, fibrinogen, cholesterol, apolipoprotein B, the apolipoprotein A/apolipoprotein B ratio, high density lipoprotein, and vitamin D. Markers for secondary cardiovascular events include, from high to low result: cardiac troponins I and T, C-reactive protein, serum creatinine, and cystatin C. For primary stroke, fibrinogen and serum uric acid are strong risk markers. Limitations reside in that there is no acknowledged search strategy for prognostic studies or meta-analyses. Conclusions For primary cardiovascular events, markers with strong predictive potential are mainly associated with lipids. For secondary cardiovascular events, markers are more associated with ischemia. Fibrinogen is a strong predictor for primary stroke.
Page 1 /556258
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.