Search results for "Coal"
showing 10 items of 354 documents
Bayesian estimation of partial population continuity using ancient DNA and spatially explicit simulations.
2017
Abstract The retrieval of ancient DNA from osteological material provides direct evidence of human genetic diversity in the past. Ancient DNA samples are often used to investigate whether there was population continuity in the settlement history of an area. Methods based on the serial coalescent algorithm have been developed to test whether the population continuity hypothesis can be statistically rejected by analysing DNA samples from the same region but of different ages. Rejection of this hypothesis is indicative of a large genetic shift, possibly due to immigration occurring between two sampling times. However, this approach is only able to reject a model of full continuity model (a tot…
A view of the vegetation and economic exploitation of the forest in the Late Neolithic sites of Les Jovades and Niuet (Alicante, Spain)
1992
SummaryThe results of the charcoal analysis obtained in two open air sites of the Late Neolithic, although contrasting with what is known so far about their economy, as well as with the results of different palaeoamblental studies undertaken in other sites, mainly caves with long sequences, within the same area or in other near areas, form the main interest of this paper. We will begin presenting the data pertaining to both sites individually which, in the final part, will be assessed in order to reach a better understanding of the relationship between men and their natural environment during the Neolithic period.
Stages in the compaction of peat; examples from the Stephanian and Permian of the Massif Central, France
1987
Thick coal seams in the intramontane basins of the Massif Central allow a detailed study of peat/coal compaction. Three stages of compaction can be detected. Stage 1—occurred during the deposition of the peat. Coal beds which thicken and dip away from penecontemporaneous sandstones suggest rapid compaction. Stage 2—compaction of peat related to overburden pressure in some cases resulted in the formation of lakes over peat beds. The thickness of the lacustrine deposits may give an indication of the amount of compaction that took place. One possibility is that the early compaction was related to the progradation of siliciclastics over the peat. Stage 3—occurred after the organic sediment achi…
Elevated polycyclic aromatic hydrocarbons in a river floodplain soil due to coal mining activities
2007
Elevated PAH concentrations were found in soil samples collected along the Mosel River. These contaminations were associated with the occurrence of coal particles found in the soil. The majority of the PAH contamination in the soils was linked to coal mining activities in the Saar region. Density and grain size separation showed a similar PAH distribution pattern in all of the fractions, indicating a uniform origin of PAHs. Together with coal petrography a good correlation between TOC and PAHs concentration confirmed the impact of former coal mining activity on the PAHs distribution in study area.
A multi-gene approach reveals a complex evolutionary history in the Cyanistes species group
2011
Quaternary climatic oscillations have been considered decisive in shaping much of the phylogeographic structure around the Mediterranean Basin. Within this paradigm, peripheral islands are usually considered as the endpoints of the colonization processes. Here, we use nuclear and mitochondrial markers to investigate the phylogeography of the blue tit complex (blue tit Cyanistes caeruleus, Canary blue tit C. teneriffae and azure tit C. cyanus), and assess the role of the Canary Islands for the geographic structuring of genetic variation. The Canary blue tit exhibits strong genetic differentiation within the Canary Islands and, in combination with other related continental species, provides a…
Mid-Holocene forests from Eastern Hungary: New anthracological data
2013
Charcoal remains found in five archaeological sites provided an important source of information about the woody vegetation that developed during the Atlantic period in eastern Hungary. The results are presented jointly since all sites are located in very similar habitats, they reflect Neolithic cultures and present comparable floral compositions. The reconstruction of past forest communities from the Great Hungarian Plain in the Atlantic period is based on pollen analysis and new anthracological data offer significant complementary information to the established pollen sequences. These data were obtained from more than 5000 charcoal fragments in which 28 taxa were identified. The main contr…
An anthracological approach to understanding Late Classic period cultural collapse in Mesoamerica’s northwestern frontier
2012
International audience; For over 50 years, researchers have suggested that increased regional rainfall over the highland deserts of Mesoamerica's northwestern frontier zone during the Classic period (AD 200-900) allowed for the colonization of the zone by farming groups who originated from Central and/or West Mexico. A severe and prolonged drought is hypothesized to have later provoked the abandonment of the region by these sedentary populations by AD 900. However, very little research has been carried out in the zone to detect evidence of this proposed climate change. I present results from the first systematic study of wood charcoal from the northwestern frontier, comparing the data from …
Micro-scale post-fire surface cover changes monitored using high spatial resolution photography in a semiarid environment: A useful tool in the study…
2012
[ES] Although post-fire soil erosion has been studied, little attention has been paid to changes in soil surface cover following fires, despite this being a key factor in understanding the water and sediment yield. This study, at Peñaflor (Spain), investigated the effect of fire on soil erosion using data from soil erosion plots and high spatial resolution photography (HSRP). Measurements were made from October 2003 to October 2005 in a control plot and a plot experimentally exposed to a fire in October 2004. Ground cover components were identified, including vegetation, bare soil, stones, charcoal and ash. Runoff and sediment concentrations were low because of the absence of intense rainfa…
Successful treatment of paraquat poisoning: activated charcoal per os and "continuous hemoperfusion".
1982
AbstractIngestion of paraquat results in an extremely dangerous poisoning. The first aim is to clear the gastrointestinal tract by inducing emesis and performing gastric/gut lavage; as much activated charcoal as possible should be administered per os and as quickly as possible. The best measure to eliminate paraquat from blood and tissue is hemoperfusion with coated activated charcoal; it has to be performed in the sense of “continuous hemoperfusion” about 8 h/d over a period of 2–3 weeks. These measures give a chance to lower the lethality of paraquat poisoning.
Versuche zur Herstellung linolsäurearmen Ölsäureesters über eine Hydrierung mit Palladium
1980
Uber eine Hydrierung mit Palladium auf Aktivkohle konnen geringe Gehalte an Linolsaure in Gegenwart eines hohen Olsaureuberschusses recht selektiv reduziert werden. Der Linolsauregehalt eines Fettsauremethylestergemisches wurde von 10% auf 2% gesenkt, dabei entstanden 3% cis-, 4% trans-Monoenfettsauren sowie 1% Stearinsaure. The Preparation of Oleic Ester with Reduced Linoleic Acid Content by Hydrogenation with Palladium By hydrogenation with palladium on charcoal low contents of linoleic acid can be reduced quite selectively in the presence of an excess of oleic acid ester. In a mixture of fatty acid methylesters the content of linoleic acid was reduced from 10% to 2% with the formation of…