نتایج جستجو برای: calcareous nannofossils
تعداد نتایج: 3502 فیلتر نتایج به سال:
The South Downs Area of Outstanding Natural Beauty, UK, is an internationally and nationally important landscape, which contains a significant proportion (28%) of the southeast of England's calcareous grassland resource. The traditional calcareous grassland habitats characteristic of the downland landscape have suffered significant losses since the Second World War, and the remaining sites are ...
Despite the heightened awareness of ocean acidification (OA) effects on marine organisms, few studies empirically juxtapose biological responses to CO2 manipulations across functionally distinct primary producers, particularly benthic algae. Algal responses to OA may vary because increasing CO2 has the potential to fertilize photosynthesis but impair biomineralization. Using a series of repeate...
The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a referen...
The avalanche statistics in porous materials and ferroelastic domain wall systems has been studied for slowly increasing compressive uniaxial stress with stress rates between 0.2 and 17 kPa s-1. Velocity peaks [Formula: see text] are calculated from the measured strain drops and used to determine the corresponding Energy distributions [Formula: see text]. Power law distributions [Formula: see t...
It is difficult to obtain high quality samples of natural material covering a range of densities and degree of cementation, so study on the sample preparation techniques with similar mechanical properties of natural samples are very important. Experiments were carried out to study the effects of cementation of different materials on the mechanical properties of calcareous sand, e.g., the effect...
Phytoremediation appears to be a promising technique for metal soil clean up, although its successful application on a large scale still remains a challenge. Field experiments for six scented Pelargonium cultivars, conducted on two Pb-contaminated calcareous and acidic soils, revealed vigorous plant growth, with no symptoms of morpho-phytotoxicity in spite of high Pb accumulation levels. Lead c...
Time-dependent natural weathering processes suffered by historic bricks in Toledo (Spain) improve their physicomechanical properties by porous infill with gypsum, ettringite and mainly calcite. Both, these bricks and their experimental replica bricks, made from the original calcareous clays fired at the probable historical temperatures (700o 900oC), have been analyzed by X-ray diffraction, opti...
Morphological similarities indicate that Palaeozoic problematic tubeworms, e.g. tentaculitids, cornulitids, microconchids, trypanoporids, Anticalyptraea, and Tymbochoos, form a monophyletic group. This group may also include hederelloids. Members of this group share affinities with lophophorates and their evolution could have partly been driven by predation. The extinction of Palaeozoic tubewor...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید