Trapped or residual air (or gas) is known to affect the multiphase hydraulic properties of both soils and rocks. Trapped air is known to impact many vadose zone hydrologic applications such as infiltration and flow in the capillary fringe, but is also a major issue affecting recoverable oil reserves. Although many studies have focused on the relationship between porosity and trapped gas saturation (Sgt) in sandstones, far fewer studies have been carried out for carbonate rocks. This work aims to analyze the influence of porous media properties on trapped gas saturation in carbonate rocks. For this we used thirteen Indiana Limestone and Silurian dolomite rock samples from the USA, and several coquinas from the Morro do Chaves formation in Brazil. Pore size distributions were obtained for all samples using Nuclear Magnetic Resonance (NMR), and Mercury Injection Capillary Pressure (MICP) data from three of the samples to determine their pore throat size distributions. Additionally, 3D microtomography (microCT) images were used to quantify macropore profiles and pore connectivities. Results indicate a lower capacity of gas trapping in carbonate rocks in which micro- and mesopores predominate. Results also indicate that in carbonate rocks, pore size exerts a greater influence on the ability of gas trapping compared to pore connectivity, so that rocks with a predominance of macropores have greater capacity for gas trapping, even when the macropores are well interconnected. These findings show that pore characteristics very much affect the processes governing gas trapping in carbonate rocks, and indirectly the multiphase hydraulic properties and recoverable oil reserves of carbonate rock reservoirs.
This paper presents the results of an experimental study to quantify the effects of bed slope and relative submergence on incipient motion of sediment under decelerating flows. Experiments were conducted in an experimental tilting-flume of 8 m long 0.4 m wide and 0.6 m deep with glass-walls. Three uniform sediments with median grain sizes of 0.95, 1.8 and 3.8 mm and three bed slopes of 0.0075, 0.0125 and 0.015 were used under decelerating flow. The main conclusion is that the Shields diagram, which is commonly used to evaluate the critical shear stress, is not suitable to predict the critical shear stress under decelerating flows.
Biochars, depending on the types of feedstocks and technological conditions of pyrolysis, can vary significantly in their properties and, therefore, it is difficult to predict biochar-induced effects on nitrous oxide (N2O) emissions from various soils, their physical properties and water availability. The objectives of this study were (1) to quantify effects of slow pyrolysis biochar (BC) and fast pyrolysis biochar (PYRO) on physical and hydro-physical properties of sandy soil (Haplic Arenosol) and clayey loam soil (Gleyic Fluvisol), and (2) to assess corresponding N2O emissions from these two soils. The study included a 63-day long laboratory investigation. Two doses of BC or PYRO (15 t ha–1 and 30 t ha–1) were applied to the soils in combination or without nitrogen fertilizer (NH4NO3, 90 kg N ha–1). The obtained results have shown a significant decrease in the bulk density of sandy soil after it was amended with either rate of BC or PYRO. Water retention capacity of the soils in all the treatments with BC or PYRO increased considerably although no changes was found in the soil water-filled pore space (WFPS) which was higher than 60%. BC was increasing N2O emission rates from the sandy soil treated with N fertilizer, and reducing N2O emission rates from the clayey loam soil treated with N fertilizer. PYRO was more efficient and was reducing N2O emissions from both fertilized soils, but for the sandy soil the reduction was statistically significant only at higher dose (30 t ha–1) of the biochar.
This paper shows that there is a quantum-physical and evolution-biological perspective for (libertarian) free will, and that the so-called scientific arguments against it are in reality metaphysical arguments and insufficient. The paper also develops the idea of a nonphysical organ of higher organisms: the Domindar (Detector of macroscopic indetermination, and restrictor)., Tento článek ukazuje, že existuje kvantově-fyzikální a evolučně-biologická perspektiva pro (libertariánskou) svobodnou vůli a že tzv. Vědecké argumenty proti ní jsou ve skutečnosti metafyzické argumenty a nedostatečné. Příspěvek také rozvíjí myšlenku nefyzického orgánu vyšších organismů: Domindara (detektor makroskopické neurčitosti a omezovače)., and Uwe Meixner
The paper deals with semantic content of elliptic sentences and its relation to semantic content of the corresponding non-elliptic sentences. On the basis of certain kinds of examples it is shown that syntactic theories of ellipsis have serious limits. It is also demonstrated that the so-called Property Theory, which is an example of a semantic theory of ellipsis, bears serious limitations. Another semantic theory, namely that of Minimal Indexicalism, is analyzed thereafter. Theoretical tools of the theory - in particular, its criteria of linguistic expressions identity and three layers of content - that are vital to its handling of ellipsis are discussed in some detail. Finally, a new theory of ellipsis based on Transparent Intensional Logic is proposed and argued for., Příspěvek se zabývá sémantickým obsahem eliptických vět a jeho vztahem k sémantickému obsahu odpovídajících eliptických vět. Na základě určitých druhů příkladů se ukazuje, že syntaktické teorie elips mají vážné limity. Je také prokázáno, že takzvaná teorie vlastností, která je příkladem sémantické teorie elips, nese vážné omezení. Následně je analyzována další sémantická teorie, a to teorie minimálního indexismu. Teoretické nástroje teorie - zejména její kritéria identity jazykových výrazů a tří vrstev obsahu - které jsou nezbytné pro její zvládnutí elipsy, jsou podrobně diskutovány. Nakonec je navržena a argumentována nová teorie elipsy založená na transparentní intenzivní logice., and Miloš Kosterec