نتایج جستجو برای: mechanical weathering
تعداد نتایج: 242214 فیلتر نتایج به سال:
This study examined the color stability of painted Norway spruce (Picea abies) samples subjected to natural and accelerated weathering, using Duncan’s tests and correlation analyses. The following effects were studied: (1) the different initial roughness of the wood; (2) use of transparent or lightly-pigmented top-coat layers; and (3) the presence of the final water-repellent layer. Natural wea...
Global silicate weathering drives long-time-scale fluctuations in atmospheric CO(2). While tectonics, climate, and rock-type influence silicate weathering, it is unclear how these factors combine to drive global rates. Here, we explore whether local erosion rates, GCM-derived dust fluxes, temperature, and water balance can capture global variation in silicate weathering. Our spatially explicit ...
How the oil spill compositions change in the weathering process is an important topic for marine environment protection. In this study, long-term weathering simulation tests were conducted for 2 kinds of crude oils from the platforms of different blocks in Bohai Sea and 2 kinds of heavy marine fuel oils. Both floating oils and oils sunken in the seawater were analyzed. Gas chromatography (GC) r...
Negative emission technologies (NETs) target the removal of carbon dioxide (CO2) from the atmosphere, and are being actively investigated as a strategy to limit global warming to within the 1.5-2°C targets of the 2015 UN climate agreement. Enhanced silicate weathering (ESW) proposes to exploit the natural process of mineral weathering for the removal of CO2 from the atmosphere. Here, we discuss...
Mineral surface-textures on naturally weathered c of staurolite [monoclinic, pseudo-orthorhombic; Fe4Al18Sis046( rtalS indicate that staurolite weathering is general1 interface-limited. Etch pits on naturally weathered staurolites are disi-shaped, extensive parallel to (OIO), and thin perpendicular to (010). (010) is the plane of weak bonding and weak cleavage and the orientation of common stac...
Effects of CO2 and nutrient availability on mineral weathering in controlled tree growth experiments
[1] We sought to determine the effect of elevated atmospheric CO2 on mineral weathering reactions in midlatitude carbonate-bearing forest soils of differing nutrient availability. Increased plant growth and soil respiration under elevated atmospheric CO2 suggest increased rates of carbon cycling, which may affect mineral weathering. A randomized complete block experiment was conducted, where as...
[1] The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location of their discovery. Beginning on sol 1961, the Opportunity rover encountered three large iron meteorites within a few hundred meters of each other. In order of discovery, these rocks have been assigned the unofficial names Block Island, Shelter Isl...
Using in situ field measurements, laboratory analyses, and numerical modeling, we test the potential efficacy of thermal stress weathering in the flaking of millimeter-thick alteration rinds observed on cobbles and boulders of Ferrar Dolerite on Mullins Glacier, McMurdo Dry Valleys (MDV). In particular, we examine whether low-magnitude stresses, arising from temperature variations over time, re...
Various geological processes (mineral composition, structure, tectonics, weathering, etc.) affect the physical–mechanical properties of rock. Petrological and engineering characteristics paleoweathered rock (PWR) from K1/J2 contact zone are described in detail via field investigation experimental testing. This PWR exhibits mainly sandy grains mud structures, layered massive strata, calcareous a...
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