This paper presents results of an assessment of dominant hydro-geochemical processes controlling groundwater chemical composition, using an integrated application of cluster analysis and factor analysis. The area is located in south of saline playa and in Arak city. Cluster analysis classified samples into two main clusters according to their dominant chemical composition: cluster A (dominant c...

[1] Chemical weathering is an integral part of both the rock and carbon cycles and is being affected by changes in land use, particularly as a result of agricultural practices such as tilling, mineral fertilization, or liming to adjust soil pH. These human activities have already altered the terrestrial chemical cycles and land-ocean flux of major elements, although the extent remains difficult...

[1] Pits in rocks on the surface of Mars have been observed at several locations. Similar pits are observed in rocks in the Mars‐like hyperarid, hypothermal stable upland zone of the Antarctic Dry Valleys; these form by very localized chemical weathering due to transient melting of small amounts of snow on dark dolerite boulders preferentially heated above the melting point of water by sunlight...

In a headwater catchment in the Oregon Coast Range, we find that solid-phase mass losses due to chemical weathering are equivalent in the bedrock and the soil. However, the long-term rate of mass loss per unit volume of parent rock is greater in the soil than in the rock. We attribute this finding to the effects of biotic processes in the soil and to hydrologic conditions that maximize contact ...

Abstract: In this presentation and article, we synthesize findings from a workshop about our understanding of the interplay between crude oil photochemical oxidation spill response, emphasizing how has evolved since 2010 DWH spill. Our discussion is guided by one overarching questions: what role does play towards informing effective response operations? We show that prior to spill, relative imp...

To improve bacterial removal, a traditional stormwater biofilter can be augmented with biochar, but it is unknown whether bacterial removal remains consistent as the biochar weathers during intermittent exposure to stormwater under dry-wet and freeze-thaw cycles. To examine the effect of weathering on bacterial removal capacity of biochar, we subjected biochar-augmented sand filters (or simplif...

Timber is a sustainable, economical, completely renewable, CO2-neutral organic material, which requires less energy to process than other construction materials. Wood is also a strong, aesthetically pleasing, and very durable material when properly maintained and used. However, under certain conditions of exposure or use — particularly when it becomes wet — wood may be rapidly decomposed due to...

Physical and chemical reactions occurring as a result of the high-velocity impacts of meteorites and micrometeorites and of cosmic rays and solar-wind particles are major causes of space weathering on airless planetary bodies, such as the Moon, Mercury, and asteroids. These weathering processes are responsible for the formation of their regolith and soil. We report here the natural occurrence o...

[1] We have studied the effects of 4 keV He ion irradiation on olivine while measuring, in situ, changes in the near-infrared (NIR) reflectance and in the chemical composition of the surface. The observed changes in reflectance are reddening and the attenuation of the Fe-3d absorption bands in the NIR. Spectral reddening of irradiated olivine powder (<45 mm) correlates with the amount of metall...

a r t i c l e i n f o a b s t r a c t Classic low-albedo regions of the martian surface are investigated using combined reflectance and emission (" pan-spectral ") data to constrain the types of alteration mineral phases that are present at spectrally significant abundances (>10–15%). The lack of hydrated mineral species observed using near-infrared data suggests that anhydrous chemical alterat...