The dissolution kinetics of pandermite and hydroboracite, present in an Iranian borate ore, in sulfuric acid has been comparatively studied. The effect of particle size, temperature, and acid concentration on their dissolution rate was investigated. Dissolution rates of both minerals increased by reducing the particle size and by raising the temperature. Although, an increase in the acid concen...

Abstract. Rapid and continuous analysis of radiocarbon (14C) concentration in carbonate samples at spatial resolution down to 100 µm has been made possible with the new LA-AMS (laser ablation accelerator mass spectrometry) technique. This novel approach can provide data a similar that stable carbon (C) isotope measurements by ratio spectrometry micromilled and, thus, help interpret δ13C signatu...

agh darreh tailing dam located in 23 km north of takab, west azarbayjan province is used for disposal of mine tailings. the tailing dam and its reservoir were constructed on gypsiferous marlstones. this is emphasis on geotechnical and environmental importance of the site. although construction of dams on gypsum rocks were not yet prohibited, but the dissolution of gypsum in contact with water i...

Accurate identification of nitrate (NO3−) sources is critical to addressing groundwater pollution, especially in highly vulnerable karst aquifers. The hydrochemistry and δ15NNO3 δ18ONO3 isotopes were analyzed samples taken from the Jinan Spring Catchment, which has been affected by urbanization agricultural activities. study highlighted use hydrochemistry, environmental isotopes, a multisource ...

Variation in tree stem diameter results from reversible shrinking and swelling and irreversible radial growth, all processes that are influenced by tree water status. To assess the causal effects of water and temperature on stem radial variation (DeltaR) and maximum daily shrinkage (MDS), the diurnal cycle was divided into three phases: contraction, expansion and stem radius increment. Diurnal ...

Diffusion-controlled dissolution and precipitation reactions occur in many biological systems and some non-stirred in vitro systems. Previous studies have shown that differences in the diffusion rates of the ions involved in a dissolution/precipitation reaction can produce significant effects on the rate and course of the reaction. We report here results of a study that show inter-diffusion of ...

Substantial amounts of self-boiling, Al-rich, hyperalkaline, and saline high-level waste fluids (HLWF) were deposited to the vadose zone at the Hanford Site, in Washington State. The objective of this study was to investigate the effects of similar fluids on the extent of dissolution and precipitation in the sediments. Metal- and glass-free systems were used to conduct batch experiments at 323 ...