The specific objective of this paper is to develop a fully implicit compositional simulator for modeling asphaltene deposition during natural depletion. In this study, a mathematical model for asphaltene deposition modeling is presented followed by the solution approach using the fully implicit scheme. A thermodynamic model for asphaltene precipitation and the numerical methods for performing f...

The tensile strength of water increases when solid particles are filtered out, and it becomes greater the smaller the remaining particles are. Natural particles are of random shape, making parametric studies on the relationship between tensile strength and particle characteristics difficult. In this investigation, using degased tap water from which natural particles larger than about 1 (m were ...

A method employing dual competitive ligand exchange followed by solid phase extraction (CLE-SPE) for characterizing the complexation of inorganic Hg(II) in natural waters is described. This method employs parallel use of two competing ligands: diethyldithiolcarbamate (DEDC), which forms hydrophobic complexes with Hg(II), and thiosalicylic acid (TSA), which forms hydrophilic complexes with Hg(II...

The number of colors discernible by normal trichromats has been estimated for the idealized object-color solid. How well these estimates apply to natural scenes is an open question, as it is unknown how much their colors approach the theoretical limits. The aim of this work was to estimate the number of discernible colors based on a database of hyperspectral images of 50 natural scenes. The col...

The leaching kinetics of smithsonite ore in acetic acid solutions, an environmental friend, and natural reagent was investigated. The influence of parameters such as reaction temperature, particle size, solid-liquid ratio and acid concentration was studied in order to reveal the leaching kinetics of smithsonite ore. In this study, experimental and statistical methods were carried out in order t...

Comparing a solution phase route to a solid phase route in the synthesis of the cytotoxic natural product urukthapelstatin A (Ustat A) confirmed that a solid phase method is superior. The solution phase approach was tedious and involved cyclization of a ridged heterocyclic precursor, while solid phase allowed the rapid generation of a flexible linear peptide. Cyclization of the linear peptide w...

The main aims of solid waste management are to protect the environment and human health; and, to conserve natural resources. However, increasing consumption, environmental issues and resource depletion threaten its sustainability. Solid waste management policies usually fail to reduce consumption, decrease environmental impacts, conserve raw materials and develop sustainable products. These pro...

A facile, dissolution-free route to direct synthesis of hexagonal magnesium hydroxide nanoplates from natural brucite is reported. Stable brucite undergoes disaggregation into thin nanosheets and subsequent solid-solid transformation in the presence of p-toluene sulfonate, circumventing the threshold of size effect from bulk brucite to Mg(OH)(2) nanoplates.

A tetrazole-based traceless linker for Diels-Alder reactions on solid support which can be cleaved by Pd(0)-, Cu(I)- and Ag(I)-assisted nucleophilic displacements has been developed and applied to the solid-phase/traceless release synthesis of natural product inspired cis-decalins.