The kinetics and reaction network of hydrodemetallation (HDM) reactions and the pattern of metal deposition have been investigated using a model residuum oil, consisting of nickel porphyrins (Nietioporphyrin (Ni-EP), Ni-tetraphenylporphyrin (Ni-TPP), and Nitetra(3-methylphenyl)porphyrin (Ni-T3MPP)) dissolved in a clean (N and S free) mineral oil. Reactions were carried out over a commercial CoO...

Aggregates containing certain constituents can react with alkali hydroxides in concrete. The reactivity is potentially harmful only when it produces significant expansion (Mather 1975). This alkali-aggregate reactivity (AAR) has two forms—alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR, sometimes called alkali-carbonate rock reaction, or ACRR). ASR is more often a concern than A...

Aggregates containing certain constituents can react with alkali hydroxides in concrete. The reactivity is potentially harmful only when it produces significant expansion (Mather 1975). This alkali-aggregate reactivity (AAR) has two forms—alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR, sometimes called alkali-carbonate rock reaction, or ACRR). ASR is more often a concern than A...

purpose : studies show that phenytoin is effective in improvement of different chronic ulcers such as venous stasis ulcers, and diabetic ulcers. the exact mechanism is yet not clear investigators thought that phenytoin might help to heal intractable corneal ulcers by reducing inflammation, differentiating limbal fibroblasts, and promoting the invasion of the cornea with new blood vessels as sho...

Abstract The gasification of biomass produces a syngas that can be used for electricity generation and fuels/chemicals production. However, tar is generated along with the as by-product which causes problematic issues in end-use syngas, such blockages, plugging corrosion. Catalytic steam reforming suitable option to convert into more presence nickel-based catalysts, preferred catalyst, mainly d...

Aqueous biphasic catalysis is a convenient approach to convert organic, partially soluble molecules in water. However, converting more hydrophobic substrates is much more challenging as their solubility in water is extremely low. During the past ten years, substantial progress has been made towards improving the contact between hydrophobic substrates and a hydrophilic transition-metal catalyst....

This paper argues that Information Technology (IT) needs to be demystified, through critical consciousness, for educators to focus on IT as a means to enhance learning. It goes on to define the technical, sociohistorical and political-ideological levels of IT and to identify four theoretical constructs: tutorial, machine-as-human, tool kit and catalyst. Pervading these constructs is the underst...