BACKGROUND Butyrate is an important energy source for the colon and its metabolism has been reported to be defective in ulcerative colitis. One mechanism for defective butyrate metabolism in patients with ulcerative colitis could be an enzyme deficiency in the beta-oxidation pathway of butyrate. AIMS This study was undertaken to measure the activity of each enzyme involved in the beta-oxidati...

Wet air oxidation (WAO) is an old process developed in the middle of the XX century, but still the centre of very active and contemporary research especially in what concerns catalyst development. In ideal conditions soluble hydrocarbons can be oxidized in aqueous solution to carbon dioxide and water. Organic pollutants with heteroatoms are more challenging, because they require harsh condition...

Catalytic wet air oxidation is a promising alternative for the treatment of phenolic waste water which cannot be treated in conventional sewage plants. Catalytic wet air oxidation of an aqueous phenol solution was conducted in a ®xed bed reactor operating in trickle ̄ow regime. Either active carbon or a commercial copper oxide supported over -alumina was used as catalyst. The performance of bot...

Textile industry is an important source of water contamination. Some of the organic contaminants cannot be eliminated by nature in a reasonable period. Heterogeneous catalytic wet air oxidation is one of the most effective methods to purify wastewater with organic contaminants. In this work, catalysts based on copper supported on activated carbon were synthesized. The activated carbons were obt...

The production of carboxylic acids by partial wet oxidation of alkali lignin at elevated temperatures and pressures was studied experimentally. Two different heteropoly acids, phosphotungstic acid (H₃PW12O40) and phosphomolybdic acid (H₃PMo12O40), were used to catalyze the oxidation of lignin under hydrothermal conditions. Factors influencing the total yield of carboxylic acids formed during th...

Production of bio-oil or biocrude from thermochemical processes such as pyrolysis and hydrothermal liquefaction (HTL) respectively, is considered a promising path for the production alternative fuels chemicals. However, these technologies create an aqueous phase byproduct contaminated with high concentrations organic compounds. Traditional wastewater rely on biological processing which not resi...

sponge iron (dri) due to the high surface area, often shows a high tendency to re-oxidation and at some cases spontaneous combustion (autoignition). in this work, re-oxidation behavior and autoignition of sponge iron, produced from different types of iron ore has been investigated. isothermal and non-isothermal re-oxidation experiments were carried out on each type of dri and their autoignition...

The formation of a hydroxylated native oxide layer on Si(001) under wet conditions is studied by means of first principles molecular dynamics simulations. Water molecules are found to adsorb and dissociate on the oxidised surface leading to rupture of Si-O bonds and producing reactive sites for attack by dissolved dioxygen or hydrogen peroxide molecules. Tensile strain is found to enhance the d...

Catalytic wet oxidation has proved to be effective at eliminating hazardous organic compounds, such as phenol, from waste waters. However, the lack of active long-life oxidation catalysts which can perform in aqueous phase is its main drawback. This study explores the ability of bimetallic supported catalysts to oxidize aqueous phenol solutions using air as oxidant. Combinations of 2% of CoO, F...

We have studied the wet thermal oxidation of In0.52Al0.48As and its potential application in current and optical confinement in vertical cavity surface emitting lasers VCSELs . Two types of InP-based heterostructures were used to study the effect of adjacent layer compositions on the lateral oxidation behavior of the InAlAs. It was found that the oxidation of In0.52Al0.48As with InP adjacent la...