We apply a cubic-plus-association equation of state to study the asphaltene precipitation from n-alkane diluted model solutions (asphalteneþtoluene), and heavy oils and bitumens. Heavy oils and bitumens are characterized in terms of saturates, aromatics/resins, and asphaltenes; n-alkanes are treated independently. The asphaltene precipitation is modeled as liquid-liquid phase equilibrium. The s...

Candida albicans produces and accumulates large amounts of the polyols d-arabitol and glycerol in culture, and/or in infected mammalian tissues. However, the effects of environmental stresses on production and accumulation of these polyols, and the means by which polyol production and accumulation are regulated have not been studied. C. albicans grown in glucose at 30 degrees C (i) produced max...

Six genes of the Arabidopsis thaliana monosaccharide transporter-like (MST-like) superfamily share significant homology with polyol transporter genes previously identified in plants translocating polyols (mannitol or sorbitol) in their phloem (celery [Apium graveolens], common plantain [Plantago major], or sour cherry [Prunus cerasus]). The physiological role and the functional properties of th...

Stereo-selectively synthesized 1,3-poly-alcohols are introduced as low-dimensional spectroscopic model systems for molecular dynamics in hydrogen-bonded networks. The molecular and vibrational structures of the artificial networks are studied by means of density functional theory. The flexibility of the networks and the time scales associated with hydrogen-bond breakage and formation are invest...

Polymerization at the liquid–liquid interface has attracted much attention for synthesizing ultrathin polymer films molecular sieving. However, it remains a major challenge to conduct this process outside alkane–water since not only suffers water-caused side reactions but also is limited water-soluble monomers. Here, we report interfacial polymerization alkane/ionic liquid (IP@AILI) where ionic...

The catalytic properties of Al2O3-supported vanadia with a wide range of VOx surface density (1.4-34.2 V/nm) and structure were examined for the oxidative dehydrogenation of ethane and propane. UV-visible and Raman spectra showed that vanadia is dispersed predominately as isolated monovanadate species below ~2.3 V/nm. As surface densities increase, two-dimensional polyvanadates appear (2.3-7.0 ...

In Acinetobacter sp. strain ADP1, alkane degradation depends on at least five essential genes. rubAB and xcpR are constitutively transcribed. Here we describe inducible transcription of alkM, which strictly depends on the presence of the transcriptional activator AlkR. alkR itself is expressed at a low level, while a chromosomally located alkM::lacZ fusion is inducible by middle-chain-length al...

For phytoremediation of organic contaminants, plants have to host an efficiently degrading microflora. To assess the role of endophytes in alkane degradation, Italian ryegrass was grown in sterile soil with 0, 1 or 2% diesel and inoculated either with an alkane degrading bacterial strain originally derived from the rhizosphere of Italian ryegrass or with an endophyte. We studied plant colonizat...

Biotransformation using alkane-oxidizing bacteria or their alkane hydroxylase (AH) systems have been little studied at the molecular level. We have cloned and sequenced genes from Gordonia sp. TF6 encoding an AH system, alkB2 (alkane 1-monooxygenase), rubA3 (rubredoxin), rubA4 (rubredoxin), and rubB (rubredoxin reductase). When expressed in Escherichia coli, these genes allowed the construction...