Sorption of hydrophobic organic compounds (HOCs) to hydrophilic inorganic surfaces in aqueous systems is an important process, because HOCs are common contaminants and the sorption controls their concentration and rate of transport in the environment. Furthermore, in environmental chemistry and analysis, sorption of HOCs to inorganic surfaces, in particular to untreated (uncoated) glass surface...

This work puts forward a toolkit that enables the conversion of alkanes by Escherichia coli and presents a proof of principle of its applicability. The toolkit consists of multiple standard interchangeable parts (BioBricks)(9) addressing the conversion of alkanes, regulation of gene expression and survival in toxic hydrocarbon-rich environments. A three-step pathway for alkane degradation was i...

Lung function tests have been of increasing interest in the use for qualitative and quantitative evaluation of pulmonary function in patients with abnormalities of cardiorespiratory system (1). Petroleum refining products are constituted by cycloalkanes, straight and branched chain alkenes which are continued source of pollution in various occupational settings (2). With the increasing use of p...

In this work, we developed an interatomic potential for saturated hydrocarbons using the modified embedded-atom method (MEAM), a reactive semi-empirical many-body potential based on density functional theory and pair potentials. We parameterized the potential by fitting to a large experimental and first-principles (FP) database consisting of (1) bond distances, bond angles, and atomization ener...

The removal of hydrogen from alkanes to give alkenes is an important commercial objective, as alkenes are widely used as organic feedstocks in industrial processes involving chemical synthesis and polymerisation. This reaction is, however, significantly endothermic, needing up to 30 kcal per mole, and normally occurring at temperatures exceeding 400°C in the presence of heterogeneous supported ...

Sources of methane (CH4) and nitrous oxide (N2O) were investigated using measurements from a site in southeast Bakersfield as part of the CalNex (California at the Nexus of Air Quality and Climate Change) experiment from mid-May to the end of June 2010. Typical daily minimum mixing ratios of CH4 and N2O were higher than daily minima that were simultaneously observed at a mid-oceanic background ...

A novel topological approach for obtaining a family of new molecular descriptors is proposed. In this connection, a vector space E (molecular vector space), whose elements are organic molecules, is defined as a “direct sum” of different R i spaces. In this way we can represent molecules having a total of i atoms as elements (vectors) of the vector spaces R i (i=1, 2, 3,..., n; where n is number...

Highly electron deficient scandocene derivatives of the types (q5-CsMe&ScR, {(q5-CsMe4)2SiMe2}ScR and {(q5-C5H3CMe3)2SiMe2}ScR catalyze the polymerization of ethylene, the head-to-tail dimerization of a olefins, the cyclization of a,w dienes to meth lene cycloalkanes, and the branching of 1,4 pentadienes to isoprenes. The mechanisms oythe individual steps have been studied. Key steps involve se...

In the development of the MM3 force field, vibrational frequencies were considered for a set of eight relatively simple hydrocarbons. The 213 observed experimental frequencies over this set were fit to within a root-mean-square error of 35 cm-I, of which the largest errors occur in the CC-H bending frequencies. The torsional frequencies are generally calculated to a much higher accuracy, which ...