The relationships between the degree of exposure to a carcinogen and both the risk that neoplasms will occur and the time of their appearance serve as a basis to explain the nature of carcinogenesis (1, 2). There is usually a constant probability of carcinogenic effect per unit of dose-a linear doseresponse relationship-but that statement must be qualified. The number of animals affected by neo...

The atom-bond connectivity (ABC) index of a graph ( , ) G V E is defined as ( ) [ ( ) ( ) 2] / [ ( ) ( )] uv E ABC G d u d v d u d v , where ( ) d u denotes the degree of vertex u of G . This recently introduced molecular structure descriptor found interesting applications in the study of the thermodynamic stability of acyclic saturated hydrocarbons, and the strain energy of their cyclic congen...

The mechanisms of the thermolytic decomposition of a series of unsaturated cyclic C8 hydrocarbons adsorbed on a platinum(111) single crystal surface are described. This study both confirms and extends the results reported by Frei and Campbell which corrected errors in an earlier report from our laboratory on the mechanisms of thermal decomposition seen in this adsorbate system. We find that the...

Two series of para-substituted benzenesulfonamides have been examined as inhibitors for bovine carbonic anhydrase II (CAII, EC 4.2.1.1). Both series have hydrophobic alkyl group R connected by amide linkages to the aromatic ring (H2NO2SC6H4-CH2NHCOR1 and H2NO2SC6H4-CONR2R3). The free energy of partitioning (delta Gp) of these ligands between water and octanol had similar, linear correlations wi...

Metal–organic frameworks (MOFs) are promising materials for storing natural gas in vehicular applications. Evaluation of these materials has focused on adsorption of pure methane, although commercial natural gas also contains small amounts of higher hydrocarbons such as ethane and propane, which adsorb more strongly than methane. There is, thus, a possibility that these higher hydrocarbons will...

Crossed molecular beams experiments on dicarbon molecules, C2(X1sigmag+/a3piu), with unsaturated hydrocarbons acetylene (C2H2(X1sigmag+), ethylene (C2H4(X1Ag)), methylacetylene (CH3CCH(X1A1)), and allene (H2CCCH2 (X1A1)) were carried out at 18 collision energies between 10.6 and 50.3 kJ mol(-1) utilizing a universal crossed beams machine to untangle the reaction dynamics forming hydrogen defici...

The structures and reactivities of various cyclic C5 and C6 hydrocarbons (cyclopentene, cyclopentadiene, cyclohexene, 1,3-cyclohexadiene, and 1,4-cyclohexadiene) adsorbed on Pt(111) have been examined by means of reflection-absorption infrared (RAIR) spectroscopy. At temperatures below 200 K, these molecules bind intact to the Pt(111) surface by means of strong interactions with CdC double bond...

Petroleum refineries utilize thermal cracking, catalytic cracking and hydrogenation processes to produce high quality oil products. Hydrodesulfurization is one of the most important methods to remove sulfur from petroleum fractions. Heavy oil contains various types of sulfur compound. The structure of the sulfur compounds affects the ease of sulfur removal1). Acyclic sulfur compounds including ...

Cyclic and aromatic hydrocarbons are important components of usual commercial fuels, with C6-rings being among the most abundant cyclic structures. The combustion chemistry involves different levels unsaturation, either as initial fuels (aromatics, naphtenes, …) or intermediates formed during their combustion. In this work ignition delays cyclohexane, cyclohexene, 1,3-cyclohexadiene 1,4-cyclohe...