Polychlorinated biphenyls (PCBs) are ubiquitous global contaminants that have been intensively investigated for three decades. They are broad-acting toxicants occurring in complex mixtures and accurate risk assessment has proven to be elusive. Focusing on a limited set of end points and emphasizing a fixed set of congeners have led to more streamlined data sets that are meant to expedite hazard...

Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of ...

The photodissociation of methane atLyman cz (1216 3,) has been the focus of much scrutiny over the past few years. Methane photolysis leads to the formation of H2 molecules as well as H, CH, 1CH2, 3CH2, and CH3 radicals, which promote he propagation f hydrocarbon chemistry. However, recent studies [Mordaunt et al., 1993; Romani, 1996; Smith and Raulin, 1999] have not fully resolved the issue of...

The ability of croton oil to elicit epithelial tu mors in mice in areas previously treated with subcarcinogenic amounts of carcinogenic hydrocar bons is a well documented fact. In the typical ex periment tumors are initiated in the skin of mice by the single application of a solution of some car cinogenic hydrocarbon at a level that induces few if any tumors. The repeated application of croton ...

Hybrid clones segregating human chromosomes were prepared by fusing mouse RAG cells to fresh human bone marrow cells and tested for the mixed-function oxygenase [flavoprotein-linked monooxygenase; RH, reduced-flavoprotein:oxygen oxidoreductase (RH-hydroxylating); EC 1.14.14.1] arylhydrocarbon hydrocarbon hydroxylase. Neither constitutive nor induced aryl hydrocarbon hydroxylase activity was det...

Hydrocarbon profiles on the cuticle of social insects act as multi-component recognition cues used to identify membership in a species, a colony or, within colonies, cues about its reproductive status or task group. To examine the role of structural complexity in ant hydrocarbon recognition cues, we studied the species recognition response of two ant species, Linepithema humile and Aphaenogaste...

The entrapment of residual hydrocarbon ganglia during water table fluctuations can produce a long-term contamination threat to groundwater supplies that is difficult to remove. The mobilization of entrapped hydrocarbon ganglia depends on the balance between capillary and gravitational forces represented by the Bond number. The present work focuses on the influence of the interfacial tension bet...

Group VII atom containing polymers such as chlorine rubber, and fluorine rubber tend to show a high degree polarity due to their high molar attraction constants [1]. Their practical applications include molded parts, cable, hose, o-rings, etc., which require chemical resistance. In molding the final products, there are several problems such as shrinkage, porosity, blisters, poor knitting, backr...

alkyl imidazolines have been reportedly used in a wide range of industrial formulations with different applications. ethoxylated alkyl imidazolines with appropriate ethoxylation degrees can be used as antioxidants and retarders in the formation of peroxides resulting from oxidation in hydrocarbon media. in this work, ethoxylated imidazolines were shown to be more effective in hydrocarbon media ...

The fate of hydrocarbons in the subsurface near Bemidji, Minnesota, has been investigated by a multidisciplinary group of scientists for over a quarter century. Research at Bemidji has involved extensive investigations of multiphase flow and transport, volatilization, dissolution, geochemical interactions, microbial populations, and biodegradation with the goal of providing an improved understa...