Adverse health effects of airborne toxicants, especially small respirable particles and their associated adsorbed chemicals, are of growing concern to health professionals, governmental agencies, and the general public. Areas rich in petrochemical processing facilities (e.g., eastern Texas and southern California) chronically have poor air quality. Atmospheric releases of products of incomplete...

1,3-Butadiene, a high-production volume chemical used largely in the manufacture of synthetic rubber, is a multiple organ carcinogen in rats and mice. In inhalation studies conducted in mice by the National Toxicology Program, high rates of early lethal lymphomas occurring at exposure levels of 625 ppm or higher reduced the development and expression of later developing tumors at other sites. U...

Stilbene and butadiene derivatives display NLO activity with SHG intensities up to 32 times that of urea for 2-chloro-3,4-dimethoxy-4?-nitrostilbene.

Diels-Alder reactions of 2(1H)-quinolones having an electron-withdrawing group at the 4-position with 1,3-butadiene derivatives were carried out to give the phenanthridones richly functionalized under the conditions of atmospheric and high pressure. Furthermore, the reactivities of 4-substituted 2(1H)-quinolones acting as a dienophile were examined using MO calculation.

We first found experimentally a cycloaddition reaction of a molecule on a symmetry Si pair, 1,3-butadiene on the Si adatom pair of Si(111)7x7, while up to now only asymmetric Si pairs were reported to be involved in cycloaddition reactions on Si surfaces. As the symmetry of a Si pair is expected to influence significantly a cycloaddition product and a reaction pathway, the [4+2]-like cycloaddit...

1,3-Butadiene is a major industrial chemical that has been shown to be a carcinogen at multiple sites in mice and rats at concentrations as low as 6.25 ppm. Occupational exposures have been reduced in response to these findings, but it may not be possible to determine by using traditional epidemiological methods, whether current exposure levels are adequate for protection of worker health. Howe...

In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulat...

The Utah Surrogate Mechanism was extended in order to model a stoichiometric premixed cyclohexane flame (P = 30 Torr). Generic rates were assigned to reaction classes of hydrogen abstraction, beta scission, and isomerization, and the resulting mechanism was found to be adequate in describing the combustion chemistry of cyclohexane. Satisfactory results were obtained in comparison with the exper...

II. Preparation of polyelectrolytic hydrogels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Monomers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Polymer synt...