Seven types of carbon black used in type production were subjected to hygienic evaluation. The coal tar pitch volatiles (CTPVs), toluene solubles, were determined by the gravimetric method and benzo/a/pyrene by HPLC with a spectrophotometric detector. Toluene solubles were found to amount to 0.12-0.25% (by weight). Benzo/a/pyrene (1.44-3.07 ppm) was detected in five out of the seven carbon blac...

THE employment of tar in dermatology has a long history. According to Hebra (1868), Theophrastus, Dioscorides and Pliny advocated its use in the treatment of diseases of the skin. For many centuries this treatment fell into disfavour, partly on account of the general acceptance of Galen's " acrimonia sanguinis " theory ofthe causation ofskin disease which discouraged the use oflocal application...

Drops of coal tar introduced into the subcutaneous tissue attract the fibroblasts, endothelial and other cells to them. These cells suffer degenerative changes through this action of the tar and the animal suffers cachectic-like changes and death from large doses of it introduced into the subcutaneous tissue. This action of the coal tar is limited to a short period of time, after which it becom...

In this work, the results of studies on the evaluation of colloidal structure of coal-tar pitch compositions with selected waste polymers by fluorescence microscope. For pitch-polymer compositions containing 10-50 wt% waste polymer, softening point, coking value and content of components insoluble in toluene and quinoline were carried out. The results indicate that pitch-polymer compositions ca...

The main purpose of this work is the identification and quantification of phenolic compounds in coal tar samples from a ceramics factory in Cocal (SC), Brazil. The samples were subjected to preparative scale liquid chromatography, using Amberlyst A-27 ion-exchange resin as stationary phase. The fractions obtained were classified as “acids” and “BN” (bases and neutrals). The identification and q...

Introduction The unique properties of carbon foam mainly depend on the precursor features and synthesis conditions. For the highly thermal and electrical conductive carbon foam, an anisotropic pitch precursor is required [1, 2]. A lot of factors influence the foaming process, but temperature and pressure are the most critical aspects [3]. The aim of the present investigations is to adjust by ap...

INTRODUCTION This longitudinal field study was designed to encourage Appalachian coal miners in West Virginia and Pennsylvania to engage in hearing-protection behaviors. METHOD Participants were mailed postcards that featured either a positive, negative, or neutral message on the outside of the postcard and a message encouraging hearing protection behaviors on the inside. The first posttest m...