Use of cosmetics by Danish women
acrylic compound such as trimethyl propane trimethacrylate (TPC). This is of considerable significance since TPC may cause allergic contact dermatitis in ultraviolet cured printing inks (Nethercott 1978). Finally, Chung & Giles (1977) showed that guinea pigs could be strongly sensitized to methyl-, ethyland n-butyl methacrylate in ethanol or olive oil by the topical route, or in saline by the intradermal route. For elicitation of skin reactions, topical challenge with the compounds in olive oil or intradermal challenge with saline as the solvent was necessary. All sensitized animals responded strongly not only to the inducting methacrylate but also to the other methacrylates, showing that mutual cross-sensitivity had occurred. They concluded by stating that, "Since methyl methacrylate has been reported to be a potent sensitizer in humans, the guinea pig model described here may be useful for screening products before marketing."
Allergic contact dermatitis to sculptured nails.
Sculptured artificial nails are a popular method of improving the cosmetic appearance of natural nails. They are made by mixing a liquid monomer with a powder polymer and then molding this acrylic compound onto the natural nail. We have recently seen a patient with allergic contact dermatitis to ethyl methacrylate, the liquid monomer used in these artificial fingernails. The purpose of this article is to report a case in which ethyl methacrylate was the sensitizer in the nail, and to demonstrate cross-sensitivity to methyl and N-butyl methacrylate. Report of a Case A 50-year-old woman used artificial fingernails for 1 1/2 years because of nail fragility. This process involved the mixing of ethyl methacrylate monomer with acrylic polymers. For several months prior to being seen in the clinic, a paronychial and eyelid dermatitis (Figure) occurred two days after each new application of the nails. Using the aluminum patch test technique, the
Surface roughness monitoring by singular spectrum analysis of vibration signals
Abstract This study assessed two methods for enhanced surface roughness (Ra) monitoring based on the application of singular spectrum analysis (SSA) to vibrations signals generated in workpiece-cutting tool interaction in CNC finish turning operations i.e., the individual analysis of principal components (I-SSA), and the grouping analysis of correlated principal components (G-SSA). Singular spectrum analysis is a non-parametric technique of time series analysis that decomposes a signal into a set of independent additive time series referred to as principal components. A number of experiments with different cutting conditions were performed to assess surface roughness monitoring using both of these methods. The results show that singular spectrum analysis of vibration signal processing discriminated the frequency ranges effective for predicting surface roughness. Grouping analysis of correlated principal components (G-SSA) proved to be the most efficient method for monitoring surface roughness, with optimum prediction and reliability results at a lower analytical-computational cost. Finally, the results show that singular spectrum analysis is an ideal method for analyzing vibration signals applied to the on-line monitoring of surface roughness.