Design Rule Checker for Sheet MetalComponents using Medial Axis Transforms andGeometric
Design Rule Checker is an essential component of design automation and for making design, process planning and manufacturing concurrent. In this paper, a set of algorithms are presented for detecting design violations in sheet metal components. Violations in sheet metal components occur when holes, slots, or other features are too close to one another. These violations, if undetected during design, increase the design life cycle of the product. Thus it is very essential to detect, if not eliminate these violations at the early stages of design. Typically sheet metal components have a number of features serving various purposes which include ventilation and fastening. As the contour of the parts gets complicated and the number of features on the sheet metal part increases it is diicult to check the rules exhaustively as it may lead to combinatorial explosion. 1 The algorithm presented here, uses Medial axis transformation to decompose a given domain thus preventing a combinatorial explosion, and also provides a means to integrate the rule checker with a design adviser.
Voronoi Diagram for Multiply-Connected Polygonal Domains I: Algorithm
Voronoi diagrams of multiply-connected polygonal domains (polygons with holes) can be of use in computer-aided design. We describe a simple algorithm that computes such Voronoi diagrams in O(N(log
 2 N+H)) time, where N is the number of edges and H is the number of holes.
Inhibition of Mild Steel Corrosion Using L-tryptophan and Synergistic Surfactant Additives
The corrosion inhibition characteristics of nitrogen containing amino acid L-tryptophan on mild steel in 0.1 M HCl solution, in the temperature range of 30-50 o C, was studied by weight loss and potentiodynamic polarization measurements. L-tryptophan significantly reduces the corrosion rates of mild steel; the maximum inhibition efficiency being 83% at 50 o C in presence of inhibitor concentration of 500 ppm. The effect of the addition of very small concentrations of anionic surfactant, sodium dodecyl sulfate (SDS), and of cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), on the corrosion inhibition behavior of L-tryptophan was also studied. The inhibition efficiency (IE) of L-tryptophan significantly improved in presence of both surfactants. The effect of SDS and CTAB on the corrosion inhibition behavior of L-tryptophan appears to be synergistic in nature, the values of synergism parameter being greater than unity. The adsorption of inhibitors on mild steel surface obeyed Langmuir’s adsorption isotherm. The calculated thermodynamic parameters for adsorption reveal a strong interaction between the inhibitors and the mild steel surface. The results obtained by electrochemical studies are consistent with the results of the weight loss measurements. L-tryptophan acts more anodic than cathodic inhibitor.