Parametric study of cost-effective synthesis of crystalline copper nanoparticles and their crystallographic characterization
Abstract Pure and high-crystalline copper nanoparticles were synthesized at room temperature by reduction of copper nitrate with hydrazine hydrate in cetyltrimethyl ammonium bromide (CTAB) solution without using any extra gases. A parametric study has been carried out in terms of hydrazine concentration, solution pH, and stirring. Pure copper nanoparticles without oxidation were obtained at 0.1–0.2 M N2H4 and pH = 10. The growth mechanism of various shaped copper nanoparticles is discussed based on structural analysis by transmission electron microscopy and selected area electron diffraction.
Parameterization of a 3D triangular mesh is a fundamental problem in various applications of meshes. The convex combination approach is widely used for parameterization because of its good properties, such as fast computation and one-to-one embedding. However, the approach has a drawback: most boundary triangles have high distortion in the embedding compared with interior ones. In this paper, we present an extension of the convex combination approach that resolves the drawback by using a virtual boundary. Since the virtual boundary is fixed onto a given convex polygon instead of the real boundary, the real boundary triangles can better reflect the shape of the corresponding 3D triangles. The proposedapproach obtains a parameterization of a 3D mesh with less d istortion than with the original convex combination approach. r 2002 Elsevier Science Ltd. All rights reserved.