Algorithm for Pocket Milling using Zig-zag Tool Path

Pocket-milling operations are widely used for scooping out materials during the machiningof aircraft components. This paper presents a tool-path planning algorithm for pocket-millingusing zig-zag method. The algorithm consists of basically three modules, viz., generating toolpathelements using pocket geometry entities as input, finding out intersection points (edgepoints), and rearranging points in a zig-zag fashion. OPTPATH algorithm1,2 is used for generatingtool-path elements. These elements thus generated are used to find out the intersection pointswith all entities. The valid points are arranged in a zig-zag way, which are used for machiningany pocket considered. This algorithm works satisfactorily for all the pocket boundaries havingline-line, line-arc, and arc-arc geometry entities

Separation of Scandium and Calcium by Liquid-Liquid Extraction using Tri-N-Butyl Phosphate as Solvent

Equilibrium data have been obtained for the systems Ca(N03)2- HNO3- TBP- H20 and Sc(N03)3- Ca(N03)2- HNO3- TBP- H20 over a wide range of concentration of the metal nitrates in the aqueous solution. Equilibrium acid concentration was used as a parameter for the equilibrium curves. For the system Sc(N03)3- Ca(NO3)2- HNO3- TBP- H20 the distribution coefficients of scandium and calcium decreased with increasing acidity of the aqueous phase. The distribution coefficient of scandium was largely dependent on the calcium concentration in the aqueous phase rather than the scandium concentration as a result of the salting-out effect of calcium nitrate. The separation factor of scandium with respect to calcium was in the range 11 - 295 depending on the total metal nitrate concentration in the aqueous phase and the acidity of the aqueous phase. It was also observed that the separation factor was not a function of the ratio of scandium to calcium in the aqueous phase. The solvent TBP was found to be highly selective for scandium than for calcium

Molecules to materials. 1. An overview of functional molecular solids

With the advent of modern physics and chemistry, fundamentally new types of materials have been created in this century. Various types of forces operating in different classes of solids are exploited in the design of molecular materials. A variety of fabrication techniques have been developed to make materials with the desired properties. An overview of these aspects is provided in this article

Molecule matters. Carbon dioxide: molecular states and beyond

Carbon dioxide is a fascinating molecule; its gaseous, liquid, solid and even supercritical fluid states have unique properties and applications. The linear triatomic structure of carbon dioxide molecule with two carbon-oxygen double bonds is all too familiar. However a whole new world has been opened up by high pressure-high temperature experiments that effected the polymerization of this small molecule into a covalent network structure with carbon-oxygen single bonds. The crystalline and amorphous forms of carbonia are built up of linked tetrahedral CO4 units

Molecules to materials.4. Molecular nonlinear optical materials

Design of molecular nonlinear optical materials is presented; their inherent advantages are highlighted and their current status appraised

Molecules to materials. 5. Molecular material devices

Earlier articles in this series provided several examples to illustrate the controlled assembly of bulk structures with desired solid state properties using specifically designed molecules. The ultimate goal of these exercises is the development of devices whose building blocks are molecules. This article and the next attempt to impart the flavour of this exciting field of research and technology through brief discussions of several molecular devices. This article will focus on devices, which utilise the bulk properties of molecular materials; the examples selected are electroluminiscent device, thin film transistor and an electro-optic device