No abstract

Scaling of quantum capacitances and valence electron detachment energies is studied for icosahedral and nonicosahedral fullerenes. Scaling trends are considered from zero to infinite average radius, where a fullerene's local surface properties are similar to those of graphene. Detailed density functional theory calculations are performed to determine the geometries and detachment energies of icosahedral fullerenes, while values of these quantities are obtained for nonicosahedral species from previously published experimental results. Strongly linear, quasiclassical scaling versus average radii rn is seen for the quantum capacitances, but on two di↵erent scaling lines for icosahedral and nonicosahedral species, respectively. By contrast, nonclassical, nonlinear scaling versus 1/rn is seen for the electron detachment energies-i.e., the valence ionization potentials and electron a nities. This nonlinearity is not accounted for by classical theories that are used to explain trends in electronic properties of fullerenes and usually give accurate quantitative estimates. Instead, simple quantum equations are derived to account for nonlinearities in the metal-particle-like electron detachment energy scaling and to show that these are responsible for nonclassical, nonzero intercepts in the capacitance scaling lines of the fullerenes. Lastly, it is found that points representing the carbon atom and the graphene limit lie on scaling lines for icosahedral fullerenes, so their quantum capacitances and their detachment energies scale smoothly from one C atom, through C 60, to graphene.

The design of a simple sensing system to determine the specific gravity of liquids is described. The evaluation of a prototype system to measure the specific gravity of alcoholwater mixtures is discussed. The system is fully automatic and data processing is achieved in an off-line manner, Further possible areas of application are discussed.

The paper describes a data-processing system that uses a combination of electronic hardware and specific software to analyse the data from two twin-column AutoAnalyzer amino-acid analysers working in parallel. The system incorporates readily available electronic components and the data is punched on to paper tape. A Remote Batch Terminal is used to transmit and receive the data from a computer bureau. The software is designed to produce a full report from the available analytical data.

The following is a summary of one of the papers presented at a Meeting of the Automatic Methods Group held on February 26th, 1975, and reported in the March issue of Proceedings (Pa 76).