Discrete Packages Research Articles

A discrete system simulation package for a mini computer

Although the breadth and quality of the software available for 16-bit mini computers has improved dramatically in recent years, there are few if any mini computers for which a general purpose discrete simulation language or package is available. As many modern minis have sufficient computation power and storage to attack non-trivial simulation problems, this lack is surprising and unfortunate. In this paper, we describe a general purpose discrete simulation package which has been implemented on a Hewlett-Packard 2100A mini computer at Monash University, using Fortran as a host language.

Scanning Electron Microscope Observations of Herbicide Dispersal Using Cathodoluminescence as the Detection Mode

When high energy electrons strike a specimen in an electron microscope a number of phenomena occur. Some electrons are reflected with little or no energy loss. Others actually penetrate the specimen to some degree and excite molecules within a volume of the solid. Some molecules divest themselves of their surplus energy by allowing excited electrons to escape from their orbitals. If these electrons are able to escape from the specimen, they are known as secondary electrons. If the excited electrons do not leave the molecule but instead fall back to their ground state, they must transfer their surplus energy to other molecules or emit it as discrete packages of energy. The emission can be heat, infrared to visible light, or x-rays (for further details of these processes see 1, 4, 7, 8). We will confine ourselves to a consideration of the infrared to visible light production and reflected electron phenomena in this communication. Researchers working with herbicides frequently have a need to know the spatial location of an herbicide in or upon a plant. A common method for obtaining such information is that of radioautography (9). Radioautography, while certainly adequate for many studies, often requires weeks of exposure time to produce a sufficiently intense film image and also involves the expense of radioactively labeled compounds. A number of compounds will fluoresce3 under electron bombardment (3). We have used a scanning electron microscope equipped to detect this fluorescence (cathodoluminescence) and wish to report a new, rapid method for spatially localizing herbicides on leaf surfaces.

Design concepts for an exploding bridge-wire electronic ignition system

An exploding bridge wire (EBW) is a fine wire conductor that is fused and vaporized by the discharge of a discrete package of electric energy in an extremely short time period. It can be used as a localized source of heat. Electrical and mechanical design features of the electronic firing unit used to actuate the various EBW devices on space vehicles are described and advantages of this ignition system over low-voltage squib iginition are pointed out