Ampacities of power cables wound on reels

This paper presents a mathematical model that is capable of calculating the ampacity of a wide variety of power cable designs consisting of an arbitrary number of layers on a cable reel. The model considers round cables with copper conductors. The validity and accuracy of the ampacity model were verified by comparing the predicted temperature distribution within the reel with measured temperatures collected during an extensive testing program conducted at the US Bureau of Mines (USBM). The mathematical model predicted a temperature distribution within the cable layers that was very close to the measured variation in temperature. The value of the program is illustrated by calculating ampacities for several copper conductor sizes     

Annular slot-coupled dielectric resonator antenna

An annular slot-coupled dielectric resonator antenna is investigated experimentally. As compared with the previous rectangular-slot version, the new configuration offers a much wider bandwidth of 18%. The return loss, radiation patterns, and antenna gain of the configuration have been measured and are discussed     

Operations and management of a campus packet network

The operation and management of the Kansas University Packet Switch Network (KUPSN),which provides interactive and file transfer services to its users, is discussed, focussing on the problems encountered and solutions developed. Areas of network management of particular concern are identified, and tools developed to deal with them are described. Management system integration and the evolution of problem-handling procedures are discussed     

Why are experts not better in judging the danger of filmed traffic conflicts?

Earlier studies on the subject of subjective judgment of traffic conflicts showed that untrained subjects can reliably judge the dangerousness of filmed traffic conflicts. It was concluded that these judgements were based on a concept of dangerousness. In line with these findings two experiments were conducted. Experiment 1 tested the hypothesis that traffic experts (traffic engineers trained to evaluate and improve traffic safety) and lay people use the same concept of dangerousness when judging filmed conflicts. Experiment 2 investigated which aspects of the conflicts are considered by experts when making these judgements. The results show that (i) experts and lay people are equally reliable in judging traffic conflicts, (ii) experts base their judgement on the same concept of dangerousness, (iii) experts do not base their judgement on aspects that they themselves regard as important for the conflict, (iv) a weak relation is found between violations of traffic regulations and judgements of dangerousness.     

Process integration in CASE environments

Research in CASE environments has focused on two kinds of integration: tool and object. A higher level of integration, process integration, which represents development activities explicitly in a software process model to guide and coordinate development and to integrate tools and objects, is proposed. Process integration uses software process models (SPMs) a process driver, a tool set, and interfaces for both developers and managers to form the backbone of a process-driven CASE environment. The developer's interface, a working environment that lets developers enact an SPM, and the manager's interface which gives managers and analysts the tools to define, monitor, and control the SPMs that developers are working on concurrently are discussed. The Softman environment experiment, an implementation of process-driven CASE environments with existing CASE environments, is reviewed     

The herbicide propachlor--14 C synthesis, toxicologic problems and methodology studies on the determination of residues in corn, potatoes, water and soil

Using the synthesized agent propachlor (N-isopropyl-2-chloroacetanilid) labelled with 14C, methodical investigations revealed an extremely high steam volatility not being assumed before because of the low vapour pressure. The method of steam distillation basing on this fact is of universal application to the processing of maize, potatoes, water, and soil, in which propachlor could be quantitatively determined by gas chromatography with a detection sensitivity of 0.02 ppm. Furthermore, this methods allows a simple purification of the raw product of synthesis containing impurities up to 20%. Propachlor codistilled with steam had a purity of more than 99%. Possibly, the high steam volatility of propachlor could have economic and toxicological consequences as to its application (volatilization in the open air with a high atmospheric humidity along with high temperatures). Therefore, an investigation of the steam volatility in the general screening programme for new agents is to be recommended in addition to the usual investigations of steam pressure.