Arc ignition through pre-arc from extra fine copper wire
Metal ignition wires are widely used in power arc tests on insulator sets and similar. Finer metal ignition wires are preferred from the point of view of influence on the apparatus tested. However, if the metal ignition wires are too fine, the arc cannot be sustained. To perform power arc tests successfully, therefore, they need to have some degree of thickness. With these requirements in mind, we proposed a new arc ignition method that allows the use of extra fine wires by leading to the pre-arc in a current of several dozens amperes, and examined it for practical use. In this paper, the sustainment characteristics of arcs ignited from extra fine copper wires using this new method were investigated with a gap between the rod electrodes. The results showed that kA-class arcs with a gap length of 1.5 m could be ignited through pre-arc from 0.03 mm diameter copper wire at a voltage of 12 kV. The influence of the ignition wire thickness on arc characteristics was also studied by comparing the arcs ignited by this new method with those ignited by the general method in which copper wires exceeding 0.3 mm in diameter was used.
Calculation of net emission coefficient of thermal plasmas in mixtures of gas with metallic vapour
The net emission coefficient of Ar-Cu, N2-Cu, SF6-Cu and Ar-Fe mixtures was calculated for homogeneous and isothermal plasmas at atmospheric pressure in the temperature range between 3000 and 25000 K. The increase in power radiated due to the presence of metal vapours depends on the vapour itself (the net emission is higher with iron than with copper) and on the type of gas. The influence of pressure was calculated for the SF6-Cu mixture. In the last part of the paper the values of the net emission coefficient were used to calculate the temperature profile in stationary arc in Ar-Cu and N2-Cu mixtures. The influence of copper on radiation is preponderant on the temperature field at higher currents whereas the effect on electrical conductivity is important at lower currents.
Legal Process and the Discovery of Better Policies for Fostering Innovation and Growth
Our chapter concerns how legal process can lead to efficient policies for fostering innovation and growth. Future innovation will depend at least as much on how laws are made as on a priori analyses of the optimal content of those laws. Of particular importance is whether U.S. choice of law and choice of forum rules promote an efficient market for law. Our analysis supports three suggestions for improving the law to support growth. First, the rules governing the selection of the jurisdiction whose law governs productive activity can significantly affect growth and innovation. Second, any proposal aimed at increasing growth through a change in law or legal institutions should take account of the existence of multiple jurisdictions and parties’ ability to choose the jurisdiction whose law controls their transactions. Third, we suggest harnessing the power of jurisdictional competition among the states through a federal law enforcing contracting parties’ choice of law except to the extent states legislatively override the choice of law and regulate local transactions. We apply this analysis to several areas of the law that are critical to growth and innovation: non-competition clauses, business associations, the legal profession, internet law, insurance, property law, products liability, and franchise regulation.