Polymer walls and inserts are an important design criterion in low-voltage switching devices. Besides their good insulation properties they are used to influence the switching arc. An important part of the energy dissipated in the arc is absorbed by the walls of the arc chamber. This leads to degradation and evaporation of the polymer and subsequent impact on and interaction with the switching arc. This contribution explains the enhancements of an existing simulation model for the interaction between the low-voltage switching arc and walls composed of polyamide PA 66. This includes a model of plastic ablation, the influence of the plastic vapor on the transport properties of the arc as well as on its radiation. Calculations and comparisons with experimental results show the applicability of the model in arc chambers that are close to reality.
Identifying space with a superconducting cosmic dust, the structure of the
‘world crystal’ is built. Particles moving on open geodesics are
assimilated with the ‘electron gas’ in a lattice, and those moving
on closed geodesics with nodes of the same lattice. By considering that this
kind of structure may be achieved by pinning on a background gravitomagnetic
field, the properties of such fields are studied. From this analysis and
computing the background energy we are lead to a Cantorian-fractal structure
of space–time, which allows one to interpret the gravitational
interaction in terms of a mechanism similar to the composite fermions
mechanism.
Simulation methods are routinely applied in the design and development process of power distribution devices. Arcing phenomena that occur during switching operations or fault events are modeled to optimize device performance and gain deeper insights into the behavior that testing cannot easily provide. In this contribution, some applications are presented in detail. The first example describes the distribution of debris that is generated inside a molded case circuit breaker (MCCB) during short-circuit interruption. A model is used to analyze the debris transport and to derive a solution to address issues caused by the debris. Second application example is a cooling device for hot plasma gases vented by circuit breakers. A model driven design process helps to define the device dimensions to achieve a safe temperature level of the exhaust gases. The third example deals with short-circuit behavior of a hollow core high voltage surge arrester, comparing model and experimental results.
This paper describes a relatively high power density (10–15 kW/cm2) x-ray source for x-ray lithography applications. The source utilizes a stationary solid Pd target cooled by a high velocity water flow. This source has been operated for several months in a shop environment. No degradation in performance has been observed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.