Field-enhancement calculations for a field-distortion triggered spark gap

We present the results of numerical field calculation which supplement a recent article in which we described a new design concept for field-distortion triggered spark gaps. The calculations verify the shielding and field enhancement assumptions made in the article, and they provide insight into the interaction of the design tradeoffs associated with simultaneously maximizing the holdoff voltage and the triggering capability of the gap

Use of SU8 as a stable and biocompatible adhesion layer for gold bioelectrodes.

Gold is the most widely used electrode material for bioelectronic applications due to its high electrical conductivity, good chemical stability and proven biocompatibility. However, it adheres only weakly to widely used substrate materials such as glass and silicon oxide, typically requiring the use of a thin layer of chromium between the substrate and the metal to achieve adequate adhesion. Unfortunately, this approach can reduce biocompatibility relative to pure gold films due to the risk of the underlying layer of chromium becoming exposed. Here we report on an alternative adhesion layer for gold and other metals formed from a thin layer of the negative-tone photoresist SU-8, which we find to be significantly less cytotoxic than chromium, being broadly comparable to bare glass in terms of its biocompatibility. Various treatment protocols for SU-8 were investigated, with a view to attaining high transparency and good mechanical and biochemical stability. Thermal annealing to induce partial cross-linking of the SU-8 film prior to gold deposition, with further annealing after deposition to complete cross-linking, was found to yield the best electrode properties. The optimized glass/SU8-Au electrodes were highly transparent, resilient to delamination, stable in biological culture medium, and exhibited similar biocompatibility to glass

NETWORK DESIGN FOR PERSONALIZED PUBLIC TRANSIT SERVICE

Network design requirements for personalized public transit service are presented. This concept involves diverting buses from their fixed routes to pick up passengers in the vicinity of the route. The software developed for the Dallas Area Rapid Transit to implement this concept is also discussed. A Dallas bus route is used as the case study. The service corridor is defined to be one-third of a mile on each side of the route. The software uses the real-time bus location and the schedule adherence data from a satellite-based vehicle locator system. Once it is determined that a given service request can be filled, the program generates the best diversion path and the estimated time of arrival to the caller\u27s location. The software includes modules for logging incoming calls for service, identifying passenger locations, assessing feasibility of providing service, determining the best diversion path for passenger pickup, and assessing the effect of the diversion on the schedule. The network database includes street geometry (nodes and links); link volumes, capacities, and free-flow speeds; node turning prohibitions; bus stop and timepoint locations; and route schedule including available schedule slacks

SPACELIKE HYPERSURFACES IN RIEMANNIAN OR LORENTZIAN SPACE FORMS SATISFYING L k x = Ax + b

We study connected orientable spacelike hypersurfaces (c), isometrically immersed into the Riemannian or Lorentzian space forms of curvature c = −1, 0, 1, and index q = 0, 1, satisfying the condition L k x = Ax + b, where L k is the linearized operator of the (k + 1)th mean curvature H k+1 of the hypersurface for a fixed integer 0 ≤ k < n, A is a constant matrix and b is a constant vector. We show that the only hypersurfaces satisfying that condition are hypersurfaces with zero H k+1 and constant H k (when c = 0), open pieces of totally umbilic hypersurfaces and open pieces of the standard Riemannian product of two totally umbilic hypersurfaces

A new design concept for field distortion trigger spark gaps

A common field distortion triggered spark gap utilizing geometric field enhancement at sharp edges usually operates in a cascade mode via the trigger electrode. A new trigger concept is proposed allowing strong field enhancement and direct breakdown between the two main electrodes. A test setup was designed to prove the feasibility of this concept. Experimental results on delay and jitter depending on percent breakdown voltage are presented. Best results achieved are a delay of 9 ns and a jitter of 2 ns at a self-breakdown voltage of 15 kV