Good tracking requires that the quintessence energy fraction slowly increase while the roll λ ≡ −d lnV/κdφ slowly decreases, but is not yet truly slow-rolling. The supernova bound on the present quintessence equation of state requires either (1) a cosmological constant or other finetuned ”crawling quintessence” or (2) ”roll-over quintessence” that tracked until recently, but now became slow rol...

The vortex-blob method is extended to compute vortex sheet separation at a sharp edge. A smoothing parameter con­ trols the amount of detail occuring in the rolled-up spiral. Cal­ culations are presented for the case of vortex sheet roll-up due to an impulsively started flat plate.

  In this paper, a microstrip lowpass filter with an ultra-wide stopband with sharp roll-off and compact size is designed and fabricated. To provide a very small dimension, T-shaped and stepped impedance have been used. The cut of frequency at -3 dB is 3.1 GHz. In the proposed structure, insertion loss is less than 0.12 and return loss is more than 15 dB. To achieve a -20dB attenuation level...

INTRODUCTION This paper focuses on the development of optimal deterministic, nonlinearly coupled barge motion models, identification of their system parameters and calibration of their prediction capability using experimental results. The ultimate objective is to develop accurate yet sufficiently low degree-offreedom stochastic models suitable for efficient probabilistic stability and reliabili...

Articulated liquid cargo vehicles transporting inflammable fuels and dangerous chemical products require special consideration when traveling on urban roads or cruising at highway speeds. The road safety and handling of these kinds of vehicles may be adversely affected when negotiating sharp turns or travelling on slippery roads, which may result in either lateral instabilities or complete roll...