Results from the extended life test of the Deep Space One flight spare ion engine show that enlargement of the discharge cathode assembly orifice due to erosion of the orifice by ion bombardment limits the throughput of the ion thruster, and therefore limits its operational lifetime to approximately three years. Future deep-space missions will require significantly longer operational lifetime, ...

The flows induced by different modes of plasma discharge over a 20 conical forefody are studied with a two-dimensional particle image velocimetry in a still air chamber with one atmosphere pressure. The effects of pulse duty ratio on the induced maximum crossflow velocity and maximum axial vorticity are compared with those of steady discharge. Effects of pulse frequency and ac voltage are discu...

• Novel pre-chamber test rig with dual schlieren setups. Nanosecond repetitively pulsed discharge and inductive ignition systems. Spark on the turbulent jet main chamber. Flame front propagation in affects probability Ignition of very lean conditions is possible by combining NRPD TJI. The optimization combustion process spark engines has led to novel strategies ignite low reactivity mixtures, s...

Astronauts working in zero-gravity (0-G) often experience visual reorientation illusions (VRIs). For example, when floating upside down, they commonly misperceive the spacecraft floor as a ceiling and have a reversed sense of direction. Previous studies have identified a population of neurons in the rat's brain that discharge as a function of the rat's head direction (HD) in a gravitationally h...

A computational analysis of flow in simplex fuel atomizers using the arbitrary-Lagrangian–Eulerian method is presented. It is well established that the geometry of an atomizer plays an important role in governing its performance. We have investigated the effect on atomizer performance of four geometric parameters, namely, inlet slot angle, spin chamber convergence angle, trumpet angle, and trum...

Objective. To determine if robot-assisted myomectomy (RAM) is feasible for women with large uterine myomas. Methods. Retrospective review of one gynecologic surgeon's RAM cases between May 2010 and July 2013. Large uterine myomas, defined as the largest myoma ≥9 cm by preoperative magnetic resonance imaging, was age- and time-matched to controls with the largest myoma <9 cm. Primary surgical ou...

The formation of plasma channels with nonuniformity of about ± 3.5% has been demonstrated. The channels had a density of 1.2×10 cm with a radius of 15 μm and with length ≥ 2.5 mm. The channels were formed by 0.3 J, 100 ps laser pulses in a nonflowing gas, contained in a cylindrical chamber. The laser beam passed through the chamber along its axis via pinholes in the chamber walls. A plasma chan...