The shear swirling flow vibration cementing (SSFVC) technique rotates the downhole eccentric cascade by circulating cementing fluid. It makes the casing eccentrically revolve at high speed around the borehole axis. It produces strong agitation action to the annulus fluid, makes it in the state of shear turbulent flow, and results in the formation of pulse pressure which affects the surrounding ...

Nonlinear optical applications depend on pulse duration and coherence of the laser pulses. Characterization of high-repetition rate pulsed laser sources can be complicated by their pulse-to-pulse instabilities. Here, we introduce and demonstrate experimentally a quantitative measurement that can be used to determine the pulse-to-pulse fidelity of ultrafast laser sources. Numerical simulations a...

the effect of repetitive electrical field stimulation and the response of the guinea-pig and rat ileal longitudinal muscle to single pulse stimulations was examined. single pulse field stimulation produced twitch contraction which was inhibited by repetitive field stimulation (10 hz, 40v, 0.5 msec for 5 m). this inhibition was largely, though never completely, reversed by naloxone. contractions...

We present the effect of dual-pulse temporal shaping on ultraviolet nanosecond laser damage characteristics a fused silica exit surface in high fluence regime. The pre- and post-pulse have opposite effects behavior at pulse delay 20 ns. pre-pulse irradiation significantly increases main-pulse threshold, making it much higher than that single-pulse while has little threshold. For near-threshold ...

In this paper, the effect of optical pulse shape on the performance of direct sequence optical code division multiple access in presence of fiber group velocity dispersion (GVD) and pulse linear chirp is analyzed. In our analysis, chirp-Gaussian shape and chirp-Hyperbolic-Secant shape optical orthogonal codes are employed as address sequence. Avalanche photodiode (APD) is used in an optical cor...

nephritis remains an important problem in patients with systemic lupus erythematosus (sle). we conducted retrospective study to evaluate the efficiency of intravenous pulse cyclophosphamide in lupus nephritis: from 1983 to 1993, we reviewed 133 patients with biopsy proven lupus nephritis, 47 of them excluded because of short period of follow-up or defective laboratory data. eighty six patients ...

Objective The Holmium:yttrium-aluminum-garnet (Ho:YAG) laser is the standard lithotrite for ureteroscopy. This paper is to evaluate a Ho:YAG laser with a novel effect function in vitro, which allows a real-time variation of pulse duration and pulse peak power. Methods Two types of phantom calculi with four degrees of hardness were made for fragmentation and retropulsion experiments. Fragmenta...