Pulsing frequency

Data transmission rate per foot is a function of both pulse frequency and rate of penetration. Sensors acquire and transmit data samples at fixed time intervals and therefore the sampling per foot is a function of rate of penetration. Current tools allow a real time sampling and transmission rate similar to wireline tools as long as the penetration rate does not exceed about 100 ft/h. If drilling progresses faster or if there are significant variations in penetration rate, resampling by depth as opposed to time intervals may be required. 

Trebino R and Kane D J 1993 Using phase retrieval to measure the intensity and phase of ultrafast pulses frequency-resolved optical gating J. Opt. Soc. Am. A 10 1101-11... 

F = wave or pulse frequency Tj = kinematic viscosity in ftVs... 

Figure 20. Influence of light pulsing frequency on PMC peaks of n-Si, in contact with a 10 nm Au at 20 mW cm-1 light intensity, compared with influence on photocurrcnt. Pulsing frequencies were 110, 1520, and 2930 cps.

Figure 23. Influence of light pulsing frequency on peak height and peak position of n-WSe2 in contact with 50 mMFe2+/3+ (5 mM H2SO4). Pulsing frequencies between 11 and 110 cps are compared forthe PMC and photocurrent curves (hght intensity, 50 mW cm-2).

Light pulsing frequency, effect on photo currents, 474... 

Photo current-potential curves, as a function of pulsing frequency, 477 Photo currents... 

Pulsing frequency, photo current-potential curves as a function of, 477... 

Figure 4, Differential pulse voltammetry of a freshly polished, activated glassy carbon surface (a) and a digital simulation of the DPV (b). The pulse frequency vas2 Hz with an amplitude of 10 mV. The DC scan rate was 2 mV s...

The method of potentiostatic pulses is sometimes combined with the DME (called pulse polarography). hi this case the pulse frequency should match the drop frequency, where each pulse is used at a definite time in the drop life, hi Barker s method, large pulse amphrndes are used. Other versions of the potentiostatic pulse technique are square-wave and staircase voltammetry here smaU-amphtude pulses are used. 

Figure 3.4 Falloff of power with frequency from central pulse frequency.

In order to determine the thermal time constant of the microhotplate in dynamic measurements, a square-shape voltage pulse was applied to the heater. The pulse frequency was 5 Hz for uncoated and 2.5 Hz for coated membranes. The amplitude of the pulse was adjusted to produce a temperature rise of 50 °C. The temperature sensor was fed from a constant-current source, and the voltage drop across the temperature sensor was amplified with an operational amplifier. The dynamic response of the temperature sensor was recorded by an oscilloscope. The thermal time constant was calculated from these data with a curve fit using Eq. (3.29). As already mentioned in the context of Eq. (3.37), self-heating occurs with a resistive heater, so that the thermal time constant has to be determined during the cooHng cycle. 

K.A. Tillman, D.T. Reid, D. Artigas, J. Hellstrom, V. Pasiskevicius, and F. Laurell, Low-threshold, high-repetition-frequency femtosecond optical parametric oscillator based on chirped-pulse frequency conversion, Journal of the Optical Society of America B 20 1309 (2003). 

The electrons are bunched by the action of the RF accelerating field and therefore the emission occurs in sharp pulses, only tens of picoseconds in width, with frequency corresponding to the bunch spacing. For maximnm beam cnrrent many bnnches are used, giving a pulse frequency of typically 500 MHz. When only one bnnch is injected into the ring, the period drops to a few megahertz, while the pnlse width remains at a few picoseconds. This featnre has been used extensively for finorescence lifetime measnrements and may also be exploited in stroboscopic topography. 

A description of a fast laser photolysis experimental arrangement has been given by Porter and Topp who used a 1.5 Joule, 20nsec ruby giant pulse, frequency doubled in ADP, to measure singlet lifetimes in phenantrene, pyrene and other organic molecules. 

Most goats in the northern hemisphere breed in fall and winter. Decreasing day length stimulates ovarian cycles. In addition to photoperiod, male pheromones stimulate pulse frequency of LH in the blood plasma of females (Martin etal., 1986). This not only enhances the seasonal onset of ovarian function, but also synchronizes breeding and subsequent lambing. 

Thus, the average polymerization rate increases by a factor of (1 + r) 2 as the cycle (pulse) frequency increases from a low value to a very high value compared with l/xs. 

Stimulus pulse width may vary from 0.5 to 2.0 milliseconds. A recent study compared 0.5 msecond pulse width to 1.0 mseconds the shorter pulse width was found to be more efficient in inducing a seizure of adequate duration and less likely to result in a failed or an abortive seizure, and the associated peak heart rate was lower (Swartz and Manly, 2000). The authors also found that the pulse frequency (30 Hz vs. 60 Hz) did not influence the outcome. They concluded that a shorter pulse width was more efficient than a wider pulse width. Since data regarding pulse width are based on ETC in adults, until similar studies are conducted in adolescents, a shorter pulse width is preferable for adolescents. 

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